pageserver - reserve while building delta metadata

The caller is now responsible for lookin up the predecessor layer,
instead. This makes the code simpler, as you don't need to update the
predecessor reference when a layer is frozen or written to disk.

There was a bug in that, as Konstantin noted on discord:

    Assume that freeze doesn't create new inmem layer
    (maybe_new_open=None). Then we temporary place in historics frozen
    layer. Assume that now new put_wal_record request arrives. There is
    no open in-mem layer, so it has to create new one. It is looking for
    previous layer for read and set it as new in-mem layer
    predecessor. But as far as I understand, prev layer should be our
    temporary frozen layer. Which will be then removed from
    historics.

That leaves the predecessor field of the new in-memory layer pointing
at the frozen in-memory layer that has been removed from the layer map,
preventing it from being removed from memory.

This makes two subtle changes:

1. When the first new layer is created on a branch for a segment that
   existed on the ancestor branch, the start_lsn of the new layer is now
   the branch point + 1. We were previously slightly confused on what
   the branch point LSN meant. It means that all the WAL up to and
   *including* the LSN on the old branch is visible to the new branch.
   If we mark the start LSN of the new layer as equal to the branch point,
   that's wrong, because if there is a WAL record with that LSN on the
   predecessor layer, the new layer would hide it. This bug was hidden
   when the layer on the new branch contained a direct reference to the
   layer in the old branch, as get_page_reconstruct_data() followed that
   reference directly when it didn't find the page version in the new
   layer. But now that the caller performs the lookup, it will look up
   the new layer that doesn't contain the record, and you get an error.

2. InMemoryLayer now always stores the segment size at the beginning
   of the layer's LSN range. Previously, get_seg_size() might have
   recursed into the predecessor layer to get the size, but now we
   avoid that by always copying over the last size from the previous
   layer, when a new layer is created.

.circleci/config.yml

@@ -24,6 +24,12 @@ jobs:
   # A job to build postgres
   build-postgres:
     executor: zenith-build-executor
+    parameters:
+      build_type:
+        type: enum
+        enum: ["debug", "release"]
+    environment:
+      BUILD_TYPE: << parameters.build_type >>
     steps:
         # Checkout the git repo (circleci doesn't have a flag to enable submodules here)
       - checkout
@@ -39,7 +45,7 @@ jobs:
           name: Restore postgres cache
           keys:
             # Restore ONLY if the rev key matches exactly
-            - v03-postgres-cache-{{ checksum "/tmp/cache-key-postgres" }}
+            - v04-postgres-cache-<< parameters.build_type >>-{{ checksum "/tmp/cache-key-postgres" }}
 
         # FIXME We could cache our own docker container, instead of installing packages every time.
       - run:
@@ -59,12 +65,12 @@ jobs:
             if [ ! -e tmp_install/bin/postgres ]; then
               # "depth 1" saves some time by not cloning the whole repo
               git submodule update --init --depth 1
-              make postgres
+              make postgres -j8
             fi
 
       - save_cache:
           name: Save postgres cache
-          key: v03-postgres-cache-{{ checksum "/tmp/cache-key-postgres" }}
+          key: v04-postgres-cache-<< parameters.build_type >>-{{ checksum "/tmp/cache-key-postgres" }}
           paths:
             - tmp_install
 
@@ -96,7 +102,7 @@ jobs:
           name: Restore postgres cache
           keys:
             # Restore ONLY if the rev key matches exactly
-            - v03-postgres-cache-{{ checksum "/tmp/cache-key-postgres" }}
+            - v04-postgres-cache-<< parameters.build_type >>-{{ checksum "/tmp/cache-key-postgres" }}
 
       - restore_cache:
           name: Restore rust cache
@@ -128,6 +134,14 @@ jobs:
             - ~/.cargo/git
             - target
 
+        # Run style checks
+        # has to run separately from cargo fmt section
+        # since needs to run with dependencies
+      - run:
+          name: clippy
+          command: |
+            ./run_clippy.sh
+
         # Run rust unit tests
       - run: cargo test
 
@@ -193,6 +207,9 @@ jobs:
       needs_postgres_source:
         type: boolean
         default: false
+      run_in_parallel:
+        type: boolean
+        default: true
     steps:
       - attach_workspace:
           at: /tmp/zenith
@@ -221,6 +238,9 @@ jobs:
               echo "test_selection must be set"
               exit 1
             fi
+            if << parameters.run_in_parallel >>; then
+              EXTRA_PARAMS="-n4 $EXTRA_PARAMS"
+            fi;
             # Run the tests.
             #
             # The junit.xml file allows CircleCI to display more fine-grained test information
@@ -230,6 +250,7 @@ jobs:
             # --verbose prints name of each test (helpful when there are
             # multiple tests in one file)
             # -rA prints summary in the end
+            # -n4 uses four processes to run tests via pytest-xdist
             pipenv run pytest --junitxml=$TEST_OUTPUT/junit.xml --tb=short -s --verbose -rA $TEST_SELECTION $EXTRA_PARAMS
       - run:
           # CircleCI artifacts are preserved one file at a time, so skipping
@@ -239,7 +260,7 @@ jobs:
           when: always
           command: |
             du -sh /tmp/test_output/*
-            find /tmp/test_output -type f ! -name "pg.log" ! -name "pageserver.log" ! -name "wal_acceptor.log" ! -name "regression.diffs" ! -name "junit.xml" -delete
+            find /tmp/test_output -type f ! -name "pg.log" ! -name "pageserver.log" ! -name "wal_acceptor.log" ! -name "regression.diffs" ! -name "junit.xml" ! -name "*.filediff" ! -name "*.stdout" ! -name "*.stderr" -delete
             du -sh /tmp/test_output/*
       - store_artifacts:
           path: /tmp/test_output
@@ -264,20 +285,69 @@ jobs:
             echo $DOCKER_PWD | docker login -u $DOCKER_LOGIN --password-stdin
             docker build -t zenithdb/zenith:latest . && docker push zenithdb/zenith:latest
 
+  # Trigger a new remote CI job
+  remote-ci-trigger:
+    docker:
+      - image: cimg/base:2021.04
+    parameters:
+      remote_repo:
+        type: string
+    environment:
+      REMOTE_REPO: << parameters.remote_repo >>
+    steps:
+      - run:
+          name: Set PR's status to pending
+          command: |
+            LOCAL_REPO=$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME
+
+            curl -f -X POST \
+            https://api.github.com/repos/$LOCAL_REPO/statuses/$CIRCLE_SHA1 \
+            -H "Accept: application/vnd.github.v3+json" \
+            --user "$CI_ACCESS_TOKEN" \
+            --data \
+              "{
+                \"state\": \"pending\",
+                \"context\": \"zenith-remote-ci\",
+                \"description\": \"[$REMOTE_REPO] Remote CI job is about to start\"
+              }"
+      - run:
+          name: Request a remote CI test
+          command: |
+            LOCAL_REPO=$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME
+
+            curl -f -X POST \
+            https://api.github.com/repos/$REMOTE_REPO/actions/workflows/testing.yml/dispatches \
+            -H "Accept: application/vnd.github.v3+json" \
+            --user "$CI_ACCESS_TOKEN" \
+            --data \
+              "{
+                \"ref\": \"main\",
+                \"inputs\": {
+                  \"ci_job_name\": \"zenith-remote-ci\",
+                  \"commit_hash\": \"$CIRCLE_SHA1\",
+                  \"remote_repo\": \"$LOCAL_REPO\",
+                  \"zenith_image_branch\": \"$CIRCLE_BRANCH\"
+                }
+              }"
+
 workflows:
   build_and_test:
     jobs:
       - check-codestyle
-      - build-postgres
+      - build-postgres:
+          name: build-postgres-<< matrix.build_type >>
+          matrix:
+            parameters:
+              build_type: ["debug", "release"]
       - build-zenith:
           name: build-zenith-<< matrix.build_type >>
           matrix:
             parameters:
               build_type: ["debug", "release"]
           requires:
-            - build-postgres
+            - build-postgres-<< matrix.build_type >>
       - run-pytest:
-          name: pg_regress tests << matrix.build_type >>
+          name: pg_regress-tests-<< matrix.build_type >>
           matrix:
             parameters:
               build_type: ["debug", "release"]
@@ -286,7 +356,7 @@ workflows:
           requires:
             - build-zenith-<< matrix.build_type >>
       - run-pytest:
-          name: other tests << matrix.build_type >>
+          name: other-tests-<< matrix.build_type >>
           matrix:
             parameters:
               build_type: ["debug", "release"]
@@ -297,6 +367,7 @@ workflows:
           name: benchmarks
           build_type: release
           test_selection: performance
+          run_in_parallel: false
           requires:
             - build-zenith-release
       - docker-image:
@@ -308,5 +379,16 @@ workflows:
               only:
                 - main
           requires:
-            - pg_regress tests release
-            - other tests release
+            - pg_regress-tests-release
+            - other-tests-release
+      - remote-ci-trigger:
+          # Context passes credentials for gh api
+          context: CI_ACCESS_TOKEN
+          remote_repo: "zenithdb/console"
+          requires:
+            # XXX: Successful build doesn't mean everything is OK, but
+            # the job to be triggered takes so much time to complete (~22 min)
+            # that it's better not to wait for the commented-out steps
+            - build-zenith-debug
+            # - pg_regress-tests-release
+            # - other-tests-release

.dockerignore

@@ -2,12 +2,17 @@
 **/__pycache__
 **/.pytest_cache
 
-/target
-/tmp_check
-/tmp_install
-/tmp_check_cli
-/test_output
-/.vscode
-/.zenith
-/integration_tests/.zenith
-/Dockerfile
+.git
+target
+tmp_check
+tmp_install
+tmp_check_cli
+test_output
+.vscode
+.zenith
+integration_tests/.zenith
+.mypy_cache
+
+Dockerfile
+.dockerignore
+

Cargo.lock

@@ -307,6 +307,26 @@ dependencies = [
  "vec_map",
 ]
 
+[[package]]
+name = "const_format"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4556f63e28a78fa5e6f310cfea5647a25636def49a338ab69e33b34a3382057b"
+dependencies = [
+ "const_format_proc_macros",
+]
+
+[[package]]
+name = "const_format_proc_macros"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "552782506c398da94466b364973b563887e0ca078bf33a76d4163736165e3594"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-xid",
+]
+
 [[package]]
 name = "control_plane"
 version = "0.1.0"
@@ -325,6 +345,7 @@ dependencies = [
  "serde",
  "serde_json",
  "tar",
+ "thiserror",
  "toml",
  "url",
  "walkeeper",
@@ -1172,33 +1193,33 @@ name = "pageserver"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "async-trait",
  "bookfile",
  "byteorder",
  "bytes",
  "chrono",
  "clap",
+ "const_format",
  "crc32c",
  "daemonize",
  "futures",
  "hex",
+ "hex-literal",
  "humantime",
  "hyper",
  "lazy_static",
  "log",
  "postgres",
- "postgres-protocol 0.6.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
- "postgres-types 0.2.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
+ "postgres-protocol",
+ "postgres-types",
  "postgres_ffi",
  "rand",
  "regex",
  "routerify",
+ "rust-s3",
  "scopeguard",
  "serde",
  "serde_json",
- "slog",
- "slog-scope",
- "slog-stdlog",
- "slog-term",
  "tar",
  "thiserror",
  "tokio",
@@ -1301,27 +1322,9 @@ dependencies = [
  "fallible-iterator",
  "futures",
  "log",
- "postgres-protocol 0.6.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
+ "postgres-protocol",
  "tokio",
- "tokio-postgres 0.7.1",
-]
-
-[[package]]
-name = "postgres-protocol"
-version = "0.6.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ff3e0f70d32e20923cabf2df02913be7c1842d4c772db8065c00fcfdd1d1bff3"
-dependencies = [
- "base64 0.13.0",
- "byteorder",
- "bytes",
- "fallible-iterator",
- "hmac",
- "md-5",
- "memchr",
- "rand",
- "sha2",
- "stringprep",
+ "tokio-postgres",
 ]
 
 [[package]]
@@ -1342,17 +1345,6 @@ dependencies = [
  "stringprep",
 ]
 
-[[package]]
-name = "postgres-types"
-version = "0.2.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "430f4131e1b7657b0cd9a2b0c3408d77c9a43a042d300b8c77f981dffcc43a2f"
-dependencies = [
- "bytes",
- "fallible-iterator",
- "postgres-protocol 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
-]
-
 [[package]]
 name = "postgres-types"
 version = "0.2.1"
@@ -1360,7 +1352,7 @@ source = "git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b
 dependencies = [
  "bytes",
  "fallible-iterator",
- "postgres-protocol 0.6.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
+ "postgres-protocol",
 ]
 
 [[package]]
@@ -1423,16 +1415,9 @@ dependencies = [
  "lazy_static",
  "memchr",
  "parking_lot",
- "protobuf",
  "thiserror",
 ]
 
-[[package]]
-name = "protobuf"
-version = "2.24.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "db50e77ae196458ccd3dc58a31ea1a90b0698ab1b7928d89f644c25d72070267"
-
 [[package]]
 name = "proxy"
 version = "0.1.0"
@@ -1443,11 +1428,12 @@ dependencies = [
  "hex",
  "md5",
  "rand",
+ "reqwest",
  "rustls",
  "serde",
  "serde_json",
  "tokio",
- "tokio-postgres 0.7.2",
+ "tokio-postgres",
  "zenith_utils",
 ]
 
@@ -2135,9 +2121,9 @@ checksum = "cda74da7e1a664f795bb1f8a87ec406fb89a02522cf6e50620d016add6dbbf5c"
 
 [[package]]
 name = "tokio"
-version = "1.8.1"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "98c8b05dc14c75ea83d63dd391100353789f5f24b8b3866542a5e85c8be8e985"
+checksum = "b4efe6fc2395938c8155973d7be49fe8d03a843726e285e100a8a383cc0154ce"
 dependencies = [
  "autocfg",
  "bytes",
@@ -2146,7 +2132,6 @@ dependencies = [
  "mio",
  "num_cpus",
  "once_cell",
- "parking_lot",
  "pin-project-lite",
  "signal-hook-registry",
  "tokio-macros",
@@ -2189,31 +2174,8 @@ dependencies = [
  "percent-encoding",
  "phf",
  "pin-project-lite",
- "postgres-protocol 0.6.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
- "postgres-types 0.2.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
- "socket2",
- "tokio",
- "tokio-util",
-]
-
-[[package]]
-name = "tokio-postgres"
-version = "0.7.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2d2b1383c7e4fb9a09e292c7c6afb7da54418d53b045f1c1fac7a911411a2b8b"
-dependencies = [
- "async-trait",
- "byteorder",
- "bytes",
- "fallible-iterator",
- "futures",
- "log",
- "parking_lot",
- "percent-encoding",
- "phf",
- "pin-project-lite",
- "postgres-protocol 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "postgres-types 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "postgres-protocol",
+ "postgres-types",
  "socket2",
  "tokio",
  "tokio-util",
@@ -2386,16 +2348,12 @@ dependencies = [
  "log",
  "pageserver",
  "postgres",
- "postgres-protocol 0.6.1 (git+https://github.com/zenithdb/rust-postgres.git?rev=9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858)",
+ "postgres-protocol",
  "postgres_ffi",
  "regex",
  "rust-s3",
  "serde",
- "slog",
- "slog-async",
- "slog-scope",
- "slog-stdlog",
- "slog-term",
+ "serde_json",
  "tokio",
  "tokio-stream",
  "walkdir",
@@ -2620,6 +2578,7 @@ version = "0.1.0"
 dependencies = [
  "lazy_static",
  "libc",
+ "once_cell",
  "prometheus",
 ]
 
@@ -2644,6 +2603,12 @@ dependencies = [
  "rustls-split",
  "serde",
  "serde_json",
+ "slog",
+ "slog-async",
+ "slog-scope",
+ "slog-stdlog",
+ "slog-term",
+ "tempfile",
  "thiserror",
  "tokio",
  "webpki",

Dockerfile

@@ -10,39 +10,21 @@ FROM zenithdb/build:buster AS pg-build
 WORKDIR /zenith
 COPY ./vendor/postgres vendor/postgres
 COPY ./Makefile Makefile
+ENV BUILD_TYPE release
 RUN make -j $(getconf _NPROCESSORS_ONLN) -s postgres
-
-#
-# Calculate cargo dependencies.
-# This will always run, but only generate recipe.json with list of dependencies without
-# installing them.
-#
-FROM zenithdb/build:buster AS cargo-deps-inspect
-WORKDIR /zenith
-COPY . .
-RUN cargo chef prepare --recipe-path /zenith/recipe.json
-
-#
-# Build cargo dependencies.
-# This temp cantainner should be rebuilt only if recipe.json was changed.
-#
-FROM zenithdb/build:buster AS deps-build
-WORKDIR /zenith
-COPY --from=pg-build /zenith/tmp_install/include/postgresql/server tmp_install/include/postgresql/server
-COPY --from=cargo-deps-inspect /usr/local/cargo/bin/cargo-chef /usr/local/cargo/bin/
-COPY --from=cargo-deps-inspect /zenith/recipe.json recipe.json
-RUN ROCKSDB_LIB_DIR=/usr/lib/ cargo chef cook --release --recipe-path recipe.json
+RUN rm -rf postgres_install/build
 
 #
 # Build zenith binaries
 #
+# TODO: build cargo deps as separate layer. We used cargo-chef before but that was
+# net time waste in a lot of cases. Copying Cargo.lock with empty lib.rs should do the work.
+#
 FROM zenithdb/build:buster AS build
 WORKDIR /zenith
-COPY . .
-# Copy cached dependencies
 COPY --from=pg-build /zenith/tmp_install/include/postgresql/server tmp_install/include/postgresql/server
-COPY --from=deps-build /zenith/target target
-COPY --from=deps-build /usr/local/cargo/ /usr/local/cargo/
+
+COPY . .
 RUN cargo build --release
 
 #
@@ -51,7 +33,7 @@ RUN cargo build --release
 FROM debian:buster-slim
 WORKDIR /data
 
-RUN apt-get update && apt-get -yq install librocksdb-dev libseccomp-dev openssl && \
+RUN apt-get update && apt-get -yq install libreadline-dev libseccomp-dev openssl ca-certificates && \
     mkdir zenith_install
 
 COPY --from=build /zenith/target/release/pageserver /usr/local/bin

Dockerfile.build

@@ -9,7 +9,7 @@ WORKDIR /zenith
 # Install postgres and zenith build dependencies
 # clang is for rocksdb
 RUN apt-get update && apt-get -yq install automake libtool build-essential bison flex libreadline-dev zlib1g-dev libxml2-dev \
-                                          libseccomp-dev pkg-config libssl-dev librocksdb-dev clang
+                                          libseccomp-dev pkg-config libssl-dev clang
 
 # Install rust tools
-RUN rustup component add clippy && cargo install cargo-chef cargo-audit
+RUN rustup component add clippy && cargo install cargo-audit

Makefile

@@ -6,6 +6,18 @@ else
 	SECCOMP =
 endif
 
+#
+# We differentiate between release / debug build types using the BUILD_TYPE
+# environment variable.
+#
+ifeq ($(BUILD_TYPE),release)
+	PG_CONFIGURE_OPTS = --enable-debug
+	PG_CFLAGS = -O2 -g3 ${CFLAGS}
+else
+	PG_CONFIGURE_OPTS = --enable-debug --enable-cassert --enable-depend
+	PG_CFLAGS = -O0 -g3 ${CFLAGS}
+endif
+
 #
 # Top level Makefile to build Zenith and PostgreSQL
 #
@@ -30,10 +42,8 @@ tmp_install/build/config.status:
 	+@echo "Configuring postgres build"
 	mkdir -p tmp_install/build
 	(cd tmp_install/build && \
-	../../vendor/postgres/configure CFLAGS='-O0 -g3 $(CFLAGS)' \
-		--enable-cassert \
-		--enable-debug \
-		--enable-depend \
+	../../vendor/postgres/configure CFLAGS='$(PG_CFLAGS)' \
+		$(PG_CONFIGURE_OPTS) \
 		$(SECCOMP) \
 		--prefix=$(abspath tmp_install) > configure.log)
 

README.md

@@ -6,7 +6,7 @@ Zenith substitutes PostgreSQL storage layer and redistributes data across a clus
 
 A Zenith installation consists of Compute nodes and Storage engine.
 
-Compute nodes are stateles PostgreSQL nodes, backed by zenith storage.
+Compute nodes are stateless PostgreSQL nodes, backed by zenith storage.
 
 Zenith storage engine consists of two major components:
 - Pageserver. Scalable storage backend for compute nodes.
@@ -25,7 +25,7 @@ Pageserver consists of:
 On Ubuntu or Debian this set of packages should be sufficient to build the code:
 ```text
 apt install build-essential libtool libreadline-dev zlib1g-dev flex bison libseccomp-dev \
-libssl-dev clang
+libssl-dev clang pkg-config libpq-dev
 ```
 
 [Rust] 1.52 or later is also required.
@@ -108,6 +108,13 @@ postgres=# insert into t values(2,2);
 INSERT 0 1
 ```
 
+6. If you want to run tests afterwards (see below), you have to stop pageserver and all postgres instances you have just started:
+```sh
+> ./target/debug/zenith pg stop migration_check
+> ./target/debug/zenith pg stop main
+> ./target/debug/zenith stop
+```
+
 ## Running tests
 
 ```sh
@@ -125,9 +132,19 @@ Now we use README files to cover design ideas and overall architecture for each
 
 To view your `rustdoc` documentation in a browser, try running `cargo doc --no-deps --open`
 
+### Postgres-specific terms
+
+Due to Zenith's very close relation with PostgreSQL internals, there are numerous specific terms used.
+Same applies to certain spelling: i.e. we use MB to denote 1024 * 1024 bytes, while MiB would be technically more correct, it's inconsistent with what PostgreSQL code and its documentation use.
+
+To get more familiar with this aspect, refer to:
+
+- [Zenith glossary](/docs/glossary.md)
+- [PostgreSQL glossary](https://www.postgresql.org/docs/13/glossary.html)
+- Other PostgreSQL documentation and sources (Zenith fork sources can be found [here](https://github.com/zenithdb/postgres))
+
 ## Join the development
 
 - Read `CONTRIBUTING.md` to learn about project code style and practices.
-- Use glossary in [/docs/glossary.md](/docs/glossary.md)
 - To get familiar with a source tree layout, use [/docs/sourcetree.md](/docs/sourcetree.md).
 - To learn more about PostgreSQL internals, check http://www.interdb.jp/pg/index.html

control_plane/Cargo.toml

@@ -16,6 +16,7 @@ toml = "0.5"
 lazy_static = "1.4"
 regex = "1"
 anyhow = "1.0"
+thiserror = "1"
 bytes = "1.0.1"
 nix = "0.20"
 url = "2.2.2"

control_plane/src/compute.rs

@@ -1,22 +1,24 @@
-use std::fs::{self, File, OpenOptions};
+use std::collections::BTreeMap;
+use std::fs::{self, File};
 use std::io::Write;
 use std::net::SocketAddr;
 use std::net::TcpStream;
 use std::os::unix::fs::PermissionsExt;
-use std::process::Command;
+use std::path::PathBuf;
+use std::process::{Command, Stdio};
+use std::str::FromStr;
 use std::sync::Arc;
 use std::time::Duration;
-use std::{collections::BTreeMap, path::PathBuf};
 
 use anyhow::{Context, Result};
-use lazy_static::lazy_static;
-use regex::Regex;
 use zenith_utils::connstring::connection_host_port;
+use zenith_utils::lsn::Lsn;
 use zenith_utils::postgres_backend::AuthType;
 use zenith_utils::zid::ZTenantId;
 use zenith_utils::zid::ZTimelineId;
 
 use crate::local_env::LocalEnv;
+use crate::postgresql_conf::PostgresConf;
 use crate::storage::PageServerNode;
 
 //
@@ -86,40 +88,31 @@ impl ComputeControlPlane {
         &mut self,
         tenantid: ZTenantId,
         branch_name: &str,
-        config_only: bool,
+        port: Option<u16>,
     ) -> Result<Arc<PostgresNode>> {
         let timeline_id = self
             .pageserver
             .branch_get_by_name(&tenantid, branch_name)?
             .timeline_id;
 
+        let port = port.unwrap_or_else(|| self.get_port());
         let node = Arc::new(PostgresNode {
             name: branch_name.to_owned(),
-            address: SocketAddr::new("127.0.0.1".parse().unwrap(), self.get_port()),
+            address: SocketAddr::new("127.0.0.1".parse().unwrap(), port),
             env: self.env.clone(),
             pageserver: Arc::clone(&self.pageserver),
             is_test: false,
             timelineid: timeline_id,
             tenantid,
+            uses_wal_proposer: false,
         });
 
-        node.init_from_page_server(self.env.auth_type, config_only)?;
+        node.create_pgdata()?;
+        node.setup_pg_conf(self.env.auth_type)?;
+
         self.nodes
             .insert((tenantid, node.name.clone()), Arc::clone(&node));
 
-        // Configure the node to stream WAL directly to the pageserver
-        node.append_conf(
-            "postgresql.conf",
-            format!(
-                concat!(
-                    "synchronous_standby_names = 'pageserver'\n", // TODO: add a new function arg?
-                    "zenith.callmemaybe_connstring = '{}'\n",     // FIXME escaping
-                ),
-                node.connstr(),
-            )
-            .as_str(),
-        )?;
-
         Ok(node)
     }
 }
@@ -135,6 +128,7 @@ pub struct PostgresNode {
     is_test: bool,
     pub timelineid: ZTimelineId,
     pub tenantid: ZTenantId,
+    uses_wal_proposer: bool,
 }
 
 impl PostgresNode {
@@ -150,74 +144,25 @@ impl PostgresNode {
             );
         }
 
-        lazy_static! {
-            static ref CONF_PORT_RE: Regex = Regex::new(r"(?m)^\s*port\s*=\s*(\d+)\s*$").unwrap();
-            static ref CONF_TIMELINE_RE: Regex =
-                Regex::new(r"(?m)^\s*zenith.zenith_timeline\s*=\s*'(\w+)'\s*$").unwrap();
-            static ref CONF_TENANT_RE: Regex =
-                Regex::new(r"(?m)^\s*zenith.zenith_tenant\s*=\s*'(\w+)'\s*$").unwrap();
-        }
-
         // parse data directory name
         let fname = entry.file_name();
         let name = fname.to_str().unwrap().to_string();
 
-        // find out tcp port in config file
+        // Read config file into memory
         let cfg_path = entry.path().join("postgresql.conf");
-        let config = fs::read_to_string(cfg_path.clone()).with_context(|| {
-            format!(
-                "failed to read config file in {}",
-                cfg_path.to_str().unwrap()
-            )
-        })?;
+        let cfg_path_str = cfg_path.to_string_lossy();
+        let mut conf_file = File::open(&cfg_path)
+            .with_context(|| format!("failed to open config file in {}", cfg_path_str))?;
+        let conf = PostgresConf::read(&mut conf_file)
+            .with_context(|| format!("failed to read config file in {}", cfg_path_str))?;
 
-        // parse port
-        let err_msg = format!(
-            "failed to find port definition in config file {}",
-            cfg_path.to_str().unwrap()
-        );
-        let port: u16 = CONF_PORT_RE
-            .captures(config.as_str())
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 1"))?
-            .iter()
-            .last()
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 2"))?
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 3"))?
-            .as_str()
-            .parse()
-            .with_context(|| err_msg)?;
+        // Read a few options from the config file
+        let context = format!("in config file {}", cfg_path_str);
+        let port: u16 = conf.parse_field("port", &context)?;
+        let timelineid: ZTimelineId = conf.parse_field("zenith.zenith_timeline", &context)?;
+        let tenantid: ZTenantId = conf.parse_field("zenith.zenith_tenant", &context)?;
 
-        // parse timeline
-        let err_msg = format!(
-            "failed to find timeline definition in config file {}",
-            cfg_path.to_str().unwrap()
-        );
-        let timelineid: ZTimelineId = CONF_TIMELINE_RE
-            .captures(config.as_str())
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 1"))?
-            .iter()
-            .last()
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 2"))?
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 3"))?
-            .as_str()
-            .parse()
-            .with_context(|| err_msg)?;
-
-        // parse tenant
-        let err_msg = format!(
-            "failed to find tenant definition in config file {}",
-            cfg_path.to_str().unwrap()
-        );
-        let tenantid = CONF_TENANT_RE
-            .captures(config.as_str())
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 1"))?
-            .iter()
-            .last()
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 2"))?
-            .ok_or_else(|| anyhow::Error::msg(err_msg.clone() + " 3"))?
-            .as_str()
-            .parse()
-            .with_context(|| err_msg)?;
+        let uses_wal_proposer = conf.get("wal_acceptors").is_some();
 
         // ok now
         Ok(PostgresNode {
@@ -228,15 +173,54 @@ impl PostgresNode {
             is_test: false,
             timelineid,
             tenantid,
+            uses_wal_proposer,
         })
     }
 
+    fn sync_walkeepers(&self) -> Result<Lsn> {
+        let pg_path = self.env.pg_bin_dir().join("postgres");
+        let sync_handle = Command::new(pg_path)
+            .arg("--sync-safekeepers")
+            .env_clear()
+            .env("LD_LIBRARY_PATH", self.env.pg_lib_dir().to_str().unwrap())
+            .env("DYLD_LIBRARY_PATH", self.env.pg_lib_dir().to_str().unwrap())
+            .env("PGDATA", self.pgdata().to_str().unwrap())
+            .stdout(Stdio::piped())
+            // Comment this to avoid capturing stderr (useful if command hangs)
+            .stderr(Stdio::piped())
+            .spawn()
+            .expect("postgres --sync-safekeepers failed to start");
+
+        let sync_output = sync_handle
+            .wait_with_output()
+            .expect("postgres --sync-safekeepers failed");
+        if !sync_output.status.success() {
+            anyhow::bail!(
+                "sync-safekeepers failed: '{}'",
+                String::from_utf8_lossy(&sync_output.stderr)
+            );
+        }
+
+        let lsn = Lsn::from_str(std::str::from_utf8(&sync_output.stdout)?.trim())?;
+        println!("Walkeepers synced on {}", lsn);
+        Ok(lsn)
+    }
+
     /// Get basebackup from the pageserver as a tar archive and extract it
     /// to the `self.pgdata()` directory.
-    pub fn do_basebackup(&self) -> Result<()> {
-        let pgdata = self.pgdata();
+    fn do_basebackup(&self, lsn: Option<Lsn>) -> Result<()> {
+        println!(
+            "Extracting base backup to create postgres instance: path={} port={}",
+            self.pgdata().display(),
+            self.address.port()
+        );
+
+        let sql = if let Some(lsn) = lsn {
+            format!("basebackup {} {} {}", self.tenantid, self.timelineid, lsn)
+        } else {
+            format!("basebackup {} {}", self.tenantid, self.timelineid)
+        };
 
-        let sql = format!("basebackup {} {}", self.tenantid, self.timelineid);
         let mut client = self
             .pageserver
             .page_server_psql_client()
@@ -248,99 +232,104 @@ impl PostgresNode {
 
         // Read the archive directly from the `CopyOutReader`
         tar::Archive::new(copyreader)
-            .unpack(&pgdata)
+            .unpack(&self.pgdata())
             .with_context(|| "extracting page backup failed")?;
 
         Ok(())
     }
 
-    /// Connect to a pageserver, get basebackup, and untar it to initialize a
-    /// new data directory
-    pub fn init_from_page_server(&self, auth_type: AuthType, config_only: bool) -> Result<()> {
-        let pgdata = self.pgdata();
-
-        println!(
-            "Extracting base backup to create postgres instance: path={} port={}",
-            pgdata.display(),
-            self.address.port()
-        );
-
-        // initialize data directory
-        if self.is_test {
-            fs::remove_dir_all(&pgdata).ok();
-        }
-
-        fs::create_dir_all(&pgdata)
-            .with_context(|| format!("could not create data directory {}", pgdata.display()))?;
-        fs::set_permissions(pgdata.as_path(), fs::Permissions::from_mode(0o700)).with_context(
-            || {
+    fn create_pgdata(&self) -> Result<()> {
+        fs::create_dir_all(&self.pgdata()).with_context(|| {
+            format!(
+                "could not create data directory {}",
+                self.pgdata().display()
+            )
+        })?;
+        fs::set_permissions(self.pgdata().as_path(), fs::Permissions::from_mode(0o700))
+            .with_context(|| {
                 format!(
                     "could not set permissions in data directory {}",
-                    pgdata.display()
+                    self.pgdata().display()
                 )
-            },
-        )?;
-
-        if config_only {
-            //Just create an empty config file
-            File::create(self.pgdata().join("postgresql.conf").to_str().unwrap())?;
-        } else {
-            self.do_basebackup()?;
-            fs::create_dir_all(self.pgdata().join("pg_wal"))?;
-            fs::create_dir_all(self.pgdata().join("pg_wal").join("archive_status"))?;
-        }
+            })
+    }
 
+    // Connect to a page server, get base backup, and untar it to initialize a
+    // new data directory
+    fn setup_pg_conf(&self, auth_type: AuthType) -> Result<()> {
+        let mut conf = PostgresConf::new();
+        conf.append("max_wal_senders", "10");
         // wal_log_hints is mandatory when running against pageserver (see gh issue#192)
         // TODO: is it possible to check wal_log_hints at pageserver side via XLOG_PARAMETER_CHANGE?
-        self.append_conf(
-            "postgresql.conf",
-            &format!(
-                "max_wal_senders = 10\n\
-                 wal_log_hints = on\n\
-                 max_replication_slots = 10\n\
-                 hot_standby = on\n\
-                 shared_buffers = 1MB\n\
-                 fsync = off\n\
-                 max_connections = 100\n\
-                 wal_sender_timeout = 0\n\
-                 wal_level = replica\n\
-                 listen_addresses = '{address}'\n\
-                 port = {port}\n",
-                address = self.address.ip(),
-                port = self.address.port()
-            ),
-        )?;
+        conf.append("wal_log_hints", "on");
+        conf.append("max_replication_slots", "10");
+        conf.append("hot_standby", "on");
+        conf.append("shared_buffers", "1MB");
+        conf.append("fsync", "off");
+        conf.append("max_connections", "100");
+        conf.append("wal_sender_timeout", "0");
+        conf.append("wal_level", "replica");
+        conf.append("listen_addresses", &self.address.ip().to_string());
+        conf.append("port", &self.address.port().to_string());
 
         // Never clean up old WAL. TODO: We should use a replication
         // slot or something proper, to prevent the compute node
         // from removing WAL that hasn't been streamed to the safekeeper or
         // page server yet. (gh issue #349)
-        self.append_conf("postgresql.conf", "wal_keep_size='10TB'\n")?;
+        conf.append("wal_keep_size", "10TB");
 
-        // set up authentication
-        let password = if let AuthType::ZenithJWT = auth_type {
-            "$ZENITH_AUTH_TOKEN"
+        // Configure the node to fetch pages from pageserver
+        let pageserver_connstr = {
+            let (host, port) = connection_host_port(&self.pageserver.pg_connection_config);
+
+            // Set up authentication
+            //
+            // $ZENITH_AUTH_TOKEN will be replaced with value from environment
+            // variable during compute pg startup. It is done this way because
+            // otherwise user will be able to retrieve the value using SHOW
+            // command or pg_settings
+            let password = if let AuthType::ZenithJWT = auth_type {
+                "$ZENITH_AUTH_TOKEN"
+            } else {
+                ""
+            };
+
+            format!("host={} port={} password={}", host, port, password)
+        };
+        conf.append("shared_preload_libraries", "zenith");
+        conf.append_line("");
+        conf.append("zenith.page_server_connstring", &pageserver_connstr);
+        conf.append("zenith.zenith_tenant", &self.tenantid.to_string());
+        conf.append("zenith.zenith_timeline", &self.timelineid.to_string());
+        conf.append_line("");
+
+        // Configure the node to stream WAL directly to the pageserver
+        conf.append("synchronous_standby_names", "pageserver"); // TODO: add a new function arg?
+        conf.append("zenith.callmemaybe_connstring", &self.connstr());
+
+        let mut file = File::create(self.pgdata().join("postgresql.conf"))?;
+        file.write_all(conf.to_string().as_bytes())?;
+
+        Ok(())
+    }
+
+    fn load_basebackup(&self) -> Result<()> {
+        let lsn = if self.uses_wal_proposer {
+            // LSN 0 means that it is bootstrap and we need to download just
+            // latest data from the pageserver. That is a bit clumsy but whole bootstrap
+            // procedure evolves quite actively right now, so let's think about it again
+            // when things would be more stable (TODO).
+            let lsn = self.sync_walkeepers()?;
+            if lsn == Lsn(0) {
+                None
+            } else {
+                Some(lsn)
+            }
         } else {
-            ""
+            None
         };
 
-        // Configure that node to take pages from pageserver
-        let (host, port) = connection_host_port(&self.pageserver.pg_connection_config);
-        self.append_conf(
-            "postgresql.conf",
-            format!(
-                concat!(
-                    "shared_preload_libraries = zenith\n",
-                    // $ZENITH_AUTH_TOKEN will be replaced with value from environment variable during compute pg startup
-                    // it is done this way because otherwise user will be able to retrieve the value using SHOW command or pg_settings
-                    "zenith.page_server_connstring = 'host={} port={} password={}'\n",
-                    "zenith.zenith_timeline='{}'\n",
-                    "zenith.zenith_tenant='{}'\n",
-                ),
-                host, port, password, self.timelineid, self.tenantid,
-            )
-            .as_str(),
-        )?;
+        self.do_basebackup(lsn)?;
 
         Ok(())
     }
@@ -362,14 +351,6 @@ impl PostgresNode {
         }
     }
 
-    pub fn append_conf(&self, config: &str, opts: &str) -> Result<()> {
-        OpenOptions::new()
-            .append(true)
-            .open(self.pgdata().join(config).to_str().unwrap())?
-            .write_all(opts.as_bytes())?;
-        Ok(())
-    }
-
     fn pg_ctl(&self, args: &[&str], auth_token: &Option<String>) -> Result<()> {
         let pg_ctl_path = self.env.pg_bin_dir().join("pg_ctl");
         let mut cmd = Command::new(pg_ctl_path);
@@ -408,38 +389,22 @@ impl PostgresNode {
         }
 
         // 1. We always start compute node from scratch, so
-        // if old dir exists, preserve config files and drop the directory
-
-        // XXX Now we only use 'postgresql.conf'.
-        // If we will need 'pg_hba.conf', support it here too
-
+        // if old dir exists, preserve 'postgresql.conf' and drop the directory
         let postgresql_conf_path = self.pgdata().join("postgresql.conf");
-        let postgresql_conf = fs::read(postgresql_conf_path.clone()).with_context(|| {
+        let postgresql_conf = fs::read(&postgresql_conf_path).with_context(|| {
             format!(
                 "failed to read config file in {}",
                 postgresql_conf_path.to_str().unwrap()
             )
         })?;
-
-        println!(
-            "Destroying postgres data directory '{}'",
-            self.pgdata().to_str().unwrap()
-        );
         fs::remove_dir_all(&self.pgdata())?;
+        self.create_pgdata()?;
 
-        // 2. Create new node
-        self.init_from_page_server(self.env.auth_type, false)?;
+        // 2. Bring back config files
+        fs::write(&postgresql_conf_path, postgresql_conf)?;
 
-        // 3. Bring back config files
-
-        if let Ok(mut file) = OpenOptions::new()
-            .append(false)
-            .write(true)
-            .open(&postgresql_conf_path)
-        {
-            file.write_all(&postgresql_conf)?;
-            file.sync_all()?;
-        }
+        // 3. Load basebackup
+        self.load_basebackup()?;
 
         // 4. Finally start the compute node postgres
         println!("Starting postgres node at '{}'", self.connstr());
@@ -451,13 +416,22 @@ impl PostgresNode {
     }
 
     pub fn stop(&self, destroy: bool) -> Result<()> {
-        self.pg_ctl(&["-m", "immediate", "stop"], &None)?;
+        // If we are going to destroy data directory,
+        // use immediate shutdown mode, otherwise,
+        // shutdown gracefully to leave the data directory sane.
+        //
+        // Compute node always starts from scratch, so stop
+        // without destroy only used for testing and debugging.
+        //
         if destroy {
+            self.pg_ctl(&["-m", "immediate", "stop"], &None)?;
             println!(
                 "Destroying postgres data directory '{}'",
                 self.pgdata().to_str().unwrap()
             );
             fs::remove_dir_all(&self.pgdata())?;
+        } else {
+            self.pg_ctl(&["stop"], &None)?;
         }
         Ok(())
     }
@@ -478,9 +452,7 @@ impl PostgresNode {
             .output()
             .expect("failed to execute whoami");
 
-        if !output.status.success() {
-            panic!("whoami failed");
-        }
+        assert!(output.status.success(), "whoami failed");
 
         String::from_utf8(output.stdout).unwrap().trim().to_string()
     }

control_plane/src/lib.rs

@@ -12,6 +12,7 @@ use std::path::Path;
 
 pub mod compute;
 pub mod local_env;
+pub mod postgresql_conf;
 pub mod storage;
 
 /// Read a PID file

control_plane/src/local_env.rs

@@ -4,27 +4,24 @@
 // Now it also provides init method which acts like a stub for proper installation
 // script which will use local paths.
 //
-use anyhow::{anyhow, Context, Result};
-use hex;
+use anyhow::{Context, Result};
 use serde::{Deserialize, Serialize};
+use std::env;
 use std::fs;
 use std::path::PathBuf;
 use std::process::{Command, Stdio};
-use std::{collections::BTreeMap, env};
-use url::Url;
 use zenith_utils::auth::{encode_from_key_path, Claims, Scope};
 use zenith_utils::postgres_backend::AuthType;
 use zenith_utils::zid::ZTenantId;
 
-pub type Remotes = BTreeMap<String, String>;
-
 //
 // This data structures represent deserialized zenith CLI config
 //
 #[derive(Serialize, Deserialize, Clone, Debug)]
 pub struct LocalEnv {
-    // Pageserver connection strings
-    pub pageserver_connstring: String,
+    // Pageserver connection settings
+    pub pageserver_pg_port: u16,
+    pub pageserver_http_port: u16,
 
     // Base directory for both pageserver and compute nodes
     pub base_data_dir: PathBuf,
@@ -35,8 +32,8 @@ pub struct LocalEnv {
     // to four separate paths and match OS-specific installation layout.
     pub pg_distrib_dir: PathBuf,
 
-    // Path to pageserver binary. Empty for remote pageserver.
-    pub zenith_distrib_dir: Option<PathBuf>,
+    // Path to pageserver binary.
+    pub zenith_distrib_dir: PathBuf,
 
     // keeping tenant id in config to reduce copy paste when running zenith locally with single tenant
     #[serde(with = "hex")]
@@ -50,8 +47,6 @@ pub struct LocalEnv {
 
     // used to issue tokens during e.g pg start
     pub private_key_path: PathBuf,
-
-    pub remotes: Remotes,
 }
 
 impl LocalEnv {
@@ -64,11 +59,7 @@ impl LocalEnv {
     }
 
     pub fn pageserver_bin(&self) -> Result<PathBuf> {
-        Ok(self
-            .zenith_distrib_dir
-            .as_ref()
-            .ok_or_else(|| anyhow!("Can not manage remote pageserver"))?
-            .join("pageserver"))
+        Ok(self.zenith_distrib_dir.join("pageserver"))
     }
 
     pub fn pg_data_dirs_path(&self) -> PathBuf {
@@ -98,7 +89,8 @@ fn base_path() -> PathBuf {
 // Initialize a new Zenith repository
 //
 pub fn init(
-    remote_pageserver: Option<&str>,
+    pageserver_pg_port: u16,
+    pageserver_http_port: u16,
     tenantid: ZTenantId,
     auth_type: AuthType,
 ) -> Result<()> {
@@ -165,39 +157,22 @@ pub fn init(
     let auth_token =
         encode_from_key_path(&Claims::new(None, Scope::PageServerApi), &private_key_path)?;
 
-    let conf = if let Some(addr) = remote_pageserver {
-        // check that addr is parsable
-        let _uri = Url::parse(addr).map_err(|e| anyhow!("{}: {}", addr, e))?;
+    // Find zenith binaries.
+    let zenith_distrib_dir = env::current_exe()?.parent().unwrap().to_owned();
+    if !zenith_distrib_dir.join("pageserver").exists() {
+        anyhow::bail!("Can't find pageserver binary.",);
+    }
 
-        LocalEnv {
-            pageserver_connstring: format!("postgresql://{}/", addr),
-            pg_distrib_dir,
-            zenith_distrib_dir: None,
-            base_data_dir: base_path,
-            remotes: BTreeMap::default(),
-            tenantid,
-            auth_token,
-            auth_type,
-            private_key_path,
-        }
-    } else {
-        // Find zenith binaries.
-        let zenith_distrib_dir = env::current_exe()?.parent().unwrap().to_owned();
-        if !zenith_distrib_dir.join("pageserver").exists() {
-            anyhow::bail!("Can't find pageserver binary.",);
-        }
-
-        LocalEnv {
-            pageserver_connstring: "postgresql://127.0.0.1:6400".to_string(),
-            pg_distrib_dir,
-            zenith_distrib_dir: Some(zenith_distrib_dir),
-            base_data_dir: base_path,
-            remotes: BTreeMap::default(),
-            tenantid,
-            auth_token,
-            auth_type,
-            private_key_path,
-        }
+    let conf = LocalEnv {
+        pageserver_pg_port,
+        pageserver_http_port,
+        pg_distrib_dir,
+        zenith_distrib_dir,
+        base_data_dir: base_path,
+        tenantid,
+        auth_token,
+        auth_type,
+        private_key_path,
     };
 
     fs::create_dir_all(conf.pg_data_dirs_path())?;
@@ -225,12 +200,3 @@ pub fn load_config() -> Result<LocalEnv> {
     let config = fs::read_to_string(repopath.join("config"))?;
     toml::from_str(config.as_str()).map_err(|e| e.into())
 }
-
-// Save config. We use that to change set of remotes from CLI itself.
-pub fn save_config(conf: &LocalEnv) -> Result<()> {
-    let config_path = base_path().join("config");
-    let conf_str = toml::to_string_pretty(conf)?;
-
-    fs::write(config_path, conf_str)?;
-    Ok(())
-}

control_plane/src/postgresql_conf.rs

@@ -0,0 +1,212 @@
+///
+/// Module for parsing postgresql.conf file.
+///
+/// NOTE: This doesn't implement the full, correct postgresql.conf syntax. Just
+/// enough to extract a few settings we need in Zenith, assuming you don't do
+/// funny stuff like include-directives or funny escaping.
+use anyhow::{anyhow, bail, Context, Result};
+use lazy_static::lazy_static;
+use regex::Regex;
+use std::collections::HashMap;
+use std::fmt;
+use std::io::BufRead;
+use std::str::FromStr;
+
+/// In-memory representation of a postgresql.conf file
+#[derive(Default)]
+pub struct PostgresConf {
+    lines: Vec<String>,
+    hash: HashMap<String, String>,
+}
+
+lazy_static! {
+    static ref CONF_LINE_RE: Regex = Regex::new(r"^((?:\w|\.)+)\s*=\s*(\S+)$").unwrap();
+}
+
+impl PostgresConf {
+    pub fn new() -> PostgresConf {
+        PostgresConf::default()
+    }
+
+    /// Read file into memory
+    pub fn read(read: impl std::io::Read) -> Result<PostgresConf> {
+        let mut result = Self::new();
+
+        for line in std::io::BufReader::new(read).lines() {
+            let line = line?;
+
+            // Store each line in a vector, in original format
+            result.lines.push(line.clone());
+
+            // Also parse each line and insert key=value lines into a hash map.
+            //
+            // FIXME: This doesn't match exactly the flex/bison grammar in PostgreSQL.
+            // But it's close enough for our usage.
+            let line = line.trim();
+            if line.starts_with('#') {
+                // comment, ignore
+                continue;
+            } else if let Some(caps) = CONF_LINE_RE.captures(line) {
+                let name = caps.get(1).unwrap().as_str();
+                let raw_val = caps.get(2).unwrap().as_str();
+
+                if let Ok(val) = deescape_str(raw_val) {
+                    // Note: if there's already an entry in the hash map for
+                    // this key, this will replace it. That's the behavior what
+                    // we want; when PostgreSQL reads the file, each line
+                    // overrides any previous value for the same setting.
+                    result.hash.insert(name.to_string(), val.to_string());
+                }
+            }
+        }
+        Ok(result)
+    }
+
+    /// Return the current value of 'option'
+    pub fn get(&self, option: &str) -> Option<&str> {
+        self.hash.get(option).map(|x| x.as_ref())
+    }
+
+    /// Return the current value of a field, parsed to the right datatype.
+    ///
+    /// This calls the FromStr::parse() function on the value of the field. If
+    /// the field does not exist, or parsing fails, returns an error.
+    ///
+    pub fn parse_field<T>(&self, field_name: &str, context: &str) -> Result<T>
+    where
+        T: FromStr,
+        <T as FromStr>::Err: std::error::Error + Send + Sync + 'static,
+    {
+        self.get(field_name)
+            .ok_or_else(|| anyhow!("could not find '{}' option {}", field_name, context))?
+            .parse::<T>()
+            .with_context(|| format!("could not parse '{}' option {}", field_name, context))
+    }
+
+    ///
+    /// Note: if you call this multiple times for the same option, the config
+    /// file will a line for each call. It would be nice to have a function
+    /// to change an existing line, but that's a TODO.
+    ///
+    pub fn append(&mut self, option: &str, value: &str) {
+        self.lines
+            .push(format!("{}={}\n", option, escape_str(value)));
+        self.hash.insert(option.to_string(), value.to_string());
+    }
+
+    /// Append an arbitrary non-setting line to the config file
+    pub fn append_line(&mut self, line: &str) {
+        self.lines.push(line.to_string());
+    }
+}
+
+impl fmt::Display for PostgresConf {
+    /// Return the whole configuration file as a string
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        for line in self.lines.iter() {
+            f.write_str(line)?;
+        }
+        Ok(())
+    }
+}
+
+/// Escape a value for putting in postgresql.conf.
+fn escape_str(s: &str) -> String {
+    // If the string doesn't contain anything that needs quoting or escaping, return it
+    // as it is.
+    //
+    // The first part of the regex, before the '|', matches the INTEGER rule in the
+    // PostgreSQL flex grammar (guc-file.l). It matches plain integers like "123" and
+    // "-123", and also accepts units like "10MB". The second part of the regex matches
+    // the UNQUOTED_STRING rule, and accepts strings that contain a single word, beginning
+    // with a letter. That covers words like "off" or "posix". Everything else is quoted.
+    //
+    // This regex is a bit more conservative than the rules in guc-file.l, so we quote some
+    // strings that PostgreSQL would accept without quoting, but that's OK.
+    lazy_static! {
+        static ref UNQUOTED_RE: Regex =
+            Regex::new(r"(^[-+]?[0-9]+[a-zA-Z]*$)|(^[a-zA-Z][a-zA-Z0-9]*$)").unwrap();
+    }
+    if UNQUOTED_RE.is_match(s) {
+        s.to_string()
+    } else {
+        // Otherwise escape and quote it
+        let s = s
+            .replace('\\', "\\\\")
+            .replace('\n', "\\n")
+            .replace('\'', "''");
+
+        "\'".to_owned() + &s + "\'"
+    }
+}
+
+/// De-escape a possibly-quoted value.
+///
+/// See `DeescapeQuotedString` function in PostgreSQL sources for how PostgreSQL
+/// does this.
+fn deescape_str(s: &str) -> Result<String> {
+    // If the string has a quote at the beginning and end, strip them out.
+    if s.len() >= 2 && s.starts_with('\'') && s.ends_with('\'') {
+        let mut result = String::new();
+
+        let mut iter = s[1..(s.len() - 1)].chars().peekable();
+        while let Some(c) = iter.next() {
+            let newc = if c == '\\' {
+                match iter.next() {
+                    Some('b') => '\x08',
+                    Some('f') => '\x0c',
+                    Some('n') => '\n',
+                    Some('r') => '\r',
+                    Some('t') => '\t',
+                    Some('0'..='7') => {
+                        // TODO
+                        bail!("octal escapes not supported");
+                    }
+                    Some(n) => n,
+                    None => break,
+                }
+            } else if c == '\'' && iter.peek() == Some(&'\'') {
+                // doubled quote becomes just one quote
+                iter.next().unwrap()
+            } else {
+                c
+            };
+
+            result.push(newc);
+        }
+        Ok(result)
+    } else {
+        Ok(s.to_string())
+    }
+}
+
+#[test]
+fn test_postgresql_conf_escapes() -> Result<()> {
+    assert_eq!(escape_str("foo bar"), "'foo bar'");
+    // these don't need to be quoted
+    assert_eq!(escape_str("foo"), "foo");
+    assert_eq!(escape_str("123"), "123");
+    assert_eq!(escape_str("+123"), "+123");
+    assert_eq!(escape_str("-10"), "-10");
+    assert_eq!(escape_str("1foo"), "1foo");
+    assert_eq!(escape_str("foo1"), "foo1");
+    assert_eq!(escape_str("10MB"), "10MB");
+    assert_eq!(escape_str("-10kB"), "-10kB");
+
+    // these need quoting and/or escaping
+    assert_eq!(escape_str("foo bar"), "'foo bar'");
+    assert_eq!(escape_str("fo'o"), "'fo''o'");
+    assert_eq!(escape_str("fo\no"), "'fo\\no'");
+    assert_eq!(escape_str("fo\\o"), "'fo\\\\o'");
+    assert_eq!(escape_str("10 cats"), "'10 cats'");
+
+    // Test de-escaping
+    assert_eq!(deescape_str(&escape_str("foo"))?, "foo");
+    assert_eq!(deescape_str(&escape_str("fo'o\nba\\r"))?, "fo'o\nba\\r");
+    assert_eq!(deescape_str("'\\b\\f\\n\\r\\t'")?, "\x08\x0c\n\r\t");
+
+    // octal-escapes are currently not supported
+    assert!(deescape_str("'foo\\7\\07\\007'").is_err());
+
+    Ok(())
+}

control_plane/src/storage.rs

@@ -1,17 +1,19 @@
-use std::collections::HashMap;
+use std::io::Write;
 use std::net::TcpStream;
 use std::path::PathBuf;
 use std::process::Command;
-use std::thread;
 use std::time::Duration;
+use std::{io, result, thread};
 
-use anyhow::{anyhow, bail, ensure, Result};
+use anyhow::{anyhow, bail};
 use nix::sys::signal::{kill, Signal};
 use nix::unistd::Pid;
 use pageserver::http::models::{BranchCreateRequest, TenantCreateRequest};
 use postgres::{Config, NoTls};
-use reqwest::blocking::{Client, RequestBuilder};
-use reqwest::{IntoUrl, Method, StatusCode};
+use reqwest::blocking::{Client, RequestBuilder, Response};
+use reqwest::{IntoUrl, Method};
+use thiserror::Error;
+use zenith_utils::http::error::HttpErrorBody;
 use zenith_utils::postgres_backend::AuthType;
 use zenith_utils::zid::ZTenantId;
 
@@ -20,7 +22,38 @@ use crate::read_pidfile;
 use pageserver::branches::BranchInfo;
 use zenith_utils::connstring::connection_address;
 
-const HTTP_BASE_URL: &str = "http://127.0.0.1:9898/v1";
+#[derive(Error, Debug)]
+pub enum PageserverHttpError {
+    #[error("Reqwest error: {0}")]
+    Transport(#[from] reqwest::Error),
+
+    #[error("Error: {0}")]
+    Response(String),
+}
+
+type Result<T> = result::Result<T, PageserverHttpError>;
+
+pub trait ResponseErrorMessageExt: Sized {
+    fn error_from_body(self) -> Result<Self>;
+}
+
+impl ResponseErrorMessageExt for Response {
+    fn error_from_body(self) -> Result<Self> {
+        let status = self.status();
+        if !(status.is_client_error() || status.is_server_error()) {
+            return Ok(self);
+        }
+
+        // reqwest do not export it's error construction utility functions, so lets craft the message ourselves
+        let url = self.url().to_owned();
+        Err(PageserverHttpError::Response(
+            match self.json::<HttpErrorBody>() {
+                Ok(err_body) => format!("Error: {}", err_body.msg),
+                Err(_) => format!("Http error ({}) at {}.", status.as_u16(), url),
+            },
+        ))
+    }
+}
 
 //
 // Control routines for pageserver.
@@ -46,27 +79,36 @@ impl PageServerNode {
 
         PageServerNode {
             kill_on_exit: false,
-            pg_connection_config: Self::default_config(password), // default
+            pg_connection_config: Self::pageserver_connection_config(
+                password,
+                env.pageserver_pg_port,
+            ),
             env: env.clone(),
             http_client: Client::new(),
-            http_base_url: HTTP_BASE_URL.to_owned(),
+            http_base_url: format!("http://localhost:{}/v1", env.pageserver_http_port),
         }
     }
 
-    fn default_config(password: &str) -> Config {
-        format!("postgresql://no_user:{}@localhost:64000/no_db", password)
+    fn pageserver_connection_config(password: &str, port: u16) -> Config {
+        format!("postgresql://no_user:{}@localhost:{}/no_db", password, port)
             .parse()
             .unwrap()
     }
 
-    pub fn init(&self, create_tenant: Option<&str>, enable_auth: bool) -> Result<()> {
+    pub fn init(&self, create_tenant: Option<&str>, enable_auth: bool) -> anyhow::Result<()> {
         let mut cmd = Command::new(self.env.pageserver_bin()?);
+        let listen_pg = format!("localhost:{}", self.env.pageserver_pg_port);
+        let listen_http = format!("localhost:{}", self.env.pageserver_http_port);
         let mut args = vec![
             "--init",
             "-D",
             self.env.base_data_dir.to_str().unwrap(),
             "--postgres-distrib",
             self.env.pg_distrib_dir.to_str().unwrap(),
+            "--listen-pg",
+            &listen_pg,
+            "--listen-http",
+            &listen_http,
         ];
 
         if enable_auth {
@@ -74,7 +116,10 @@ impl PageServerNode {
             args.extend(&["--auth-type", "ZenithJWT"]);
         }
 
-        create_tenant.map(|tenantid| args.extend(&["--create-tenant", tenantid]));
+        if let Some(tenantid) = create_tenant {
+            args.extend(&["--create-tenant", tenantid])
+        }
+
         let status = cmd
             .args(args)
             .env_clear()
@@ -97,12 +142,13 @@ impl PageServerNode {
         self.repo_path().join("pageserver.pid")
     }
 
-    pub fn start(&self) -> Result<()> {
-        println!(
-            "Starting pageserver at '{}' in {}",
+    pub fn start(&self) -> anyhow::Result<()> {
+        print!(
+            "Starting pageserver at '{}' in '{}'",
             connection_address(&self.pg_connection_config),
             self.repo_path().display()
         );
+        io::stdout().flush().unwrap();
 
         let mut cmd = Command::new(self.env.pageserver_bin()?);
         cmd.args(&["-D", self.repo_path().to_str().unwrap()])
@@ -119,25 +165,41 @@ impl PageServerNode {
 
         // It takes a while for the page server to start up. Wait until it is
         // open for business.
-        for retries in 1..15 {
+        const RETRIES: i8 = 15;
+        for retries in 1..RETRIES {
             match self.check_status() {
                 Ok(_) => {
-                    println!("Pageserver started");
+                    println!("\nPageserver started");
                     return Ok(());
                 }
                 Err(err) => {
-                    println!(
-                        "Pageserver not responding yet, err {} retrying ({})...",
-                        err, retries
-                    );
+                    match err {
+                        PageserverHttpError::Transport(err) => {
+                            if err.is_connect() && retries < 5 {
+                                print!(".");
+                                io::stdout().flush().unwrap();
+                            } else {
+                                if retries == 5 {
+                                    println!() // put a line break after dots for second message
+                                }
+                                println!(
+                                    "Pageserver not responding yet, err {} retrying ({})...",
+                                    err, retries
+                                );
+                            }
+                        }
+                        PageserverHttpError::Response(msg) => {
+                            bail!("pageserver failed to start: {} ", msg)
+                        }
+                    }
                     thread::sleep(Duration::from_secs(1));
                 }
             }
         }
-        bail!("pageserver failed to start");
+        bail!("pageserver failed to start in {} seconds", RETRIES);
     }
 
-    pub fn stop(&self) -> Result<()> {
+    pub fn stop(&self) -> anyhow::Result<()> {
         let pid = read_pidfile(&self.pid_file())?;
         let pid = Pid::from_raw(pid);
         if kill(pid, Signal::SIGTERM).is_err() {
@@ -166,7 +228,7 @@ impl PageServerNode {
         client.simple_query(sql).unwrap()
     }
 
-    pub fn page_server_psql_client(&self) -> Result<postgres::Client, postgres::Error> {
+    pub fn page_server_psql_client(&self) -> result::Result<postgres::Client, postgres::Error> {
         self.pg_connection_config.connect(NoTls)
     }
 
@@ -179,14 +241,9 @@ impl PageServerNode {
     }
 
     pub fn check_status(&self) -> Result<()> {
-        let status = self
-            .http_request(Method::GET, format!("{}/{}", self.http_base_url, "status"))
+        self.http_request(Method::GET, format!("{}/{}", self.http_base_url, "status"))
             .send()?
-            .status();
-        ensure!(
-            status == StatusCode::OK,
-            format!("got unexpected response status {}", status)
-        );
+            .error_from_body()?;
         Ok(())
     }
 
@@ -194,7 +251,7 @@ impl PageServerNode {
         Ok(self
             .http_request(Method::GET, format!("{}/{}", self.http_base_url, "tenant"))
             .send()?
-            .error_for_status()?
+            .error_from_body()?
             .json()?)
     }
 
@@ -205,7 +262,7 @@ impl PageServerNode {
                 tenant_id: tenantid,
             })
             .send()?
-            .error_for_status()?
+            .error_from_body()?
             .json()?)
     }
 
@@ -216,7 +273,7 @@ impl PageServerNode {
                 format!("{}/branch/{}", self.http_base_url, tenantid),
             )
             .send()?
-            .error_for_status()?
+            .error_from_body()?
             .json()?)
     }
 
@@ -227,35 +284,30 @@ impl PageServerNode {
         tenantid: &ZTenantId,
     ) -> Result<BranchInfo> {
         Ok(self
-            .http_request(Method::POST, format!("{}/{}", self.http_base_url, "branch"))
+            .http_request(Method::POST, format!("{}/branch", self.http_base_url))
             .json(&BranchCreateRequest {
                 tenant_id: tenantid.to_owned(),
                 name: branch_name.to_owned(),
                 start_point: startpoint.to_owned(),
             })
             .send()?
-            .error_for_status()?
+            .error_from_body()?
             .json()?)
     }
 
-    // TODO: make this a separate request type and avoid loading all the branches
     pub fn branch_get_by_name(
         &self,
         tenantid: &ZTenantId,
         branch_name: &str,
     ) -> Result<BranchInfo> {
-        let branch_infos = self.branch_list(tenantid)?;
-        let branch_by_name: Result<HashMap<String, BranchInfo>> = branch_infos
-            .into_iter()
-            .map(|branch_info| Ok((branch_info.name.clone(), branch_info)))
-            .collect();
-        let branch_by_name = branch_by_name?;
-
-        let branch = branch_by_name
-            .get(branch_name)
-            .ok_or_else(|| anyhow!("Branch {} not found", branch_name))?;
-
-        Ok(branch.clone())
+        Ok(self
+            .http_request(
+                Method::GET,
+                format!("{}/branch/{}/{}", self.http_base_url, tenantid, branch_name),
+            )
+            .send()?
+            .error_for_status()?
+            .json()?)
     }
 }
 

docs/README.md

@@ -10,4 +10,5 @@
 - [pageserver/README](/pageserver/README) — pageserver overview.
 - [postgres_ffi/README](/postgres_ffi/README) — Postgres FFI overview.
 - [test_runner/README.md](/test_runner/README.md) — tests infrastructure overview.
-- [walkeeper/README](/walkeeper/README.md) — WAL service overview.
+- [walkeeper/README](/walkeeper/README) — WAL service overview.
+- [core_changes.md](core_changes.md) - Description of Zenith changes in Postgres core

docs/core_changes.md

@@ -0,0 +1,202 @@
+1. Add t_cid to XLOG record
+- Why?
+  The cmin/cmax on a heap page is a real bummer. I don't see any other way to fix that than bite the bullet and modify the WAL-logging routine to include the cmin/cmax.
+
+  To recap, the problem is that the XLOG_HEAP_INSERT record does not include the command id of the inserted row. And same with deletion/update. So in the primary, a row is inserted with current xmin + cmin. But in the replica, the cmin is always set to 1. That works, because the command id is only relevant to the inserting transaction itself. After commit/abort, no one cares abut it anymore.
+
+- Alternatives?
+  I don't know
+
+2. Add PD_WAL_LOGGED.
+- Why?
+  Postgres sometimes writes data to the page before it is wal-logged. If such page ais swapped out, we  will loose this change. The problem is currently solved by setting PD_WAL_LOGGED bit in page header. When page without this bit set is written to the SMGR, then it is forced to be written to the WAL as FPI using log_newpage_copy() function.
+
+  There was wrong assumption that it can happen only during construction of some exotic indexes (like gist). It is not true. The same situation can happen with COPY,VACUUM and when record hint bits are set.
+
+- Discussion:
+  https://discord.com/channels/869525774699462656/882681420986851359
+
+- Alternatives:
+  Do not store this flag in page header, but associate this bit with shared buffer. Logically it is more correct but in practice we will get not advantages: neither in space, neither in CPU overhead.
+
+
+3. XLogReadBufferForRedo not always loads and pins requested buffer. So we need to add extra checks that buffer is really pinned. Also do not use BufferGetBlockNumber for buffer returned by XLogReadBufferForRedo.
+- Why?
+  XLogReadBufferForRedo is not pinning pages which are not requested by wal-redo. It is specific only for wal-redo Postgres.
+
+- Alternatives?
+  No
+
+
+4. Eliminate reporting of some warnings related with hint bits, for example
+"page is not marked all-visible but visibility map bit is set in relation".
+- Why?
+  Hint bit may be not WAL logged.
+
+- Alternative?
+  Always wal log any page changes.
+
+
+5. Maintain last written LSN.
+- Why?
+  When compute node requests page from page server, we need to specify LSN. Ideally it should be LSN
+  of WAL record performing last update of this pages. But we do not know it, because we do not have page.
+  We can use current WAL flush position, but in this case there is high probability that page server
+  will be blocked until this peace of WAL is delivered.
+  As better approximation we can keep max LSN of written page. It will be better to take in account LSNs only of evicted pages,
+  but SMGR API doesn't provide such knowledge.
+
+- Alternatives?
+  Maintain map of LSNs of evicted pages.
+
+
+6. Launching Postgres without WAL.
+- Why?
+  According to Zenith architecture compute node is stateless. So when we are launching
+  compute node, we need to provide some dummy PG_DATADIR. Relation pages
+  can be requested on demand from page server. But Postgres still need some non-relational data:
+  control and configuration files, SLRUs,...
+  It is currently implemented  using basebackup (do not mix with pg_basebackup) which is created
+  by pageserver. It includes in this tarball config/control files, SLRUs and required directories.
+  As far as pageserver do not have original (non-scattered) WAL segments, it includes in
+  this tarball dummy WAL segment which contains only SHUTDOWN_CHECKPOINT record at the beginning of segment,
+  which redo field points to the end of wal. It allows to load checkpoint record in more or less
+  standard way with minimal changes of Postgres, but then some special handling is needed,
+  including restoring previous record position from zenith.signal file.
+  Also we have to correctly initialize header of last WAL page (pointed by checkpoint.redo)
+  to pass checks performed by XLogReader.
+
+- Alternatives?
+  We may not include fake WAL segment in tarball at all and modify xlog.c to load checkpoint record
+  in special way. But it may only increase number of changes in xlog.c
+
+7. Add redo_read_buffer_filter callback to XLogReadBufferForRedoExtended
+- Why?
+  We need a way in wal-redo Postgres to ignore pages which are not requested by pageserver.
+  So wal-redo Postgres reconstructs only requested page and for all other returns BLK_DONE
+  which means that recovery for them is not needed.
+
+- Alternatives?
+  No
+
+8. Enforce WAL logging of sequence updates.
+- Why?
+  Due to performance reasons Postgres don't want to log each fetching of a value from a sequence,
+  so we pre-log a few fetches in advance. In the event of crash we can lose
+  (skip over) as many values as we pre-logged.
+  But it doesn't work with Zenith because page with sequence value can be evicted from buffer cache
+  and we will get a gap in sequence values even without crash.
+
+- Alternatives:
+  Do not try to preserve sequential order but avoid performance penalty.
+
+
+9. Treat unlogged tables as normal (permanent) tables.
+- Why?
+  Unlogged tables are not transient, so them have to survive node restart (unlike temporary tables).
+  But as far as compute node is stateless, we need to persist their data to storage node.
+  And it can only be done through the WAL.
+
+- Alternatives?
+  * Store unlogged tables locally (violates requirement of stateless compute nodes).
+  * Prohibit unlogged tables at all.
+
+
+10. Support start Postgres in wal-redo mode
+- Why?
+  To be able to apply WAL record and reconstruct pages at page server.
+
+- Alternatives?
+  * Rewrite redo handlers in Rust
+  * Do not reconstruct pages at page server at all and do it at compute node.
+
+
+11. WAL proposer
+- Why?
+  WAL proposer is communicating with safekeeper and ensures WAL durability by quorum writes.
+  It is currently implemented as patch to standard WAL sender.
+
+- Alternatives?
+  Can be moved to extension if some extra callbacks will be added to wal sender code.
+
+
+12. Secure Computing BPF API wrapper.
+- Why?
+  Pageserver delegates complex WAL decoding duties to Postgres,
+  which means that the latter might fall victim to carefully designed
+  malicious WAL records and start doing harmful things to the system.
+  To prevent this, it has been decided to limit possible interactions
+  with the outside world using the Secure Computing BPF mode.
+
+- Alternatives:
+  * Rewrite redo handlers in Rust.
+  * Add more checks to guarantee correctness of WAL records.
+  * Move seccomp.c to extension
+  * Many other discussed approaches to neutralize incorrect WAL records vulnerabilities.
+
+
+13. Callbacks for replica feedbacks
+- Why?
+  Allowing waproposer to interact with walsender code.
+
+- Alternatives
+  Copy walsender code to walproposer.
+
+
+14. Support multiple SMGR implementations.
+- Why?
+  Postgres provides abstract API for storage manager but it has only one implementation
+  and provides no way to replace it with custom storage manager.
+
+- Alternatives?
+  None.
+
+
+15. Calculate database size as sum of all database relations.
+- Why?
+  Postgres is calculating database size by traversing data directory
+  but as far as Zenith compute node is stateless we can not do it.
+
+- Alternatives?
+  Send this request directly to pageserver and calculate real (physical) size
+  of Zenith representation of database/timeline, rather than sum logical size of all relations.
+
+
+-----------------------------------------------
+Not currently committed but proposed:
+
+1. Disable ring buffer buffer manager strategies
+- Why?
+  Postgres tries to avoid cache flushing by bulk operations (copy, seqscan, vacuum,...).
+  Even if there are free space in buffer cache, pages may be evicted.
+  Negative effect of it can be somehow compensated by file system cache, but in case of Zenith
+  cost of requesting page from page server is much higher.
+
+- Alternatives?
+  Instead of just prohibiting ring buffer we may try to implement more flexible eviction policy,
+  for example copy evicted page from ring buffer to some other buffer if there is free space
+  in buffer cache.
+
+2. Disable marking page as dirty when hint bits are set.
+- Why?
+  Postgres has to modify page twice: first time when some tuple is updated and second time when
+  hint bits are set. Wal logging hint bits updates requires FPI which significantly increase size of WAL.
+
+- Alternatives?
+  Add special WAL record for setting page hints.
+
+3. Prefetching
+- Why?
+  As far as pages in Zenith are loaded on demand, to reduce node startup time
+  and also sppedup some massive queries we need some mechanism for bulk loading to
+  reduce page request round-trip overhead.
+
+  Currently Postgres is supporting prefetching only for bitmap scan.
+  In Zenith we also use prefetch for sequential and index scan. For sequential scan we prefetch
+  some number of following pages. For index scan we prefetch pages of heap relation addressed by TIDs.
+
+4. Prewarming.
+- Why?
+  Short downtime (or, in other words, fast compute node restart time) is one of the key feature of Zenith.
+  But overhead of request-response round-trip for loading pages on demand can make started node warm-up quite slow.
+  We can capture state of compute node buffer cache and send bulk request for this pages at startup.

docs/glossary.md

@@ -26,32 +26,51 @@ A checkpoint record in the WAL marks a point in the WAL sequence at which it is
 NOTE: This is an overloaded term.
 
 Whenever enough WAL has been accumulated in memory, the page server []
-writes out the changes in memory into new layer files[]. This process
+writes out the changes from in-memory layers into new layer files[]. This process
 is called "checkpointing". The page server only creates layer files for
 relations that have been modified since the last checkpoint. 
 
+Configuration parameter `checkpoint_distance` defines the distance
+from current LSN to perform checkpoint of in-memory layers.
+Default is `DEFAULT_CHECKPOINT_DISTANCE`.
+Set this parameter to `0` to force checkpoint of every layer.
+
+Configuration parameter `checkpoint_period` defines the interval between checkpoint iterations.
+Default is `DEFAULT_CHECKPOINT_PERIOD`.
 ### Compute node
 
 Stateless Postgres node that stores data in pageserver.
 
 ### Garbage collection
 
+The process of removing old on-disk layers that are not needed by any timeline anymore.
 ### Fork
 
 Each of the separate segmented file sets in which a relation is stored. The main fork is where the actual data resides. There also exist two secondary forks for metadata: the free space map and the visibility map.
 Each PostgreSQL fork is considered a separate relish.
 
-### Layer file
+### Layer
+
+Each layer corresponds to the specific version of a relish Segment in a range of LSNs.
+There are two kinds of layers, in-memory and on-disk layers. In-memory
+layers are used to ingest incoming WAL, and provide fast access
+to the recent page versions. On-disk layers are stored as files on disk, and
+are immutable.
+### Layer file (on-disk layer)
 
 Layered repository on-disk format is based on immutable files.  The
-files are called "layer files". Each file corresponds to one 10 MB
+files are called "layer files". Each file corresponds to one RELISH_SEG_SIZE
 segment of a PostgreSQL relation fork. There are two kinds of layer
 files: image files and delta files. An image file contains a
 "snapshot" of the segment at a particular LSN, and a delta file
 contains WAL records applicable to the segment, in a range of LSNs.
 
+### Layer map
+
+The layer map tracks what layers exist for all the relishes in a timeline.
 ### Layered repository
 
+Zenith repository implementation that keeps data in layers.
 ### LSN
 
 
@@ -111,6 +130,20 @@ One repository corresponds to one Tenant.
 
 How much history do we need to keep around for PITR and read-only nodes?
 
+### Segment (PostgreSQL)
+
+NOTE: This is an overloaded term.
+
+A physical file that stores data for a given relation. File segments are
+limited in size by a compile-time setting (1 gigabyte by default), so if a
+relation exceeds that size, it is split into multiple segments.
+
+### Segment (Layered Repository)
+
+NOTE: This is an overloaded term.
+
+Segment is a RELISH_SEG_SIZE slice of relish (identified by a SegmentTag).
+
 ### SLRU
 
 SLRUs include pg_clog, pg_multixact/members, and
@@ -121,7 +154,7 @@ Each SLRU segment is considered a separate relish[].
 
 ### Tenant (Multitenancy)
 Tenant represents a single customer, interacting with Zenith.
-Wal redo[] activity, timelines[], snapshots[] are managed for each tenant independently.
+Wal redo[] activity, timelines[], layers[] are managed for each tenant independently.
 One pageserver[] can serve multiple tenants at once.
 One safekeeper 
 

docs/multitenancy.md

@@ -37,7 +37,7 @@ On the page server tenants introduce one level of indirection, so data directory
    ├── de182bc61fb11a5a6b390a8aed3a804a
    └── ee6016ec31116c1b7c33dfdfca38891f
 ```
-Wal redo activity, timelines, snapshots are managed for each tenant independently.
+Wal redo activity and timelines are managed for each tenant independently.
 
 For local environment used for example in tests there also new level of indirection for tenants. It touches `pgdatadirs` directory. Now it contains `tenants` subdirectory so the structure looks the following way:
 

pageserver/Cargo.toml

@@ -4,8 +4,6 @@ version = "0.1.0"
 authors = ["Stas Kelvich <stas@zenith.tech>"]
 edition = "2018"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
 bookfile = "^0.3"
 chrono = "0.4.19"
@@ -16,14 +14,10 @@ byteorder = "1.4.3"
 futures = "0.3.13"
 hyper = "0.14"
 lazy_static = "1.4.0"
-slog-stdlog = "4.1.0"
-slog-scope = "4.4.0"
-slog-term = "2.8.0"
-slog = "2.7.0"
 log = "0.4.14"
 clap = "2.33.0"
 daemonize = "0.4.1"
-tokio = { version = "1.5.0", features = ["full"] }
+tokio = { version = "1.11", features = ["process", "macros", "fs"] }
 postgres-types = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }
 postgres-protocol = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }
 postgres = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }
@@ -38,8 +32,14 @@ serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 toml = "0.5"
 scopeguard = "1.1.0"
+rust-s3 = { version = "0.27.0-rc4", features = ["no-verify-ssl"] }
+async-trait = "0.1"
+const_format = "0.2.21"
 
 postgres_ffi = { path = "../postgres_ffi" }
 zenith_metrics = { path = "../zenith_metrics" }
 zenith_utils = { path = "../zenith_utils" }
 workspace_hack = { path = "../workspace_hack" }
+
+[dev-dependencies]
+hex-literal = "0.3"

pageserver/README

@@ -7,8 +7,9 @@ The Page Server has a few different duties:
 - Replay WAL that's applicable to the chunks that the Page Server maintains
 - Backup to S3
 
-
-
+S3 is the main fault-tolerant storage of all data, as there are no Page Server
+replicas. We use a separate fault-tolerant WAL service to reduce latency. It
+keeps track of WAL records which are not syncted to S3 yet.
 
 The Page Server consists of multiple threads that operate on a shared
 repository of page versions:

pageserver/src/basebackup.rs

@@ -10,6 +10,7 @@
 //! This module is responsible for creation of such tarball
 //! from data stored in object storage.
 //!
+use anyhow::Result;
 use bytes::{BufMut, BytesMut};
 use log::*;
 use std::io;
@@ -22,7 +23,7 @@ use crate::relish::*;
 use crate::repository::Timeline;
 use postgres_ffi::xlog_utils::*;
 use postgres_ffi::*;
-use zenith_utils::lsn::{Lsn, RecordLsn};
+use zenith_utils::lsn::Lsn;
 
 /// This is short-living object only for the time of tarball creation,
 /// created mostly to avoid passing a lot of parameters between various functions
@@ -46,30 +47,51 @@ impl<'a> Basebackup<'a> {
         write: &'a mut dyn Write,
         timeline: &'a Arc<dyn Timeline>,
         req_lsn: Option<Lsn>,
-    ) -> Basebackup<'a> {
-        let RecordLsn {
-            last: lsn,
-            prev: prev_record_lsn,
-        } = if let Some(lsn) = req_lsn {
-            // FIXME: that wouldn't work since we don't know prev for old LSN's.
-            // Probably it is better to avoid using prev in compute node start
-            // at all and acept the fact that first WAL record in the timeline would
-            // have zero as prev. https://github.com/zenithdb/zenith/issues/506
-            RecordLsn {
-                last: lsn,
-                prev: lsn,
+    ) -> Result<Basebackup<'a>> {
+        // Compute postgres doesn't have any previous WAL files, but the first
+        // record that it's going to write needs to include the LSN of the
+        // previous record (xl_prev). We include prev_record_lsn in the
+        // "zenith.signal" file, so that postgres can read it during startup.
+        //
+        // We don't keep full history of record boundaries in the page server,
+        // however, only the predecessor of the latest record on each
+        // timeline. So we can only provide prev_record_lsn when you take a
+        // base backup at the end of the timeline, i.e. at last_record_lsn.
+        // Even at the end of the timeline, we sometimes don't have a valid
+        // prev_lsn value; that happens if the timeline was just branched from
+        // an old LSN and it doesn't have any WAL of its own yet. We will set
+        // prev_lsn to Lsn(0) if we cannot provide the correct value.
+        let (backup_prev, backup_lsn) = if let Some(req_lsn) = req_lsn {
+            // Backup was requested at a particular LSN. Wait for it to arrive.
+            timeline.wait_lsn(req_lsn)?;
+
+            // If the requested point is the end of the timeline, we can
+            // provide prev_lsn. (get_last_record_rlsn() might return it as
+            // zero, though, if no WAL has been generated on this timeline
+            // yet.)
+            let end_of_timeline = timeline.get_last_record_rlsn();
+            if req_lsn == end_of_timeline.last {
+                (end_of_timeline.prev, req_lsn)
+            } else {
+                (Lsn(0), req_lsn)
             }
         } else {
-            // Atomically get last and prev LSN's
-            timeline.get_last_record_rlsn()
+            // Backup was requested at end of the timeline.
+            let end_of_timeline = timeline.get_last_record_rlsn();
+            (end_of_timeline.prev, end_of_timeline.last)
         };
 
-        Basebackup {
+        info!(
+            "taking basebackup lsn={}, prev_lsn={}",
+            backup_prev, backup_lsn
+        );
+
+        Ok(Basebackup {
             ar: Builder::new(write),
             timeline,
-            lsn,
-            prev_record_lsn,
-        }
+            lsn: backup_lsn,
+            prev_record_lsn: backup_prev,
+        })
     }
 
     pub fn send_tarball(&mut self) -> anyhow::Result<()> {
@@ -84,10 +106,10 @@ impl<'a> Basebackup<'a> {
         for filepath in pg_constants::PGDATA_SPECIAL_FILES.iter() {
             if *filepath == "pg_hba.conf" {
                 let data = pg_constants::PG_HBA.as_bytes();
-                let header = new_tar_header(&filepath, data.len() as u64)?;
-                self.ar.append(&header, &data[..])?;
+                let header = new_tar_header(filepath, data.len() as u64)?;
+                self.ar.append(&header, data)?;
             } else {
-                let header = new_tar_header(&filepath, 0)?;
+                let header = new_tar_header(filepath, 0)?;
                 self.ar.append(&header, &mut io::empty())?;
             }
         }
@@ -137,11 +159,9 @@ impl<'a> Basebackup<'a> {
         let mut slru_buf: Vec<u8> =
             Vec::with_capacity(nblocks as usize * pg_constants::BLCKSZ as usize);
         for blknum in 0..nblocks {
-            let img = self.timeline.get_page_at_lsn_nowait(
-                RelishTag::Slru { slru, segno },
-                blknum,
-                self.lsn,
-            )?;
+            let img =
+                self.timeline
+                    .get_page_at_lsn(RelishTag::Slru { slru, segno }, blknum, self.lsn)?;
             assert!(img.len() == pg_constants::BLCKSZ as usize);
 
             slru_buf.extend_from_slice(&img);
@@ -160,20 +180,18 @@ impl<'a> Basebackup<'a> {
     // Along with them also send PG_VERSION for each database.
     //
     fn add_relmap_file(&mut self, spcnode: u32, dbnode: u32) -> anyhow::Result<()> {
-        let img = self.timeline.get_page_at_lsn_nowait(
+        let img = self.timeline.get_page_at_lsn(
             RelishTag::FileNodeMap { spcnode, dbnode },
             0,
             self.lsn,
         )?;
         let path = if spcnode == pg_constants::GLOBALTABLESPACE_OID {
-            let dst_path = "PG_VERSION";
             let version_bytes = pg_constants::PG_MAJORVERSION.as_bytes();
-            let header = new_tar_header(&dst_path, version_bytes.len() as u64)?;
-            self.ar.append(&header, &version_bytes[..])?;
+            let header = new_tar_header("PG_VERSION", version_bytes.len() as u64)?;
+            self.ar.append(&header, version_bytes)?;
 
-            let dst_path = format!("global/PG_VERSION");
-            let header = new_tar_header(&dst_path, version_bytes.len() as u64)?;
-            self.ar.append(&header, &version_bytes[..])?;
+            let header = new_tar_header("global/PG_VERSION", version_bytes.len() as u64)?;
+            self.ar.append(&header, version_bytes)?;
 
             String::from("global/pg_filenode.map") // filenode map for global tablespace
         } else {
@@ -188,7 +206,7 @@ impl<'a> Basebackup<'a> {
             let dst_path = format!("base/{}/PG_VERSION", dbnode);
             let version_bytes = pg_constants::PG_MAJORVERSION.as_bytes();
             let header = new_tar_header(&dst_path, version_bytes.len() as u64)?;
-            self.ar.append(&header, &version_bytes[..])?;
+            self.ar.append(&header, version_bytes)?;
 
             format!("base/{}/pg_filenode.map", dbnode)
         };
@@ -204,7 +222,7 @@ impl<'a> Basebackup<'a> {
     fn add_twophase_file(&mut self, xid: TransactionId) -> anyhow::Result<()> {
         let img = self
             .timeline
-            .get_page_at_lsn_nowait(RelishTag::TwoPhase { xid }, 0, self.lsn)?;
+            .get_page_at_lsn(RelishTag::TwoPhase { xid }, 0, self.lsn)?;
 
         let mut buf = BytesMut::new();
         buf.extend_from_slice(&img[..]);
@@ -222,12 +240,12 @@ impl<'a> Basebackup<'a> {
     // Also send zenith.signal file with extra bootstrap data.
     //
     fn add_pgcontrol_file(&mut self) -> anyhow::Result<()> {
-        let checkpoint_bytes =
-            self.timeline
-                .get_page_at_lsn_nowait(RelishTag::Checkpoint, 0, self.lsn)?;
+        let checkpoint_bytes = self
+            .timeline
+            .get_page_at_lsn(RelishTag::Checkpoint, 0, self.lsn)?;
         let pg_control_bytes =
             self.timeline
-                .get_page_at_lsn_nowait(RelishTag::ControlFile, 0, self.lsn)?;
+                .get_page_at_lsn(RelishTag::ControlFile, 0, self.lsn)?;
         let mut pg_control = ControlFileData::decode(&pg_control_bytes)?;
         let mut checkpoint = CheckPoint::decode(&checkpoint_bytes)?;
 
@@ -238,7 +256,7 @@ impl<'a> Basebackup<'a> {
             XLOG_SIZE_OF_XLOG_LONG_PHD as u32,
             pg_constants::WAL_SEGMENT_SIZE,
         );
-        checkpoint.redo = self.lsn.0 + self.lsn.calc_padding(8u32);
+        checkpoint.redo = normalize_lsn(self.lsn, pg_constants::WAL_SEGMENT_SIZE).0;
 
         //reset some fields we don't want to preserve
         //TODO Check this.
@@ -251,9 +269,14 @@ impl<'a> Basebackup<'a> {
         pg_control.state = pg_constants::DB_SHUTDOWNED;
 
         // add zenith.signal file
+        let xl_prev = if self.prev_record_lsn == Lsn(0) {
+            0xBAD0 // magic value to indicate that we don't know prev_lsn
+        } else {
+            self.prev_record_lsn.0
+        };
         self.ar.append(
             &new_tar_header("zenith.signal", 8)?,
-            &self.prev_record_lsn.0.to_le_bytes()[..],
+            &xl_prev.to_le_bytes()[..],
         )?;
 
         //send pg_control

pageserver/src/bin/pageserver.rs

@@ -3,43 +3,64 @@
 //
 
 use log::*;
+use pageserver::defaults::*;
 use serde::{Deserialize, Serialize};
 use std::{
     env,
     net::TcpListener,
     path::{Path, PathBuf},
-    process::exit,
     str::FromStr,
     thread,
-    time::Duration,
 };
-use zenith_utils::{auth::JwtAuth, postgres_backend::AuthType};
+use zenith_utils::{auth::JwtAuth, logging, postgres_backend::AuthType};
 
-use anyhow::{ensure, Result};
+use anyhow::{bail, ensure, Context, Result};
 use clap::{App, Arg, ArgMatches};
 use daemonize::Daemonize;
 
-use pageserver::{branches, http, logger, page_service, tenant_mgr, PageServerConf};
+use pageserver::{
+    branches,
+    defaults::{
+        DEFAULT_HTTP_LISTEN_ADDR, DEFAULT_PG_LISTEN_ADDR,
+        DEFAULT_RELISH_STORAGE_MAX_CONCURRENT_SYNC_LIMITS,
+    },
+    http, page_service, relish_storage, tenant_mgr, PageServerConf, RelishStorageConfig,
+    RelishStorageKind, S3Config, LOG_FILE_NAME,
+};
 use zenith_utils::http::endpoint;
 
-const DEFAULT_LISTEN_ADDR: &str = "127.0.0.1:64000";
-const DEFAULT_HTTP_ENDPOINT_ADDR: &str = "127.0.0.1:9898";
-
-const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
-const DEFAULT_GC_PERIOD: Duration = Duration::from_secs(10);
-
-const DEFAULT_SUPERUSER: &str = "zenith_admin";
+use const_format::formatcp;
 
 /// String arguments that can be declared via CLI or config file
 #[derive(Serialize, Deserialize)]
 struct CfgFileParams {
-    listen_addr: Option<String>,
-    http_endpoint_addr: Option<String>,
+    listen_pg_addr: Option<String>,
+    listen_http_addr: Option<String>,
+    checkpoint_distance: Option<String>,
+    checkpoint_period: Option<String>,
     gc_horizon: Option<String>,
     gc_period: Option<String>,
     pg_distrib_dir: Option<String>,
     auth_validation_public_key_path: Option<String>,
     auth_type: Option<String>,
+    // see https://github.com/alexcrichton/toml-rs/blob/6c162e6562c3e432bf04c82a3d1d789d80761a86/examples/enum_external.rs for enum deserialisation examples
+    relish_storage: Option<RelishStorage>,
+    relish_storage_max_concurrent_sync: Option<String>,
+}
+
+#[derive(Serialize, Deserialize, Clone)]
+enum RelishStorage {
+    Local {
+        local_path: String,
+    },
+    AwsS3 {
+        bucket_name: String,
+        bucket_region: String,
+        #[serde(skip_serializing)]
+        access_key_id: Option<String>,
+        #[serde(skip_serializing)]
+        secret_access_key: Option<String>,
+    },
 }
 
 impl CfgFileParams {
@@ -49,14 +70,33 @@ impl CfgFileParams {
             arg_matches.value_of(arg_name).map(str::to_owned)
         };
 
+        let relish_storage = if let Some(local_path) = get_arg("relish-storage-local-path") {
+            Some(RelishStorage::Local { local_path })
+        } else if let Some((bucket_name, bucket_region)) =
+            get_arg("relish-storage-s3-bucket").zip(get_arg("relish-storage-region"))
+        {
+            Some(RelishStorage::AwsS3 {
+                bucket_name,
+                bucket_region,
+                access_key_id: get_arg("relish-storage-access-key"),
+                secret_access_key: get_arg("relish-storage-secret-access-key"),
+            })
+        } else {
+            None
+        };
+
         Self {
-            listen_addr: get_arg("listen"),
-            http_endpoint_addr: get_arg("http_endpoint"),
+            listen_pg_addr: get_arg("listen-pg"),
+            listen_http_addr: get_arg("listen-http"),
+            checkpoint_distance: get_arg("checkpoint_distance"),
+            checkpoint_period: get_arg("checkpoint_period"),
             gc_horizon: get_arg("gc_horizon"),
             gc_period: get_arg("gc_period"),
             pg_distrib_dir: get_arg("postgres-distrib"),
             auth_validation_public_key_path: get_arg("auth-validation-public-key-path"),
             auth_type: get_arg("auth-type"),
+            relish_storage,
+            relish_storage_max_concurrent_sync: get_arg("relish-storage-max-concurrent-sync"),
         }
     }
 
@@ -64,8 +104,10 @@ impl CfgFileParams {
     fn or(self, other: CfgFileParams) -> Self {
         // TODO cleaner way to do this
         Self {
-            listen_addr: self.listen_addr.or(other.listen_addr),
-            http_endpoint_addr: self.http_endpoint_addr.or(other.http_endpoint_addr),
+            listen_pg_addr: self.listen_pg_addr.or(other.listen_pg_addr),
+            listen_http_addr: self.listen_http_addr.or(other.listen_http_addr),
+            checkpoint_distance: self.checkpoint_distance.or(other.checkpoint_distance),
+            checkpoint_period: self.checkpoint_period.or(other.checkpoint_period),
             gc_horizon: self.gc_horizon.or(other.gc_horizon),
             gc_period: self.gc_period.or(other.gc_period),
             pg_distrib_dir: self.pg_distrib_dir.or(other.pg_distrib_dir),
@@ -73,6 +115,10 @@ impl CfgFileParams {
                 .auth_validation_public_key_path
                 .or(other.auth_validation_public_key_path),
             auth_type: self.auth_type.or(other.auth_type),
+            relish_storage: self.relish_storage.or(other.relish_storage),
+            relish_storage_max_concurrent_sync: self
+                .relish_storage_max_concurrent_sync
+                .or(other.relish_storage_max_concurrent_sync),
         }
     }
 
@@ -80,14 +126,23 @@ impl CfgFileParams {
     fn try_into_config(&self) -> Result<PageServerConf> {
         let workdir = PathBuf::from(".");
 
-        let listen_addr = match self.listen_addr.as_ref() {
+        let listen_pg_addr = match self.listen_pg_addr.as_ref() {
             Some(addr) => addr.clone(),
-            None => DEFAULT_LISTEN_ADDR.to_owned(),
+            None => DEFAULT_PG_LISTEN_ADDR.to_owned(),
         };
 
-        let http_endpoint_addr = match self.http_endpoint_addr.as_ref() {
+        let listen_http_addr = match self.listen_http_addr.as_ref() {
             Some(addr) => addr.clone(),
-            None => DEFAULT_HTTP_ENDPOINT_ADDR.to_owned(),
+            None => DEFAULT_HTTP_LISTEN_ADDR.to_owned(),
+        };
+
+        let checkpoint_distance: u64 = match self.checkpoint_distance.as_ref() {
+            Some(checkpoint_distance_str) => checkpoint_distance_str.parse()?,
+            None => DEFAULT_CHECKPOINT_DISTANCE,
+        };
+        let checkpoint_period = match self.checkpoint_period.as_ref() {
+            Some(checkpoint_period_str) => humantime::parse_duration(checkpoint_period_str)?,
+            None => DEFAULT_CHECKPOINT_PERIOD,
         };
 
         let gc_horizon: u64 = match self.gc_horizon.as_ref() {
@@ -113,11 +168,11 @@ impl CfgFileParams {
             .auth_type
             .as_ref()
             .map_or(Ok(AuthType::Trust), |auth_type| {
-                AuthType::from_str(&auth_type)
+                AuthType::from_str(auth_type)
             })?;
 
         if !pg_distrib_dir.join("bin/postgres").exists() {
-            anyhow::bail!("Can't find postgres binary at {:?}", pg_distrib_dir);
+            bail!("Can't find postgres binary at {:?}", pg_distrib_dir);
         }
 
         if auth_type == AuthType::ZenithJWT {
@@ -132,11 +187,42 @@ impl CfgFileParams {
             );
         }
 
+        let max_concurrent_sync = match self.relish_storage_max_concurrent_sync.as_deref() {
+            Some(relish_storage_max_concurrent_sync) => {
+                relish_storage_max_concurrent_sync.parse()?
+            }
+            None => DEFAULT_RELISH_STORAGE_MAX_CONCURRENT_SYNC_LIMITS,
+        };
+        let relish_storage_config = self.relish_storage.as_ref().map(|storage_params| {
+            let storage = match storage_params.clone() {
+                RelishStorage::Local { local_path } => {
+                    RelishStorageKind::LocalFs(PathBuf::from(local_path))
+                }
+                RelishStorage::AwsS3 {
+                    bucket_name,
+                    bucket_region,
+                    access_key_id,
+                    secret_access_key,
+                } => RelishStorageKind::AwsS3(S3Config {
+                    bucket_name,
+                    bucket_region,
+                    access_key_id,
+                    secret_access_key,
+                }),
+            };
+            RelishStorageConfig {
+                max_concurrent_sync,
+                storage,
+            }
+        });
+
         Ok(PageServerConf {
             daemonize: false,
 
-            listen_addr,
-            http_endpoint_addr,
+            listen_pg_addr,
+            listen_http_addr,
+            checkpoint_distance,
+            checkpoint_period,
             gc_horizon,
             gc_period,
 
@@ -148,19 +234,29 @@ impl CfgFileParams {
 
             auth_validation_public_key_path,
             auth_type,
+            relish_storage_config,
         })
     }
 }
 
 fn main() -> Result<()> {
+    zenith_metrics::set_common_metrics_prefix("pageserver");
     let arg_matches = App::new("Zenith page server")
         .about("Materializes WAL stream to pages and serves them to the postgres")
         .arg(
-            Arg::with_name("listen")
+            Arg::with_name("listen-pg")
                 .short("l")
-                .long("listen")
+                .long("listen-pg")
+                .alias("listen") // keep some compatibility
                 .takes_value(true)
-                .help("listen for incoming page requests on ip:port (default: 127.0.0.1:5430)"),
+                .help(formatcp!("listen for incoming page requests on ip:port (default: {DEFAULT_PG_LISTEN_ADDR})")),
+        )
+        .arg(
+            Arg::with_name("listen-http")
+                .long("listen-http")
+                .alias("http_endpoint") // keep some compatibility
+                .takes_value(true)
+                .help(formatcp!("http endpoint address for metrics and management API calls on ip:port (default: {DEFAULT_HTTP_LISTEN_ADDR})")),
         )
         .arg(
             Arg::with_name("daemonize")
@@ -175,6 +271,18 @@ fn main() -> Result<()> {
                 .takes_value(false)
                 .help("Initialize pageserver repo"),
         )
+        .arg(
+            Arg::with_name("checkpoint_distance")
+                .long("checkpoint_distance")
+                .takes_value(true)
+                .help("Distance from current LSN to perform checkpoint of in-memory layers"),
+        )
+        .arg(
+            Arg::with_name("checkpoint_period")
+                .long("checkpoint_period")
+                .takes_value(true)
+                .help("Interval between checkpoint iterations"),
+        )
         .arg(
             Arg::with_name("gc_horizon")
                 .long("gc_horizon")
@@ -219,10 +327,56 @@ fn main() -> Result<()> {
                 .takes_value(true)
                 .help("Authentication scheme type. One of: Trust, MD5, ZenithJWT"),
         )
+        .arg(
+            Arg::with_name("relish-storage-local-path")
+                .long("relish-storage-local-path")
+                .takes_value(true)
+                .help("Path to the local directory, to be used as an external relish storage")
+                .conflicts_with_all(&[
+                    "relish-storage-s3-bucket",
+                    "relish-storage-region",
+                    "relish-storage-access-key",
+                    "relish-storage-secret-access-key",
+                ]),
+        )
+        .arg(
+            Arg::with_name("relish-storage-s3-bucket")
+                .long("relish-storage-s3-bucket")
+                .takes_value(true)
+                .help("Name of the AWS S3 bucket to use an external relish storage")
+                .requires("relish-storage-region"),
+        )
+        .arg(
+            Arg::with_name("relish-storage-region")
+                .long("relish-storage-region")
+                .takes_value(true)
+                .help("Region of the AWS S3 bucket"),
+        )
+        .arg(
+            Arg::with_name("relish-storage-access-key")
+                .long("relish-storage-access-key")
+                .takes_value(true)
+                .help("Credentials to access the AWS S3 bucket"),
+        )
+        .arg(
+            Arg::with_name("relish-storage-secret-access-key")
+                .long("relish-storage-secret-access-key")
+                .takes_value(true)
+                .help("Credentials to access the AWS S3 bucket"),
+        )
+        .arg(
+            Arg::with_name("relish-storage-max-concurrent-sync")
+                .long("relish-storage-max-concurrent-sync")
+                .takes_value(true)
+                .help("Maximum allowed concurrent synchronisations with storage"),
+        )
         .get_matches();
 
     let workdir = Path::new(arg_matches.value_of("workdir").unwrap_or(".zenith"));
-    let cfg_file_path = workdir.canonicalize()?.join("pageserver.toml");
+    let cfg_file_path = workdir
+        .canonicalize()
+        .with_context(|| format!("Error opening workdir '{}'", workdir.display()))?
+        .join("pageserver.toml");
 
     let args_params = CfgFileParams::from_args(&arg_matches);
 
@@ -234,22 +388,37 @@ fn main() -> Result<()> {
         args_params
     } else {
         // Supplement the CLI arguments with the config file
-        let cfg_file_contents = std::fs::read_to_string(&cfg_file_path)?;
-        let file_params: CfgFileParams = toml::from_str(&cfg_file_contents)?;
+        let cfg_file_contents = std::fs::read_to_string(&cfg_file_path)
+            .with_context(|| format!("No pageserver config at '{}'", cfg_file_path.display()))?;
+        let file_params: CfgFileParams = toml::from_str(&cfg_file_contents).with_context(|| {
+            format!(
+                "Failed to read '{}' as pageserver config",
+                cfg_file_path.display()
+            )
+        })?;
         args_params.or(file_params)
     };
 
     // Set CWD to workdir for non-daemon modes
-    env::set_current_dir(&workdir)?;
+    env::set_current_dir(&workdir).with_context(|| {
+        format!(
+            "Failed to set application's current dir to '{}'",
+            workdir.display()
+        )
+    })?;
 
     // Ensure the config is valid, even if just init-ing
-    let mut conf = params.try_into_config()?;
+    let mut conf = params.try_into_config().with_context(|| {
+        format!(
+            "Pageserver config at '{}' is not valid",
+            cfg_file_path.display()
+        )
+    })?;
 
     conf.daemonize = arg_matches.is_present("daemonize");
 
     if init && conf.daemonize {
-        eprintln!("--daemonize cannot be used with --init");
-        exit(1);
+        bail!("--daemonize cannot be used with --init")
     }
 
     // The configuration is all set up now. Turn it into a 'static
@@ -259,32 +428,46 @@ fn main() -> Result<()> {
 
     // Create repo and exit if init was requested
     if init {
-        branches::init_pageserver(conf, create_tenant)?;
+        branches::init_pageserver(conf, create_tenant).context("Failed to init pageserver")?;
         // write the config file
-        let cfg_file_contents = toml::to_string_pretty(&params)?;
+        let cfg_file_contents = toml::to_string_pretty(&params)
+            .context("Failed to create pageserver config contents for initialisation")?;
         // TODO support enable-auth flag
-        std::fs::write(&cfg_file_path, cfg_file_contents)?;
-
-        return Ok(());
+        std::fs::write(&cfg_file_path, cfg_file_contents).with_context(|| {
+            format!(
+                "Failed to initialize pageserver config at '{}'",
+                cfg_file_path.display()
+            )
+        })?;
+        Ok(())
+    } else {
+        start_pageserver(conf).context("Failed to start pageserver")
     }
-
-    start_pageserver(conf)
 }
 
 fn start_pageserver(conf: &'static PageServerConf) -> Result<()> {
     // Initialize logger
-    let (_scope_guard, log_file) = logger::init_logging(&conf, "pageserver.log")?;
-    let _log_guard = slog_stdlog::init()?;
-
-    // Note: this `info!(...)` macro comes from `log` crate
-    info!("standard logging redirected to slog");
+    let (_scope_guard, log_file) = logging::init(LOG_FILE_NAME, conf.daemonize)?;
 
     // TODO: Check that it looks like a valid repository before going further
 
+    // bind sockets before daemonizing so we report errors early and do not return until we are listening
+    info!(
+        "Starting pageserver http handler on {}",
+        conf.listen_http_addr
+    );
+    let http_listener = TcpListener::bind(conf.listen_http_addr.clone())?;
+
+    info!(
+        "Starting pageserver pg protocol handler on {}",
+        conf.listen_pg_addr
+    );
+    let pageserver_listener = TcpListener::bind(conf.listen_pg_addr.clone())?;
+
     if conf.daemonize {
         info!("daemonizing...");
 
-        // There should'n be any logging to stdin/stdout. Redirect it to the main log so
+        // There shouldn't be any logging to stdin/stdout. Redirect it to the main log so
         // that we will see any accidental manual fprintf's or backtraces.
         let stdout = log_file.try_clone().unwrap();
         let stderr = log_file;
@@ -297,10 +480,20 @@ fn start_pageserver(conf: &'static PageServerConf) -> Result<()> {
 
         match daemonize.start() {
             Ok(_) => info!("Success, daemonized"),
-            Err(e) => error!("Error, {}", e),
+            Err(e) => error!("could not daemonize: {:#}", e),
         }
     }
 
+    // keep join handles for spawned threads
+    // don't spawn threads before daemonizing
+    let mut join_handles = Vec::new();
+
+    if let Some(handle) = relish_storage::run_storage_sync_thread(conf)? {
+        join_handles.push(handle);
+    }
+    // Initialize tenant manager.
+    tenant_mgr::init(conf);
+
     // initialize authentication for incoming connections
     let auth = match &conf.auth_type {
         AuthType::Trust | AuthType::MD5 => None,
@@ -313,21 +506,16 @@ fn start_pageserver(conf: &'static PageServerConf) -> Result<()> {
     info!("Using auth: {:#?}", conf.auth_type);
 
     // Spawn a new thread for the http endpoint
+    // bind before launching separate thread so the error reported before startup exits
     let cloned = auth.clone();
-    thread::Builder::new()
+    let http_endpoint_thread = thread::Builder::new()
         .name("http_endpoint_thread".into())
         .spawn(move || {
             let router = http::make_router(conf, cloned);
-            endpoint::serve_thread_main(router, conf.http_endpoint_addr.clone())
+            endpoint::serve_thread_main(router, http_listener)
         })?;
 
-    // Check that we can bind to address before starting threads to simplify shutdown
-    // sequence if port is occupied.
-    info!("Starting pageserver on {}", conf.listen_addr);
-    let pageserver_listener = TcpListener::bind(conf.listen_addr.clone())?;
-
-    // Initialize tenant manager.
-    tenant_mgr::init(conf);
+    join_handles.push(http_endpoint_thread);
 
     // Spawn a thread to listen for connections. It will spawn further threads
     // for each connection.
@@ -337,9 +525,13 @@ fn start_pageserver(conf: &'static PageServerConf) -> Result<()> {
             page_service::thread_main(conf, auth, pageserver_listener, conf.auth_type)
         })?;
 
-    page_service_thread
-        .join()
-        .expect("Page service thread has panicked")?;
+    join_handles.push(page_service_thread);
 
+    for handle in join_handles.into_iter() {
+        handle
+            .join()
+            .expect("thread panicked")
+            .expect("thread exited with an error")
+    }
     Ok(())
 }

pageserver/src/branches.rs

@@ -17,22 +17,78 @@ use std::{
 use zenith_utils::zid::{ZTenantId, ZTimelineId};
 
 use log::*;
+use zenith_utils::crashsafe_dir;
+use zenith_utils::logging;
 use zenith_utils::lsn::Lsn;
 
-use crate::logger;
-use crate::restore_local_repo;
 use crate::tenant_mgr;
 use crate::walredo::WalRedoManager;
 use crate::{repository::Repository, PageServerConf};
+use crate::{restore_local_repo, LOG_FILE_NAME};
 
 #[derive(Serialize, Deserialize, Clone)]
 pub struct BranchInfo {
     pub name: String,
     #[serde(with = "hex")]
     pub timeline_id: ZTimelineId,
-    pub latest_valid_lsn: Option<Lsn>,
+    pub latest_valid_lsn: Lsn,
     pub ancestor_id: Option<String>,
     pub ancestor_lsn: Option<String>,
+    pub current_logical_size: usize,
+    pub current_logical_size_non_incremental: usize,
+}
+
+impl BranchInfo {
+    pub fn from_path<T: AsRef<Path>>(
+        path: T,
+        conf: &PageServerConf,
+        tenantid: &ZTenantId,
+        repo: &Arc<dyn Repository>,
+    ) -> Result<Self> {
+        let name = path
+            .as_ref()
+            .file_name()
+            .unwrap()
+            .to_str()
+            .unwrap()
+            .to_string();
+        let timeline_id = std::fs::read_to_string(path)?.parse::<ZTimelineId>()?;
+
+        let timeline = repo.get_timeline(timeline_id)?;
+
+        let ancestor_path = conf.ancestor_path(&timeline_id, tenantid);
+        let mut ancestor_id: Option<String> = None;
+        let mut ancestor_lsn: Option<String> = None;
+
+        if ancestor_path.exists() {
+            let ancestor = std::fs::read_to_string(ancestor_path)?;
+            let mut strings = ancestor.split('@');
+
+            ancestor_id = Some(
+                strings
+                    .next()
+                    .with_context(|| "wrong branch ancestor point in time format")?
+                    .to_owned(),
+            );
+            ancestor_lsn = Some(
+                strings
+                    .next()
+                    .with_context(|| "wrong branch ancestor point in time format")?
+                    .to_owned(),
+            );
+        }
+
+        Ok(BranchInfo {
+            name,
+            timeline_id,
+            latest_valid_lsn: timeline.get_last_record_lsn(),
+            ancestor_id,
+            ancestor_lsn,
+            current_logical_size: timeline.get_current_logical_size(),
+            current_logical_size_non_incremental: timeline
+                .get_current_logical_size_non_incremental(timeline.get_last_record_lsn())?,
+        })
+    }
 }
 
 #[derive(Debug, Clone, Copy)]
@@ -43,8 +99,8 @@ pub struct PointInTime {
 
 pub fn init_pageserver(conf: &'static PageServerConf, create_tenant: Option<&str>) -> Result<()> {
     // Initialize logger
-    let (_scope_guard, _log_file) = logger::init_logging(&conf, "pageserver.log")?;
-    let _log_guard = slog_stdlog::init()?;
+    // use true as daemonize parameter because otherwise we pollute zenith cli output with a few pages long output of info messages
+    let (_scope_guard, _log_file) = logging::init(LOG_FILE_NAME, true)?;
 
     // We don't use the real WAL redo manager, because we don't want to spawn the WAL redo
     // process during repository initialization.
@@ -63,7 +119,7 @@ pub fn init_pageserver(conf: &'static PageServerConf, create_tenant: Option<&str
         println!("initializing tenantid {}", tenantid);
         create_repo(conf, tenantid, dummy_redo_mgr).with_context(|| "failed to create repo")?;
     }
-    fs::create_dir_all(conf.tenants_path())?;
+    crashsafe_dir::create_dir_all(conf.tenants_path())?;
 
     println!("pageserver init succeeded");
     Ok(())
@@ -80,15 +136,12 @@ pub fn create_repo(
     }
 
     // top-level dir may exist if we are creating it through CLI
-    fs::create_dir_all(&repo_dir)
+    crashsafe_dir::create_dir_all(&repo_dir)
         .with_context(|| format!("could not create directory {}", repo_dir.display()))?;
 
-    // Note: this `info!(...)` macro comes from `log` crate
-    info!("standard logging redirected to slog");
-
-    fs::create_dir(conf.timelines_path(&tenantid))?;
-    fs::create_dir_all(conf.branches_path(&tenantid))?;
-    fs::create_dir_all(conf.tags_path(&tenantid))?;
+    crashsafe_dir::create_dir(conf.timelines_path(&tenantid))?;
+    crashsafe_dir::create_dir_all(conf.branches_path(&tenantid))?;
+    crashsafe_dir::create_dir_all(conf.tags_path(&tenantid))?;
 
     info!("created directory structure in {}", repo_dir.display());
 
@@ -98,12 +151,13 @@ pub fn create_repo(
         conf,
         wal_redo_manager,
         tenantid,
+        false,
     ));
 
     // Load data into pageserver
     // TODO To implement zenith import we need to
     //      move data loading out of create_repo()
-    bootstrap_timeline(conf, tenantid, tli, &*repo)?;
+    bootstrap_timeline(conf, tenantid, tli, repo.as_ref())?;
 
     Ok(repo)
 }
@@ -118,7 +172,7 @@ fn get_lsn_from_controlfile(path: &Path) -> Result<Lsn> {
     Ok(Lsn(lsn))
 }
 
-// Create the cluster temporarily in a initdbpath directory inside the repository
+// Create the cluster temporarily in 'initdbpath' directory inside the repository
 // to get bootstrap data for timeline initialization.
 //
 fn run_initdb(conf: &'static PageServerConf, initdbpath: &Path) -> Result<()> {
@@ -166,11 +220,15 @@ fn bootstrap_timeline(
 
     info!("bootstrap_timeline {:?} at lsn {}", pgdata_path, lsn);
 
-    let timeline = repo.create_empty_timeline(tli, lsn)?;
-    restore_local_repo::import_timeline_from_postgres_datadir(&pgdata_path, &*timeline, lsn)?;
-
-    let wal_dir = pgdata_path.join("pg_wal");
-    restore_local_repo::import_timeline_wal(&wal_dir, &*timeline, timeline.get_last_record_lsn())?;
+    // Import the contents of the data directory at the initial checkpoint
+    // LSN, and any WAL after that.
+    let timeline = repo.create_empty_timeline(tli)?;
+    restore_local_repo::import_timeline_from_postgres_datadir(
+        &pgdata_path,
+        timeline.as_ref(),
+        lsn,
+    )?;
+    timeline.checkpoint()?;
 
     println!(
         "created initial timeline {} timeline.lsn {}",
@@ -201,7 +259,7 @@ pub(crate) fn get_tenants(conf: &PageServerConf) -> Result<Vec<String>> {
 }
 
 pub(crate) fn get_branches(conf: &PageServerConf, tenantid: &ZTenantId) -> Result<Vec<BranchInfo>> {
-    let repo = tenant_mgr::get_repository_for_tenant(tenantid)?;
+    let repo = tenant_mgr::get_repository_for_tenant(*tenantid)?;
 
     // Each branch has a corresponding record (text file) in the refs/branches
     // with timeline_id.
@@ -210,43 +268,7 @@ pub(crate) fn get_branches(conf: &PageServerConf, tenantid: &ZTenantId) -> Resul
     std::fs::read_dir(&branches_dir)?
         .map(|dir_entry_res| {
             let dir_entry = dir_entry_res?;
-            let name = dir_entry.file_name().to_str().unwrap().to_string();
-            let timeline_id = std::fs::read_to_string(dir_entry.path())?.parse::<ZTimelineId>()?;
-
-            let latest_valid_lsn = repo
-                .get_timeline(timeline_id)
-                .map(|timeline| timeline.get_last_record_lsn())
-                .ok();
-
-            let ancestor_path = conf.ancestor_path(&timeline_id, tenantid);
-            let mut ancestor_id: Option<String> = None;
-            let mut ancestor_lsn: Option<String> = None;
-
-            if ancestor_path.exists() {
-                let ancestor = std::fs::read_to_string(ancestor_path)?;
-                let mut strings = ancestor.split('@');
-
-                ancestor_id = Some(
-                    strings
-                        .next()
-                        .with_context(|| "wrong branch ancestor point in time format")?
-                        .to_owned(),
-                );
-                ancestor_lsn = Some(
-                    strings
-                        .next()
-                        .with_context(|| "wrong branch ancestor point in time format")?
-                        .to_owned(),
-                );
-            }
-
-            Ok(BranchInfo {
-                name,
-                timeline_id,
-                latest_valid_lsn,
-                ancestor_id,
-                ancestor_lsn,
-            })
+            BranchInfo::from_path(dir_entry.path(), conf, tenantid, &repo)
         })
         .collect()
 }
@@ -257,21 +279,36 @@ pub(crate) fn create_branch(
     startpoint_str: &str,
     tenantid: &ZTenantId,
 ) -> Result<BranchInfo> {
-    let repo = tenant_mgr::get_repository_for_tenant(tenantid)?;
+    let repo = tenant_mgr::get_repository_for_tenant(*tenantid)?;
 
     if conf.branch_path(branchname, tenantid).exists() {
         anyhow::bail!("branch {} already exists", branchname);
     }
 
     let mut startpoint = parse_point_in_time(conf, startpoint_str, tenantid)?;
-
+    let timeline = repo.get_timeline(startpoint.timelineid)?;
     if startpoint.lsn == Lsn(0) {
         // Find end of WAL on the old timeline
-        let end_of_wal = repo
-            .get_timeline(startpoint.timelineid)?
-            .get_last_record_lsn();
+        let end_of_wal = timeline.get_last_record_lsn();
         info!("branching at end of WAL: {}", end_of_wal);
         startpoint.lsn = end_of_wal;
+    } else {
+        // Wait for the WAL to arrive and be processed on the parent branch up
+        // to the requested branch point. The repository code itself doesn't
+        // require it, but if we start to receive WAL on the new timeline,
+        // decoding the new WAL might need to look up previous pages, relation
+        // sizes etc. and that would get confused if the previous page versions
+        // are not in the repository yet.
+        timeline.wait_lsn(startpoint.lsn)?;
+    }
+    startpoint.lsn = startpoint.lsn.align();
+    if timeline.get_start_lsn() > startpoint.lsn {
+        anyhow::bail!(
+            "invalid startpoint {} for the branch {}: less than timeline start {}",
+            startpoint.lsn,
+            branchname,
+            timeline.get_start_lsn()
+        );
     }
 
     // create a new timeline directory for it
@@ -284,14 +321,16 @@ pub(crate) fn create_branch(
     // FIXME: there's a race condition, if you create a branch with the same
     // name concurrently.
     let data = newtli.to_string();
-    fs::write(conf.branch_path(&branchname, tenantid), data)?;
+    fs::write(conf.branch_path(branchname, tenantid), data)?;
 
     Ok(BranchInfo {
         name: branchname.to_string(),
         timeline_id: newtli,
-        latest_valid_lsn: Some(startpoint.lsn),
+        latest_valid_lsn: startpoint.lsn,
         ancestor_id: None,
         ancestor_lsn: None,
+        current_logical_size: 0,
+        current_logical_size_non_incremental: 0,
     })
 }
 
@@ -333,21 +372,21 @@ fn parse_point_in_time(
 
     // Check if it's a tag
     if lsn.is_none() {
-        let tagpath = conf.tag_path(name, &tenantid);
+        let tagpath = conf.tag_path(name, tenantid);
         if tagpath.exists() {
             let pointstr = fs::read_to_string(tagpath)?;
 
-            return parse_point_in_time(conf, &pointstr, &tenantid);
+            return parse_point_in_time(conf, &pointstr, tenantid);
         }
     }
 
     // Check if it's a branch
     // Check if it's branch @ LSN
-    let branchpath = conf.branch_path(name, &tenantid);
+    let branchpath = conf.branch_path(name, tenantid);
     if branchpath.exists() {
         let pointstr = fs::read_to_string(branchpath)?;
 
-        let mut result = parse_point_in_time(conf, &pointstr, &tenantid)?;
+        let mut result = parse_point_in_time(conf, &pointstr, tenantid)?;
 
         result.lsn = lsn.unwrap_or(Lsn(0));
         return Ok(result);
@@ -356,7 +395,7 @@ fn parse_point_in_time(
     // Check if it's a timelineid
     // Check if it's timelineid @ LSN
     if let Ok(timelineid) = ZTimelineId::from_str(name) {
-        let tlipath = conf.timeline_path(&timelineid, &tenantid);
+        let tlipath = conf.timeline_path(&timelineid, tenantid);
         if tlipath.exists() {
             return Ok(PointInTime {
                 timelineid,
@@ -380,7 +419,6 @@ fn create_timeline(
     let timelinedir = conf.timeline_path(&timelineid, tenantid);
 
     fs::create_dir(&timelinedir)?;
-    fs::create_dir(&timelinedir.join("wal"))?;
 
     if let Some(ancestor) = ancestor {
         let data = format!("{}@{}", ancestor.timelineid, ancestor.lsn);

pageserver/src/http/openapi_spec.yml

@@ -54,7 +54,52 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/ForbiddenError"
-
+        "500":
+          description: Generic operation error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+  /v1/branch/{tenant_id}/{branch_name}:
+    parameters:
+      - name: tenant_id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: hex
+      - name: branch_name
+        in: path
+        required: true
+        schema:
+          type: string
+    get:
+      description: Get branches for tenant
+      responses:
+        "200":
+          description: BranchInfo
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/BranchInfo"
+        "400":
+          description: Error when no tenant id found in path or no branch name
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+        "401":
+          description: Unauthorized Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UnauthorizedError"
+        "403":
+          description: Forbidden Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ForbiddenError"
         "500":
           description: Generic operation error
           content:
@@ -203,6 +248,9 @@ components:
       required:
         - name
         - timeline_id
+        - latest_valid_lsn
+        - current_logical_size
+        - current_logical_size_non_incremental
       properties:
         name:
           type: string
@@ -213,6 +261,10 @@ components:
           type: string
         ancestor_lsn:
           type: string
+        current_logical_size:
+          type: integer
+        current_logical_size_non_incremental:
+          type: integer
     Error:
       type: object
       required:

pageserver/src/http/routes.rs

@@ -1,3 +1,4 @@
+use std::str::FromStr;
 use std::sync::Arc;
 
 use anyhow::Result;
@@ -18,10 +19,8 @@ use zenith_utils::http::{
 
 use super::models::BranchCreateRequest;
 use super::models::TenantCreateRequest;
-use crate::{
-    branches::{self},
-    tenant_mgr, PageServerConf, ZTenantId,
-};
+use crate::branches::BranchInfo;
+use crate::{branches, tenant_mgr, PageServerConf, ZTenantId};
 
 #[derive(Debug)]
 struct State {
@@ -57,6 +56,33 @@ fn get_config(request: &Request<Body>) -> &'static PageServerConf {
     get_state(request).conf
 }
 
+fn get_request_param<'a>(
+    request: &'a Request<Body>,
+    param_name: &str,
+) -> Result<&'a str, ApiError> {
+    match request.param(param_name) {
+        Some(arg) => Ok(arg),
+        None => {
+            return Err(ApiError::BadRequest(format!(
+                "no {} specified in path param",
+                param_name
+            )))
+        }
+    }
+}
+
+fn parse_request_param<T: FromStr>(
+    request: &Request<Body>,
+    param_name: &str,
+) -> Result<T, ApiError> {
+    match get_request_param(request, param_name)?.parse() {
+        Ok(v) => Ok(v),
+        Err(_) => Err(ApiError::BadRequest(
+            "failed to parse tenant id".to_string(),
+        )),
+    }
+}
+
 // healthcheck handler
 async fn status_handler(_: Request<Body>) -> Result<Response<Body>, ApiError> {
     Ok(Response::builder()
@@ -85,16 +111,7 @@ async fn branch_create_handler(mut request: Request<Body>) -> Result<Response<Bo
 }
 
 async fn branch_list_handler(request: Request<Body>) -> Result<Response<Body>, ApiError> {
-    let tenantid: ZTenantId = match request.param("tenant_id") {
-        Some(arg) => arg
-            .parse()
-            .map_err(|_| ApiError::BadRequest("failed to parse tenant id".to_string()))?,
-        None => {
-            return Err(ApiError::BadRequest(
-                "no tenant id specified in path param".to_string(),
-            ))
-        }
-    };
+    let tenantid: ZTenantId = parse_request_param(&request, "tenant_id")?;
 
     check_permission(&request, Some(tenantid))?;
 
@@ -106,6 +123,23 @@ async fn branch_list_handler(request: Request<Body>) -> Result<Response<Body>, A
     Ok(json_response(StatusCode::OK, response_data)?)
 }
 
+// TODO add to swagger
+async fn branch_detail_handler(request: Request<Body>) -> Result<Response<Body>, ApiError> {
+    let tenantid: ZTenantId = parse_request_param(&request, "tenant_id")?;
+    let branch_name: &str = get_request_param(&request, "branch_name")?;
+    let conf = get_state(&request).conf;
+    let path = conf.branch_path(branch_name, &tenantid);
+
+    let response_data = tokio::task::spawn_blocking(move || {
+        let repo = tenant_mgr::get_repository_for_tenant(tenantid)?;
+        BranchInfo::from_path(path, conf, &tenantid, &repo)
+    })
+    .await
+    .map_err(ApiError::from_err)??;
+
+    Ok(json_response(StatusCode::OK, response_data)?)
+}
+
 async fn tenant_list_handler(request: Request<Body>) -> Result<Response<Body>, ApiError> {
     // check for management permission
     check_permission(&request, None)?;
@@ -159,6 +193,7 @@ pub fn make_router(
         .data(Arc::new(State::new(conf, auth)))
         .get("/v1/status", status_handler)
         .get("/v1/branch/:tenant_id", branch_list_handler)
+        .get("/v1/branch/:tenant_id/:branch_name", branch_detail_handler)
         .post("/v1/branch", branch_create_handler)
         .get("/v1/tenant", tenant_list_handler)
         .post("/v1/tenant", tenant_create_handler)

pageserver/src/layered_repository/README.md

@@ -4,15 +4,69 @@ The on-disk format is based on immutable files. The page server
 receives a stream of incoming WAL, parses the WAL records to determine
 which pages they apply to, and accumulates the incoming changes in
 memory. Every now and then, the accumulated changes are written out to
-new files.
+new immutable files. This process is called checkpointing. Old versions
+of on-disk files that are not needed by any timeline are removed by GC
+process.
 
-The files are called "snapshot files". Each snapshot file corresponds
-to one 10 MB slice of a PostgreSQL relation fork. The snapshot files
+# Terms used in layered repository
+
+- Relish - one PostgreSQL relation or similarly treated file.
+- Segment - one slice of a Relish that is stored in a LayeredTimeline.
+- Layer -  specific version of a relish Segment in a range of LSNs.
+
+Layers can be InMemory or OnDisk:
+- InMemory layer is not durably stored and needs to rebuild from WAL on pageserver start.
+- OnDisk layer is durably stored.
+
+OnDisk layers can be Image or Delta:
+- ImageLayer represents an image or a snapshot of a segment at one particular LSN.
+- DeltaLayer represents a collection of WAL records or page images in a range of LSNs.
+
+Dropped segments are always represented on disk by DeltaLayer.
+
+LSN range defined by start_lsn and end_lsn:
+- start_lsn is inclusive.
+- end_lsn is exclusive.
+
+For an open in-memory layer, the end_lsn is MAX_LSN. For a frozen
+in-memory layer or a delta layer, it is a valid end bound. An image
+layer represents snapshot at one LSN, so end_lsn is always the
+snapshot LSN + 1
+
+Layers can be open or historical:
+- Open layer is a writeable one. Only InMemory layer can be open.
+FIXME: If open layer is dropped, it is not writeable, so it should be turned into historical, 
+but now it is not implemented - see bug #569.
+- Historical layer is the one that cannot be modified anymore. Now only OnDisk layers can be historical.
+
+- LayerMap - a map that tracks what layers exist for all the relishes in a timeline.
+
+LayerMap consists of two data structures:
+- segs - All the layers keyed by segment tag
+- open_layers - data structure that hold all open layers ordered by oldest_pending_lsn for quick access during checkpointing. oldest_pending_lsn is the LSN of the oldest page version stored in this layer.
+
+All operations that update InMemory Layers should update both structures to keep them up-to-date.
+
+- LayeredTimeline - implements Timeline interface.
+
+All methods of LayeredTimeline are aware of its ancestors and return data taking them into account.
+TODO: Are there any exceptions to this?
+For example, timeline.list_rels(lsn) will return all segments that are visible in this timeline at the LSN,
+including ones that were not modified in this timeline and thus don't have a layer in the timeline's LayerMap.
+
+TODO:
+Describe GC and checkpoint interval settings.
+
+# Layer files (On-disk layers)
+
+The files are called "layer files". Each layer file corresponds
+to one RELISH_SEG_SIZE slice of a PostgreSQL relation fork or
+non-rel file in a range of LSNs. The layer files
 for each timeline are stored in the timeline's subdirectory under
 .zenith/tenants/<tenantid>/timelines.
 
-There are two kind of snapshot file: base images, and deltas. A base
-image file contains a snapshot of a segment as it was at one LSN,
+There are two kind of layer file: base images, and deltas. A base
+image file contains a layer of a segment as it was at one LSN,
 whereas a delta file contains modifications to a segment - mostly in
 the form of WAL records - in a range of LSN
 
@@ -44,7 +98,7 @@ managed, except that the first part of file names is different.
 Internally, the relations and non-relation files that are managed in
 the versioned store are together called "relishes".
 
-If a file has been dropped, the last snapshot file for it is created
+If a file has been dropped, the last layer file for it is created
 with the _DROPPED suffix, e.g.
 
     rel_1663_13990_2609_0_10_000000000169C348_0000000001702000_DROPPED
@@ -67,7 +121,7 @@ for 'orders' table on 'main' branch is represented like this:
     main/orders_100_200
 
 
-# Creating snapshot files
+# Creating layer files
 
 Let's start with a simple example with a system that contains one
 branch called 'main' and two tables, 'orders' and 'customers'. The end
@@ -86,10 +140,10 @@ end of WAL at 250 are kept in memory. If the page server crashes, the
 latest records between 200-250 need to be re-read from the WAL.
 
 Whenever enough WAL has been accumulated in memory, the page server
-writes out the changes in memory into new snapshot files. This process
+writes out the changes in memory into new layer files. This process
 is called "checkpointing" (not to be confused with the PostgreSQL
 checkpoints, that's a different thing). The page server only creates
-snapshot files for relations that have been modified since the last
+layer files for relations that have been modified since the last
 checkpoint. For example, if the current end of WAL is at LSN 450, and
 the last checkpoint happened at LSN 400 but there hasn't been any
 recent changes to 'customers' table, you would have these files on
@@ -108,7 +162,7 @@ disk:
 
 If the customers table is modified later, a new file is created for it
 at the next checkpoint. The new file will cover the "gap" from the
-last snapshot file, so the LSN ranges are always contiguous:
+last layer file, so the LSN ranges are always contiguous:
 
 	main/orders_100
 	main/orders_100_200
@@ -130,13 +184,13 @@ page server needs to reconstruct the requested page, as it was at the
 requested LSN. To do that, the page server first checks the recent
 in-memory layer; if the requested page version is found there, it can
 be returned immediatedly without looking at the files on
-disk. Otherwise the page server needs to locate the snapshot file that
+disk. Otherwise the page server needs to locate the layer file that
 contains the requested page version.
 
 For example, if a request comes in for table 'orders' at LSN 250, the
 page server would load the 'main/orders_200_300' file into memory, and
 reconstruct and return the requested page from it, as it was at
-LSN 250. Because the snapshot file consists of a full image of the
+LSN 250. Because the layer file consists of a full image of the
 relation at the start LSN and the WAL, reconstructing the page
 involves replaying any WAL records applicable to the page between LSNs
 200-250, starting from the base image at LSN 200.
@@ -171,7 +225,7 @@ Then, the 'orders' table is updated differently on the 'main' and
 
 Because the 'customers' table hasn't been modified on the child
 branch, there is no file for it there. If you request a page for it on
-the 'child' branch, the page server will not find any snapshot file
+the 'child' branch, the page server will not find any layer file
 for it in the 'child' directory, so it will recurse to look into the
 parent 'main' branch instead.
 
@@ -217,7 +271,7 @@ branch at a historic LSN, is how we support PITR in Zenith.
 
 # Garbage collection
 
-In this scheme, we keep creating new snapshot files over time. We also
+In this scheme, we keep creating new layer files over time. We also
 need a mechanism to remove old files that are no longer needed,
 because disk space isn't infinite.
 
@@ -245,7 +299,7 @@ of the branch is LSN 525, so that the GC horizon is currently at
 	main/customers_200
 
 We can remove the following files because the end LSNs of those files are
-older than GC horizon 375, and there are more recent snapshot files for the
+older than GC horizon 375, and there are more recent layer files for the
 table:
 
 	main/orders_100       DELETE
@@ -262,7 +316,7 @@ table:
 	main/customers_200      KEEP, NO NEWER VERSION
 
 'main/customers_100_200' is old enough, but it cannot be
-removed because there is no newer snapshot file for the table.
+removed because there is no newer layer file for the table.
 
 Things get slightly more complicated with multiple branches. All of
 the above still holds, but in addition to recent files we must also
@@ -308,7 +362,7 @@ new base image and delta file for it on the child:
 
 After this, the 'main/orders_100' and 'main/orders_100_200' file could
 be removed. It is no longer needed by the child branch, because there
-is a newer snapshot file there. TODO: This optimization hasn't been
+is a newer layer file there. TODO: This optimization hasn't been
 implemented! The GC algorithm will currently keep the file on the
 'main' branch anyway, for as long as the child branch exists.
 
@@ -346,7 +400,7 @@ It would also be OK to have overlapping LSN ranges for the same relation:
 	main/orders_300_400
 	main/orders_400
 
-The code that reads the snapshot files should cope with this, but this
+The code that reads the layer files should cope with this, but this
 situation doesn't arise either, because the checkpointing code never
 does that.  It could be useful, however, as a transient state when
 garbage collecting around branch points, or explicit recovery
@@ -360,6 +414,6 @@ points. For example, if we start with this:
 
 And there is a branch or explicit recovery point at LSN 150, we could
 replace 'main/orders_100_200' with 'main/orders_150' to keep a
-snapshot only at that exact point that's still needed, removing the
+layer only at that exact point that's still needed, removing the
 other page versions around it. But such compaction has not been
 implemented yet.

pageserver/src/layered_repository/blob.rs

@@ -16,14 +16,14 @@ pub fn read_blob(reader: &BoundedReader<&'_ File>, range: &BlobRange) -> Result<
     Ok(buf)
 }
 
-pub struct BlobWriter {
-    writer: ChapterWriter<File>,
+pub struct BlobWriter<W> {
+    writer: ChapterWriter<W>,
     offset: u64,
 }
 
-impl BlobWriter {
+impl<W: Write> BlobWriter<W> {
     // This function takes a BookWriter and creates a new chapter to ensure offset is 0.
-    pub fn new(book_writer: BookWriter<File>, chapter_id: impl Into<ChapterId>) -> Self {
+    pub fn new(book_writer: BookWriter<W>, chapter_id: impl Into<ChapterId>) -> Self {
         let writer = book_writer.new_chapter(chapter_id);
         Self { writer, offset: 0 }
     }
@@ -39,7 +39,7 @@ impl BlobWriter {
         Ok(range)
     }
 
-    pub fn close(self) -> bookfile::Result<BookWriter<File>> {
+    pub fn close(self) -> bookfile::Result<BookWriter<W>> {
         self.writer.close()
     }
 }

pageserver/src/layered_repository/delta_layer.rs

@@ -42,24 +42,22 @@ use crate::layered_repository::filename::{DeltaFileName, PathOrConf};
 use crate::layered_repository::storage_layer::{
     Layer, PageReconstructData, PageReconstructResult, PageVersion, SegmentTag,
 };
-use crate::repository::WALRecord;
 use crate::waldecoder;
 use crate::PageServerConf;
 use crate::{ZTenantId, ZTimelineId};
-use anyhow::{bail, Result};
-use bytes::Bytes;
+use anyhow::{bail, ensure, Result};
 use log::*;
 use serde::{Deserialize, Serialize};
-use std::collections::BTreeMap;
+use zenith_utils::vec_map::VecMap;
 // avoid binding to Write (conflicts with std::io::Write)
 // while being able to use std::fmt::Write's methods
 use std::fmt::Write as _;
 use std::fs;
 use std::fs::File;
-use std::io::Write;
+use std::io::{BufWriter, Write};
 use std::ops::Bound::Included;
 use std::path::{Path, PathBuf};
-use std::sync::{Arc, Mutex, MutexGuard};
+use std::sync::{Mutex, MutexGuard};
 
 use bookfile::{Book, BookWriter};
 
@@ -67,9 +65,10 @@ use zenith_utils::bin_ser::BeSer;
 use zenith_utils::lsn::Lsn;
 
 use super::blob::{read_blob, BlobRange};
+use super::page_versions::OrderedBlockIter;
 
 // Magic constant to identify a Zenith delta file
-static DELTA_FILE_MAGIC: u32 = 0x5A616E01;
+pub const DELTA_FILE_MAGIC: u32 = 0x5A616E01;
 
 /// Mapping from (block #, lsn) -> page/WAL record
 /// byte ranges in PAGE_VERSIONS_CHAPTER
@@ -79,10 +78,34 @@ static PAGE_VERSION_METAS_CHAPTER: u64 = 1;
 static PAGE_VERSIONS_CHAPTER: u64 = 2;
 static REL_SIZES_CHAPTER: u64 = 3;
 
-#[derive(Serialize, Deserialize)]
-struct PageVersionMeta {
-    page_image_range: Option<BlobRange>,
-    record_range: Option<BlobRange>,
+/// Contains the [`Summary`] struct
+static SUMMARY_CHAPTER: u64 = 4;
+
+#[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
+struct Summary {
+    tenantid: ZTenantId,
+    timelineid: ZTimelineId,
+    seg: SegmentTag,
+
+    start_lsn: Lsn,
+    end_lsn: Lsn,
+
+    dropped: bool,
+}
+
+impl From<&DeltaLayer> for Summary {
+    fn from(layer: &DeltaLayer) -> Self {
+        Self {
+            tenantid: layer.tenantid,
+            timelineid: layer.timelineid,
+            seg: layer.seg,
+
+            start_lsn: layer.start_lsn,
+            end_lsn: layer.end_lsn,
+
+            dropped: layer.dropped,
+        }
+    }
 }
 
 ///
@@ -109,9 +132,6 @@ pub struct DeltaLayer {
 
     dropped: bool,
 
-    /// Predecessor layer
-    predecessor: Option<Arc<dyn Layer>>,
-
     inner: Mutex<DeltaLayerInner>,
 }
 
@@ -122,31 +142,31 @@ pub struct DeltaLayerInner {
 
     /// All versions of all pages in the file are are kept here.
     /// Indexed by block number and LSN.
-    page_version_metas: BTreeMap<(u32, Lsn), PageVersionMeta>,
+    page_version_metas: VecMap<(u32, Lsn), BlobRange>,
 
     /// `relsizes` tracks the size of the relation at different points in time.
-    relsizes: BTreeMap<Lsn, u32>,
+    relsizes: VecMap<Lsn, u32>,
 }
 
 impl Layer for DeltaLayer {
     fn get_timeline_id(&self) -> ZTimelineId {
-        return self.timelineid;
+        self.timelineid
     }
 
     fn get_seg_tag(&self) -> SegmentTag {
-        return self.seg;
+        self.seg
     }
 
     fn is_dropped(&self) -> bool {
-        return self.dropped;
+        self.dropped
     }
 
     fn get_start_lsn(&self) -> Lsn {
-        return self.start_lsn;
+        self.start_lsn
     }
 
     fn get_end_lsn(&self) -> Lsn {
-        return self.end_lsn;
+        self.end_lsn
     }
 
     fn filename(&self) -> PathBuf {
@@ -161,6 +181,20 @@ impl Layer for DeltaLayer {
         )
     }
 
+    fn path(&self) -> Option<PathBuf> {
+        Some(Self::path_for(
+            &self.path_or_conf,
+            self.timelineid,
+            self.tenantid,
+            &DeltaFileName {
+                seg: self.seg,
+                start_lsn: self.start_lsn,
+                end_lsn: self.end_lsn,
+                dropped: self.dropped,
+            },
+        ))
+    }
+
     /// Look up given page in the cache.
     fn get_page_reconstruct_data(
         &self,
@@ -168,13 +202,13 @@ impl Layer for DeltaLayer {
         lsn: Lsn,
         reconstruct_data: &mut PageReconstructData,
     ) -> Result<PageReconstructResult> {
-        let mut cont_lsn: Option<Lsn> = Some(lsn);
+        let mut need_image = true;
 
         assert!(self.seg.blknum_in_seg(blknum));
 
         {
             // Open the file and lock the metadata in memory
-            // TODO: avoid opening the snapshot file for each read
+            // TODO: avoid opening the file for each read
             let (_path, book) = self.open_book()?;
             let page_version_reader = book.chapter_reader(PAGE_VERSIONS_CHAPTER)?;
             let inner = self.load()?;
@@ -182,27 +216,26 @@ impl Layer for DeltaLayer {
             // Scan the metadata BTreeMap backwards, starting from the given entry.
             let minkey = (blknum, Lsn(0));
             let maxkey = (blknum, lsn);
-            let mut iter = inner
+            let iter = inner
                 .page_version_metas
-                .range((Included(&minkey), Included(&maxkey)));
-            while let Some(((_blknum, entry_lsn), entry)) = iter.next_back() {
-                if let Some(img_range) = &entry.page_image_range {
+                .slice_range((Included(&minkey), Included(&maxkey)))
+                .iter()
+                .rev();
+            for ((_blknum, _lsn), blob_range) in iter {
+                let pv = PageVersion::des(&read_blob(&page_version_reader, blob_range)?)?;
+
+                if let Some(img) = pv.page_image {
                     // Found a page image, return it
-                    let img = Bytes::from(read_blob(&page_version_reader, img_range)?);
                     reconstruct_data.page_img = Some(img);
-                    cont_lsn = None;
+                    need_image = false;
                     break;
-                } else if let Some(rec_range) = &entry.record_range {
-                    let rec = WALRecord::des(&read_blob(&page_version_reader, rec_range)?)?;
+                } else if let Some(rec) = pv.record {
                     let will_init = rec.will_init;
                     reconstruct_data.records.push(rec);
                     if will_init {
                         // This WAL record initializes the page, so no need to go further back
-                        cont_lsn = None;
+                        need_image = false;
                         break;
-                    } else {
-                        // This WAL record needs to be applied against an older page image
-                        cont_lsn = Some(*entry_lsn);
                     }
                 } else {
                     // No base image, and no WAL record. Huh?
@@ -214,16 +247,9 @@ impl Layer for DeltaLayer {
         }
 
         // If an older page image is needed to reconstruct the page, let the
-        // caller know about the predecessor layer.
-        if let Some(cont_lsn) = cont_lsn {
-            if let Some(cont_layer) = &self.predecessor {
-                Ok(PageReconstructResult::Continue(
-                    cont_lsn,
-                    Arc::clone(cont_layer),
-                ))
-            } else {
-                Ok(PageReconstructResult::Missing(cont_lsn))
-            }
+        // caller know.
+        if need_image {
+            Ok(PageReconstructResult::Continue(self.start_lsn))
         } else {
             Ok(PageReconstructResult::Complete)
         }
@@ -232,21 +258,22 @@ impl Layer for DeltaLayer {
     /// Get size of the relation at given LSN
     fn get_seg_size(&self, lsn: Lsn) -> Result<u32> {
         assert!(lsn >= self.start_lsn);
+        ensure!(
+            self.seg.rel.is_blocky(),
+            "get_seg_size() called on a non-blocky rel"
+        );
 
         // Scan the BTreeMap backwards, starting from the given entry.
         let inner = self.load()?;
-        let mut iter = inner.relsizes.range((Included(&Lsn(0)), Included(&lsn)));
+        let slice = inner
+            .relsizes
+            .slice_range((Included(&Lsn(0)), Included(&lsn)));
 
-        let result;
-        if let Some((_entry_lsn, entry)) = iter.next_back() {
-            result = *entry;
-        // Use the base image if needed
-        } else if let Some(predecessor) = &self.predecessor {
-            result = predecessor.get_seg_size(lsn)?;
+        if let Some((_entry_lsn, entry)) = slice.last() {
+            Ok(*entry)
         } else {
-            result = 0;
+            Err(anyhow::anyhow!("could not find seg size in delta layer"))
         }
-        Ok(result)
     }
 
     /// Does this segment exist at given LSN?
@@ -266,15 +293,17 @@ impl Layer for DeltaLayer {
     ///
     fn unload(&self) -> Result<()> {
         let mut inner = self.inner.lock().unwrap();
-        inner.page_version_metas = BTreeMap::new();
-        inner.relsizes = BTreeMap::new();
+        inner.page_version_metas = VecMap::default();
+        inner.relsizes = VecMap::default();
         inner.loaded = false;
         Ok(())
     }
 
     fn delete(&self) -> Result<()> {
         // delete underlying file
-        fs::remove_file(self.path())?;
+        if let Some(path) = self.path() {
+            fs::remove_file(path)?;
+        }
         Ok(())
     }
 
@@ -285,28 +314,28 @@ impl Layer for DeltaLayer {
     /// debugging function to print out the contents of the layer
     fn dump(&self) -> Result<()> {
         println!(
-            "----- delta layer for {} {}-{} ----",
-            self.seg, self.start_lsn, self.end_lsn
+            "----- delta layer for ten {} tli {} seg {} {}-{} ----",
+            self.tenantid, self.timelineid, self.seg, self.start_lsn, self.end_lsn
         );
 
         println!("--- relsizes ---");
         let inner = self.load()?;
-        for (k, v) in inner.relsizes.iter() {
+        for (k, v) in inner.relsizes.as_slice() {
             println!("  {}: {}", k, v);
         }
         println!("--- page versions ---");
         let (_path, book) = self.open_book()?;
         let chapter = book.chapter_reader(PAGE_VERSIONS_CHAPTER)?;
-        for (k, v) in inner.page_version_metas.iter() {
+        for ((blk, lsn), blob_range) in inner.page_version_metas.as_slice() {
             let mut desc = String::new();
 
-            if let Some(page_image_range) = v.page_image_range.as_ref() {
-                let image = read_blob(&chapter, &page_image_range)?;
-                write!(&mut desc, " img {} bytes", image.len())?;
+            let buf = read_blob(&chapter, blob_range)?;
+            let pv = PageVersion::des(&buf)?;
+
+            if let Some(img) = pv.page_image.as_ref() {
+                write!(&mut desc, " img {} bytes", img.len())?;
             }
-            if let Some(record_range) = v.record_range.as_ref() {
-                let record_bytes = read_blob(&chapter, record_range)?;
-                let rec = WALRecord::des(&record_bytes)?;
+            if let Some(rec) = pv.record.as_ref() {
                 let wal_desc = waldecoder::describe_wal_record(&rec.rec);
                 write!(
                     &mut desc,
@@ -316,7 +345,7 @@ impl Layer for DeltaLayer {
                     wal_desc
                 )?;
             }
-            println!("  blk {} at {}: {}", k.0, k.1, desc);
+            println!("  blk {} at {}: {}", blk, lsn, desc);
         }
 
         Ok(())
@@ -324,20 +353,6 @@ impl Layer for DeltaLayer {
 }
 
 impl DeltaLayer {
-    fn path(&self) -> PathBuf {
-        Self::path_for(
-            &self.path_or_conf,
-            self.timelineid,
-            self.tenantid,
-            &DeltaFileName {
-                seg: self.seg,
-                start_lsn: self.start_lsn,
-                end_lsn: self.end_lsn,
-                dropped: self.dropped,
-            },
-        )
-    }
-
     fn path_for(
         path_or_conf: &PathOrConf,
         timelineid: ZTimelineId,
@@ -352,12 +367,14 @@ impl DeltaLayer {
         }
     }
 
-    /// Create a new delta file, using the given btreemaps containing the page versions and
-    /// relsizes.
+    /// Create a new delta file, using the given page versions and relsizes.
+    /// The page versions are passed by an iterator; the iterator must return
+    /// page versions in blknum+lsn order.
     ///
     /// This is used to write the in-memory layer to disk. The in-memory layer uses the same
     /// data structure with two btreemaps as we do, so passing the btreemaps is currently
     /// expedient.
+    #[allow(clippy::too_many_arguments)]
     pub fn create(
         conf: &'static PageServerConf,
         timelineid: ZTimelineId,
@@ -366,82 +383,91 @@ impl DeltaLayer {
         start_lsn: Lsn,
         end_lsn: Lsn,
         dropped: bool,
-        predecessor: Option<Arc<dyn Layer>>,
-        page_versions: BTreeMap<(u32, Lsn), PageVersion>,
-        relsizes: BTreeMap<Lsn, u32>,
+        page_versions: OrderedBlockIter,
+        relsizes: VecMap<Lsn, u32>,
     ) -> Result<DeltaLayer> {
-        let delta_layer = DeltaLayer {
+        if seg.rel.is_blocky() {
+            assert!(!relsizes.is_empty());
+        }
+
+        let mut delta_layer = DeltaLayer {
             path_or_conf: PathOrConf::Conf(conf),
-            timelineid: timelineid,
-            tenantid: tenantid,
-            seg: seg,
-            start_lsn: start_lsn,
+            timelineid,
+            tenantid,
+            seg,
+            start_lsn,
             end_lsn,
             dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: true,
-                page_version_metas: BTreeMap::new(),
-                relsizes: relsizes,
+                page_version_metas: VecMap::default(),
+                relsizes,
             }),
-            predecessor,
         };
-        let mut inner = delta_layer.inner.lock().unwrap();
 
         // Write the in-memory btreemaps into a file
-        let path = delta_layer.path();
+        let path = delta_layer
+            .path()
+            .expect("DeltaLayer is supposed to have a layer path on disk");
+
+        let inner = delta_layer.inner.get_mut().unwrap();
 
         // Note: This overwrites any existing file. There shouldn't be any.
         // FIXME: throw an error instead?
         let file = File::create(&path)?;
-        let book = BookWriter::new(file, DELTA_FILE_MAGIC)?;
+        let buf_writer = BufWriter::new(file);
+        let book = BookWriter::new(buf_writer, DELTA_FILE_MAGIC)?;
 
         let mut page_version_writer = BlobWriter::new(book, PAGE_VERSIONS_CHAPTER);
 
-        for (key, page_version) in page_versions {
-            let page_image_range = page_version
-                .page_image
-                .map(|page_image| page_version_writer.write_blob(page_image.as_ref()))
-                .transpose()?;
+        for (blknum, history) in page_versions {
+            inner.page_version_metas.reserve(history.len());
 
-            let record_range = page_version
-                .record
-                .map(|record| {
-                    let buf = WALRecord::ser(&record)?;
-                    page_version_writer.write_blob(&buf)
-                })
-                .transpose()?;
+            for (lsn, page_version) in history {
+                let buf = PageVersion::ser(page_version)?;
+                let blob_range = page_version_writer.write_blob(&buf)?;
 
-            let old = inner.page_version_metas.insert(
-                key,
-                PageVersionMeta {
-                    page_image_range,
-                    record_range,
-                },
-            );
-
-            assert!(old.is_none());
+                inner
+                    .page_version_metas
+                    .append((blknum, *lsn), blob_range)
+                    .unwrap();
+            }
         }
 
         let book = page_version_writer.close()?;
 
         // Write out page versions
         let mut chapter = book.new_chapter(PAGE_VERSION_METAS_CHAPTER);
-        let buf = BTreeMap::ser(&inner.page_version_metas)?;
+        let buf = VecMap::ser(&inner.page_version_metas)?;
         chapter.write_all(&buf)?;
         let book = chapter.close()?;
 
         // and relsizes to separate chapter
         let mut chapter = book.new_chapter(REL_SIZES_CHAPTER);
-        let buf = BTreeMap::ser(&inner.relsizes)?;
+        let buf = VecMap::ser(&inner.relsizes)?;
         chapter.write_all(&buf)?;
         let book = chapter.close()?;
 
-        book.close()?;
+        let mut chapter = book.new_chapter(SUMMARY_CHAPTER);
+        let summary = Summary {
+            tenantid,
+            timelineid,
+            seg,
+
+            start_lsn,
+            end_lsn,
+
+            dropped,
+        };
+        Summary::ser_into(&summary, &mut chapter)?;
+        let book = chapter.close()?;
+
+        // This flushes the underlying 'buf_writer'.
+        let writer = book.close()?;
+        writer.get_ref().sync_all()?;
 
         trace!("saved {}", &path.display());
 
-        drop(inner);
-
         Ok(delta_layer)
     }
 
@@ -477,11 +503,36 @@ impl DeltaLayer {
 
         let (path, book) = self.open_book()?;
 
+        match &self.path_or_conf {
+            PathOrConf::Conf(_) => {
+                let chapter = book.read_chapter(SUMMARY_CHAPTER)?;
+                let actual_summary = Summary::des(&chapter)?;
+
+                let expected_summary = Summary::from(self);
+
+                if actual_summary != expected_summary {
+                    bail!("in-file summary does not match expected summary. actual = {:?} expected = {:?}", actual_summary, expected_summary);
+                }
+            }
+            PathOrConf::Path(path) => {
+                let actual_filename = Path::new(path.file_name().unwrap());
+                let expected_filename = self.filename();
+
+                if actual_filename != expected_filename {
+                    println!(
+                        "warning: filename does not match what is expected from in-file summary"
+                    );
+                    println!("actual: {:?}", actual_filename);
+                    println!("expected: {:?}", expected_filename);
+                }
+            }
+        }
+
         let chapter = book.read_chapter(PAGE_VERSION_METAS_CHAPTER)?;
-        let page_version_metas = BTreeMap::des(&chapter)?;
+        let page_version_metas = VecMap::des(&chapter)?;
 
         let chapter = book.read_chapter(REL_SIZES_CHAPTER)?;
-        let relsizes = BTreeMap::des(&chapter)?;
+        let relsizes = VecMap::des(&chapter)?;
 
         debug!("loaded from {}", &path.display());
 
@@ -500,7 +551,6 @@ impl DeltaLayer {
         timelineid: ZTimelineId,
         tenantid: ZTenantId,
         filename: &DeltaFileName,
-        predecessor: Option<Arc<dyn Layer>>,
     ) -> DeltaLayer {
         DeltaLayer {
             path_or_conf: PathOrConf::Conf(conf),
@@ -512,36 +562,32 @@ impl DeltaLayer {
             dropped: filename.dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: false,
-                page_version_metas: BTreeMap::new(),
-                relsizes: BTreeMap::new(),
+                page_version_metas: VecMap::default(),
+                relsizes: VecMap::default(),
             }),
-            predecessor,
         }
     }
 
     /// Create a DeltaLayer struct representing an existing file on disk.
     ///
     /// This variant is only used for debugging purposes, by the 'dump_layerfile' binary.
-    pub fn new_for_path(
-        path: &Path,
-        timelineid: ZTimelineId,
-        tenantid: ZTenantId,
-        filename: &DeltaFileName,
-    ) -> DeltaLayer {
-        DeltaLayer {
+    pub fn new_for_path(path: &Path, book: &Book<File>) -> Result<Self> {
+        let chapter = book.read_chapter(SUMMARY_CHAPTER)?;
+        let summary = Summary::des(&chapter)?;
+
+        Ok(DeltaLayer {
             path_or_conf: PathOrConf::Path(path.to_path_buf()),
-            timelineid,
-            tenantid,
-            seg: filename.seg,
-            start_lsn: filename.start_lsn,
-            end_lsn: filename.end_lsn,
-            dropped: filename.dropped,
+            timelineid: summary.timelineid,
+            tenantid: summary.tenantid,
+            seg: summary.seg,
+            start_lsn: summary.start_lsn,
+            end_lsn: summary.end_lsn,
+            dropped: summary.dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: false,
-                page_version_metas: BTreeMap::new(),
-                relsizes: BTreeMap::new(),
+                page_version_metas: VecMap::default(),
+                relsizes: VecMap::default(),
             }),
-            predecessor: None,
-        }
+        })
     }
 }

pageserver/src/layered_repository/filename.rs

@@ -111,8 +111,10 @@ impl DeltaFileName {
             dropped,
         })
     }
+}
 
-    fn to_string(&self) -> String {
+impl fmt::Display for DeltaFileName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let basename = match self.seg.rel {
             RelishTag::Relation(reltag) => format!(
                 "rel_{}_{}_{}_{}",
@@ -134,11 +136,12 @@ impl DeltaFileName {
                 format!("pg_filenodemap_{}_{}", spcnode, dbnode)
             }
             RelishTag::TwoPhase { xid } => format!("pg_twophase_{}", xid),
-            RelishTag::Checkpoint => format!("pg_control_checkpoint"),
-            RelishTag::ControlFile => format!("pg_control"),
+            RelishTag::Checkpoint => "pg_control_checkpoint".to_string(),
+            RelishTag::ControlFile => "pg_control".to_string(),
         };
 
-        format!(
+        write!(
+            f,
             "{}_{}_{:016X}_{:016X}{}",
             basename,
             self.seg.segno,
@@ -149,12 +152,6 @@ impl DeltaFileName {
     }
 }
 
-impl fmt::Display for DeltaFileName {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{}", self.to_string())
-    }
-}
-
 #[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone)]
 pub struct ImageFileName {
     pub seg: SegmentTag,
@@ -233,8 +230,10 @@ impl ImageFileName {
 
         Some(ImageFileName { seg, lsn })
     }
+}
 
-    fn to_string(&self) -> String {
+impl fmt::Display for ImageFileName {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let basename = match self.seg.rel {
             RelishTag::Relation(reltag) => format!(
                 "rel_{}_{}_{}_{}",
@@ -256,11 +255,12 @@ impl ImageFileName {
                 format!("pg_filenodemap_{}_{}", spcnode, dbnode)
             }
             RelishTag::TwoPhase { xid } => format!("pg_twophase_{}", xid),
-            RelishTag::Checkpoint => format!("pg_control_checkpoint"),
-            RelishTag::ControlFile => format!("pg_control"),
+            RelishTag::Checkpoint => "pg_control_checkpoint".to_string(),
+            RelishTag::ControlFile => "pg_control".to_string(),
         };
 
-        format!(
+        write!(
+            f,
             "{}_{}_{:016X}",
             basename,
             self.seg.segno,
@@ -269,12 +269,6 @@ impl ImageFileName {
     }
 }
 
-impl fmt::Display for ImageFileName {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{}", self.to_string())
-    }
-}
-
 /// Scan timeline directory and create ImageFileName and DeltaFilename
 /// structs representing all files on disk
 ///
@@ -296,13 +290,13 @@ pub fn list_files(
             deltafiles.push(deltafilename);
         } else if let Some(imgfilename) = ImageFileName::from_str(fname) {
             imgfiles.push(imgfilename);
-        } else if fname == "wal" || fname == "metadata" || fname == "ancestor" {
+        } else if fname == "metadata" || fname == "ancestor" || fname.ends_with(".old") {
             // ignore these
         } else {
             warn!("unrecognized filename in timeline dir: {}", fname);
         }
     }
-    return Ok((imgfiles, deltafiles));
+    Ok((imgfiles, deltafiles))
 }
 
 /// Helper enum to hold a PageServerConf, or a path

pageserver/src/layered_repository/image_layer.rs

@@ -2,8 +2,9 @@
 //! It is stored in a file on disk.
 //!
 //! On disk, the image files are stored in timelines/<timelineid> directory.
-//! Currently, there are no subdirectories, and each snapshot file is named like this:
+//! Currently, there are no subdirectories, and each image layer file is named like this:
 //!
+//! Note that segno is
 //!    <spcnode>_<dbnode>_<relnode>_<forknum>_<segno>_<LSN>
 //!
 //! For example:
@@ -15,10 +16,10 @@
 //! Only metadata is loaded into memory by the load function.
 //! When images are needed, they are read directly from disk.
 //!
-//! For blocky segments, the images are stored in BLOCKY_IMAGES_CHAPTER.
+//! For blocky relishes, the images are stored in BLOCKY_IMAGES_CHAPTER.
 //! All the images are required to be BLOCK_SIZE, which allows for random access.
 //!
-//! For non-blocky segments, the image can be found in NONBLOCKY_IMAGE_CHAPTER.
+//! For non-blocky relishes, the image can be found in NONBLOCKY_IMAGE_CHAPTER.
 //!
 use crate::layered_repository::filename::{ImageFileName, PathOrConf};
 use crate::layered_repository::storage_layer::{
@@ -28,27 +29,53 @@ use crate::layered_repository::LayeredTimeline;
 use crate::layered_repository::RELISH_SEG_SIZE;
 use crate::PageServerConf;
 use crate::{ZTenantId, ZTimelineId};
-use anyhow::{anyhow, ensure, Result};
+use anyhow::{anyhow, bail, ensure, Result};
 use bytes::Bytes;
 use log::*;
+use serde::{Deserialize, Serialize};
 use std::convert::TryInto;
 use std::fs;
 use std::fs::File;
-use std::io::Write;
+use std::io::{BufWriter, Write};
 use std::path::{Path, PathBuf};
 use std::sync::{Mutex, MutexGuard};
 
 use bookfile::{Book, BookWriter};
 
+use zenith_utils::bin_ser::BeSer;
 use zenith_utils::lsn::Lsn;
 
 // Magic constant to identify a Zenith segment image file
-const IMAGE_FILE_MAGIC: u32 = 0x5A616E01 + 1;
+pub const IMAGE_FILE_MAGIC: u32 = 0x5A616E01 + 1;
 
 /// Contains each block in block # order
 const BLOCKY_IMAGES_CHAPTER: u64 = 1;
 const NONBLOCKY_IMAGE_CHAPTER: u64 = 2;
 
+/// Contains the [`Summary`] struct
+const SUMMARY_CHAPTER: u64 = 3;
+
+#[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
+struct Summary {
+    tenantid: ZTenantId,
+    timelineid: ZTimelineId,
+    seg: SegmentTag,
+
+    lsn: Lsn,
+}
+
+impl From<&ImageLayer> for Summary {
+    fn from(layer: &ImageLayer) -> Self {
+        Self {
+            tenantid: layer.tenantid,
+            timelineid: layer.timelineid,
+            seg: layer.seg,
+
+            lsn: layer.lsn,
+        }
+    }
+}
+
 const BLOCK_SIZE: usize = 8192;
 
 ///
@@ -96,24 +123,37 @@ impl Layer for ImageLayer {
         )
     }
 
+    fn path(&self) -> Option<PathBuf> {
+        Some(Self::path_for(
+            &self.path_or_conf,
+            self.timelineid,
+            self.tenantid,
+            &ImageFileName {
+                seg: self.seg,
+                lsn: self.lsn,
+            },
+        ))
+    }
+
     fn get_timeline_id(&self) -> ZTimelineId {
-        return self.timelineid;
+        self.timelineid
     }
 
     fn get_seg_tag(&self) -> SegmentTag {
-        return self.seg;
+        self.seg
     }
 
     fn is_dropped(&self) -> bool {
-        return false;
+        false
     }
 
     fn get_start_lsn(&self) -> Lsn {
-        return self.lsn;
+        self.lsn
     }
 
     fn get_end_lsn(&self) -> Lsn {
-        return self.lsn;
+        // End-bound is exclusive
+        self.lsn + 1
     }
 
     /// Look up given page in the file
@@ -182,7 +222,9 @@ impl Layer for ImageLayer {
 
     fn delete(&self) -> Result<()> {
         // delete underlying file
-        fs::remove_file(self.path())?;
+        if let Some(path) = self.path() {
+            fs::remove_file(path)?;
+        }
         Ok(())
     }
 
@@ -192,7 +234,10 @@ impl Layer for ImageLayer {
 
     /// debugging function to print out the contents of the layer
     fn dump(&self) -> Result<()> {
-        println!("----- image layer for {} at {} ----", self.seg, self.lsn);
+        println!(
+            "----- image layer for ten {} tli {} seg {} at {} ----",
+            self.tenantid, self.timelineid, self.seg, self.lsn
+        );
 
         let inner = self.load()?;
 
@@ -210,18 +255,6 @@ impl Layer for ImageLayer {
 }
 
 impl ImageLayer {
-    fn path(&self) -> PathBuf {
-        Self::path_for(
-            &self.path_or_conf,
-            self.timelineid,
-            self.tenantid,
-            &ImageFileName {
-                seg: self.seg,
-                lsn: self.lsn,
-            },
-        )
-    }
-
     fn path_for(
         path_or_conf: &PathOrConf,
         timelineid: ZTimelineId,
@@ -255,10 +288,10 @@ impl ImageLayer {
 
         let layer = ImageLayer {
             path_or_conf: PathOrConf::Conf(conf),
-            timelineid: timelineid,
-            tenantid: tenantid,
-            seg: seg,
-            lsn: lsn,
+            timelineid,
+            tenantid,
+            seg,
+            lsn,
             inner: Mutex::new(ImageLayerInner {
                 loaded: true,
                 image_type: image_type.clone(),
@@ -267,12 +300,14 @@ impl ImageLayer {
         let inner = layer.inner.lock().unwrap();
 
         // Write the images into a file
-        let path = layer.path();
-
+        let path = layer
+            .path()
+            .expect("ImageLayer is supposed to have a layer path on disk");
         // Note: This overwrites any existing file. There shouldn't be any.
         // FIXME: throw an error instead?
         let file = File::create(&path)?;
-        let book = BookWriter::new(file, IMAGE_FILE_MAGIC)?;
+        let buf_writer = BufWriter::new(file);
+        let book = BookWriter::new(buf_writer, IMAGE_FILE_MAGIC)?;
 
         let book = match &image_type {
             ImageType::Blocky { .. } => {
@@ -290,7 +325,20 @@ impl ImageLayer {
             }
         };
 
-        book.close()?;
+        let mut chapter = book.new_chapter(SUMMARY_CHAPTER);
+        let summary = Summary {
+            tenantid,
+            timelineid,
+            seg,
+
+            lsn,
+        };
+        Summary::ser_into(&summary, &mut chapter)?;
+        let book = chapter.close()?;
+
+        // This flushes the underlying 'buf_writer'.
+        let writer = book.close()?;
+        writer.get_ref().sync_all()?;
 
         trace!("saved {}", &path.display());
 
@@ -350,6 +398,31 @@ impl ImageLayer {
 
         let (path, book) = self.open_book()?;
 
+        match &self.path_or_conf {
+            PathOrConf::Conf(_) => {
+                let chapter = book.read_chapter(SUMMARY_CHAPTER)?;
+                let actual_summary = Summary::des(&chapter)?;
+
+                let expected_summary = Summary::from(self);
+
+                if actual_summary != expected_summary {
+                    bail!("in-file summary does not match expected summary. actual = {:?} expected = {:?}", actual_summary, expected_summary);
+                }
+            }
+            PathOrConf::Path(path) => {
+                let actual_filename = Path::new(path.file_name().unwrap());
+                let expected_filename = self.filename();
+
+                if actual_filename != expected_filename {
+                    println!(
+                        "warning: filename does not match what is expected from in-file summary"
+                    );
+                    println!("actual: {:?}", actual_filename);
+                    println!("expected: {:?}", expected_filename);
+                }
+            }
+        }
+
         let image_type = if self.seg.rel.is_blocky() {
             let chapter = book.chapter_reader(BLOCKY_IMAGES_CHAPTER)?;
             let images_len = chapter.len();
@@ -411,22 +484,20 @@ impl ImageLayer {
     /// Create an ImageLayer struct representing an existing file on disk.
     ///
     /// This variant is only used for debugging purposes, by the 'dump_layerfile' binary.
-    pub fn new_for_path(
-        path: &Path,
-        timelineid: ZTimelineId,
-        tenantid: ZTenantId,
-        filename: &ImageFileName,
-    ) -> ImageLayer {
-        ImageLayer {
+    pub fn new_for_path(path: &Path, book: &Book<File>) -> Result<ImageLayer> {
+        let chapter = book.read_chapter(SUMMARY_CHAPTER)?;
+        let summary = Summary::des(&chapter)?;
+
+        Ok(ImageLayer {
             path_or_conf: PathOrConf::Path(path.to_path_buf()),
-            timelineid,
-            tenantid,
-            seg: filename.seg,
-            lsn: filename.lsn,
+            timelineid: summary.timelineid,
+            tenantid: summary.tenantid,
+            seg: summary.seg,
+            lsn: summary.lsn,
             inner: Mutex::new(ImageLayerInner {
                 loaded: false,
                 image_type: ImageType::Blocky { num_blocks: 0 },
             }),
-        }
+        })
     }
 }

pageserver/src/layered_repository/inmemory_layer.rs

@@ -7,20 +7,24 @@ use crate::layered_repository::storage_layer::{
     Layer, PageReconstructData, PageReconstructResult, PageVersion, SegmentTag, RELISH_SEG_SIZE,
 };
 use crate::layered_repository::LayeredTimeline;
+use crate::layered_repository::ZERO_PAGE;
 use crate::layered_repository::{DeltaLayer, ImageLayer};
 use crate::repository::WALRecord;
 use crate::PageServerConf;
 use crate::{ZTenantId, ZTimelineId};
-use anyhow::{bail, Result};
+use anyhow::{bail, ensure, Result};
 use bytes::Bytes;
 use log::*;
-use std::collections::BTreeMap;
-use std::ops::Bound::Included;
+use std::cmp::min;
 use std::path::PathBuf;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, RwLock};
+use zenith_utils::vec_map::VecMap;
 
+use zenith_utils::accum::Accum;
 use zenith_utils::lsn::Lsn;
 
+use super::page_versions::PageVersions;
+
 pub struct InMemoryLayer {
     conf: &'static PageServerConf,
     tenantid: ZTenantId,
@@ -29,20 +33,22 @@ pub struct InMemoryLayer {
 
     ///
     /// This layer contains all the changes from 'start_lsn'. The
-    /// start is inclusive. There is no end LSN; we only use in-memory
-    /// layer at the end of a timeline.
+    /// start is inclusive.
     ///
     start_lsn: Lsn,
 
+    /// Frozen in-memory layers have an inclusive end LSN.
+    end_lsn: Option<Lsn>,
+
     /// LSN of the oldest page version stored in this layer
     oldest_pending_lsn: Lsn,
 
     /// The above fields never change. The parts that do change are in 'inner',
     /// and protected by mutex.
-    inner: Mutex<InMemoryLayerInner>,
+    inner: RwLock<InMemoryLayerInner>,
 
-    /// Predecessor layer
-    predecessor: Option<Arc<dyn Layer>>,
+    /// Predecessor layer might be needed?
+    incremental: bool,
 }
 
 pub struct InMemoryLayerInner {
@@ -53,23 +59,40 @@ pub struct InMemoryLayerInner {
     /// All versions of all pages in the layer are are kept here.
     /// Indexed by block number and LSN.
     ///
-    page_versions: BTreeMap<(u32, Lsn), PageVersion>,
+    page_versions: PageVersions,
 
     ///
     /// `segsizes` tracks the size of the segment at different points in time.
     ///
-    segsizes: BTreeMap<Lsn, u32>,
+    /// For a blocky rel, there is always one entry, at the layer's start_lsn,
+    /// so that determining the size never depends on the predecessor layer. For
+    /// a non-blocky rel, 'segsizes' is not used and is always empty.
+    ///
+    segsizes: VecMap<Lsn, u32>,
+
+    /// Writes are only allowed when true.
+    /// Set to false when this layer is in the process of being replaced.
+    writeable: bool,
 }
 
 impl InMemoryLayerInner {
+    fn check_writeable(&self) -> WriteResult<()> {
+        if self.writeable {
+            Ok(())
+        } else {
+            Err(NonWriteableError)
+        }
+    }
+
     fn get_seg_size(&self, lsn: Lsn) -> u32 {
         // Scan the BTreeMap backwards, starting from the given entry.
-        let mut iter = self.segsizes.range((Included(&Lsn(0)), Included(&lsn)));
+        let slice = self.segsizes.slice_range(..=lsn);
 
-        if let Some((_entry_lsn, entry)) = iter.next_back() {
+        // We make sure there is always at least one entry
+        if let Some((_entry_lsn, entry)) = slice.last() {
             *entry
         } else {
-            0
+            panic!("could not find seg size in in-memory layer");
         }
     }
 }
@@ -78,7 +101,7 @@ impl Layer for InMemoryLayer {
     // An in-memory layer doesn't really have a filename as it's not stored on disk,
     // but we construct a filename as if it was a delta layer
     fn filename(&self) -> PathBuf {
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
 
         let end_lsn;
         let dropped;
@@ -93,28 +116,36 @@ impl Layer for InMemoryLayer {
         let delta_filename = DeltaFileName {
             seg: self.seg,
             start_lsn: self.start_lsn,
-            end_lsn: end_lsn,
-            dropped: dropped,
+            end_lsn,
+            dropped,
         }
         .to_string();
 
         PathBuf::from(format!("inmem-{}", delta_filename))
     }
 
+    fn path(&self) -> Option<PathBuf> {
+        None
+    }
+
     fn get_timeline_id(&self) -> ZTimelineId {
-        return self.timelineid;
+        self.timelineid
     }
 
     fn get_seg_tag(&self) -> SegmentTag {
-        return self.seg;
+        self.seg
     }
 
     fn get_start_lsn(&self) -> Lsn {
-        return self.start_lsn;
+        self.start_lsn
     }
 
     fn get_end_lsn(&self) -> Lsn {
-        let inner = self.inner.lock().unwrap();
+        if let Some(end_lsn) = self.end_lsn {
+            return Lsn(end_lsn.0 + 1);
+        }
+
+        let inner = self.inner.read().unwrap();
 
         if let Some(drop_lsn) = inner.drop_lsn {
             drop_lsn
@@ -124,7 +155,7 @@ impl Layer for InMemoryLayer {
     }
 
     fn is_dropped(&self) -> bool {
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
         inner.drop_lsn.is_some()
     }
 
@@ -135,53 +166,46 @@ impl Layer for InMemoryLayer {
         lsn: Lsn,
         reconstruct_data: &mut PageReconstructData,
     ) -> Result<PageReconstructResult> {
-        let mut cont_lsn: Option<Lsn> = Some(lsn);
+        let mut need_image = true;
 
         assert!(self.seg.blknum_in_seg(blknum));
 
         {
-            let inner = self.inner.lock().unwrap();
+            let inner = self.inner.read().unwrap();
 
-            // Scan the BTreeMap backwards, starting from reconstruct_data.lsn.
-            let minkey = (blknum, Lsn(0));
-            let maxkey = (blknum, lsn);
-            let mut iter = inner
+            // Scan the page versions backwards, starting from `lsn`.
+            let iter = inner
                 .page_versions
-                .range((Included(&minkey), Included(&maxkey)));
-            while let Some(((_blknum, entry_lsn), entry)) = iter.next_back() {
+                .get_block_lsn_range(blknum, ..=lsn)
+                .iter()
+                .rev();
+            for (_entry_lsn, entry) in iter {
                 if let Some(img) = &entry.page_image {
                     reconstruct_data.page_img = Some(img.clone());
-                    cont_lsn = None;
+                    need_image = false;
                     break;
                 } else if let Some(rec) = &entry.record {
                     reconstruct_data.records.push(rec.clone());
                     if rec.will_init {
                         // This WAL record initializes the page, so no need to go further back
-                        cont_lsn = None;
+                        need_image = false;
                         break;
-                    } else {
-                        // This WAL record needs to be applied against an older page image
-                        cont_lsn = Some(*entry_lsn);
                     }
                 } else {
                     // No base image, and no WAL record. Huh?
                     bail!("no page image or WAL record for requested page");
                 }
             }
-
             // release lock on 'inner'
         }
 
         // If an older page image is needed to reconstruct the page, let the
-        // caller know about the predecessor layer.
-        if let Some(cont_lsn) = cont_lsn {
-            if let Some(cont_layer) = &self.predecessor {
-                Ok(PageReconstructResult::Continue(
-                    cont_lsn,
-                    Arc::clone(cont_layer),
-                ))
+        // caller know
+        if need_image {
+            if self.incremental {
+                Ok(PageReconstructResult::Continue(Lsn(self.start_lsn.0 - 1)))
             } else {
-                Ok(PageReconstructResult::Missing(cont_lsn))
+                Ok(PageReconstructResult::Missing(self.start_lsn))
             }
         } else {
             Ok(PageReconstructResult::Complete)
@@ -191,14 +215,23 @@ impl Layer for InMemoryLayer {
     /// Get size of the relation at given LSN
     fn get_seg_size(&self, lsn: Lsn) -> Result<u32> {
         assert!(lsn >= self.start_lsn);
+        ensure!(
+            self.seg.rel.is_blocky(),
+            "get_seg_size() called on a non-blocky rel"
+        );
 
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
         Ok(inner.get_seg_size(lsn))
     }
 
     /// Does this segment exist at given LSN?
     fn get_seg_exists(&self, lsn: Lsn) -> Result<bool> {
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
+
+        // If the segment created after requested LSN,
+        // it doesn't exist in the layer. But we shouldn't
+        // have requested it in the first place.
+        assert!(lsn >= self.start_lsn);
 
         // Is the requested LSN after the segment was dropped?
         if let Some(drop_lsn) = inner.drop_lsn {
@@ -225,12 +258,12 @@ impl Layer for InMemoryLayer {
     }
 
     fn is_incremental(&self) -> bool {
-        self.predecessor.is_some()
+        self.incremental
     }
 
     /// debugging function to print out the contents of the layer
     fn dump(&self) -> Result<()> {
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
 
         let end_str = inner
             .drop_lsn
@@ -239,22 +272,50 @@ impl Layer for InMemoryLayer {
             .unwrap_or_default();
 
         println!(
-            "----- in-memory layer for {} {}-{} ----",
-            self.seg, self.start_lsn, end_str
+            "----- in-memory layer for tli {} seg {} {}-{} ----",
+            self.timelineid, self.seg, self.start_lsn, end_str
         );
 
-        for (k, v) in inner.segsizes.iter() {
-            println!("{}: {}", k, v);
+        for (k, v) in inner.segsizes.as_slice() {
+            println!("segsizes {}: {}", k, v);
+        }
+
+        for (blknum, history) in inner.page_versions.ordered_block_iter(None) {
+            for (lsn, pv) in history {
+                println!(
+                    "blk {} at {}: {}/{}\n",
+                    blknum,
+                    lsn,
+                    pv.page_image.is_some(),
+                    pv.record.is_some()
+                );
+            }
         }
-        //for (k, v) in inner.page_versions.iter() {
-        //    println!("blk {} at {}: {}/{}", k.0, k.1, v.page_image.is_some(), v.record.is_some());
-        //}
 
         Ok(())
     }
 }
 
+/// Write failed because the layer is in process of being replaced.
+/// See [`LayeredTimeline::perform_write_op`] for how to handle this error.
+#[derive(Debug)]
+pub struct NonWriteableError;
+
+pub type WriteResult<T> = std::result::Result<T, NonWriteableError>;
+
+/// Helper struct to cleanup `InMemoryLayer::freeze` return signature.
+pub struct FreezeLayers {
+    /// Replacement layer for the layer which freeze was called on.
+    pub frozen: Arc<InMemoryLayer>,
+    /// New open layer containing leftover data.
+    pub open: Option<Arc<InMemoryLayer>>,
+}
+
 impl InMemoryLayer {
+    fn assert_not_frozen(&self) {
+        assert!(self.end_lsn.is_none());
+    }
+
     /// Return the oldest page version that's stored in this layer
     pub fn get_oldest_pending_lsn(&self) -> Lsn {
         self.oldest_pending_lsn
@@ -278,26 +339,34 @@ impl InMemoryLayer {
             start_lsn
         );
 
+        // The segment is initially empty, so initialize 'segsizes' with 0.
+        let mut segsizes = VecMap::default();
+        if seg.rel.is_blocky() {
+            segsizes.append(start_lsn, 0).unwrap();
+        }
+
         Ok(InMemoryLayer {
             conf,
             timelineid,
             tenantid,
             seg,
             start_lsn,
+            end_lsn: None,
             oldest_pending_lsn,
-            inner: Mutex::new(InMemoryLayerInner {
+            incremental: false,
+            inner: RwLock::new(InMemoryLayerInner {
                 drop_lsn: None,
-                page_versions: BTreeMap::new(),
-                segsizes: BTreeMap::new(),
+                page_versions: PageVersions::default(),
+                segsizes,
+                writeable: true,
             }),
-            predecessor: None,
         })
     }
 
     // Write operations
 
     /// Remember new page version, as a WAL record over previous version
-    pub fn put_wal_record(&self, blknum: u32, rec: WALRecord) -> Result<()> {
+    pub fn put_wal_record(&self, blknum: u32, rec: WALRecord) -> WriteResult<u32> {
         self.put_page_version(
             blknum,
             rec.lsn,
@@ -309,7 +378,7 @@ impl InMemoryLayer {
     }
 
     /// Remember new page version, as a full page image
-    pub fn put_page_image(&self, blknum: u32, lsn: Lsn, img: Bytes) -> Result<()> {
+    pub fn put_page_image(&self, blknum: u32, lsn: Lsn, img: Bytes) -> WriteResult<u32> {
         self.put_page_version(
             blknum,
             lsn,
@@ -322,7 +391,8 @@ impl InMemoryLayer {
 
     /// Common subroutine of the public put_wal_record() and put_page_image() functions.
     /// Adds the page version to the in-memory tree
-    pub fn put_page_version(&self, blknum: u32, lsn: Lsn, pv: PageVersion) -> Result<()> {
+    pub fn put_page_version(&self, blknum: u32, lsn: Lsn, pv: PageVersion) -> WriteResult<u32> {
+        self.assert_not_frozen();
         assert!(self.seg.blknum_in_seg(blknum));
 
         trace!(
@@ -332,9 +402,11 @@ impl InMemoryLayer {
             self.timelineid,
             lsn
         );
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.write().unwrap();
 
-        let old = inner.page_versions.insert((blknum, lsn), pv);
+        inner.check_writeable()?;
+
+        let old = inner.page_versions.append_or_update_last(blknum, lsn, pv);
 
         if old.is_some() {
             // We already had an entry for this LSN. That's odd..
@@ -348,7 +420,7 @@ impl InMemoryLayer {
         if self.seg.rel.is_blocky() {
             let newsize = blknum - self.seg.segno * RELISH_SEG_SIZE + 1;
 
-            // use inner get_seg_size, since calling self.get_seg_size will try to acquire self.inner.lock
+            // use inner get_seg_size, since calling self.get_seg_size will try to acquire the lock,
             // which we've just acquired above
             let oldsize = inner.get_seg_size(lsn);
             if newsize > oldsize {
@@ -359,17 +431,62 @@ impl InMemoryLayer {
                     newsize,
                     lsn
                 );
-                inner.segsizes.insert(lsn, newsize);
+
+                // If we are extending the relation by more than one page, initialize the "gap"
+                // with zeros
+                //
+                // XXX: What if the caller initializes the gap with subsequent call with same LSN?
+                // I don't think that can happen currently, but that is highly dependent on how
+                // PostgreSQL writes its WAL records and there's no guarantee of it. If it does
+                // happen, we would hit the "page version already exists" warning above on the
+                // subsequent call to initialize the gap page.
+                let gapstart = self.seg.segno * RELISH_SEG_SIZE + oldsize;
+                for gapblknum in gapstart..blknum {
+                    let zeropv = PageVersion {
+                        page_image: Some(ZERO_PAGE.clone()),
+                        record: None,
+                    };
+                    trace!(
+                        "filling gap blk {} with zeros for write of {}",
+                        gapblknum,
+                        blknum
+                    );
+                    let old = inner
+                        .page_versions
+                        .append_or_update_last(gapblknum, lsn, zeropv);
+                    // We already had an entry for this LSN. That's odd..
+
+                    if old.is_some() {
+                        warn!(
+                            "Page version of rel {} blk {} at {} already exists",
+                            self.seg.rel, blknum, lsn
+                        );
+                    }
+                }
+
+                inner.segsizes.append_or_update_last(lsn, newsize).unwrap();
+                return Ok(newsize - oldsize);
             }
         }
-
-        Ok(())
+        Ok(0)
     }
 
     /// Remember that the relation was truncated at given LSN
-    pub fn put_truncation(&self, lsn: Lsn, segsize: u32) -> anyhow::Result<()> {
-        let mut inner = self.inner.lock().unwrap();
-        let old = inner.segsizes.insert(lsn, segsize);
+    pub fn put_truncation(&self, lsn: Lsn, segsize: u32) -> WriteResult<()> {
+        assert!(
+            self.seg.rel.is_blocky(),
+            "put_truncation() called on a non-blocky rel"
+        );
+        self.assert_not_frozen();
+
+        let mut inner = self.inner.write().unwrap();
+        inner.check_writeable()?;
+
+        // check that this we truncate to a smaller size than segment was before the truncation
+        let oldsize = inner.get_seg_size(lsn);
+        assert!(segsize < oldsize);
+
+        let old = inner.segsizes.append_or_update_last(lsn, segsize).unwrap();
 
         if old.is_some() {
             // We already had an entry for this LSN. That's odd..
@@ -380,13 +497,18 @@ impl InMemoryLayer {
     }
 
     /// Remember that the segment was dropped at given LSN
-    pub fn put_unlink(&self, lsn: Lsn) -> anyhow::Result<()> {
-        let mut inner = self.inner.lock().unwrap();
+    pub fn drop_segment(&self, lsn: Lsn) -> WriteResult<()> {
+        self.assert_not_frozen();
+
+        let mut inner = self.inner.write().unwrap();
+
+        inner.check_writeable()?;
 
         assert!(inner.drop_lsn.is_none());
         inner.drop_lsn = Some(lsn);
+        inner.writeable = false;
 
-        info!("dropped segment {} at {}", self.seg, lsn);
+        trace!("dropped segment {} at {}", self.seg, lsn);
 
         Ok(())
     }
@@ -405,6 +527,9 @@ impl InMemoryLayer {
     ) -> Result<InMemoryLayer> {
         let seg = src.get_seg_tag();
 
+        assert!(oldest_pending_lsn.is_aligned());
+        assert!(oldest_pending_lsn >= start_lsn);
+
         trace!(
             "initializing new InMemoryLayer for writing {} on timeline {} at {}",
             seg,
@@ -412,11 +537,11 @@ impl InMemoryLayer {
             start_lsn,
         );
 
-        // For convenience, copy the segment size from the predecessor layer
-        let mut segsizes = BTreeMap::new();
+        // Copy the segment size at the start LSN from the predecessor layer.
+        let mut segsizes = VecMap::default();
         if seg.rel.is_blocky() {
             let size = src.get_seg_size(start_lsn)?;
-            segsizes.insert(start_lsn, size);
+            segsizes.append(start_lsn, size).unwrap();
         }
 
         Ok(InMemoryLayer {
@@ -425,97 +550,177 @@ impl InMemoryLayer {
             tenantid,
             seg,
             start_lsn,
+            end_lsn: None,
             oldest_pending_lsn,
-            inner: Mutex::new(InMemoryLayerInner {
+            incremental: true,
+            inner: RwLock::new(InMemoryLayerInner {
                 drop_lsn: None,
-                page_versions: BTreeMap::new(),
-                segsizes: segsizes,
+                page_versions: PageVersions::default(),
+                segsizes,
+                writeable: true,
             }),
-            predecessor: Some(src),
         })
     }
 
-    ///
-    /// Write the this in-memory layer to disk, as a snapshot layer.
-    ///
-    /// The cutoff point for the layer that's written to disk is 'end_lsn'.
-    ///
-    /// Returns new layers that replace this one. Always returns a new image
-    /// layer containing the page versions at the cutoff LSN, that were written
-    /// to disk, and usually also a DeltaLayer that includes all the WAL records
-    /// between start LSN and the cutoff. (The delta layer is not needed when
-    /// a new relish is created with a single LSN, so that the start and end LSN
-    /// are the same.) If there were page versions newer than 'end_lsn', also
-    /// returns a new in-memory layer containing those page versions. The caller
-    /// replaces this layer with the returned layers in the layer map.
-    ///
-    pub fn freeze(
-        &self,
-        cutoff_lsn: Lsn,
-        // This is needed just to call materialize_page()
-        timeline: &LayeredTimeline,
-    ) -> Result<(Vec<Arc<dyn Layer>>, Option<Arc<InMemoryLayer>>)> {
+    pub fn is_writeable(&self) -> bool {
+        let inner = self.inner.read().unwrap();
+        inner.writeable
+    }
+
+    /// Splits `self` into two InMemoryLayers: `frozen` and `open`.
+    /// All data up to and including `cutoff_lsn`
+    /// is copied to `frozen`, while the remaining data is copied to `open`.
+    /// After completion, self is non-writeable, but not frozen.
+    pub fn freeze(self: Arc<Self>, cutoff_lsn: Lsn) -> Result<FreezeLayers> {
         info!(
-            "freezing in memory layer for {} on timeline {} at {}",
-            self.seg, self.timelineid, cutoff_lsn
+            "freezing in memory layer {} on timeline {} at {} (oldest {})",
+            self.filename().display(),
+            self.timelineid,
+            cutoff_lsn,
+            self.oldest_pending_lsn
         );
 
-        let inner = self.inner.lock().unwrap();
+        self.assert_not_frozen();
 
-        // Normally, use the cutoff LSN as the end of the frozen layer.
-        // But if the relation was dropped, we know that there are no
-        // more changes coming in for it, and in particular we know that
-        // there are no changes "in flight" for the LSN anymore, so we use
-        // the drop LSN instead. The drop-LSN could be ahead of the
-        // caller-specified LSN!
-        let dropped = inner.drop_lsn.is_some();
-        let end_lsn = if dropped {
-            inner.drop_lsn.unwrap()
-        } else {
-            cutoff_lsn
-        };
+        let self_ref = self.clone();
+        let mut inner = self_ref.inner.write().unwrap();
+        // Dropped layers don't need any special freeze actions,
+        // they are marked as non-writeable at drop and just
+        // written out to disk by checkpointer.
+        if inner.drop_lsn.is_some() {
+            assert!(!inner.writeable);
+            info!(
+                "freezing in memory layer for {} on timeline {} is dropped at {}",
+                self.seg,
+                self.timelineid,
+                inner.drop_lsn.unwrap()
+            );
 
-        // Divide all the page versions into old and new at the 'end_lsn' cutoff point.
-        let mut before_page_versions;
-        let mut before_segsizes;
-        let mut after_page_versions;
-        let mut after_segsizes;
-        if !dropped {
-            before_segsizes = BTreeMap::new();
-            after_segsizes = BTreeMap::new();
-            for (lsn, size) in inner.segsizes.iter() {
-                if *lsn > end_lsn {
-                    after_segsizes.insert(*lsn, *size);
-                } else {
-                    before_segsizes.insert(*lsn, *size);
-                }
-            }
+            // There should be no newer layer that refers this non-writeable layer,
+            // because layer that is created after dropped one represents a new rel.
+            return Ok(FreezeLayers {
+                frozen: self,
+                open: None,
+            });
+        }
+        assert!(inner.writeable);
+        inner.writeable = false;
 
-            before_page_versions = BTreeMap::new();
-            after_page_versions = BTreeMap::new();
-            for ((blknum, lsn), pv) in inner.page_versions.iter() {
-                if *lsn == end_lsn {
-                    // Page versions at the cutoff LSN will be stored in the
-                    // materialized image layer.
-                } else if *lsn > end_lsn {
-                    after_page_versions.insert((*blknum, *lsn), pv.clone());
-                } else {
-                    before_page_versions.insert((*blknum, *lsn), pv.clone());
-                }
-            }
-        } else {
-            before_page_versions = inner.page_versions.clone();
-            before_segsizes = inner.segsizes.clone();
-            after_segsizes = BTreeMap::new();
-            after_page_versions = BTreeMap::new();
+        // Divide all the page versions into old and new
+        // at the 'cutoff_lsn' point.
+        let mut after_oldest_lsn: Accum<Lsn> = Accum(None);
+
+        let cutoff_lsn_exclusive = Lsn(cutoff_lsn.0 + 1);
+
+        let (before_segsizes, mut after_segsizes) = inner.segsizes.split_at(&cutoff_lsn_exclusive);
+        if let Some((lsn, _size)) = after_segsizes.as_slice().first() {
+            after_oldest_lsn.accum(min, *lsn);
         }
 
-        // we can release the lock now.
-        drop(inner);
+        let (before_page_versions, after_page_versions) = inner
+            .page_versions
+            .split_at(cutoff_lsn_exclusive, &mut after_oldest_lsn);
+
+        let frozen = Arc::new(InMemoryLayer {
+            conf: self.conf,
+            tenantid: self.tenantid,
+            timelineid: self.timelineid,
+            seg: self.seg,
+            start_lsn: self.start_lsn,
+            end_lsn: Some(cutoff_lsn),
+            oldest_pending_lsn: self.start_lsn,
+            incremental: self.incremental,
+            inner: RwLock::new(InMemoryLayerInner {
+                drop_lsn: inner.drop_lsn,
+                page_versions: before_page_versions,
+                segsizes: before_segsizes,
+                writeable: false,
+            }),
+        });
+
+        let open = if !after_segsizes.is_empty() || !after_page_versions.is_empty() {
+            let mut new_open = Self::create_successor_layer(
+                self.conf,
+                frozen.clone(),
+                self.timelineid,
+                self.tenantid,
+                cutoff_lsn + 1,
+                after_oldest_lsn.0.unwrap(),
+            )?;
+
+            let new_inner = new_open.inner.get_mut().unwrap();
+            // Ensure page_versions doesn't contain anything
+            // so we can just replace it
+            assert!(new_inner.page_versions.is_empty());
+            new_inner.page_versions = after_page_versions;
+            new_inner.segsizes.extend(&mut after_segsizes).unwrap();
+
+            Some(Arc::new(new_open))
+        } else {
+            None
+        };
+
+        Ok(FreezeLayers { frozen, open })
+    }
+
+    /// Write the this frozen in-memory layer to disk.
+    ///
+    /// Returns new layers that replace this one.
+    /// If not dropped, returns a new image layer containing the page versions
+    /// at the `end_lsn`. Can also return a DeltaLayer that includes all the
+    /// WAL records between start and end LSN. (The delta layer is not needed
+    /// when a new relish is created with a single LSN, so that the start and
+    /// end LSN are the same.)
+    pub fn write_to_disk(&self, timeline: &LayeredTimeline) -> Result<Vec<Arc<dyn Layer>>> {
+        trace!(
+            "write_to_disk {} end_lsn is {} get_end_lsn is {}",
+            self.filename().display(),
+            self.end_lsn.unwrap_or(Lsn(0)),
+            self.get_end_lsn()
+        );
+
+        // Grab the lock in read-mode. We hold it over the I/O, but because this
+        // layer is not writeable anymore, no one should be trying to aquire the
+        // write lock on it, so we shouldn't block anyone. There's one exception
+        // though: another thread might have grabbed a reference to this layer
+        // in `get_layer_for_write' just before the checkpointer called
+        // `freeze`, and then `write_to_disk` on it. When the thread gets the
+        // lock, it will see that it's not writeable anymore and retry, but it
+        // would have to wait until we release it. That race condition is very
+        // rare though, so we just accept the potential latency hit for now.
+        let inner = self.inner.read().unwrap();
+        assert!(!inner.writeable);
+
+        if let Some(drop_lsn) = inner.drop_lsn {
+            let delta_layer = DeltaLayer::create(
+                self.conf,
+                self.timelineid,
+                self.tenantid,
+                self.seg,
+                self.start_lsn,
+                drop_lsn,
+                true,
+                inner.page_versions.ordered_block_iter(None),
+                inner.segsizes.clone(),
+            )?;
+            trace!(
+                "freeze: created delta layer for dropped segment {} {}-{}",
+                self.seg,
+                self.start_lsn,
+                drop_lsn
+            );
+            return Ok(vec![Arc::new(delta_layer)]);
+        }
+
+        let end_lsn = self.end_lsn.unwrap();
+
+        let mut before_page_versions = inner.page_versions.ordered_block_iter(Some(end_lsn));
 
         let mut frozen_layers: Vec<Arc<dyn Layer>> = Vec::new();
 
         if self.start_lsn != end_lsn {
+            let (before_segsizes, _after_segsizes) = inner.segsizes.split_at(&Lsn(end_lsn.0 + 1));
+
             // Write the page versions before the cutoff to disk.
             let delta_layer = DeltaLayer::create(
                 self.conf,
@@ -524,13 +729,11 @@ impl InMemoryLayer {
                 self.seg,
                 self.start_lsn,
                 end_lsn,
-                dropped,
-                self.predecessor.clone(),
+                false,
                 before_page_versions,
                 before_segsizes,
             )?;
-            let delta_layer_rc: Arc<dyn Layer> = Arc::new(delta_layer);
-            frozen_layers.push(delta_layer_rc);
+            frozen_layers.push(Arc::new(delta_layer));
             trace!(
                 "freeze: created delta layer {} {}-{}",
                 self.seg,
@@ -538,64 +741,16 @@ impl InMemoryLayer {
                 end_lsn
             );
         } else {
-            assert!(before_page_versions.is_empty());
+            assert!(before_page_versions.next().is_none());
         }
 
-        let mut new_open_rc = None;
-        if !dropped {
-            // Write a new base image layer at the cutoff point
-            let imgfile = ImageLayer::create_from_src(self.conf, timeline, self, end_lsn)?;
-            let imgfile_rc: Arc<dyn Layer> = Arc::new(imgfile);
-            frozen_layers.push(Arc::clone(&imgfile_rc));
-            trace!("freeze: created image layer {} at {}", self.seg, end_lsn);
+        drop(inner);
 
-            // If there were any page versions newer than the cutoff, initialize a new in-memory
-            // layer to hold them
-            if !after_segsizes.is_empty() || !after_page_versions.is_empty() {
-                let new_open = Self::create_successor_layer(
-                    self.conf,
-                    imgfile_rc,
-                    self.timelineid,
-                    self.tenantid,
-                    end_lsn,
-                    end_lsn,
-                )?;
-                let mut new_inner = new_open.inner.lock().unwrap();
-                new_inner.page_versions.append(&mut after_page_versions);
-                new_inner.segsizes.append(&mut after_segsizes);
-                drop(new_inner);
-                trace!("freeze: created new in-mem layer {} {}-", self.seg, end_lsn);
+        // Write a new base image layer at the cutoff point
+        let image_layer = ImageLayer::create_from_src(self.conf, timeline, self, end_lsn)?;
+        frozen_layers.push(Arc::new(image_layer));
+        trace!("freeze: created image layer {} at {}", self.seg, end_lsn);
 
-                new_open_rc = Some(Arc::new(new_open))
-            }
-        }
-
-        Ok((frozen_layers, new_open_rc))
-    }
-
-    /// debugging function to print out the contents of the layer
-    #[allow(unused)]
-    pub fn dump(&self) -> String {
-        let mut result = format!(
-            "----- inmemory layer for {} {}-> ----\n",
-            self.seg, self.start_lsn
-        );
-
-        let inner = self.inner.lock().unwrap();
-
-        for (k, v) in inner.segsizes.iter() {
-            result += &format!("{}: {}\n", k, v);
-        }
-        for (k, v) in inner.page_versions.iter() {
-            result += &format!(
-                "blk {} at {}: {}/{}\n",
-                k.0,
-                k.1,
-                v.page_image.is_some(),
-                v.record.is_some()
-            );
-        }
-
-        result
+        Ok(frozen_layers)
     }
 }

pageserver/src/layered_repository/interval_tree.rs

@@ -0,0 +1,468 @@
+///
+/// IntervalTree is data structure for holding intervals. It is generic
+/// to make unit testing possible, but the only real user of it is the layer map,
+///
+/// It's inspired by the "segment tree" or a "statistic tree" as described in
+/// https://en.wikipedia.org/wiki/Segment_tree. However, we use a B-tree to hold
+/// the points instead of a binary tree. This is called an "interval tree" instead
+/// of "segment tree" because the term "segment" is already using Zenith to mean
+/// something else. To add to the confusion, there is another data structure known
+/// as "interval tree" out there (see https://en.wikipedia.org/wiki/Interval_tree),
+/// for storing intervals, but this isn't that.
+///
+/// The basic idea is to have a B-tree of "interesting Points". At each Point,
+/// there is a list of intervals that contain the point. The Points are formed
+/// from the start bounds of each interval; there is a Point for each distinct
+/// start bound.
+///
+/// Operations:
+///
+/// To find intervals that contain a given point, you search the b-tree to find
+/// the nearest Point <= search key. Then you just return the list of intervals.
+///
+/// To insert an interval, find the Point with start key equal to the inserted item.
+/// If the Point doesn't exist yet, create it, by copying all the items from the
+/// previous Point that cover the new Point. Then walk right, inserting the new
+/// interval to all the Points that are contained by the new interval (including the
+/// newly created Point).
+///
+/// To remove an interval, you scan the tree for all the Points that are contained by
+/// the removed interval, and remove it from the list in each Point.
+///
+/// Requirements and assumptions:
+///
+/// - Can store overlapping items
+/// - But there are not many overlapping items
+/// - The interval bounds don't change after it is added to the tree
+/// - Intervals are uniquely identified by pointer equality. You must not be insert the
+///   same interval object twice, and `remove` uses pointer equality to remove the right
+///   interval. It is OK to have two intervals with the same bounds, however.
+///
+use std::collections::BTreeMap;
+use std::fmt::Debug;
+use std::ops::Range;
+use std::sync::Arc;
+
+pub struct IntervalTree<I: ?Sized>
+where
+    I: IntervalItem,
+{
+    points: BTreeMap<I::Key, Point<I>>,
+}
+
+struct Point<I: ?Sized> {
+    /// All intervals that contain this point, in no particular order.
+    ///
+    /// We assume that there aren't a lot of overlappingg intervals, so that this vector
+    /// never grows very large. If that assumption doesn't hold, we could keep this ordered
+    /// by the end bound, to speed up `search`. But as long as there are only a few elements,
+    /// a linear search is OK.
+    elements: Vec<Arc<I>>,
+}
+
+/// Abstraction for an interval that can be stored in the tree
+///
+/// The start bound is inclusive and the end bound is exclusive. End must be greater
+/// than start.
+pub trait IntervalItem {
+    type Key: Ord + Copy + Debug + Sized;
+
+    fn start_key(&self) -> Self::Key;
+    fn end_key(&self) -> Self::Key;
+
+    fn bounds(&self) -> Range<Self::Key> {
+        self.start_key()..self.end_key()
+    }
+}
+
+impl<I: ?Sized> IntervalTree<I>
+where
+    I: IntervalItem,
+{
+    /// Return an element that contains 'key', or precedes it.
+    ///
+    /// If there are multiple candidates, returns the one with the highest 'end' key.
+    pub fn search(&self, key: I::Key) -> Option<Arc<I>> {
+        // Find the greatest point that precedes or is equal to the search key. If there is
+        // none, returns None.
+        let (_, p) = self.points.range(..=key).next_back()?;
+
+        // Find the element with the highest end key at this point
+        let highest_item = p
+            .elements
+            .iter()
+            .reduce(|a, b| {
+                // starting with Rust 1.53, could use `std::cmp::min_by_key` here
+                if a.end_key() > b.end_key() {
+                    a
+                } else {
+                    b
+                }
+            })
+            .unwrap();
+        Some(Arc::clone(highest_item))
+    }
+
+    /// Iterate over all items with start bound >= 'key'
+    pub fn iter_newer(&self, key: I::Key) -> IntervalIter<I> {
+        IntervalIter {
+            point_iter: self.points.range(key..),
+            elem_iter: None,
+        }
+    }
+
+    /// Iterate over all items
+    pub fn iter(&self) -> IntervalIter<I> {
+        IntervalIter {
+            point_iter: self.points.range(..),
+            elem_iter: None,
+        }
+    }
+
+    pub fn insert(&mut self, item: Arc<I>) {
+        let start_key = item.start_key();
+        let end_key = item.end_key();
+        assert!(start_key < end_key);
+        let bounds = start_key..end_key;
+
+        // Find the starting point and walk forward from there
+        let mut found_start_point = false;
+        let iter = self.points.range_mut(bounds);
+        for (point_key, point) in iter {
+            if *point_key == start_key {
+                found_start_point = true;
+                // It is an error to insert the same item to the tree twice.
+                assert!(
+                    !point.elements.iter().any(|x| Arc::ptr_eq(x, &item)),
+                    "interval is already in the tree"
+                );
+            }
+            point.elements.push(Arc::clone(&item));
+        }
+        if !found_start_point {
+            // Create a new Point for the starting point
+
+            // Look at the previous point, and copy over elements that overlap with this
+            // new point
+            let mut new_elements: Vec<Arc<I>> = Vec::new();
+            if let Some((_, prev_point)) = self.points.range(..start_key).next_back() {
+                let overlapping_prev_elements = prev_point
+                    .elements
+                    .iter()
+                    .filter(|x| x.bounds().contains(&start_key))
+                    .cloned();
+
+                new_elements.extend(overlapping_prev_elements);
+            }
+            new_elements.push(item);
+
+            let new_point = Point {
+                elements: new_elements,
+            };
+            self.points.insert(start_key, new_point);
+        }
+    }
+
+    pub fn remove(&mut self, item: &Arc<I>) {
+        // range search points
+        let start_key = item.start_key();
+        let end_key = item.end_key();
+        let bounds = start_key..end_key;
+
+        let mut points_to_remove: Vec<I::Key> = Vec::new();
+        let mut found_start_point = false;
+        for (point_key, point) in self.points.range_mut(bounds) {
+            if *point_key == start_key {
+                found_start_point = true;
+            }
+            let len_before = point.elements.len();
+            point.elements.retain(|other| !Arc::ptr_eq(other, item));
+            let len_after = point.elements.len();
+            assert_eq!(len_after + 1, len_before);
+            if len_after == 0 {
+                points_to_remove.push(*point_key);
+            }
+        }
+        assert!(found_start_point);
+
+        for k in points_to_remove {
+            self.points.remove(&k).unwrap();
+        }
+    }
+}
+
+pub struct IntervalIter<'a, I: ?Sized>
+where
+    I: IntervalItem,
+{
+    point_iter: std::collections::btree_map::Range<'a, I::Key, Point<I>>,
+    elem_iter: Option<(I::Key, std::slice::Iter<'a, Arc<I>>)>,
+}
+
+impl<'a, I> Iterator for IntervalIter<'a, I>
+where
+    I: IntervalItem + ?Sized,
+{
+    type Item = Arc<I>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // Iterate over all elements in all the points in 'point_iter'. To avoid
+        // returning the same element twice, we only return each element at its
+        // starting point.
+        loop {
+            // Return next remaining element from the current point
+            if let Some((point_key, elem_iter)) = &mut self.elem_iter {
+                for elem in elem_iter {
+                    if elem.start_key() == *point_key {
+                        return Some(Arc::clone(elem));
+                    }
+                }
+            }
+            // No more elements at this point. Move to next point.
+            if let Some((point_key, point)) = self.point_iter.next() {
+                self.elem_iter = Some((*point_key, point.elements.iter()));
+                continue;
+            } else {
+                // No more points, all done
+                return None;
+            }
+        }
+    }
+}
+
+impl<I: ?Sized> Default for IntervalTree<I>
+where
+    I: IntervalItem,
+{
+    fn default() -> Self {
+        IntervalTree {
+            points: BTreeMap::new(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fmt;
+
+    #[derive(Debug)]
+    struct MockItem {
+        start_key: u32,
+        end_key: u32,
+        val: String,
+    }
+    impl IntervalItem for MockItem {
+        type Key = u32;
+
+        fn start_key(&self) -> u32 {
+            self.start_key
+        }
+        fn end_key(&self) -> u32 {
+            self.end_key
+        }
+    }
+    impl MockItem {
+        fn new(start_key: u32, end_key: u32) -> Self {
+            MockItem {
+                start_key,
+                end_key,
+                val: format!("{}-{}", start_key, end_key),
+            }
+        }
+        fn new_str(start_key: u32, end_key: u32, val: &str) -> Self {
+            MockItem {
+                start_key,
+                end_key,
+                val: format!("{}-{}: {}", start_key, end_key, val),
+            }
+        }
+    }
+    impl fmt::Display for MockItem {
+        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+            write!(f, "{}", self.val)
+        }
+    }
+    #[rustfmt::skip]
+    fn assert_search(
+        tree: &IntervalTree<MockItem>,
+        key: u32,
+        expected: &[&str],
+    ) -> Option<Arc<MockItem>> {
+        if let Some(v) = tree.search(key) {
+            let vstr = v.to_string();
+
+            assert!(!expected.is_empty(), "search with {} returned {}, expected None", key, v);
+            assert!(
+                expected.contains(&vstr.as_str()),
+                "search with {} returned {}, expected one of: {:?}",
+                key, v, expected,
+            );
+
+            Some(v)
+        } else {
+            assert!(
+                expected.is_empty(),
+                "search with {} returned None, expected one of {:?}",
+                key, expected
+            );
+            None
+        }
+    }
+
+    fn assert_contents(tree: &IntervalTree<MockItem>, expected: &[&str]) {
+        let mut contents: Vec<String> = tree.iter().map(|e| e.to_string()).collect();
+        contents.sort();
+        assert_eq!(contents, expected);
+    }
+
+    fn dump_tree(tree: &IntervalTree<MockItem>) {
+        for (point_key, point) in tree.points.iter() {
+            print!("{}:", point_key);
+            for e in point.elements.iter() {
+                print!(" {}", e);
+            }
+            println!();
+        }
+    }
+
+    #[test]
+    fn test_interval_tree_simple() {
+        let mut tree: IntervalTree<MockItem> = IntervalTree::default();
+
+        // Simple, non-overlapping ranges.
+        tree.insert(Arc::new(MockItem::new(10, 11)));
+        tree.insert(Arc::new(MockItem::new(11, 12)));
+        tree.insert(Arc::new(MockItem::new(12, 13)));
+        tree.insert(Arc::new(MockItem::new(18, 19)));
+        tree.insert(Arc::new(MockItem::new(17, 18)));
+        tree.insert(Arc::new(MockItem::new(15, 16)));
+
+        assert_search(&tree, 9, &[]);
+        assert_search(&tree, 10, &["10-11"]);
+        assert_search(&tree, 11, &["11-12"]);
+        assert_search(&tree, 12, &["12-13"]);
+        assert_search(&tree, 13, &["12-13"]);
+        assert_search(&tree, 14, &["12-13"]);
+        assert_search(&tree, 15, &["15-16"]);
+        assert_search(&tree, 16, &["15-16"]);
+        assert_search(&tree, 17, &["17-18"]);
+        assert_search(&tree, 18, &["18-19"]);
+        assert_search(&tree, 19, &["18-19"]);
+        assert_search(&tree, 20, &["18-19"]);
+
+        // remove a few entries and search around them again
+        tree.remove(&assert_search(&tree, 10, &["10-11"]).unwrap()); // first entry
+        tree.remove(&assert_search(&tree, 12, &["12-13"]).unwrap()); // entry in the middle
+        tree.remove(&assert_search(&tree, 18, &["18-19"]).unwrap()); // last entry
+        assert_search(&tree, 9, &[]);
+        assert_search(&tree, 10, &[]);
+        assert_search(&tree, 11, &["11-12"]);
+        assert_search(&tree, 12, &["11-12"]);
+        assert_search(&tree, 14, &["11-12"]);
+        assert_search(&tree, 15, &["15-16"]);
+        assert_search(&tree, 17, &["17-18"]);
+        assert_search(&tree, 18, &["17-18"]);
+    }
+
+    #[test]
+    fn test_interval_tree_overlap() {
+        let mut tree: IntervalTree<MockItem> = IntervalTree::default();
+
+        // Overlapping items
+        tree.insert(Arc::new(MockItem::new(22, 24)));
+        tree.insert(Arc::new(MockItem::new(23, 25)));
+        let x24_26 = Arc::new(MockItem::new(24, 26));
+        tree.insert(Arc::clone(&x24_26));
+        let x26_28 = Arc::new(MockItem::new(26, 28));
+        tree.insert(Arc::clone(&x26_28));
+        tree.insert(Arc::new(MockItem::new(25, 27)));
+
+        assert_search(&tree, 22, &["22-24"]);
+        assert_search(&tree, 23, &["22-24", "23-25"]);
+        assert_search(&tree, 24, &["23-25", "24-26"]);
+        assert_search(&tree, 25, &["24-26", "25-27"]);
+        assert_search(&tree, 26, &["25-27", "26-28"]);
+        assert_search(&tree, 27, &["26-28"]);
+        assert_search(&tree, 28, &["26-28"]);
+        assert_search(&tree, 29, &["26-28"]);
+
+        tree.remove(&x24_26);
+        tree.remove(&x26_28);
+        assert_search(&tree, 23, &["22-24", "23-25"]);
+        assert_search(&tree, 24, &["23-25"]);
+        assert_search(&tree, 25, &["25-27"]);
+        assert_search(&tree, 26, &["25-27"]);
+        assert_search(&tree, 27, &["25-27"]);
+        assert_search(&tree, 28, &["25-27"]);
+        assert_search(&tree, 29, &["25-27"]);
+    }
+
+    #[test]
+    fn test_interval_tree_nested() {
+        let mut tree: IntervalTree<MockItem> = IntervalTree::default();
+
+        // Items containing other items
+        tree.insert(Arc::new(MockItem::new(31, 39)));
+        tree.insert(Arc::new(MockItem::new(32, 34)));
+        tree.insert(Arc::new(MockItem::new(33, 35)));
+        tree.insert(Arc::new(MockItem::new(30, 40)));
+
+        assert_search(&tree, 30, &["30-40"]);
+        assert_search(&tree, 31, &["30-40", "31-39"]);
+        assert_search(&tree, 32, &["30-40", "32-34", "31-39"]);
+        assert_search(&tree, 33, &["30-40", "32-34", "33-35", "31-39"]);
+        assert_search(&tree, 34, &["30-40", "33-35", "31-39"]);
+        assert_search(&tree, 35, &["30-40", "31-39"]);
+        assert_search(&tree, 36, &["30-40", "31-39"]);
+        assert_search(&tree, 37, &["30-40", "31-39"]);
+        assert_search(&tree, 38, &["30-40", "31-39"]);
+        assert_search(&tree, 39, &["30-40"]);
+        assert_search(&tree, 40, &["30-40"]);
+        assert_search(&tree, 41, &["30-40"]);
+    }
+
+    #[test]
+    fn test_interval_tree_duplicates() {
+        let mut tree: IntervalTree<MockItem> = IntervalTree::default();
+
+        // Duplicate keys
+        let item_a = Arc::new(MockItem::new_str(55, 56, "a"));
+        tree.insert(Arc::clone(&item_a));
+        let item_b = Arc::new(MockItem::new_str(55, 56, "b"));
+        tree.insert(Arc::clone(&item_b));
+        let item_c = Arc::new(MockItem::new_str(55, 56, "c"));
+        tree.insert(Arc::clone(&item_c));
+        let item_d = Arc::new(MockItem::new_str(54, 56, "d"));
+        tree.insert(Arc::clone(&item_d));
+        let item_e = Arc::new(MockItem::new_str(55, 57, "e"));
+        tree.insert(Arc::clone(&item_e));
+
+        dump_tree(&tree);
+
+        assert_search(
+            &tree,
+            55,
+            &["55-56: a", "55-56: b", "55-56: c", "54-56: d", "55-57: e"],
+        );
+        tree.remove(&item_b);
+        dump_tree(&tree);
+
+        assert_contents(&tree, &["54-56: d", "55-56: a", "55-56: c", "55-57: e"]);
+
+        tree.remove(&item_d);
+        dump_tree(&tree);
+        assert_contents(&tree, &["55-56: a", "55-56: c", "55-57: e"]);
+    }
+
+    #[test]
+    #[should_panic]
+    fn test_interval_tree_insert_twice() {
+        let mut tree: IntervalTree<MockItem> = IntervalTree::default();
+
+        // Inserting the same item twice is not cool
+        let item = Arc::new(MockItem::new(1, 2));
+        tree.insert(Arc::clone(&item));
+        tree.insert(Arc::clone(&item)); // fails assertion
+    }
+}

pageserver/src/layered_repository/layer_map.rs

@@ -1,5 +1,5 @@
 //!
-//! The layer map tracks what layers exist for all the relations in a timeline.
+//! The layer map tracks what layers exist for all the relishes in a timeline.
 //!
 //! When the timeline is first accessed, the server lists of all layer files
 //! in the timelines/<timelineid> directory, and populates this map with
@@ -9,16 +9,14 @@
 //! new image and delta layers and corresponding files are written to disk.
 //!
 
+use crate::layered_repository::interval_tree::{IntervalItem, IntervalIter, IntervalTree};
 use crate::layered_repository::storage_layer::{Layer, SegmentTag};
 use crate::layered_repository::InMemoryLayer;
 use crate::relish::*;
 use anyhow::Result;
 use lazy_static::lazy_static;
-use log::*;
 use std::cmp::Ordering;
-use std::collections::HashSet;
-use std::collections::{BTreeMap, BinaryHeap, HashMap};
-use std::ops::Bound::Included;
+use std::collections::{BinaryHeap, HashMap};
 use std::sync::Arc;
 use zenith_metrics::{register_int_gauge, IntGauge};
 use zenith_utils::lsn::Lsn;
@@ -35,57 +33,21 @@ lazy_static! {
 ///
 /// LayerMap tracks what layers exist on a timeline.
 ///
+#[derive(Default)]
 pub struct LayerMap {
     /// All the layers keyed by segment tag
     segs: HashMap<SegmentTag, SegEntry>,
 
-    /// All in-memory layers, ordered by 'oldest_pending_lsn' of each layer.
-    /// This allows easy access to the in-memory layer that contains the
-    /// oldest WAL record.
-    open_segs: BinaryHeap<OpenSegEntry>,
-}
+    /// All in-memory layers, ordered by 'oldest_pending_lsn' and generation
+    /// of each layer. This allows easy access to the in-memory layer that
+    /// contains the oldest WAL record.
+    open_layers: BinaryHeap<OpenLayerEntry>,
 
-///
-/// Per-segment entry in the LayerMap.segs hash map
-///
-/// The last layer that is open for writes is always an InMemoryLayer,
-/// and is kept in a separate field, because there can be only one for
-/// each segment. The older layers, stored on disk, are kept in a
-/// BTreeMap keyed by the layer's start LSN.
-struct SegEntry {
-    pub open: Option<Arc<InMemoryLayer>>,
-    pub historic: BTreeMap<Lsn, Arc<dyn Layer>>,
+    /// Generation number, used to distinguish newly inserted entries in the
+    /// binary heap from older entries during checkpoint.
+    current_generation: u64,
 }
 
-/// Entry held LayerMap.open_segs, with boilerplate comparison
-/// routines to implement a min-heap ordered by 'oldest_pending_lsn'
-struct OpenSegEntry {
-    pub oldest_pending_lsn: Lsn,
-    pub layer: Arc<InMemoryLayer>,
-}
-impl Ord for OpenSegEntry {
-    fn cmp(&self, other: &Self) -> Ordering {
-        // BinaryHeap is a max-heap, and we want a min-heap. Reverse the ordering here
-        // to get that.
-        other.oldest_pending_lsn.cmp(&self.oldest_pending_lsn)
-    }
-}
-impl PartialOrd for OpenSegEntry {
-    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
-        // BinaryHeap is a max-heap, and we want a min-heap. Reverse the ordering here
-        // to get that.
-        other
-            .oldest_pending_lsn
-            .partial_cmp(&self.oldest_pending_lsn)
-    }
-}
-impl PartialEq for OpenSegEntry {
-    fn eq(&self, other: &Self) -> bool {
-        self.oldest_pending_lsn.eq(&other.oldest_pending_lsn)
-    }
-}
-impl Eq for OpenSegEntry {}
-
 impl LayerMap {
     ///
     /// Look up a layer using the given segment tag and LSN. This differs from a
@@ -96,23 +58,7 @@ impl LayerMap {
     pub fn get(&self, tag: &SegmentTag, lsn: Lsn) -> Option<Arc<dyn Layer>> {
         let segentry = self.segs.get(tag)?;
 
-        if let Some(open) = &segentry.open {
-            if open.get_start_lsn() <= lsn {
-                let x: Arc<dyn Layer> = Arc::clone(&open) as _;
-                return Some(x);
-            }
-        }
-
-        if let Some((_k, v)) = segentry
-            .historic
-            .range((Included(Lsn(0)), Included(lsn)))
-            .next_back()
-        {
-            let x: Arc<dyn Layer> = Arc::clone(&v) as _;
-            Some(x)
-        } else {
-            None
-        }
+        segentry.get(lsn)
     }
 
     ///
@@ -122,48 +68,52 @@ impl LayerMap {
     pub fn get_open(&self, tag: &SegmentTag) -> Option<Arc<InMemoryLayer>> {
         let segentry = self.segs.get(tag)?;
 
-        if let Some(open) = &segentry.open {
-            Some(Arc::clone(open))
-        } else {
-            None
-        }
+        segentry.open.as_ref().map(Arc::clone)
     }
 
     ///
     /// Insert an open in-memory layer
     ///
     pub fn insert_open(&mut self, layer: Arc<InMemoryLayer>) {
-        let tag = layer.get_seg_tag();
+        let segentry = self.segs.entry(layer.get_seg_tag()).or_default();
 
-        if let Some(segentry) = self.segs.get_mut(&tag) {
-            if let Some(_old) = &segentry.open {
-                // FIXME: shouldn't exist, but check
-            }
-            segentry.open = Some(Arc::clone(&layer));
-        } else {
-            let segentry = SegEntry {
-                open: Some(Arc::clone(&layer)),
-                historic: BTreeMap::new(),
-            };
-            self.segs.insert(tag, segentry);
-        }
+        segentry.update_open(Arc::clone(&layer));
 
-        let opensegentry = OpenSegEntry {
+        let oldest_pending_lsn = layer.get_oldest_pending_lsn();
+
+        // After a crash and restart, 'oldest_pending_lsn' of the oldest in-memory
+        // layer becomes the WAL streaming starting point, so it better not point
+        // in the middle of a WAL record.
+        assert!(oldest_pending_lsn.is_aligned());
+
+        // Also add it to the binary heap
+        let open_layer_entry = OpenLayerEntry {
             oldest_pending_lsn: layer.get_oldest_pending_lsn(),
-            layer: layer,
+            layer,
+            generation: self.current_generation,
         };
-        self.open_segs.push(opensegentry);
+        self.open_layers.push(open_layer_entry);
 
         NUM_INMEMORY_LAYERS.inc();
     }
 
     /// Remove the oldest in-memory layer
     pub fn pop_oldest_open(&mut self) {
-        let opensegentry = self.open_segs.pop().unwrap();
-        let segtag = opensegentry.layer.get_seg_tag();
+        // Pop it from the binary heap
+        let oldest_entry = self.open_layers.pop().unwrap();
+        let segtag = oldest_entry.layer.get_seg_tag();
 
+        // Also remove it from the SegEntry of this segment
         let mut segentry = self.segs.get_mut(&segtag).unwrap();
-        segentry.open = None;
+        if Arc::ptr_eq(segentry.open.as_ref().unwrap(), &oldest_entry.layer) {
+            segentry.open = None;
+        } else {
+            // We could have already updated segentry.open for
+            // dropped (non-writeable) layer. This is fine.
+            assert!(!oldest_entry.layer.is_writeable());
+            assert!(oldest_entry.layer.is_dropped());
+        }
+
         NUM_INMEMORY_LAYERS.dec();
     }
 
@@ -171,21 +121,9 @@ impl LayerMap {
     /// Insert an on-disk layer
     ///
     pub fn insert_historic(&mut self, layer: Arc<dyn Layer>) {
-        let tag = layer.get_seg_tag();
-        let start_lsn = layer.get_start_lsn();
+        let segentry = self.segs.entry(layer.get_seg_tag()).or_default();
+        segentry.insert_historic(layer);
 
-        if let Some(segentry) = self.segs.get_mut(&tag) {
-            segentry.historic.insert(start_lsn, layer);
-        } else {
-            let mut historic = BTreeMap::new();
-            historic.insert(start_lsn, layer);
-
-            let segentry = SegEntry {
-                open: None,
-                historic,
-            };
-            self.segs.insert(tag, segentry);
-        }
         NUM_ONDISK_LAYERS.inc();
     }
 
@@ -194,62 +132,40 @@ impl LayerMap {
     ///
     /// This should be called when the corresponding file on disk has been deleted.
     ///
-    pub fn remove_historic(&mut self, layer: &dyn Layer) {
+    pub fn remove_historic(&mut self, layer: Arc<dyn Layer>) {
         let tag = layer.get_seg_tag();
-        let start_lsn = layer.get_start_lsn();
 
         if let Some(segentry) = self.segs.get_mut(&tag) {
-            segentry.historic.remove(&start_lsn);
+            segentry.historic.remove(&layer);
         }
         NUM_ONDISK_LAYERS.dec();
     }
 
-    // List relations that exist at the lsn
-    pub fn list_rels(&self, spcnode: u32, dbnode: u32, lsn: Lsn) -> Result<HashSet<RelTag>> {
-        let mut rels: HashSet<RelTag> = HashSet::new();
+    // List relations along with a flag that marks if they exist at the given lsn.
+    // spcnode 0 and dbnode 0 have special meanings and mean all tabespaces/databases.
+    // Pass Tag if we're only interested in some relations.
+    pub fn list_relishes(&self, tag: Option<RelTag>, lsn: Lsn) -> Result<HashMap<RelishTag, bool>> {
+        let mut rels: HashMap<RelishTag, bool> = HashMap::new();
 
         for (seg, segentry) in self.segs.iter() {
-            if let RelishTag::Relation(reltag) = seg.rel {
-                if (spcnode == 0 || reltag.spcnode == spcnode)
-                    && (dbnode == 0 || reltag.dbnode == dbnode)
-                {
-                    // Add only if it exists at the requested LSN.
-                    if let Some(open) = &segentry.open {
-                        if open.get_end_lsn() > lsn {
-                            rels.insert(reltag);
+            match seg.rel {
+                RelishTag::Relation(reltag) => {
+                    if let Some(request_rel) = tag {
+                        if (request_rel.spcnode == 0 || reltag.spcnode == request_rel.spcnode)
+                            && (request_rel.dbnode == 0 || reltag.dbnode == request_rel.dbnode)
+                        {
+                            if let Some(exists) = segentry.exists_at_lsn(lsn)? {
+                                rels.insert(seg.rel, exists);
+                            }
                         }
-                    } else if let Some((_k, _v)) = segentry
-                        .historic
-                        .range((Included(Lsn(0)), Included(lsn)))
-                        .next_back()
-                    {
-                        rels.insert(reltag);
                     }
                 }
-            }
-        }
-        Ok(rels)
-    }
-
-    // List non-relation relishes that exist at the lsn
-    pub fn list_nonrels(&self, lsn: Lsn) -> Result<HashSet<RelishTag>> {
-        let mut rels: HashSet<RelishTag> = HashSet::new();
-
-        // Scan the timeline directory to get all rels in this timeline.
-        for (seg, segentry) in self.segs.iter() {
-            if let RelishTag::Relation(_) = seg.rel {
-            } else {
-                // Add only if it exists at the requested LSN.
-                if let Some(open) = &segentry.open {
-                    if open.get_end_lsn() > lsn {
-                        rels.insert(seg.rel);
+                _ => {
+                    if tag == None {
+                        if let Some(exists) = segentry.exists_at_lsn(lsn)? {
+                            rels.insert(seg.rel, exists);
+                        }
                     }
-                } else if let Some((_k, _v)) = segentry
-                    .historic
-                    .range((Included(Lsn(0)), Included(lsn)))
-                    .next_back()
-                {
-                    rels.insert(seg.rel);
                 }
             }
         }
@@ -259,66 +175,177 @@ impl LayerMap {
     /// Is there a newer image layer for given segment?
     ///
     /// This is used for garbage collection, to determine if an old layer can
-    /// be deleted. We ignore in-memory layers because they are not durable
-    /// on disk, and delta layers because they depend on an older layer.
+    /// be deleted.
     pub fn newer_image_layer_exists(&self, seg: SegmentTag, lsn: Lsn) -> bool {
         if let Some(segentry) = self.segs.get(&seg) {
-            for (newer_lsn, layer) in segentry
-                .historic
-                .range((Included(lsn), Included(Lsn(u64::MAX))))
-            {
-                // Ignore delta layers.
-                if layer.is_incremental() {
-                    continue;
-                }
-                if layer.get_end_lsn() > lsn {
-                    trace!(
-                        "found later layer for {}, {} {}-{}",
-                        seg,
-                        lsn,
-                        newer_lsn,
-                        layer.get_end_lsn()
-                    );
-                    return true;
-                } else {
-                    trace!("found singleton layer for {}, {} {}", seg, lsn, newer_lsn);
-                    continue;
-                }
-            }
+            segentry.newer_image_layer_exists(lsn)
+        } else {
+            false
         }
-        trace!("no later layer found for {}, {}", seg, lsn);
-        false
     }
 
-    /// Return the oldest in-memory layer.
-    pub fn peek_oldest_open(&self) -> Option<Arc<InMemoryLayer>> {
-        if let Some(opensegentry) = self.open_segs.peek() {
-            Some(Arc::clone(&opensegentry.layer))
+    /// Is there any layer for given segment that is alive at the lsn?
+    ///
+    /// This is a public wrapper for SegEntry fucntion,
+    /// used for garbage collection, to determine if some alive layer
+    /// exists at the lsn. If so, we shouldn't delete a newer dropped layer
+    /// to avoid incorrectly making it visible.
+    pub fn layer_exists_at_lsn(&self, seg: SegmentTag, lsn: Lsn) -> Result<bool> {
+        Ok(if let Some(segentry) = self.segs.get(&seg) {
+            segentry.exists_at_lsn(lsn)?.unwrap_or(false)
         } else {
-            None
-        }
+            false
+        })
+    }
+
+    /// Return the oldest in-memory layer, along with its generation number.
+    pub fn peek_oldest_open(&self) -> Option<(Arc<InMemoryLayer>, u64)> {
+        self.open_layers
+            .peek()
+            .map(|oldest_entry| (Arc::clone(&oldest_entry.layer), oldest_entry.generation))
+    }
+
+    /// Increment the generation number used to stamp open in-memory layers. Layers
+    /// added with `insert_open` after this call will be associated with the new
+    /// generation. Returns the new generation number.
+    pub fn increment_generation(&mut self) -> u64 {
+        self.current_generation += 1;
+        self.current_generation
     }
 
     pub fn iter_historic_layers(&self) -> HistoricLayerIter {
         HistoricLayerIter {
-            segiter: self.segs.iter(),
+            seg_iter: self.segs.iter(),
             iter: None,
         }
     }
-}
 
-impl Default for LayerMap {
-    fn default() -> Self {
-        LayerMap {
-            segs: HashMap::new(),
-            open_segs: BinaryHeap::new(),
+    /// debugging function to print out the contents of the layer map
+    #[allow(unused)]
+    pub fn dump(&self) -> Result<()> {
+        println!("Begin dump LayerMap");
+        for (seg, segentry) in self.segs.iter() {
+            if let Some(open) = &segentry.open {
+                open.dump()?;
+            }
+
+            for layer in segentry.historic.iter() {
+                layer.dump()?;
+            }
         }
+        println!("End dump LayerMap");
+        Ok(())
     }
 }
 
+impl IntervalItem for dyn Layer {
+    type Key = Lsn;
+
+    fn start_key(&self) -> Lsn {
+        self.get_start_lsn()
+    }
+    fn end_key(&self) -> Lsn {
+        self.get_end_lsn()
+    }
+}
+
+///
+/// Per-segment entry in the LayerMap::segs hash map. Holds all the layers
+/// associated with the segment.
+///
+/// The last layer that is open for writes is always an InMemoryLayer,
+/// and is kept in a separate field, because there can be only one for
+/// each segment. The older layers, stored on disk, are kept in an
+/// IntervalTree.
+#[derive(Default)]
+struct SegEntry {
+    open: Option<Arc<InMemoryLayer>>,
+    historic: IntervalTree<dyn Layer>,
+}
+
+impl SegEntry {
+    /// Does the segment exist at given LSN?
+    /// Return None if object is not found in this SegEntry.
+    fn exists_at_lsn(&self, lsn: Lsn) -> Result<Option<bool>> {
+        if let Some(layer) = self.get(lsn) {
+            Ok(Some(layer.get_seg_exists(lsn)?))
+        } else {
+            Ok(None)
+        }
+    }
+
+    pub fn get(&self, lsn: Lsn) -> Option<Arc<dyn Layer>> {
+        if let Some(open) = &self.open {
+            if open.get_start_lsn() <= lsn {
+                let x: Arc<dyn Layer> = Arc::clone(open) as _;
+                return Some(x);
+            }
+        }
+
+        self.historic.search(lsn)
+    }
+
+    pub fn newer_image_layer_exists(&self, lsn: Lsn) -> bool {
+        // We only check on-disk layers, because
+        // in-memory layers are not durable
+
+        self.historic
+            .iter_newer(lsn)
+            .any(|layer| !layer.is_incremental())
+    }
+
+    // Set new open layer for a SegEntry.
+    // It's ok to rewrite previous open layer,
+    // but only if it is not writeable anymore.
+    pub fn update_open(&mut self, layer: Arc<InMemoryLayer>) {
+        if let Some(prev_open) = &self.open {
+            assert!(!prev_open.is_writeable());
+        }
+        self.open = Some(layer);
+    }
+
+    pub fn insert_historic(&mut self, layer: Arc<dyn Layer>) {
+        self.historic.insert(layer);
+    }
+}
+
+/// Entry held in LayerMap::open_layers, with boilerplate comparison routines
+/// to implement a min-heap ordered by 'oldest_pending_lsn' and 'generation'
+///
+/// The generation number associated with each entry can be used to distinguish
+/// recently-added entries (i.e after last call to increment_generation()) from older
+/// entries with the same 'oldest_pending_lsn'.
+struct OpenLayerEntry {
+    pub oldest_pending_lsn: Lsn, // copy of layer.get_oldest_pending_lsn()
+    pub generation: u64,
+    pub layer: Arc<InMemoryLayer>,
+}
+impl Ord for OpenLayerEntry {
+    fn cmp(&self, other: &Self) -> Ordering {
+        // BinaryHeap is a max-heap, and we want a min-heap. Reverse the ordering here
+        // to get that. Entries with identical oldest_pending_lsn are ordered by generation
+        other
+            .oldest_pending_lsn
+            .cmp(&self.oldest_pending_lsn)
+            .then_with(|| other.generation.cmp(&self.generation))
+    }
+}
+impl PartialOrd for OpenLayerEntry {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+impl PartialEq for OpenLayerEntry {
+    fn eq(&self, other: &Self) -> bool {
+        self.cmp(other) == Ordering::Equal
+    }
+}
+impl Eq for OpenLayerEntry {}
+
+/// Iterator returned by LayerMap::iter_historic_layers()
 pub struct HistoricLayerIter<'a> {
-    segiter: std::collections::hash_map::Iter<'a, SegmentTag, SegEntry>,
-    iter: Option<std::collections::btree_map::Iter<'a, Lsn, Arc<dyn Layer>>>,
+    seg_iter: std::collections::hash_map::Iter<'a, SegmentTag, SegEntry>,
+    iter: Option<IntervalIter<'a, dyn Layer>>,
 }
 
 impl<'a> Iterator for HistoricLayerIter<'a> {
@@ -328,11 +355,11 @@ impl<'a> Iterator for HistoricLayerIter<'a> {
         loop {
             if let Some(x) = &mut self.iter {
                 if let Some(x) = x.next() {
-                    return Some(Arc::clone(&*x.1));
+                    return Some(Arc::clone(&x));
                 }
             }
-            if let Some(seg) = self.segiter.next() {
-                self.iter = Some(seg.1.historic.iter());
+            if let Some((_tag, segentry)) = self.seg_iter.next() {
+                self.iter = Some(segentry.historic.iter());
                 continue;
             } else {
                 return None;
@@ -340,3 +367,78 @@ impl<'a> Iterator for HistoricLayerIter<'a> {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::PageServerConf;
+    use std::str::FromStr;
+    use zenith_utils::zid::{ZTenantId, ZTimelineId};
+
+    /// Arbitrary relation tag, for testing.
+    const TESTREL_A: RelishTag = RelishTag::Relation(RelTag {
+        spcnode: 0,
+        dbnode: 111,
+        relnode: 1000,
+        forknum: 0,
+    });
+
+    /// Construct a dummy InMemoryLayer for testing
+    fn dummy_inmem_layer(
+        conf: &'static PageServerConf,
+        segno: u32,
+        start_lsn: Lsn,
+        oldest_pending_lsn: Lsn,
+    ) -> Arc<InMemoryLayer> {
+        Arc::new(
+            InMemoryLayer::create(
+                conf,
+                ZTimelineId::from_str("00000000000000000000000000000000").unwrap(),
+                ZTenantId::from_str("00000000000000000000000000000000").unwrap(),
+                SegmentTag {
+                    rel: TESTREL_A,
+                    segno,
+                },
+                start_lsn,
+                oldest_pending_lsn,
+            )
+            .unwrap(),
+        )
+    }
+
+    #[test]
+    fn test_open_layers() -> Result<()> {
+        let conf = PageServerConf::dummy_conf(PageServerConf::test_repo_dir("dummy_inmem_layer"));
+        let conf = Box::leak(Box::new(conf));
+
+        let mut layers = LayerMap::default();
+
+        let gen1 = layers.increment_generation();
+        layers.insert_open(dummy_inmem_layer(conf, 0, Lsn(0x100), Lsn(0x100)));
+        layers.insert_open(dummy_inmem_layer(conf, 1, Lsn(0x100), Lsn(0x200)));
+        layers.insert_open(dummy_inmem_layer(conf, 2, Lsn(0x100), Lsn(0x120)));
+        layers.insert_open(dummy_inmem_layer(conf, 3, Lsn(0x100), Lsn(0x110)));
+
+        let gen2 = layers.increment_generation();
+        layers.insert_open(dummy_inmem_layer(conf, 4, Lsn(0x100), Lsn(0x110)));
+        layers.insert_open(dummy_inmem_layer(conf, 5, Lsn(0x100), Lsn(0x100)));
+
+        // A helper function (closure) to pop the next oldest open entry from the layer map,
+        // and assert that it is what we'd expect
+        let mut assert_pop_layer = |expected_segno: u32, expected_generation: u64| {
+            let (l, generation) = layers.peek_oldest_open().unwrap();
+            assert!(l.get_seg_tag().segno == expected_segno);
+            assert!(generation == expected_generation);
+            layers.pop_oldest_open();
+        };
+
+        assert_pop_layer(0, gen1); // 0x100
+        assert_pop_layer(5, gen2); // 0x100
+        assert_pop_layer(3, gen1); // 0x110
+        assert_pop_layer(4, gen2); // 0x110
+        assert_pop_layer(2, gen1); // 0x120
+        assert_pop_layer(1, gen1); // 0x200
+
+        Ok(())
+    }
+}

pageserver/src/layered_repository/page_versions.rs

@@ -0,0 +1,172 @@
+use std::{collections::HashMap, ops::RangeBounds};
+
+use zenith_utils::{accum::Accum, lsn::Lsn, vec_map::VecMap};
+
+use super::storage_layer::PageVersion;
+
+const EMPTY_SLICE: &[(Lsn, PageVersion)] = &[];
+
+#[derive(Debug, Default)]
+pub struct PageVersions(HashMap<u32, VecMap<Lsn, PageVersion>>);
+
+impl PageVersions {
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    pub fn append_or_update_last(
+        &mut self,
+        blknum: u32,
+        lsn: Lsn,
+        page_version: PageVersion,
+    ) -> Option<PageVersion> {
+        let map = self.0.entry(blknum).or_insert_with(VecMap::default);
+        map.append_or_update_last(lsn, page_version).unwrap()
+    }
+
+    /// Get all [`PageVersion`]s in a block
+    pub fn get_block_slice(&self, blknum: u32) -> &[(Lsn, PageVersion)] {
+        self.0
+            .get(&blknum)
+            .map(VecMap::as_slice)
+            .unwrap_or(EMPTY_SLICE)
+    }
+
+    /// Get a range of [`PageVersions`] in a block
+    pub fn get_block_lsn_range<R: RangeBounds<Lsn>>(
+        &self,
+        blknum: u32,
+        range: R,
+    ) -> &[(Lsn, PageVersion)] {
+        self.0
+            .get(&blknum)
+            .map(|vec_map| vec_map.slice_range(range))
+            .unwrap_or(EMPTY_SLICE)
+    }
+
+    /// Split the page version map into two.
+    ///
+    /// Left contains everything up to and not including [`cutoff_lsn`].
+    /// Right contains [`cutoff_lsn`] and everything after.
+    pub fn split_at(&self, cutoff_lsn: Lsn, after_oldest_lsn: &mut Accum<Lsn>) -> (Self, Self) {
+        let mut before_blocks = HashMap::new();
+        let mut after_blocks = HashMap::new();
+
+        for (blknum, vec_map) in self.0.iter() {
+            let (before_versions, after_versions) = vec_map.split_at(&cutoff_lsn);
+
+            if !before_versions.is_empty() {
+                let old = before_blocks.insert(*blknum, before_versions);
+                assert!(old.is_none());
+            }
+
+            if !after_versions.is_empty() {
+                let (first_lsn, _first_pv) = &after_versions.as_slice()[0];
+                after_oldest_lsn.accum(std::cmp::min, *first_lsn);
+
+                let old = after_blocks.insert(*blknum, after_versions);
+                assert!(old.is_none());
+            }
+        }
+
+        (Self(before_blocks), Self(after_blocks))
+    }
+
+    /// Iterate through block-history pairs in block order.
+    /// If a [`cutoff_lsn`] is set, only include history with `lsn < cutoff_lsn`
+    pub fn ordered_block_iter(&self, cutoff_lsn: Option<Lsn>) -> OrderedBlockIter<'_> {
+        let mut ordered_blocks: Vec<u32> = self.0.keys().cloned().collect();
+        ordered_blocks.sort_unstable();
+
+        OrderedBlockIter {
+            page_versions: self,
+            ordered_blocks,
+            cur_block_idx: 0,
+            cutoff_lsn,
+        }
+    }
+}
+
+pub struct OrderedBlockIter<'a> {
+    page_versions: &'a PageVersions,
+
+    ordered_blocks: Vec<u32>,
+    cur_block_idx: usize,
+
+    cutoff_lsn: Option<Lsn>,
+}
+
+impl<'a> Iterator for OrderedBlockIter<'a> {
+    type Item = (u32, &'a [(Lsn, PageVersion)]);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        while self.cur_block_idx < self.ordered_blocks.len() {
+            let blknum = self.ordered_blocks[self.cur_block_idx];
+            self.cur_block_idx += 1;
+
+            if let Some(cutoff_lsn) = self.cutoff_lsn.as_ref() {
+                let slice = self.page_versions.get_block_lsn_range(blknum, ..cutoff_lsn);
+                if !slice.is_empty() {
+                    return Some((blknum, slice));
+                }
+            } else {
+                return Some((blknum, self.page_versions.get_block_slice(blknum)));
+            }
+        }
+
+        None
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    const EMPTY_PAGE_VERSION: PageVersion = PageVersion {
+        page_image: None,
+        record: None,
+    };
+
+    #[test]
+    fn test_ordered_iter() {
+        let mut page_versions = PageVersions::default();
+        const BLOCKS: u32 = 1000;
+        const LSNS: u64 = 50;
+
+        for blknum in 0..BLOCKS {
+            for lsn in 0..LSNS {
+                let old = page_versions.append_or_update_last(blknum, Lsn(lsn), EMPTY_PAGE_VERSION);
+                assert!(old.is_none());
+            }
+        }
+
+        let mut iter = page_versions.ordered_block_iter(None);
+        for blknum in 0..BLOCKS {
+            let (actual_blknum, slice) = iter.next().unwrap();
+            assert_eq!(actual_blknum, blknum);
+            assert_eq!(slice.len(), LSNS as usize);
+            for lsn in 0..LSNS {
+                assert_eq!(Lsn(lsn), slice[lsn as usize].0);
+            }
+        }
+        assert!(iter.next().is_none());
+        assert!(iter.next().is_none()); // should be robust against excessive next() calls
+
+        const CUTOFF_LSN: Lsn = Lsn(30);
+        let mut iter = page_versions.ordered_block_iter(Some(CUTOFF_LSN));
+        for blknum in 0..BLOCKS {
+            let (actual_blknum, slice) = iter.next().unwrap();
+            assert_eq!(actual_blknum, blknum);
+            assert_eq!(slice.len(), CUTOFF_LSN.0 as usize);
+            for lsn in 0..CUTOFF_LSN.0 {
+                assert_eq!(Lsn(lsn), slice[lsn as usize].0);
+            }
+        }
+        assert!(iter.next().is_none());
+        assert!(iter.next().is_none()); // should be robust against excessive next() calls
+
+        let mut iter = page_versions.ordered_block_iter(Some(Lsn(0)));
+        assert!(iter.next().is_none());
+        assert!(iter.next().is_none()); // should be robust against excessive next() calls
+    }
+}

pageserver/src/layered_repository/storage_layer.rs

@@ -10,7 +10,6 @@ use bytes::Bytes;
 use serde::{Deserialize, Serialize};
 use std::fmt;
 use std::path::PathBuf;
-use std::sync::Arc;
 
 use zenith_utils::lsn::Lsn;
 
@@ -21,7 +20,7 @@ pub const RELISH_SEG_SIZE: u32 = 10 * 1024 * 1024 / 8192;
 /// Each relish stored in the repository is divided into fixed-sized "segments",
 /// with 10 MB of key-space, or 1280 8k pages each.
 ///
-#[derive(Debug, PartialEq, Eq, PartialOrd, Hash, Ord, Clone, Copy)]
+#[derive(Debug, PartialEq, Eq, PartialOrd, Hash, Ord, Clone, Copy, Serialize, Deserialize)]
 pub struct SegmentTag {
     pub rel: RelishTag,
     pub segno: u32,
@@ -87,9 +86,9 @@ pub struct PageReconstructData {
 pub enum PageReconstructResult {
     /// Got all the data needed to reconstruct the requested page
     Complete,
-    /// This layer didn't contain all the required data, the caller should collect
-    /// more data from the returned predecessor layer at the returned LSN.
-    Continue(Lsn, Arc<dyn Layer>),
+    /// This layer didn't contain all the required data, the caller should look up
+    /// the predecessor layer at the returned LSN and collect more data from there.
+    Continue(Lsn),
     /// This layer didn't contain data needed to reconstruct the page version at
     /// the returned LSN. This is usually considered an error, but might be OK
     /// in some circumstances.
@@ -97,26 +96,37 @@ pub enum PageReconstructResult {
 }
 
 ///
-/// A Layer holds all page versions for one segment of a relish, in a range of LSNs.
-/// There are two kinds of layers, in-memory and snapshot layers. In-memory
+/// A Layer corresponds to one RELISH_SEG_SIZE slice of a relish in a range of LSNs.
+/// There are two kinds of layers, in-memory and on-disk layers. In-memory
 /// layers are used to ingest incoming WAL, and provide fast access
-/// to the recent page versions. Snaphot layers are stored on disk, and
+/// to the recent page versions. On-disk layers are stored as files on disk, and
 /// are immutable. This trait presents the common functionality of
-/// in-memory and snapshot layers.
-///
-/// Each layer contains a full snapshot of the segment at the start
-/// LSN. In addition to that, it contains WAL (or more page images)
-/// needed to recontruct any page version up to the end LSN.
+/// in-memory and on-disk layers.
 ///
 pub trait Layer: Send + Sync {
-    // These functions identify the relish segment and the LSN range
-    // that this Layer holds.
+    /// Identify the timeline this relish belongs to
     fn get_timeline_id(&self) -> ZTimelineId;
+
+    /// Identify the relish segment
     fn get_seg_tag(&self) -> SegmentTag;
+
+    /// Inclusive start bound of the LSN range that this layer holds
     fn get_start_lsn(&self) -> Lsn;
+
+    /// Exclusive end bound of the LSN range that this layer holds.
+    ///
+    /// - For an open in-memory layer, this is MAX_LSN.
+    /// - For a frozen in-memory layer or a delta layer, this is a valid end bound.
+    /// - An image layer represents snapshot at one LSN, so end_lsn is always the snapshot LSN + 1
     fn get_end_lsn(&self) -> Lsn;
+
+    /// Is the segment represented by this layer dropped by PostgreSQL?
     fn is_dropped(&self) -> bool;
 
+    /// Gets the physical location of the layer on disk.
+    /// Some layers, such as in-memory, might not have the location.
+    fn path(&self) -> Option<PathBuf>;
+
     /// Filename used to store this layer on disk. (Even in-memory layers
     /// implement this, to print a handy unique identifier for the layer for
     /// log messages, even though they're never not on disk.)
@@ -134,8 +144,8 @@ pub trait Layer: Send + Sync {
     ///
     /// See PageReconstructResult for possible return values. The collected data
     /// is appended to reconstruct_data; the caller should pass an empty struct
-    /// on first call. If this returns PageReconstructResult::Continue, call
-    /// again on the returned predecessor layer with the same 'reconstruct_data'
+    /// on first call. If this returns PageReconstructResult::Continue, look up
+    /// the predecessor layer and call again with the same 'reconstruct_data'
     /// to collect more data.
     fn get_page_reconstruct_data(
         &self,

pageserver/src/lib.rs

@@ -11,9 +11,9 @@ pub mod basebackup;
 pub mod branches;
 pub mod http;
 pub mod layered_repository;
-pub mod logger;
 pub mod page_service;
 pub mod relish;
+pub mod relish_storage;
 pub mod repository;
 pub mod restore_local_repo;
 pub mod tenant_mgr;
@@ -21,6 +21,28 @@ pub mod waldecoder;
 pub mod walreceiver;
 pub mod walredo;
 
+pub mod defaults {
+    use const_format::formatcp;
+    use std::time::Duration;
+
+    pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
+    pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
+    pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
+    pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
+
+    // FIXME: This current value is very low. I would imagine something like 1 GB or 10 GB
+    // would be more appropriate. But a low value forces the code to be exercised more,
+    // which is good for now to trigger bugs.
+    pub const DEFAULT_CHECKPOINT_DISTANCE: u64 = 256 * 1024 * 1024;
+    pub const DEFAULT_CHECKPOINT_PERIOD: Duration = Duration::from_secs(1);
+
+    pub const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
+    pub const DEFAULT_GC_PERIOD: Duration = Duration::from_secs(100);
+
+    pub const DEFAULT_SUPERUSER: &str = "zenith_admin";
+    pub const DEFAULT_RELISH_STORAGE_MAX_CONCURRENT_SYNC_LIMITS: usize = 100;
+}
+
 lazy_static! {
     static ref LIVE_CONNECTIONS_COUNT: IntGaugeVec = register_int_gauge_vec!(
         "pageserver_live_connections_count",
@@ -30,11 +52,19 @@ lazy_static! {
     .expect("failed to define a metric");
 }
 
+pub const LOG_FILE_NAME: &str = "pageserver.log";
+
 #[derive(Debug, Clone)]
 pub struct PageServerConf {
     pub daemonize: bool,
-    pub listen_addr: String,
-    pub http_endpoint_addr: String,
+    pub listen_pg_addr: String,
+    pub listen_http_addr: String,
+    // Flush out an inmemory layer, if it's holding WAL older than this
+    // This puts a backstop on how much WAL needs to be re-digested if the
+    // page server crashes.
+    pub checkpoint_distance: u64,
+    pub checkpoint_period: Duration,
+
     pub gc_horizon: u64,
     pub gc_period: Duration,
     pub superuser: String,
@@ -52,6 +82,7 @@ pub struct PageServerConf {
     pub auth_type: AuthType,
 
     pub auth_validation_public_key_path: Option<PathBuf>,
+    pub relish_storage_config: Option<RelishStorageConfig>,
 }
 
 impl PageServerConf {
@@ -95,10 +126,6 @@ impl PageServerConf {
         self.timeline_path(timelineid, tenantid).join("ancestor")
     }
 
-    fn wal_dir_path(&self, timelineid: &ZTimelineId, tenantid: &ZTenantId) -> PathBuf {
-        self.timeline_path(timelineid, tenantid).join("wal")
-    }
-
     //
     // Postgres distribution paths
     //
@@ -110,4 +137,73 @@ impl PageServerConf {
     pub fn pg_lib_dir(&self) -> PathBuf {
         self.pg_distrib_dir.join("lib")
     }
+
+    #[cfg(test)]
+    fn test_repo_dir(test_name: &str) -> PathBuf {
+        PathBuf::from(format!("../tmp_check/test_{}", test_name))
+    }
+
+    #[cfg(test)]
+    fn dummy_conf(repo_dir: PathBuf) -> Self {
+        PageServerConf {
+            daemonize: false,
+            checkpoint_distance: defaults::DEFAULT_CHECKPOINT_DISTANCE,
+            checkpoint_period: Duration::from_secs(10),
+            gc_horizon: defaults::DEFAULT_GC_HORIZON,
+            gc_period: Duration::from_secs(10),
+            listen_pg_addr: defaults::DEFAULT_PG_LISTEN_ADDR.to_string(),
+            listen_http_addr: defaults::DEFAULT_HTTP_LISTEN_ADDR.to_string(),
+            superuser: "zenith_admin".to_string(),
+            workdir: repo_dir,
+            pg_distrib_dir: "".into(),
+            auth_type: AuthType::Trust,
+            auth_validation_public_key_path: None,
+            relish_storage_config: None,
+        }
+    }
+}
+
+/// External relish storage configuration, enough for creating a client for that storage.
+#[derive(Debug, Clone)]
+pub struct RelishStorageConfig {
+    /// Limits the number of concurrent sync operations between pageserver and relish storage.
+    pub max_concurrent_sync: usize,
+    /// The storage connection configuration.
+    pub storage: RelishStorageKind,
+}
+
+/// A kind of a relish storage to connect to, with its connection configuration.
+#[derive(Debug, Clone)]
+pub enum RelishStorageKind {
+    /// Storage based on local file system.
+    /// Specify a root folder to place all stored relish data into.
+    LocalFs(PathBuf),
+    /// AWS S3 based storage, storing all relishes into the root
+    /// of the S3 bucket from the config.
+    AwsS3(S3Config),
+}
+
+/// AWS S3 bucket coordinates and access credentials to manage the bucket contents (read and write).
+#[derive(Clone)]
+pub struct S3Config {
+    /// Name of the bucket to connect to.
+    pub bucket_name: String,
+    /// The region where the bucket is located at.
+    pub bucket_region: String,
+    /// "Login" to use when connecting to bucket.
+    /// Can be empty for cases like AWS k8s IAM
+    /// where we can allow certain pods to connect
+    /// to the bucket directly without any credentials.
+    pub access_key_id: Option<String>,
+    /// "Password" to use when connecting to bucket.
+    pub secret_access_key: Option<String>,
+}
+
+impl std::fmt::Debug for S3Config {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("S3Config")
+            .field("bucket_name", &self.bucket_name)
+            .field("bucket_region", &self.bucket_region)
+            .finish()
+    }
 }

pageserver/src/logger.rs

@@ -1,45 +0,0 @@
-use crate::PageServerConf;
-
-use anyhow::{Context, Result};
-use slog::{Drain, FnValue};
-use std::fs::{File, OpenOptions};
-
-pub fn init_logging(
-    _conf: &PageServerConf,
-    log_filename: &str,
-) -> Result<(slog_scope::GlobalLoggerGuard, File)> {
-    // Don't open the same file for output multiple times;
-    // the different fds could overwrite each other's output.
-    let log_file = OpenOptions::new()
-        .create(true)
-        .append(true)
-        .open(&log_filename)
-        .with_context(|| format!("failed to open {:?}", &log_filename))?;
-
-    let logger_file = log_file.try_clone().unwrap();
-
-    let decorator = slog_term::PlainSyncDecorator::new(logger_file);
-    let drain = slog_term::FullFormat::new(decorator).build();
-    let drain = slog::Filter::new(drain, |record: &slog::Record| {
-        if record.level().is_at_least(slog::Level::Info) {
-            return true;
-        }
-        false
-    });
-    let drain = std::sync::Mutex::new(drain).fuse();
-    let logger = slog::Logger::root(
-        drain,
-        slog::o!(
-            "location" =>
-                FnValue(move |record| {
-                    format!("{}, {}:{}",
-                            record.module(),
-                            record.file(),
-                            record.line()
-                    )
-                }
-                )
-        ),
-    );
-    Ok((slog_scope::set_global_logger(logger), log_file))
-}

pageserver/src/page_service.rs

@@ -10,7 +10,7 @@
 //     *callmemaybe <zenith timelineid> $url* -- ask pageserver to start walreceiver on $url
 //
 
-use anyhow::{anyhow, bail, ensure, Context, Result};
+use anyhow::{anyhow, bail, ensure, Result};
 use bytes::{Buf, BufMut, Bytes, BytesMut};
 use lazy_static::lazy_static;
 use log::*;
@@ -35,72 +35,110 @@ use zenith_utils::zid::{ZTenantId, ZTimelineId};
 use crate::basebackup;
 use crate::branches;
 use crate::relish::*;
+use crate::repository::Timeline;
 use crate::tenant_mgr;
 use crate::walreceiver;
 use crate::PageServerConf;
 
 // Wrapped in libpq CopyData
 enum PagestreamFeMessage {
-    Exists(PagestreamRequest),
-    Nblocks(PagestreamRequest),
-    Read(PagestreamRequest),
+    Exists(PagestreamExistsRequest),
+    Nblocks(PagestreamNblocksRequest),
+    GetPage(PagestreamGetPageRequest),
 }
 
 // Wrapped in libpq CopyData
 enum PagestreamBeMessage {
-    Status(PagestreamStatusResponse),
-    Nblocks(PagestreamStatusResponse),
-    Read(PagestreamReadResponse),
+    Exists(PagestreamExistsResponse),
+    Nblocks(PagestreamNblocksResponse),
+    GetPage(PagestreamGetPageResponse),
+    Error(PagestreamErrorResponse),
 }
 
 #[derive(Debug)]
-struct PagestreamRequest {
-    spcnode: u32,
-    dbnode: u32,
-    relnode: u32,
-    forknum: u8,
-    blkno: u32,
+struct PagestreamExistsRequest {
+    latest: bool,
     lsn: Lsn,
+    rel: RelTag,
 }
 
 #[derive(Debug)]
-struct PagestreamStatusResponse {
-    ok: bool,
+struct PagestreamNblocksRequest {
+    latest: bool,
+    lsn: Lsn,
+    rel: RelTag,
+}
+
+#[derive(Debug)]
+struct PagestreamGetPageRequest {
+    latest: bool,
+    lsn: Lsn,
+    rel: RelTag,
+    blkno: u32,
+}
+
+#[derive(Debug)]
+struct PagestreamExistsResponse {
+    exists: bool,
+}
+
+#[derive(Debug)]
+struct PagestreamNblocksResponse {
     n_blocks: u32,
 }
 
 #[derive(Debug)]
-struct PagestreamReadResponse {
-    ok: bool,
-    n_blocks: u32,
+struct PagestreamGetPageResponse {
     page: Bytes,
 }
 
+#[derive(Debug)]
+struct PagestreamErrorResponse {
+    message: String,
+}
+
 impl PagestreamFeMessage {
     fn parse(mut body: Bytes) -> anyhow::Result<PagestreamFeMessage> {
         // TODO these gets can fail
 
-        let smgr_tag = body.get_u8();
-        let zreq = PagestreamRequest {
-            spcnode: body.get_u32(),
-            dbnode: body.get_u32(),
-            relnode: body.get_u32(),
-            forknum: body.get_u8(),
-            blkno: body.get_u32(),
-            lsn: Lsn::from(body.get_u64()),
-        };
-
+        // these correspond to the ZenithMessageTag enum in pagestore_client.h
+        //
         // TODO: consider using protobuf or serde bincode for less error prone
         // serialization.
-        match smgr_tag {
-            0 => Ok(PagestreamFeMessage::Exists(zreq)),
-            1 => Ok(PagestreamFeMessage::Nblocks(zreq)),
-            2 => Ok(PagestreamFeMessage::Read(zreq)),
-            _ => Err(anyhow!(
-                "unknown smgr message tag: {},'{:?}'",
-                smgr_tag,
-                body
-            )),
+        let msg_tag = body.get_u8();
+        match msg_tag {
+            0 => Ok(PagestreamFeMessage::Exists(PagestreamExistsRequest {
+                latest: body.get_u8() != 0,
+                lsn: Lsn::from(body.get_u64()),
+                rel: RelTag {
+                    spcnode: body.get_u32(),
+                    dbnode: body.get_u32(),
+                    relnode: body.get_u32(),
+                    forknum: body.get_u8(),
+                },
+            })),
+            1 => Ok(PagestreamFeMessage::Nblocks(PagestreamNblocksRequest {
+                latest: body.get_u8() != 0,
+                lsn: Lsn::from(body.get_u64()),
+                rel: RelTag {
+                    spcnode: body.get_u32(),
+                    dbnode: body.get_u32(),
+                    relnode: body.get_u32(),
+                    forknum: body.get_u8(),
+                },
+            })),
+            2 => Ok(PagestreamFeMessage::GetPage(PagestreamGetPageRequest {
+                latest: body.get_u8() != 0,
+                lsn: Lsn::from(body.get_u64()),
+                rel: RelTag {
+                    spcnode: body.get_u32(),
+                    dbnode: body.get_u32(),
+                    relnode: body.get_u32(),
+                    forknum: body.get_u8(),
+                },
+                blkno: body.get_u32(),
+            })),
+            _ => bail!("unknown smgr message tag: {},'{:?}'", msg_tag, body),
         }
     }
 }
@@ -110,24 +148,26 @@ impl PagestreamBeMessage {
         let mut bytes = BytesMut::new();
 
         match self {
-            Self::Status(resp) => {
+            Self::Exists(resp) => {
                 bytes.put_u8(100); /* tag from pagestore_client.h */
-                bytes.put_u8(resp.ok as u8);
-                bytes.put_u32(resp.n_blocks);
+                bytes.put_u8(resp.exists as u8);
             }
 
             Self::Nblocks(resp) => {
                 bytes.put_u8(101); /* tag from pagestore_client.h */
-                bytes.put_u8(resp.ok as u8);
                 bytes.put_u32(resp.n_blocks);
             }
 
-            Self::Read(resp) => {
+            Self::GetPage(resp) => {
                 bytes.put_u8(102); /* tag from pagestore_client.h */
-                bytes.put_u8(resp.ok as u8);
-                bytes.put_u32(resp.n_blocks);
                 bytes.put(&resp.page[..]);
             }
+
+            Self::Error(resp) => {
+                bytes.put_u8(103); /* tag from pagestore_client.h */
+                bytes.put(resp.message.as_bytes());
+                bytes.put_u8(0); // null terminator
+            }
         }
 
         bytes.into()
@@ -154,7 +194,7 @@ pub fn thread_main(
         let local_auth = auth.clone();
         thread::spawn(move || {
             if let Err(err) = page_service_conn_main(conf, local_auth, socket, auth_type) {
-                error!("error: {}", err);
+                error!("page server thread exiting with error: {:#}", err);
             }
         });
     }
@@ -214,14 +254,6 @@ impl PageServerHandler {
         }
     }
 
-    fn handle_controlfile(&self, pgb: &mut PostgresBackend) -> io::Result<()> {
-        pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
-            .write_message_noflush(&BeMessage::ControlFile)?
-            .write_message(&BeMessage::CommandComplete(b"SELECT 1"))?;
-
-        Ok(())
-    }
-
     fn handle_pagerequests(
         &self,
         pgb: &mut PostgresBackend,
@@ -229,10 +261,7 @@ impl PageServerHandler {
         tenantid: ZTenantId,
     ) -> anyhow::Result<()> {
         // Check that the timeline exists
-        let repository = tenant_mgr::get_repository_for_tenant(&tenantid)?;
-        let timeline = repository
-            .get_timeline(timelineid)
-            .context(format!("error fetching timeline {}", timelineid))?;
+        let timeline = tenant_mgr::get_timeline_for_tenant(tenantid, timelineid)?;
 
         /* switch client to COPYBOTH */
         pgb.write_message(&BeMessage::CopyBothResponse)?;
@@ -248,88 +277,136 @@ impl PageServerHandler {
             let zenith_fe_msg = PagestreamFeMessage::parse(copy_data_bytes)?;
 
             let response = match zenith_fe_msg {
-                PagestreamFeMessage::Exists(req) => {
-                    let rel = RelTag {
-                        spcnode: req.spcnode,
-                        dbnode: req.dbnode,
-                        relnode: req.relnode,
-                        forknum: req.forknum,
-                    };
-                    let tag = RelishTag::Relation(rel);
-
-                    let exist = SMGR_QUERY_TIME
-                        .with_label_values(&["get_rel_exists"])
-                        .observe_closure_duration(|| {
-                            timeline.get_rel_exists(tag, req.lsn).unwrap_or(false)
-                        });
-
-                    PagestreamBeMessage::Status(PagestreamStatusResponse {
-                        ok: exist,
-                        n_blocks: 0,
-                    })
-                }
-                PagestreamFeMessage::Nblocks(req) => {
-                    let rel = RelTag {
-                        spcnode: req.spcnode,
-                        dbnode: req.dbnode,
-                        relnode: req.relnode,
-                        forknum: req.forknum,
-                    };
-                    let tag = RelishTag::Relation(rel);
-
-                    let n_blocks = SMGR_QUERY_TIME
-                        .with_label_values(&["get_rel_size"])
-                        .observe_closure_duration(|| {
-                            // Return 0 if relation is not found.
-                            // This is what postgres smgr expects.
-                            timeline
-                                .get_relish_size(tag, req.lsn)
-                                .unwrap_or(Some(0))
-                                .unwrap_or(0)
-                        });
-
-                    PagestreamBeMessage::Nblocks(PagestreamStatusResponse { ok: true, n_blocks })
-                }
-                PagestreamFeMessage::Read(req) => {
-                    let rel = RelTag {
-                        spcnode: req.spcnode,
-                        dbnode: req.dbnode,
-                        relnode: req.relnode,
-                        forknum: req.forknum,
-                    };
-                    let tag = RelishTag::Relation(rel);
-
-                    let read_response = SMGR_QUERY_TIME
-                        .with_label_values(&["get_page_at_lsn"])
-                        .observe_closure_duration(|| {
-                            match timeline.get_page_at_lsn(tag, req.blkno, req.lsn) {
-                                Ok(p) => PagestreamReadResponse {
-                                    ok: true,
-                                    n_blocks: 0,
-                                    page: p,
-                                },
-                                Err(e) => {
-                                    const ZERO_PAGE: [u8; 8192] = [0; 8192];
-                                    error!("get_page_at_lsn: {}", e);
-                                    PagestreamReadResponse {
-                                        ok: false,
-                                        n_blocks: 0,
-                                        page: Bytes::from_static(&ZERO_PAGE),
-                                    }
-                                }
-                            }
-                        });
-
-                    PagestreamBeMessage::Read(read_response)
-                }
+                PagestreamFeMessage::Exists(req) => SMGR_QUERY_TIME
+                    .with_label_values(&["get_rel_exists"])
+                    .observe_closure_duration(|| {
+                        self.handle_get_rel_exists_request(&*timeline, &req)
+                    }),
+                PagestreamFeMessage::Nblocks(req) => SMGR_QUERY_TIME
+                    .with_label_values(&["get_rel_size"])
+                    .observe_closure_duration(|| self.handle_get_nblocks_request(&*timeline, &req)),
+                PagestreamFeMessage::GetPage(req) => SMGR_QUERY_TIME
+                    .with_label_values(&["get_page_at_lsn"])
+                    .observe_closure_duration(|| {
+                        self.handle_get_page_at_lsn_request(&*timeline, &req)
+                    }),
             };
 
+            let response = response.unwrap_or_else(|e| {
+                // print the all details to the log with {:#}, but for the client the
+                // error message is enough
+                error!("error reading relation or page version: {:#}", e);
+                PagestreamBeMessage::Error(PagestreamErrorResponse {
+                    message: e.to_string(),
+                })
+            });
+
             pgb.write_message(&BeMessage::CopyData(&response.serialize()))?;
         }
 
         Ok(())
     }
 
+    /// Helper function to handle the LSN from client request.
+    ///
+    /// Each GetPage (and Exists and Nblocks) request includes information about
+    /// which version of the page is being requested. The client can request the
+    /// latest version of the page, or the version that's valid at a particular
+    /// LSN. The primary compute node will always request the latest page
+    /// version, while a standby will request a version at the LSN that it's
+    /// currently caught up to.
+    ///
+    /// In either case, if the page server hasn't received the WAL up to the
+    /// requested LSN yet, we will wait for it to arrive. The return value is
+    /// the LSN that should be used to look up the page versions.
+    fn wait_or_get_last_lsn(timeline: &dyn Timeline, lsn: Lsn, latest: bool) -> Result<Lsn> {
+        if latest {
+            // Latest page version was requested. If LSN is given, it is a hint
+            // to the page server that there have been no modifications to the
+            // page after that LSN. If we haven't received WAL up to that point,
+            // wait until it arrives.
+            let last_record_lsn = timeline.get_last_record_lsn();
+
+            // Note: this covers the special case that lsn == Lsn(0). That
+            // special case means "return the latest version whatever it is",
+            // and it's used for bootstrapping purposes, when the page server is
+            // connected directly to the compute node. That is needed because
+            // when you connect to the compute node, to receive the WAL, the
+            // walsender process will do a look up in the pg_authid catalog
+            // table for authentication. That poses a deadlock problem: the
+            // catalog table lookup will send a GetPage request, but the GetPage
+            // request will block in the page server because the recent WAL
+            // hasn't been received yet, and it cannot be received until the
+            // walsender completes the authentication and starts streaming the
+            // WAL.
+            if lsn <= last_record_lsn {
+                Ok(last_record_lsn)
+            } else {
+                timeline.wait_lsn(lsn)?;
+                // Since we waited for 'lsn' to arrive, that is now the last
+                // record LSN. (Or close enough for our purposes; the
+                // last-record LSN can advance immediately after we return
+                // anyway)
+                Ok(lsn)
+            }
+        } else {
+            if lsn == Lsn(0) {
+                bail!("invalid LSN(0) in request");
+            }
+            timeline.wait_lsn(lsn)?;
+            Ok(lsn)
+        }
+    }
+
+    fn handle_get_rel_exists_request(
+        &self,
+        timeline: &dyn Timeline,
+        req: &PagestreamExistsRequest,
+    ) -> Result<PagestreamBeMessage> {
+        let tag = RelishTag::Relation(req.rel);
+        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest)?;
+
+        let exists = timeline.get_rel_exists(tag, lsn)?;
+
+        Ok(PagestreamBeMessage::Exists(PagestreamExistsResponse {
+            exists,
+        }))
+    }
+
+    fn handle_get_nblocks_request(
+        &self,
+        timeline: &dyn Timeline,
+        req: &PagestreamNblocksRequest,
+    ) -> Result<PagestreamBeMessage> {
+        let tag = RelishTag::Relation(req.rel);
+        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest)?;
+
+        let n_blocks = timeline.get_relish_size(tag, lsn)?;
+
+        // Return 0 if relation is not found.
+        // This is what postgres smgr expects.
+        let n_blocks = n_blocks.unwrap_or(0);
+
+        Ok(PagestreamBeMessage::Nblocks(PagestreamNblocksResponse {
+            n_blocks,
+        }))
+    }
+
+    fn handle_get_page_at_lsn_request(
+        &self,
+        timeline: &dyn Timeline,
+        req: &PagestreamGetPageRequest,
+    ) -> Result<PagestreamBeMessage> {
+        let tag = RelishTag::Relation(req.rel);
+        let lsn = Self::wait_or_get_last_lsn(timeline, req.lsn, req.latest)?;
+
+        let page = timeline.get_page_at_lsn(tag, req.blkno, lsn)?;
+
+        Ok(PagestreamBeMessage::GetPage(PagestreamGetPageResponse {
+            page,
+        }))
+    }
+
     fn handle_basebackup_request(
         &self,
         pgb: &mut PostgresBackend,
@@ -338,18 +415,16 @@ impl PageServerHandler {
         tenantid: ZTenantId,
     ) -> anyhow::Result<()> {
         // check that the timeline exists
-        let repository = tenant_mgr::get_repository_for_tenant(&tenantid)?;
-        let timeline = repository
-            .get_timeline(timelineid)
-            .context(format!("error fetching timeline {}", timelineid))?;
+        let timeline = tenant_mgr::get_timeline_for_tenant(tenantid, timelineid)?;
+
         /* switch client to COPYOUT */
         pgb.write_message(&BeMessage::CopyOutResponse)?;
         info!("sent CopyOut");
 
-        /* Send a tarball of the latest snapshot on the timeline */
+        /* Send a tarball of the latest layer on the timeline */
         {
             let mut writer = CopyDataSink { pgb };
-            let mut basebackup = basebackup::Basebackup::new(&mut writer, &timeline, lsn);
+            let mut basebackup = basebackup::Basebackup::new(&mut writer, &timeline, lsn)?;
             basebackup.send_tarball()?;
         }
         pgb.write_message(&BeMessage::CopyDone)?;
@@ -372,7 +447,7 @@ impl PageServerHandler {
             .claims
             .as_ref()
             .expect("claims presence already checked");
-        Ok(auth::check_permission(claims, tenantid)?)
+        auth::check_permission(claims, tenantid)
     }
 }
 
@@ -389,7 +464,7 @@ impl postgres_backend::Handler for PageServerHandler {
             .as_ref()
             .as_ref()
             .unwrap()
-            .decode(&str::from_utf8(jwt_response)?)?;
+            .decode(str::from_utf8(jwt_response)?)?;
 
         if matches!(data.claims.scope, Scope::Tenant) {
             ensure!(
@@ -421,11 +496,9 @@ impl postgres_backend::Handler for PageServerHandler {
         }
         let query_string = std::str::from_utf8(&query_string)?;
 
-        if query_string.starts_with("controlfile") {
-            self.handle_controlfile(pgb)?;
-        } else if query_string.starts_with("pagestream ") {
+        if query_string.starts_with("pagestream ") {
             let (_, params_raw) = query_string.split_at("pagestream ".len());
-            let params = params_raw.split(" ").collect::<Vec<_>>();
+            let params = params_raw.split(' ').collect::<Vec<_>>();
             ensure!(
                 params.len() == 2,
                 "invalid param number for pagestream command"
@@ -479,12 +552,9 @@ impl postgres_backend::Handler for PageServerHandler {
             self.check_permission(Some(tenantid))?;
 
             // Check that the timeline exists
-            let repository = tenant_mgr::get_repository_for_tenant(&tenantid)?;
-            repository
-                .get_timeline(timelineid)
-                .context(format!("error fetching timeline {}", timelineid))?;
+            tenant_mgr::get_timeline_for_tenant(tenantid, timelineid)?;
 
-            walreceiver::launch_wal_receiver(&self.conf, timelineid, &connstr, tenantid.to_owned());
+            walreceiver::launch_wal_receiver(self.conf, timelineid, &connstr, tenantid.to_owned());
 
             pgb.write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
         } else if query_string.starts_with("branch_create ") {
@@ -492,10 +562,10 @@ impl postgres_backend::Handler for PageServerHandler {
 
             // branch_create <tenantid> <branchname> <startpoint>
             // TODO lazy static
-            // TOOD: escaping, to allow branch names with spaces
+            // TODO: escaping, to allow branch names with spaces
             let re = Regex::new(r"^branch_create ([[:xdigit:]]+) (\S+) ([^\r\n\s;]+)[\r\n\s;]*;?$")
                 .unwrap();
-            let caps = re.captures(&query_string).ok_or_else(err)?;
+            let caps = re.captures(query_string).ok_or_else(err)?;
 
             let tenantid = ZTenantId::from_str(caps.get(1).unwrap().as_str())?;
             let branchname = caps.get(2).ok_or_else(err)?.as_str().to_owned();
@@ -504,7 +574,7 @@ impl postgres_backend::Handler for PageServerHandler {
             self.check_permission(Some(tenantid))?;
 
             let branch =
-                branches::create_branch(&self.conf, &branchname, &startpoint_str, &tenantid)?;
+                branches::create_branch(self.conf, &branchname, &startpoint_str, &tenantid)?;
             let branch = serde_json::to_vec(&branch)?;
 
             pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
@@ -519,14 +589,14 @@ impl postgres_backend::Handler for PageServerHandler {
 
             let tenantid = ZTenantId::from_str(caps.get(1).unwrap().as_str())?;
 
-            let branches = crate::branches::get_branches(&self.conf, &tenantid)?;
+            let branches = crate::branches::get_branches(self.conf, &tenantid)?;
             let branches_buf = serde_json::to_vec(&branches)?;
 
             pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
                 .write_message_noflush(&BeMessage::DataRow(&[Some(&branches_buf)]))?
                 .write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
         } else if query_string.starts_with("tenant_list") {
-            let tenants = crate::branches::get_tenants(&self.conf)?;
+            let tenants = crate::branches::get_tenants(self.conf)?;
             let tenants_buf = serde_json::to_vec(&tenants)?;
 
             pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
@@ -537,13 +607,13 @@ impl postgres_backend::Handler for PageServerHandler {
 
             // tenant_create <tenantid>
             let re = Regex::new(r"^tenant_create ([[:xdigit:]]+)$").unwrap();
-            let caps = re.captures(&query_string).ok_or_else(err)?;
+            let caps = re.captures(query_string).ok_or_else(err)?;
 
             self.check_permission(None)?;
 
             let tenantid = ZTenantId::from_str(caps.get(1).unwrap().as_str())?;
 
-            tenant_mgr::create_repository_for_tenant(&self.conf, tenantid)?;
+            tenant_mgr::create_repository_for_tenant(self.conf, tenantid)?;
 
             pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
                 .write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
@@ -577,59 +647,73 @@ impl postgres_backend::Handler for PageServerHandler {
                 .map(|h| h.as_str().parse())
                 .unwrap_or(Ok(self.conf.gc_horizon))?;
 
-            let repo = tenant_mgr::get_repository_for_tenant(&tenantid)?;
+            let repo = tenant_mgr::get_repository_for_tenant(tenantid)?;
 
             let result = repo.gc_iteration(Some(timelineid), gc_horizon, true)?;
 
             pgb.write_message_noflush(&BeMessage::RowDescription(&[
-                RowDescriptor::int8_col(b"snapshot_relfiles_total"),
-                RowDescriptor::int8_col(b"snapshot_relfiles_needed_by_cutoff"),
-                RowDescriptor::int8_col(b"snapshot_relfiles_needed_by_branches"),
-                RowDescriptor::int8_col(b"snapshot_relfiles_not_updated"),
-                RowDescriptor::int8_col(b"snapshot_relfiles_removed"),
-                RowDescriptor::int8_col(b"snapshot_relfiles_dropped"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_total"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_needed_by_cutoff"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_needed_by_branches"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_not_updated"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_removed"),
-                RowDescriptor::int8_col(b"snapshot_nonrelfiles_dropped"),
+                RowDescriptor::int8_col(b"layer_relfiles_total"),
+                RowDescriptor::int8_col(b"layer_relfiles_needed_by_cutoff"),
+                RowDescriptor::int8_col(b"layer_relfiles_needed_by_branches"),
+                RowDescriptor::int8_col(b"layer_relfiles_not_updated"),
+                RowDescriptor::int8_col(b"layer_relfiles_needed_as_tombstone"),
+                RowDescriptor::int8_col(b"layer_relfiles_removed"),
+                RowDescriptor::int8_col(b"layer_relfiles_dropped"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_total"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_needed_by_cutoff"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_needed_by_branches"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_not_updated"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_needed_as_tombstone"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_removed"),
+                RowDescriptor::int8_col(b"layer_nonrelfiles_dropped"),
                 RowDescriptor::int8_col(b"elapsed"),
             ]))?
             .write_message_noflush(&BeMessage::DataRow(&[
-                Some(&result.ondisk_relfiles_total.to_string().as_bytes()),
+                Some(result.ondisk_relfiles_total.to_string().as_bytes()),
                 Some(
-                    &result
+                    result
                         .ondisk_relfiles_needed_by_cutoff
                         .to_string()
                         .as_bytes(),
                 ),
                 Some(
-                    &result
+                    result
                         .ondisk_relfiles_needed_by_branches
                         .to_string()
                         .as_bytes(),
                 ),
-                Some(&result.ondisk_relfiles_not_updated.to_string().as_bytes()),
-                Some(&result.ondisk_relfiles_removed.to_string().as_bytes()),
-                Some(&result.ondisk_relfiles_dropped.to_string().as_bytes()),
-                Some(&result.ondisk_nonrelfiles_total.to_string().as_bytes()),
+                Some(result.ondisk_relfiles_not_updated.to_string().as_bytes()),
                 Some(
-                    &result
+                    result
+                        .ondisk_relfiles_needed_as_tombstone
+                        .to_string()
+                        .as_bytes(),
+                ),
+                Some(result.ondisk_relfiles_removed.to_string().as_bytes()),
+                Some(result.ondisk_relfiles_dropped.to_string().as_bytes()),
+                Some(result.ondisk_nonrelfiles_total.to_string().as_bytes()),
+                Some(
+                    result
                         .ondisk_nonrelfiles_needed_by_cutoff
                         .to_string()
                         .as_bytes(),
                 ),
                 Some(
-                    &result
+                    result
                         .ondisk_nonrelfiles_needed_by_branches
                         .to_string()
                         .as_bytes(),
                 ),
-                Some(&result.ondisk_nonrelfiles_not_updated.to_string().as_bytes()),
-                Some(&result.ondisk_nonrelfiles_removed.to_string().as_bytes()),
-                Some(&result.ondisk_nonrelfiles_dropped.to_string().as_bytes()),
-                Some(&result.elapsed.as_millis().to_string().as_bytes()),
+                Some(result.ondisk_nonrelfiles_not_updated.to_string().as_bytes()),
+                Some(
+                    result
+                        .ondisk_nonrelfiles_needed_as_tombstone
+                        .to_string()
+                        .as_bytes(),
+                ),
+                Some(result.ondisk_nonrelfiles_removed.to_string().as_bytes()),
+                Some(result.ondisk_nonrelfiles_dropped.to_string().as_bytes()),
+                Some(result.elapsed.as_millis().to_string().as_bytes()),
             ]))?
             .write_message(&BeMessage::CommandComplete(b"SELECT 1"))?;
         } else {

pageserver/src/relish.rs

@@ -125,11 +125,7 @@ impl RelishTag {
 
     // convenience function to check if this relish is a normal relation.
     pub const fn is_relation(&self) -> bool {
-        if let RelishTag::Relation(_) = self {
-            true
-        } else {
-            false
-        }
+        matches!(self, RelishTag::Relation(_))
     }
 }
 

pageserver/src/relish_storage.rs

@@ -0,0 +1,83 @@
+//! Abstractions for the page server to store its relish layer data in the external storage.
+//!
+//! Main purpose of this module subtree is to provide a set of abstractions to manage the storage state
+//! in a way, optimal for page server.
+//!
+//! The abstractions hide multiple custom external storage API implementations,
+//! such as AWS S3, local filesystem, etc., located in the submodules.
+
+mod local_fs;
+mod rust_s3;
+/// A queue-based storage with the background machinery behind it to synchronize
+/// local page server layer files with external storage.
+mod synced_storage;
+
+use std::path::Path;
+use std::thread;
+
+use anyhow::Context;
+
+use self::local_fs::LocalFs;
+pub use self::synced_storage::schedule_timeline_upload;
+use crate::relish_storage::rust_s3::RustS3;
+use crate::{PageServerConf, RelishStorageKind};
+
+pub fn run_storage_sync_thread(
+    config: &'static PageServerConf,
+) -> anyhow::Result<Option<thread::JoinHandle<anyhow::Result<()>>>> {
+    match &config.relish_storage_config {
+        Some(relish_storage_config) => {
+            let max_concurrent_sync = relish_storage_config.max_concurrent_sync;
+            match &relish_storage_config.storage {
+                RelishStorageKind::LocalFs(root) => synced_storage::run_storage_sync_thread(
+                    config,
+                    LocalFs::new(root.clone())?,
+                    max_concurrent_sync,
+                ),
+                RelishStorageKind::AwsS3(s3_config) => synced_storage::run_storage_sync_thread(
+                    config,
+                    RustS3::new(s3_config)?,
+                    max_concurrent_sync,
+                ),
+            }
+        }
+        None => Ok(None),
+    }
+}
+
+/// Storage (potentially remote) API to manage its state.
+#[async_trait::async_trait]
+pub trait RelishStorage: Send + Sync {
+    type RelishStoragePath;
+
+    fn derive_destination(
+        page_server_workdir: &Path,
+        relish_local_path: &Path,
+    ) -> anyhow::Result<Self::RelishStoragePath>;
+
+    async fn list_relishes(&self) -> anyhow::Result<Vec<Self::RelishStoragePath>>;
+
+    async fn download_relish(
+        &self,
+        from: &Self::RelishStoragePath,
+        to: &Path,
+    ) -> anyhow::Result<()>;
+
+    async fn delete_relish(&self, path: &Self::RelishStoragePath) -> anyhow::Result<()>;
+
+    async fn upload_relish(&self, from: &Path, to: &Self::RelishStoragePath) -> anyhow::Result<()>;
+}
+
+fn strip_workspace_prefix<'a>(
+    page_server_workdir: &'a Path,
+    relish_local_path: &'a Path,
+) -> anyhow::Result<&'a Path> {
+    relish_local_path
+        .strip_prefix(page_server_workdir)
+        .with_context(|| {
+            format!(
+                "Unexpected: relish local path '{}' is not relevant to server workdir",
+                relish_local_path.display(),
+            )
+        })
+}

pageserver/src/relish_storage/local_fs.rs

@@ -0,0 +1,158 @@
+//! Local filesystem relish storage.
+//!
+//! Page server already stores layer data on the server, when freezing it.
+//! This storage serves a way to
+//!
+//! * test things locally simply
+//! * allow to compabre both binary sets
+//! * help validating the relish storage API
+
+use std::{
+    future::Future,
+    path::{Path, PathBuf},
+    pin::Pin,
+};
+
+use anyhow::{bail, Context};
+
+use super::{strip_workspace_prefix, RelishStorage};
+
+pub struct LocalFs {
+    root: PathBuf,
+}
+
+impl LocalFs {
+    /// Atetmpts to create local FS relish storage, also creates the directory provided, if not exists.
+    pub fn new(root: PathBuf) -> anyhow::Result<Self> {
+        if !root.exists() {
+            std::fs::create_dir_all(&root).with_context(|| {
+                format!(
+                    "Failed to create all directories in the given root path {}",
+                    root.display(),
+                )
+            })?;
+        }
+        Ok(Self { root })
+    }
+
+    fn resolve_in_storage(&self, path: &Path) -> anyhow::Result<PathBuf> {
+        if path.is_relative() {
+            Ok(self.root.join(path))
+        } else if path.starts_with(&self.root) {
+            Ok(path.to_path_buf())
+        } else {
+            bail!(
+                "Path '{}' does not belong to the current storage",
+                path.display()
+            )
+        }
+    }
+}
+
+#[async_trait::async_trait]
+impl RelishStorage for LocalFs {
+    type RelishStoragePath = PathBuf;
+
+    fn derive_destination(
+        page_server_workdir: &Path,
+        relish_local_path: &Path,
+    ) -> anyhow::Result<Self::RelishStoragePath> {
+        Ok(strip_workspace_prefix(page_server_workdir, relish_local_path)?.to_path_buf())
+    }
+
+    async fn list_relishes(&self) -> anyhow::Result<Vec<Self::RelishStoragePath>> {
+        Ok(get_all_files(&self.root).await?.into_iter().collect())
+    }
+
+    async fn download_relish(
+        &self,
+        from: &Self::RelishStoragePath,
+        to: &Path,
+    ) -> anyhow::Result<()> {
+        let file_path = self.resolve_in_storage(from)?;
+        if file_path.exists() && file_path.is_file() {
+            create_target_directory(to).await?;
+            tokio::fs::copy(file_path, to).await?;
+            Ok(())
+        } else {
+            bail!(
+                "File '{}' either does not exist or is not a file",
+                file_path.display()
+            )
+        }
+    }
+
+    async fn delete_relish(&self, path: &Self::RelishStoragePath) -> anyhow::Result<()> {
+        let file_path = self.resolve_in_storage(path)?;
+        if file_path.exists() && file_path.is_file() {
+            Ok(tokio::fs::remove_file(file_path).await?)
+        } else {
+            bail!(
+                "File '{}' either does not exist or is not a file",
+                file_path.display()
+            )
+        }
+    }
+
+    async fn upload_relish(&self, from: &Path, to: &Self::RelishStoragePath) -> anyhow::Result<()> {
+        let target_file_path = self.resolve_in_storage(to)?;
+        create_target_directory(&target_file_path).await?;
+
+        tokio::fs::copy(&from, &target_file_path)
+            .await
+            .with_context(|| {
+                format!(
+                    "Failed to upload relish '{}' to local storage",
+                    from.display(),
+                )
+            })?;
+        Ok(())
+    }
+}
+
+fn get_all_files<'a, P>(
+    directory_path: P,
+) -> Pin<Box<dyn Future<Output = anyhow::Result<Vec<PathBuf>>> + Send + Sync + 'a>>
+where
+    P: AsRef<Path> + Send + Sync + 'a,
+{
+    Box::pin(async move {
+        let directory_path = directory_path.as_ref();
+        if directory_path.exists() {
+            if directory_path.is_dir() {
+                let mut paths = Vec::new();
+                let mut dir_contents = tokio::fs::read_dir(directory_path).await?;
+                while let Some(dir_entry) = dir_contents.next_entry().await? {
+                    let file_type = dir_entry.file_type().await?;
+                    let entry_path = dir_entry.path();
+                    if file_type.is_symlink() {
+                        log::debug!("{:?} us a symlink, skipping", entry_path)
+                    } else if file_type.is_dir() {
+                        paths.extend(get_all_files(entry_path).await?.into_iter())
+                    } else {
+                        paths.push(dir_entry.path());
+                    }
+                }
+                Ok(paths)
+            } else {
+                bail!("Path '{}' is not a directory", directory_path.display())
+            }
+        } else {
+            Ok(Vec::new())
+        }
+    })
+}
+
+async fn create_target_directory(target_file_path: &Path) -> anyhow::Result<()> {
+    let target_dir = match target_file_path.parent() {
+        Some(parent_dir) => parent_dir,
+        None => bail!(
+            "Relish path '{}' has no parent directory",
+            target_file_path.display()
+        ),
+    };
+    if !target_dir.exists() {
+        tokio::fs::create_dir_all(target_dir).await?;
+    }
+    Ok(())
+}

pageserver/src/relish_storage/rust_s3.rs

@@ -0,0 +1,144 @@
+//! A wrapper around AWS S3 client library `rust_s3` to be used a relish storage.
+
+use std::path::Path;
+
+use anyhow::Context;
+use s3::{bucket::Bucket, creds::Credentials, region::Region};
+
+use crate::{relish_storage::strip_workspace_prefix, S3Config};
+
+use super::RelishStorage;
+
+const S3_FILE_SEPARATOR: char = '/';
+
+#[derive(Debug)]
+pub struct S3ObjectKey(String);
+
+impl S3ObjectKey {
+    fn key(&self) -> &str {
+        &self.0
+    }
+}
+
+/// AWS S3 relish storage.
+pub struct RustS3 {
+    bucket: Bucket,
+}
+
+impl RustS3 {
+    /// Creates the relish storage, errors if incorrect AWS S3 configuration provided.
+    pub fn new(aws_config: &S3Config) -> anyhow::Result<Self> {
+        let region = aws_config
+            .bucket_region
+            .parse::<Region>()
+            .context("Failed to parse the s3 region from config")?;
+        let credentials = Credentials::new(
+            aws_config.access_key_id.as_deref(),
+            aws_config.secret_access_key.as_deref(),
+            None,
+            None,
+            None,
+        )
+        .context("Failed to create the s3 credentials")?;
+        Ok(Self {
+            bucket: Bucket::new_with_path_style(
+                aws_config.bucket_name.as_str(),
+                region,
+                credentials,
+            )
+            .context("Failed to create the s3 bucket")?,
+        })
+    }
+}
+
+#[async_trait::async_trait]
+impl RelishStorage for RustS3 {
+    type RelishStoragePath = S3ObjectKey;
+
+    fn derive_destination(
+        page_server_workdir: &Path,
+        relish_local_path: &Path,
+    ) -> anyhow::Result<Self::RelishStoragePath> {
+        let relative_path = strip_workspace_prefix(page_server_workdir, relish_local_path)?;
+        let mut key = String::new();
+        for segment in relative_path {
+            key.push(S3_FILE_SEPARATOR);
+            key.push_str(&segment.to_string_lossy());
+        }
+        Ok(S3ObjectKey(key))
+    }
+
+    async fn list_relishes(&self) -> anyhow::Result<Vec<Self::RelishStoragePath>> {
+        let list_response = self
+            .bucket
+            .list(String::new(), None)
+            .await
+            .context("Failed to list s3 objects")?;
+
+        Ok(list_response
+            .into_iter()
+            .flat_map(|response| response.contents)
+            .map(|s3_object| S3ObjectKey(s3_object.key))
+            .collect())
+    }
+
+    async fn download_relish(
+        &self,
+        from: &Self::RelishStoragePath,
+        to: &Path,
+    ) -> anyhow::Result<()> {
+        let mut target_file = std::fs::OpenOptions::new()
+            .write(true)
+            .open(to)
+            .with_context(|| format!("Failed to open target s3 destination at {}", to.display()))?;
+        let code = self
+            .bucket
+            .get_object_stream(from.key(), &mut target_file)
+            .await
+            .with_context(|| format!("Failed to download s3 object with key {}", from.key()))?;
+        if code != 200 {
+            Err(anyhow::format_err!(
+                "Received non-200 exit code during downloading object from directory, code: {}",
+                code
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    async fn delete_relish(&self, path: &Self::RelishStoragePath) -> anyhow::Result<()> {
+        let (_, code) = self
+            .bucket
+            .delete_object(path.key())
+            .await
+            .with_context(|| format!("Failed to delete s3 object with key {}", path.key()))?;
+        if code != 200 {
+            Err(anyhow::format_err!(
+                "Received non-200 exit code during deleting object with key '{}', code: {}",
+                path.key(),
+                code
+            ))
+        } else {
+            Ok(())
+        }
+    }
+
+    async fn upload_relish(&self, from: &Path, to: &Self::RelishStoragePath) -> anyhow::Result<()> {
+        let mut local_file = tokio::fs::OpenOptions::new().read(true).open(from).await?;
+
+        let code = self
+            .bucket
+            .put_object_stream(&mut local_file, to.key())
+            .await
+            .with_context(|| format!("Failed to create s3 object with key {}", to.key()))?;
+        if code != 200 {
+            Err(anyhow::format_err!(
+                "Received non-200 exit code during creating object with key '{}', code: {}",
+                to.key(),
+                code
+            ))
+        } else {
+            Ok(())
+        }
+    }
+}

pageserver/src/relish_storage/synced_storage.rs

@@ -0,0 +1,52 @@
+use std::time::Duration;
+use std::{collections::BinaryHeap, sync::Mutex, thread};
+
+use crate::{relish_storage::RelishStorage, PageServerConf};
+
+lazy_static::lazy_static! {
+    static ref UPLOAD_QUEUE: Mutex<BinaryHeap<SyncTask>> = Mutex::new(BinaryHeap::new());
+}
+
+pub fn schedule_timeline_upload(_local_timeline: ()) {
+    // UPLOAD_QUEUE
+    //     .lock()
+    //     .unwrap()
+    //     .push(SyncTask::Upload(local_timeline))
+}
+
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
+enum SyncTask {}
+
+pub fn run_storage_sync_thread<
+    P: std::fmt::Debug,
+    S: 'static + RelishStorage<RelishStoragePath = P>,
+>(
+    config: &'static PageServerConf,
+    relish_storage: S,
+    max_concurrent_sync: usize,
+) -> anyhow::Result<Option<thread::JoinHandle<anyhow::Result<()>>>> {
+    let runtime = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()?;
+
+    let handle = thread::Builder::new()
+        .name("Queue based relish storage sync".to_string())
+        .spawn(move || loop {
+            let mut queue_accessor = UPLOAD_QUEUE.lock().unwrap();
+            log::debug!("Upload queue length: {}", queue_accessor.len());
+            let next_task = queue_accessor.pop();
+            drop(queue_accessor);
+            match next_task {
+                Some(task) => runtime.block_on(async {
+                    // suppress warnings
+                    let _ = (config, task, &relish_storage, max_concurrent_sync);
+                    todo!("omitted for brevity")
+                }),
+                None => {
+                    thread::sleep(Duration::from_secs(1));
+                    continue;
+                }
+            }
+        })?;
+    Ok(Some(handle))
+}

pageserver/src/repository.rs

@@ -17,11 +17,7 @@ pub trait Repository: Send + Sync {
     fn get_timeline(&self, timelineid: ZTimelineId) -> Result<Arc<dyn Timeline>>;
 
     /// Create a new, empty timeline. The caller is responsible for loading data into it
-    fn create_empty_timeline(
-        &self,
-        timelineid: ZTimelineId,
-        start_lsn: Lsn,
-    ) -> Result<Arc<dyn Timeline>>;
+    fn create_empty_timeline(&self, timelineid: ZTimelineId) -> Result<Arc<dyn Timeline>>;
 
     /// Branch a timeline
     fn branch_timeline(&self, src: ZTimelineId, dst: ZTimelineId, start_lsn: Lsn) -> Result<()>;
@@ -32,22 +28,15 @@ pub trait Repository: Send + Sync {
     ///
     /// 'timelineid' specifies the timeline to GC, or None for all.
     /// `horizon` specifies delta from last lsn to preserve all object versions (pitr interval).
-    /// `compact` parameter is used to force compaction of storage.
-    /// some storage implementation are based on lsm tree and require periodic merge (compaction).
-    /// usually storage implementation determines itself when compaction should be performed.
-    /// but for gc tests it way be useful to force compaction just after completion of gc iteration
-    /// to make sure that all detected garbage is removed.
-    /// so right now `compact` is set to true when gc explicitly requested through page srver api,
-    /// and is st to false in gc threads which infinitely repeats gc iterations in loop.
+    /// `checkpoint_before_gc` parameter is used to force compaction of storage before CG
+    /// to make tests more deterministic.
+    /// TODO Do we still need it or we can call checkpoint explicitly in tests where needed?
     fn gc_iteration(
         &self,
         timelineid: Option<ZTimelineId>,
         horizon: u64,
-        compact: bool,
+        checkpoint_before_gc: bool,
     ) -> Result<GcResult>;
-
-    // TODO get timelines?
-    //fn get_stats(&self) -> RepositoryStats;
 }
 
 ///
@@ -59,6 +48,7 @@ pub struct GcResult {
     pub ondisk_relfiles_needed_by_cutoff: u64,
     pub ondisk_relfiles_needed_by_branches: u64,
     pub ondisk_relfiles_not_updated: u64,
+    pub ondisk_relfiles_needed_as_tombstone: u64,
     pub ondisk_relfiles_removed: u64, // # of layer files removed because they have been made obsolete by newer ondisk files.
     pub ondisk_relfiles_dropped: u64, // # of layer files removed because the relation was dropped
 
@@ -66,6 +56,7 @@ pub struct GcResult {
     pub ondisk_nonrelfiles_needed_by_cutoff: u64,
     pub ondisk_nonrelfiles_needed_by_branches: u64,
     pub ondisk_nonrelfiles_not_updated: u64,
+    pub ondisk_nonrelfiles_needed_as_tombstone: u64,
     pub ondisk_nonrelfiles_removed: u64, // # of layer files removed because they have been made obsolete by newer ondisk files.
     pub ondisk_nonrelfiles_dropped: u64, // # of layer files removed because the relation was dropped
 
@@ -78,6 +69,7 @@ impl AddAssign for GcResult {
         self.ondisk_relfiles_needed_by_cutoff += other.ondisk_relfiles_needed_by_cutoff;
         self.ondisk_relfiles_needed_by_branches += other.ondisk_relfiles_needed_by_branches;
         self.ondisk_relfiles_not_updated += other.ondisk_relfiles_not_updated;
+        self.ondisk_relfiles_needed_as_tombstone += other.ondisk_relfiles_needed_as_tombstone;
         self.ondisk_relfiles_removed += other.ondisk_relfiles_removed;
         self.ondisk_relfiles_dropped += other.ondisk_relfiles_dropped;
 
@@ -85,6 +77,7 @@ impl AddAssign for GcResult {
         self.ondisk_nonrelfiles_needed_by_cutoff += other.ondisk_nonrelfiles_needed_by_cutoff;
         self.ondisk_nonrelfiles_needed_by_branches += other.ondisk_nonrelfiles_needed_by_branches;
         self.ondisk_nonrelfiles_not_updated += other.ondisk_nonrelfiles_not_updated;
+        self.ondisk_nonrelfiles_needed_as_tombstone += other.ondisk_nonrelfiles_needed_as_tombstone;
         self.ondisk_nonrelfiles_removed += other.ondisk_nonrelfiles_removed;
         self.ondisk_nonrelfiles_dropped += other.ondisk_nonrelfiles_dropped;
 
@@ -97,11 +90,16 @@ pub trait Timeline: Send + Sync {
     // Public GET functions
     //------------------------------------------------------------------------------
 
-    /// Look up given page in the cache.
-    fn get_page_at_lsn(&self, tag: RelishTag, blknum: u32, lsn: Lsn) -> Result<Bytes>;
+    ///
+    /// Wait until WAL has been received and processed up to this LSN.
+    ///
+    /// You should call this before any of the other get_* or list_* functions. Calling
+    /// those functions with an LSN that has been processed yet is an error.
+    ///
+    fn wait_lsn(&self, lsn: Lsn) -> Result<()>;
 
-    /// Look up given page in the cache.
-    fn get_page_at_lsn_nowait(&self, tag: RelishTag, blknum: u32, lsn: Lsn) -> Result<Bytes>;
+    /// Look up given page version.
+    fn get_page_at_lsn(&self, tag: RelishTag, blknum: u32, lsn: Lsn) -> Result<Bytes>;
 
     /// Get size of a relish
     fn get_relish_size(&self, tag: RelishTag, lsn: Lsn) -> Result<Option<u32>>;
@@ -109,11 +107,15 @@ pub trait Timeline: Send + Sync {
     /// Does relation exist?
     fn get_rel_exists(&self, tag: RelishTag, lsn: Lsn) -> Result<bool>;
 
-    /// Get a list of all distinct relations in given tablespace and database.
-    fn list_rels(&self, spcnode: u32, dbnode: u32, lsn: Lsn) -> Result<HashSet<RelTag>>;
+    /// Get a list of all existing relations
+    /// Pass RelTag to get relation objects or None to get nonrels.
+    fn list_relishes(&self, tag: Option<RelTag>, lsn: Lsn) -> Result<HashSet<RelishTag>>;
 
-    /// Get a list of non-relational objects
-    fn list_nonrels<'a>(&'a self, lsn: Lsn) -> Result<HashSet<RelishTag>>;
+    /// Get a list of all existing relations in given tablespace and database.
+    fn list_rels(&self, spcnode: u32, dbnode: u32, lsn: Lsn) -> Result<HashSet<RelishTag>>;
+
+    /// Get a list of all existing non-relational objects
+    fn list_nonrels(&self, lsn: Lsn) -> Result<HashSet<RelishTag>>;
 
     //------------------------------------------------------------------------------
     // Public PUT functions, to update the repository with new page versions.
@@ -133,9 +135,8 @@ pub trait Timeline: Send + Sync {
     /// Truncate relation
     fn put_truncation(&self, rel: RelishTag, lsn: Lsn, nblocks: u32) -> Result<()>;
 
-    /// Unlink relish.
-    /// This method is used for marking dropped relations and truncated SLRU segments
-    fn put_unlink(&self, tag: RelishTag, lsn: Lsn) -> Result<()>;
+    /// This method is used for marking dropped relations and truncated SLRU files and aborted two phase records
+    fn drop_relish(&self, tag: RelishTag, lsn: Lsn) -> Result<()>;
 
     /// Track end of the latest digested WAL record.
     ///
@@ -147,6 +148,7 @@ pub trait Timeline: Send + Sync {
     /// Get last or prev record separately. Same as get_last_record_rlsn().last/prev.
     fn get_last_record_lsn(&self) -> Lsn;
     fn get_prev_record_lsn(&self) -> Lsn;
+    fn get_start_lsn(&self) -> Lsn;
 
     ///
     /// Flush to disk all data that was written with the put_* functions
@@ -154,14 +156,16 @@ pub trait Timeline: Send + Sync {
     /// NOTE: This has nothing to do with checkpoint in PostgreSQL. We don't
     /// know anything about them here in the repository.
     fn checkpoint(&self) -> Result<()>;
-}
 
-#[derive(Clone)]
-pub struct RepositoryStats {
-    pub num_entries: Lsn,
-    pub num_page_images: Lsn,
-    pub num_wal_records: Lsn,
-    pub num_getpage_requests: Lsn,
+    /// Retrieve current logical size of the timeline
+    ///
+    /// NOTE: counted incrementally, includes ancestors,
+    /// doesnt support TwoPhase relishes yet
+    fn get_current_logical_size(&self) -> usize;
+
+    /// Does the same as get_current_logical_size but counted on demand.
+    /// Used in tests to ensure thet incremental and non incremental variants match.
+    fn get_current_logical_size_non_incremental(&self, lsn: Lsn) -> Result<usize>;
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq, Eq)]
@@ -201,20 +205,25 @@ impl WALRecord {
 ///
 /// Tests that should work the same with any Repository/Timeline implementation.
 ///
+#[allow(clippy::bool_assert_comparison)]
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::layered_repository::LayeredRepository;
     use crate::walredo::{WalRedoError, WalRedoManager};
     use crate::PageServerConf;
+    use hex_literal::hex;
     use postgres_ffi::pg_constants;
+    use postgres_ffi::xlog_utils::SIZEOF_CHECKPOINT;
     use std::fs;
     use std::path::PathBuf;
-    use std::str::FromStr;
-    use std::time::Duration;
-    use zenith_utils::postgres_backend::AuthType;
     use zenith_utils::zid::ZTenantId;
 
+    const TIMELINE_ID: ZTimelineId =
+        ZTimelineId::from_array(hex!("11223344556677881122334455667788"));
+    const NEW_TIMELINE_ID: ZTimelineId =
+        ZTimelineId::from_array(hex!("AA223344556677881122334455667788"));
+
     /// Arbitrary relation tag, for testing.
     const TESTREL_A: RelishTag = RelishTag::Relation(RelTag {
         spcnode: 0,
@@ -239,52 +248,64 @@ mod tests {
         buf.freeze()
     }
 
+    fn assert_current_logical_size(timeline: &Arc<dyn Timeline>, lsn: Lsn) {
+        let incremental = timeline.get_current_logical_size();
+        let non_incremental = timeline
+            .get_current_logical_size_non_incremental(lsn)
+            .unwrap();
+        assert_eq!(incremental, non_incremental);
+    }
+
     static ZERO_PAGE: Bytes = Bytes::from_static(&[0u8; 8192]);
+    static ZERO_CHECKPOINT: Bytes = Bytes::from_static(&[0u8; SIZEOF_CHECKPOINT]);
 
-    fn get_test_repo(test_name: &str) -> Result<Box<dyn Repository>> {
-        let repo_dir = PathBuf::from(format!("../tmp_check/test_{}", test_name));
-        let _ = fs::remove_dir_all(&repo_dir);
-        fs::create_dir_all(&repo_dir)?;
-        fs::create_dir_all(&repo_dir.join("timelines"))?;
+    struct RepoHarness {
+        conf: &'static PageServerConf,
+        tenant_id: ZTenantId,
+    }
 
-        let conf = PageServerConf {
-            daemonize: false,
-            gc_horizon: 64 * 1024 * 1024,
-            gc_period: Duration::from_secs(10),
-            listen_addr: "127.0.0.1:5430".to_string(),
-            http_endpoint_addr: "127.0.0.1:9898".to_string(),
-            superuser: "zenith_admin".to_string(),
-            workdir: repo_dir,
-            pg_distrib_dir: "".into(),
-            auth_type: AuthType::Trust,
-            auth_validation_public_key_path: None,
-        };
-        // Make a static copy of the config. This can never be free'd, but that's
-        // OK in a test.
-        let conf: &'static PageServerConf = Box::leak(Box::new(conf));
-        let tenantid = ZTenantId::generate();
-        fs::create_dir_all(conf.tenant_path(&tenantid)).unwrap();
+    impl RepoHarness {
+        fn create(test_name: &'static str) -> Result<Self> {
+            let repo_dir = PageServerConf::test_repo_dir(test_name);
+            let _ = fs::remove_dir_all(&repo_dir);
+            fs::create_dir_all(&repo_dir)?;
+            fs::create_dir_all(&repo_dir.join("timelines"))?;
 
-        let walredo_mgr = TestRedoManager {};
+            let conf = PageServerConf::dummy_conf(repo_dir);
+            // Make a static copy of the config. This can never be free'd, but that's
+            // OK in a test.
+            let conf: &'static PageServerConf = Box::leak(Box::new(conf));
 
-        let repo = Box::new(LayeredRepository::new(
-            conf,
-            Arc::new(walredo_mgr),
-            tenantid,
-        ));
+            let tenant_id = ZTenantId::generate();
+            fs::create_dir_all(conf.tenant_path(&tenant_id))?;
 
-        Ok(repo)
+            Ok(Self { conf, tenant_id })
+        }
+
+        fn load(&self) -> Box<dyn Repository> {
+            let walredo_mgr = Arc::new(TestRedoManager);
+
+            Box::new(LayeredRepository::new(
+                self.conf,
+                walredo_mgr,
+                self.tenant_id,
+                false,
+            ))
+        }
+
+        fn timeline_path(&self, timeline_id: &ZTimelineId) -> PathBuf {
+            self.conf.timeline_path(timeline_id, &self.tenant_id)
+        }
     }
 
     #[test]
     fn test_relsize() -> Result<()> {
-        let repo = get_test_repo("test_relsize")?;
+        let repo = RepoHarness::create("test_relsize")?.load();
         // get_timeline() with non-existent timeline id should fail
         //repo.get_timeline("11223344556677881122334455667788");
 
         // Create timeline to work on
-        let timelineid = ZTimelineId::from_str("11223344556677881122334455667788").unwrap();
-        let tline = repo.create_empty_timeline(timelineid, Lsn(0x00))?;
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
 
         tline.put_page_image(TESTREL_A, 0, Lsn(0x20), TEST_IMG("foo blk 0 at 2"))?;
         tline.put_page_image(TESTREL_A, 0, Lsn(0x20), TEST_IMG("foo blk 0 at 2"))?;
@@ -294,6 +315,8 @@ mod tests {
 
         tline.advance_last_record_lsn(Lsn(0x50));
 
+        assert_current_logical_size(&tline, Lsn(0x50));
+
         // The relation was created at LSN 2, not visible at LSN 1 yet.
         assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x10))?, false);
         assert!(tline.get_relish_size(TESTREL_A, Lsn(0x10))?.is_none());
@@ -338,6 +361,7 @@ mod tests {
         // Truncate last block
         tline.put_truncation(TESTREL_A, Lsn(0x60), 2)?;
         tline.advance_last_record_lsn(Lsn(0x60));
+        assert_current_logical_size(&tline, Lsn(0x60));
 
         // Check reported size and contents after truncation
         assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x60))?.unwrap(), 2);
@@ -357,6 +381,173 @@ mod tests {
             TEST_IMG("foo blk 2 at 5")
         );
 
+        // Truncate to zero length
+        tline.put_truncation(TESTREL_A, Lsn(0x68), 0)?;
+        tline.advance_last_record_lsn(Lsn(0x68));
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x68))?.unwrap(), 0);
+
+        // Extend from 0 to 2 blocks, leaving a gap
+        tline.put_page_image(TESTREL_A, 1, Lsn(0x70), TEST_IMG("foo blk 1"))?;
+        tline.advance_last_record_lsn(Lsn(0x70));
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x70))?.unwrap(), 2);
+        assert_eq!(tline.get_page_at_lsn(TESTREL_A, 0, Lsn(0x70))?, ZERO_PAGE);
+        assert_eq!(
+            tline.get_page_at_lsn(TESTREL_A, 1, Lsn(0x70))?,
+            TEST_IMG("foo blk 1")
+        );
+
+        // Extend a lot more, leaving a big gap that spans across segments
+        // FIXME: This is currently broken, see https://github.com/zenithdb/zenith/issues/500
+        /*
+        tline.put_page_image(TESTREL_A, 1500, Lsn(0x80), TEST_IMG("foo blk 1500"))?;
+        tline.advance_last_record_lsn(Lsn(0x80));
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x80))?.unwrap(), 1501);
+        for blk in 2..1500 {
+            assert_eq!(
+                tline.get_page_at_lsn(TESTREL_A, blk, Lsn(0x80))?,
+                ZERO_PAGE);
+        }
+        assert_eq!(
+            tline.get_page_at_lsn(TESTREL_A, 1500, Lsn(0x80))?,
+            TEST_IMG("foo blk 1500"));
+         */
+
+        Ok(())
+    }
+
+    // Test what happens if we dropped a relation
+    // and then created it again within the same layer.
+    #[test]
+    fn test_drop_extend() -> Result<()> {
+        let repo = RepoHarness::create("test_drop_extend")?.load();
+
+        // Create timeline to work on
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
+
+        tline.put_page_image(TESTREL_A, 0, Lsn(0x20), TEST_IMG("foo blk 0 at 2"))?;
+        tline.advance_last_record_lsn(Lsn(0x20));
+
+        // Check that rel exists and size is correct
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x20))?, true);
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x20))?.unwrap(), 1);
+
+        // Drop relish
+        tline.drop_relish(TESTREL_A, Lsn(0x30))?;
+        tline.advance_last_record_lsn(Lsn(0x30));
+
+        // Check that rel is not visible anymore
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x30))?, false);
+        assert!(tline.get_relish_size(TESTREL_A, Lsn(0x30))?.is_none());
+
+        // Extend it again
+        tline.put_page_image(TESTREL_A, 0, Lsn(0x40), TEST_IMG("foo blk 0 at 4"))?;
+        tline.advance_last_record_lsn(Lsn(0x40));
+
+        // Check that rel exists and size is correct
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x40))?, true);
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x40))?.unwrap(), 1);
+
+        Ok(())
+    }
+
+    // Test what happens if we truncated a relation
+    // so that one of its segments was dropped
+    // and then extended it again within the same layer.
+    #[test]
+    fn test_truncate_extend() -> Result<()> {
+        let repo = RepoHarness::create("test_truncate_extend")?.load();
+
+        // Create timeline to work on
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
+
+        //from storage_layer.rs
+        const RELISH_SEG_SIZE: u32 = 10 * 1024 * 1024 / 8192;
+        let relsize = RELISH_SEG_SIZE * 2;
+
+        // Create relation with relsize blocks
+        for blkno in 0..relsize {
+            let lsn = Lsn(0x20);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            tline.put_page_image(TESTREL_A, blkno, lsn, TEST_IMG(&data))?;
+        }
+
+        tline.advance_last_record_lsn(Lsn(0x20));
+
+        // The relation was created at LSN 2, not visible at LSN 1 yet.
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x10))?, false);
+        assert!(tline.get_relish_size(TESTREL_A, Lsn(0x10))?.is_none());
+
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x20))?, true);
+        assert_eq!(
+            tline.get_relish_size(TESTREL_A, Lsn(0x20))?.unwrap(),
+            relsize
+        );
+
+        // Check relation content
+        for blkno in 0..relsize {
+            let lsn = Lsn(0x20);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            assert_eq!(
+                tline.get_page_at_lsn(TESTREL_A, blkno, lsn)?,
+                TEST_IMG(&data)
+            );
+        }
+
+        // Truncate relation so that second segment was dropped
+        // - only leave one page
+        tline.put_truncation(TESTREL_A, Lsn(0x60), 1)?;
+        tline.advance_last_record_lsn(Lsn(0x60));
+
+        // Check reported size and contents after truncation
+        assert_eq!(tline.get_relish_size(TESTREL_A, Lsn(0x60))?.unwrap(), 1);
+
+        for blkno in 0..1 {
+            let lsn = Lsn(0x20);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            assert_eq!(
+                tline.get_page_at_lsn(TESTREL_A, blkno, Lsn(0x60))?,
+                TEST_IMG(&data)
+            );
+        }
+
+        // should still see all blocks with older LSN
+        assert_eq!(
+            tline.get_relish_size(TESTREL_A, Lsn(0x50))?.unwrap(),
+            relsize
+        );
+        for blkno in 0..relsize {
+            let lsn = Lsn(0x20);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            assert_eq!(
+                tline.get_page_at_lsn(TESTREL_A, blkno, Lsn(0x50))?,
+                TEST_IMG(&data)
+            );
+        }
+
+        // Extend relation again.
+        // Add enough blocks to create second segment
+        for blkno in 0..relsize {
+            let lsn = Lsn(0x80);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            tline.put_page_image(TESTREL_A, blkno, lsn, TEST_IMG(&data))?;
+        }
+        tline.advance_last_record_lsn(Lsn(0x80));
+
+        assert_eq!(tline.get_rel_exists(TESTREL_A, Lsn(0x80))?, true);
+        assert_eq!(
+            tline.get_relish_size(TESTREL_A, Lsn(0x80))?.unwrap(),
+            relsize
+        );
+        // Check relation content
+        for blkno in 0..relsize {
+            let lsn = Lsn(0x80);
+            let data = format!("foo blk {} at {}", blkno, lsn);
+            assert_eq!(
+                tline.get_page_at_lsn(TESTREL_A, blkno, Lsn(0x80))?,
+                TEST_IMG(&data)
+            );
+        }
+
         Ok(())
     }
 
@@ -364,9 +555,8 @@ mod tests {
     /// split into multiple 1 GB segments in Postgres.
     #[test]
     fn test_large_rel() -> Result<()> {
-        let repo = get_test_repo("test_large_rel")?;
-        let timelineid = ZTimelineId::from_str("11223344556677881122334455667788").unwrap();
-        let tline = repo.create_empty_timeline(timelineid, Lsn(0x00))?;
+        let repo = RepoHarness::create("test_large_rel")?.load();
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
 
         let mut lsn = 0x10;
         for blknum in 0..pg_constants::RELSEG_SIZE + 1 {
@@ -376,6 +566,8 @@ mod tests {
         }
         tline.advance_last_record_lsn(Lsn(lsn));
 
+        assert_current_logical_size(&tline, Lsn(lsn));
+
         assert_eq!(
             tline.get_relish_size(TESTREL_A, Lsn(lsn))?.unwrap(),
             pg_constants::RELSEG_SIZE + 1
@@ -389,6 +581,7 @@ mod tests {
             tline.get_relish_size(TESTREL_A, Lsn(lsn))?.unwrap(),
             pg_constants::RELSEG_SIZE
         );
+        assert_current_logical_size(&tline, Lsn(lsn));
 
         // Truncate another block
         lsn += 0x10;
@@ -398,6 +591,7 @@ mod tests {
             tline.get_relish_size(TESTREL_A, Lsn(lsn))?.unwrap(),
             pg_constants::RELSEG_SIZE - 1
         );
+        assert_current_logical_size(&tline, Lsn(lsn));
 
         // Truncate to 1500, and then truncate all the way down to 0, one block at a time
         // This tests the behavior at segment boundaries
@@ -413,6 +607,61 @@ mod tests {
 
             size -= 1;
         }
+        assert_current_logical_size(&tline, Lsn(lsn));
+
+        Ok(())
+    }
+
+    ///
+    /// Test list_rels() function, with branches and dropped relations
+    ///
+    #[test]
+    fn test_list_rels_drop() -> Result<()> {
+        let repo = RepoHarness::create("test_list_rels_drop")?.load();
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
+        const TESTDB: u32 = 111;
+
+        // Import initial dummy checkpoint record, otherwise the get_timeline() call
+        // after branching fails below
+        tline.put_page_image(RelishTag::Checkpoint, 0, Lsn(0x10), ZERO_CHECKPOINT.clone())?;
+
+        // Create a relation on the timeline
+        tline.put_page_image(TESTREL_A, 0, Lsn(0x20), TEST_IMG("foo blk 0 at 2"))?;
+
+        tline.advance_last_record_lsn(Lsn(0x30));
+
+        // Check that list_rels() lists it after LSN 2, but no before it
+        assert!(!tline.list_rels(0, TESTDB, Lsn(0x10))?.contains(&TESTREL_A));
+        assert!(tline.list_rels(0, TESTDB, Lsn(0x20))?.contains(&TESTREL_A));
+        assert!(tline.list_rels(0, TESTDB, Lsn(0x30))?.contains(&TESTREL_A));
+
+        // Create a branch, check that the relation is visible there
+        repo.branch_timeline(TIMELINE_ID, NEW_TIMELINE_ID, Lsn(0x30))?;
+        let newtline = repo.get_timeline(NEW_TIMELINE_ID)?;
+
+        assert!(newtline
+            .list_rels(0, TESTDB, Lsn(0x30))?
+            .contains(&TESTREL_A));
+
+        // Drop it on the branch
+        newtline.drop_relish(TESTREL_A, Lsn(0x40))?;
+        newtline.advance_last_record_lsn(Lsn(0x40));
+
+        // Check that it's no longer listed on the branch after the point where it was dropped
+        assert!(newtline
+            .list_rels(0, TESTDB, Lsn(0x30))?
+            .contains(&TESTREL_A));
+        assert!(!newtline
+            .list_rels(0, TESTDB, Lsn(0x40))?
+            .contains(&TESTREL_A));
+
+        // Run checkpoint and garbage collection and check that it's still not visible
+        newtline.checkpoint()?;
+        repo.gc_iteration(Some(NEW_TIMELINE_ID), 0, true)?;
+
+        assert!(!newtline
+            .list_rels(0, TESTDB, Lsn(0x40))?
+            .contains(&TESTREL_A));
 
         Ok(())
     }
@@ -422,13 +671,12 @@ mod tests {
     ///
     #[test]
     fn test_branch() -> Result<()> {
-        let repo = get_test_repo("test_branch")?;
-        let timelineid = ZTimelineId::from_str("11223344556677881122334455667788").unwrap();
-        let tline = repo.create_empty_timeline(timelineid, Lsn(0x00))?;
+        let repo = RepoHarness::create("test_branch")?.load();
+        let tline = repo.create_empty_timeline(TIMELINE_ID)?;
 
         // Import initial dummy checkpoint record, otherwise the get_timeline() call
         // after branching fails below
-        tline.put_page_image(RelishTag::Checkpoint, 0, Lsn(0x10), ZERO_PAGE.clone())?;
+        tline.put_page_image(RelishTag::Checkpoint, 0, Lsn(0x10), ZERO_CHECKPOINT.clone())?;
 
         // Create a relation on the timeline
         tline.put_page_image(TESTREL_A, 0, Lsn(0x20), TEST_IMG("foo blk 0 at 2"))?;
@@ -439,11 +687,11 @@ mod tests {
         tline.put_page_image(TESTREL_B, 0, Lsn(0x20), TEST_IMG("foobar blk 0 at 2"))?;
 
         tline.advance_last_record_lsn(Lsn(0x40));
+        assert_current_logical_size(&tline, Lsn(0x40));
 
         // Branch the history, modify relation differently on the new timeline
-        let newtimelineid = ZTimelineId::from_str("AA223344556677881122334455667788").unwrap();
-        repo.branch_timeline(timelineid, newtimelineid, Lsn(0x30))?;
-        let newtline = repo.get_timeline(newtimelineid)?;
+        repo.branch_timeline(TIMELINE_ID, NEW_TIMELINE_ID, Lsn(0x30))?;
+        let newtline = repo.get_timeline(NEW_TIMELINE_ID)?;
 
         newtline.put_page_image(TESTREL_A, 0, Lsn(0x40), TEST_IMG("bar blk 0 at 4"))?;
         newtline.advance_last_record_lsn(Lsn(0x40));
@@ -466,11 +714,94 @@ mod tests {
 
         assert_eq!(newtline.get_relish_size(TESTREL_B, Lsn(0x40))?.unwrap(), 1);
 
+        assert_current_logical_size(&tline, Lsn(0x40));
+
+        Ok(())
+    }
+
+    #[test]
+    fn corrupt_metadata() -> Result<()> {
+        const TEST_NAME: &str = "corrupt_metadata";
+        let harness = RepoHarness::create(TEST_NAME)?;
+        let repo = harness.load();
+
+        repo.create_empty_timeline(TIMELINE_ID)?;
+        drop(repo);
+
+        let metadata_path = harness.timeline_path(&TIMELINE_ID).join("metadata");
+
+        assert!(metadata_path.is_file());
+
+        let mut metadata_bytes = std::fs::read(&metadata_path)?;
+        assert_eq!(metadata_bytes.len(), 512);
+        metadata_bytes[512 - 4 - 2] ^= 1;
+        std::fs::write(metadata_path, metadata_bytes)?;
+
+        let new_repo = harness.load();
+        let err = new_repo.get_timeline(TIMELINE_ID).err().unwrap();
+        assert!(err.to_string().contains("checksum"));
+
+        Ok(())
+    }
+
+    #[test]
+    fn future_layerfiles() -> Result<()> {
+        const TEST_NAME: &str = "future_layerfiles";
+        let harness = RepoHarness::create(TEST_NAME)?;
+        let repo = harness.load();
+
+        repo.create_empty_timeline(TIMELINE_ID)?;
+        drop(repo);
+
+        let timeline_path = harness.timeline_path(&TIMELINE_ID);
+
+        let make_empty_file = |filename: &str| -> std::io::Result<()> {
+            let path = timeline_path.join(filename);
+
+            assert!(!path.exists());
+            std::fs::write(&path, &[])?;
+
+            Ok(())
+        };
+
+        let image_filename = format!("pg_control_0_{:016X}", 8000);
+        let delta_filename = format!("pg_control_0_{:016X}_{:016X}", 8000, 8008);
+
+        make_empty_file(&image_filename)?;
+        make_empty_file(&delta_filename)?;
+
+        let new_repo = harness.load();
+        new_repo.get_timeline(TIMELINE_ID).unwrap();
+        drop(new_repo);
+
+        let check_old = |filename: &str, num: u32| {
+            let path = timeline_path.join(filename);
+            assert!(!path.exists());
+
+            let backup_path = timeline_path.join(format!("{}.{}.old", filename, num));
+            assert!(backup_path.exists());
+        };
+
+        check_old(&image_filename, 0);
+        check_old(&delta_filename, 0);
+
+        make_empty_file(&image_filename)?;
+        make_empty_file(&delta_filename)?;
+
+        let new_repo = harness.load();
+        new_repo.get_timeline(TIMELINE_ID).unwrap();
+        drop(new_repo);
+
+        check_old(&image_filename, 0);
+        check_old(&delta_filename, 0);
+        check_old(&image_filename, 1);
+        check_old(&delta_filename, 1);
+
         Ok(())
     }
 
     // Mock WAL redo manager that doesn't do much
-    struct TestRedoManager {}
+    struct TestRedoManager;
 
     impl WalRedoManager for TestRedoManager {
         fn request_redo(

pageserver/src/restore_local_repo.rs

@@ -9,11 +9,9 @@ use std::cmp::min;
 use std::fs;
 use std::fs::File;
 use std::io::Read;
-use std::io::Seek;
-use std::io::SeekFrom;
-use std::path::{Path, PathBuf};
+use std::path::Path;
 
-use anyhow::Result;
+use anyhow::{bail, Result};
 use bytes::{Buf, Bytes};
 
 use crate::relish::*;
@@ -29,7 +27,7 @@ use zenith_utils::lsn::Lsn;
 const MAX_MBR_BLKNO: u32 =
     pg_constants::MAX_MULTIXACT_ID / pg_constants::MULTIXACT_MEMBERS_PER_PAGE as u32;
 
-const ZERO_PAGE: Bytes = Bytes::from_static(&[0u8; 8192]);
+static ZERO_PAGE: Bytes = Bytes::from_static(&[0u8; 8192]);
 
 ///
 /// Import all relation data pages from local disk into the repository.
@@ -45,15 +43,8 @@ pub fn import_timeline_from_postgres_datadir(
         match direntry.file_name().to_str() {
             None => continue,
 
-            // These special files appear in the snapshot, but are not needed by the page server
             Some("pg_control") => {
-                import_nonrel_file(timeline, lsn, RelishTag::ControlFile, &direntry.path())?;
-                // Extract checkpoint record from pg_control and store is as separate object
-                let pg_control_bytes =
-                    timeline.get_page_at_lsn_nowait(RelishTag::ControlFile, 0, lsn)?;
-                let pg_control = ControlFileData::decode(&pg_control_bytes)?;
-                let checkpoint_bytes = pg_control.checkPointCopy.encode();
-                timeline.put_page_image(RelishTag::Checkpoint, 0, lsn, checkpoint_bytes)?;
+                import_control_file(timeline, lsn, &direntry.path())?;
             }
             Some("pg_filenode.map") => import_nonrel_file(
                 timeline,
@@ -93,7 +84,6 @@ pub fn import_timeline_from_postgres_datadir(
             match direntry.file_name().to_str() {
                 None => continue,
 
-                // These special files appear in the snapshot, but are not needed by the page server
                 Some("PG_VERSION") => continue,
                 Some("pg_filenode.map") => import_nonrel_file(
                     timeline,
@@ -130,13 +120,12 @@ pub fn import_timeline_from_postgres_datadir(
     }
     for entry in fs::read_dir(path.join("pg_twophase"))? {
         let entry = entry?;
-        let xid = u32::from_str_radix(&entry.path().to_str().unwrap(), 16)?;
+        let xid = u32::from_str_radix(entry.path().to_str().unwrap(), 16)?;
         import_nonrel_file(timeline, lsn, RelishTag::TwoPhase { xid }, &entry.path())?;
     }
     // TODO: Scan pg_tblspc
 
-    timeline.advance_last_record_lsn(lsn.align());
-    timeline.checkpoint()?;
+    timeline.advance_last_record_lsn(lsn);
 
     Ok(())
 }
@@ -153,7 +142,7 @@ fn import_relfile(
 
     let p = parse_relfilename(path.file_name().unwrap().to_str().unwrap());
     if let Err(e) = p {
-        warn!("unrecognized file in snapshot: {:?} ({})", path, e);
+        warn!("unrecognized file in postgres datadir: {:?} ({})", path, e);
         return Err(e.into());
     }
     let (relnode, forknum, segno) = p.unwrap();
@@ -184,8 +173,7 @@ fn import_relfile(
                     break;
                 }
                 _ => {
-                    error!("error reading file: {:?} ({})", path, e);
-                    break;
+                    bail!("error reading file {}: {:#}", path.display(), e);
                 }
             },
         };
@@ -218,6 +206,35 @@ fn import_nonrel_file(
     Ok(())
 }
 
+///
+/// Import pg_control file into the repository.
+///
+/// The control file is imported as is, but we also extract the checkpoint record
+/// from it and store it separated.
+fn import_control_file(timeline: &dyn Timeline, lsn: Lsn, path: &Path) -> Result<()> {
+    let mut file = File::open(path)?;
+    let mut buffer = Vec::new();
+    // read the whole file
+    file.read_to_end(&mut buffer)?;
+
+    info!("importing control file {}", path.display());
+
+    // Import it as ControlFile
+    timeline.put_page_image(
+        RelishTag::ControlFile,
+        0,
+        lsn,
+        Bytes::copy_from_slice(&buffer[..]),
+    )?;
+
+    // Extract the checkpoint record and import it separately.
+    let pg_control = ControlFileData::decode(&buffer)?;
+    let checkpoint_bytes = pg_control.checkPointCopy.encode();
+    timeline.put_page_image(RelishTag::Checkpoint, 0, lsn, checkpoint_bytes)?;
+
+    Ok(())
+}
+
 ///
 /// Import an SLRU segment file
 ///
@@ -250,8 +267,7 @@ fn import_slru_file(timeline: &dyn Timeline, lsn: Lsn, slru: SlruKind, path: &Pa
                     break;
                 }
                 _ => {
-                    error!("error reading file: {:?} ({})", path, e);
-                    break;
+                    bail!("error reading file {}: {:#}", path.display(), e);
                 }
             },
         };
@@ -263,86 +279,6 @@ fn import_slru_file(timeline: &dyn Timeline, lsn: Lsn, slru: SlruKind, path: &Pa
     Ok(())
 }
 
-/// Scan PostgreSQL WAL files in given directory
-/// and load all records >= 'startpoint' into the repository.
-pub fn import_timeline_wal(walpath: &Path, timeline: &dyn Timeline, startpoint: Lsn) -> Result<()> {
-    let mut waldecoder = WalStreamDecoder::new(startpoint);
-
-    let mut segno = startpoint.segment_number(pg_constants::WAL_SEGMENT_SIZE);
-    let mut offset = startpoint.segment_offset(pg_constants::WAL_SEGMENT_SIZE);
-    let mut last_lsn = startpoint;
-
-    let checkpoint_bytes = timeline.get_page_at_lsn_nowait(RelishTag::Checkpoint, 0, startpoint)?;
-    let mut checkpoint = CheckPoint::decode(&checkpoint_bytes)?;
-
-    loop {
-        // FIXME: assume postgresql tli 1 for now
-        let filename = XLogFileName(1, segno, pg_constants::WAL_SEGMENT_SIZE);
-        let mut buf = Vec::new();
-
-        //Read local file
-        let mut path = walpath.join(&filename);
-
-        // It could be as .partial
-        if !PathBuf::from(&path).exists() {
-            path = walpath.join(filename + ".partial");
-        }
-
-        // Slurp the WAL file
-        let open_result = File::open(&path);
-        if let Err(e) = &open_result {
-            if e.kind() == std::io::ErrorKind::NotFound {
-                break;
-            }
-        }
-        let mut file = open_result?;
-
-        if offset > 0 {
-            file.seek(SeekFrom::Start(offset as u64))?;
-        }
-
-        let nread = file.read_to_end(&mut buf)?;
-        if nread != pg_constants::WAL_SEGMENT_SIZE - offset as usize {
-            // Maybe allow this for .partial files?
-            error!("read only {} bytes from WAL file", nread);
-        }
-
-        waldecoder.feed_bytes(&buf);
-
-        let mut nrecords = 0;
-        loop {
-            let rec = waldecoder.poll_decode();
-            if rec.is_err() {
-                // Assume that an error means we've reached the end of
-                // a partial WAL record. So that's ok.
-                trace!("WAL decoder error {:?}", rec);
-                break;
-            }
-            if let Some((lsn, recdata)) = rec.unwrap() {
-                let decoded = decode_wal_record(recdata.clone());
-                save_decoded_record(&mut checkpoint, timeline, &decoded, recdata, lsn)?;
-                last_lsn = lsn;
-            } else {
-                break;
-            }
-            nrecords += 1;
-        }
-
-        info!("imported {} records up to {}", nrecords, last_lsn);
-
-        segno += 1;
-        offset = 0;
-    }
-
-    info!("reached end of WAL at {}", last_lsn);
-    let checkpoint_bytes = checkpoint.encode();
-    timeline.put_page_image(RelishTag::Checkpoint, 0, last_lsn, checkpoint_bytes)?;
-
-    timeline.advance_last_record_lsn(last_lsn.align());
-    timeline.checkpoint()?;
-    Ok(())
-}
-
 ///
 /// Helper function to parse a WAL record and call the Timeline's PUT functions for all the
 /// relations/pages that the record affects.
@@ -394,18 +330,22 @@ pub fn save_decoded_record(
         {
             let dropdb = XlDropDatabase::decode(&mut buf);
 
+            // To drop the database, we need to drop all the relations in it. Like in
+            // save_xlog_dbase_create(), use the previous record's LSN in the list_rels() call
+            let req_lsn = min(timeline.get_last_record_lsn(), lsn);
+
             for tablespace_id in dropdb.tablespace_ids {
-                let rels = timeline.list_rels(tablespace_id, dropdb.db_id, lsn)?;
+                let rels = timeline.list_rels(tablespace_id, dropdb.db_id, req_lsn)?;
                 for rel in rels {
-                    timeline.put_unlink(RelishTag::Relation(rel), lsn)?;
+                    timeline.drop_relish(rel, lsn)?;
                 }
                 trace!(
-                    "Unlink FileNodeMap {}, {} at lsn {}",
+                    "Drop FileNodeMap {}, {} at lsn {}",
                     tablespace_id,
                     dropdb.db_id,
                     lsn
                 );
-                timeline.put_unlink(
+                timeline.drop_relish(
                     RelishTag::FileNodeMap {
                         spcnode: tablespace_id,
                         dbnode: dropdb.db_id,
@@ -429,7 +369,7 @@ pub fn save_decoded_record(
                 },
                 rpageno,
                 lsn,
-                ZERO_PAGE,
+                ZERO_PAGE.clone(),
             )?;
         } else {
             assert!(info == pg_constants::CLOG_TRUNCATE);
@@ -448,12 +388,12 @@ pub fn save_decoded_record(
             save_xact_record(timeline, lsn, &parsed_xact, decoded)?;
             // Remove twophase file. see RemoveTwoPhaseFile() in postgres code
             trace!(
-                "unlink twophaseFile for xid {} parsed_xact.xid {} here at {}",
+                "Drop twophaseFile for xid {} parsed_xact.xid {} here at {}",
                 decoded.xl_xid,
                 parsed_xact.xid,
                 lsn
             );
-            timeline.put_unlink(
+            timeline.drop_relish(
                 RelishTag::TwoPhase {
                     xid: parsed_xact.xid,
                 },
@@ -486,7 +426,7 @@ pub fn save_decoded_record(
                 },
                 rpageno,
                 lsn,
-                ZERO_PAGE,
+                ZERO_PAGE.clone(),
             )?;
         } else if info == pg_constants::XLOG_MULTIXACT_ZERO_MEM_PAGE {
             let pageno = buf.get_u32_le();
@@ -499,7 +439,7 @@ pub fn save_decoded_record(
                 },
                 rpageno,
                 lsn,
-                ZERO_PAGE,
+                ZERO_PAGE.clone(),
             )?;
         } else if info == pg_constants::XLOG_MULTIXACT_CREATE_ID {
             let xlrec = XlMultiXactCreate::decode(&mut buf);
@@ -534,9 +474,6 @@ pub fn save_decoded_record(
             }
         }
     }
-    // Now that this record has been handled, let the repository know that
-    // it is up-to-date to this LSN
-    timeline.advance_last_record_lsn(lsn.align());
     Ok(())
 }
 
@@ -560,56 +497,52 @@ fn save_xlog_dbase_create(timeline: &dyn Timeline, lsn: Lsn, rec: &XlCreateDatab
 
     let mut num_rels_copied = 0;
     let mut num_blocks_copied = 0;
-    for src_rel in rels {
-        assert_eq!(src_rel.spcnode, src_tablespace_id);
-        assert_eq!(src_rel.dbnode, src_db_id);
+    for rel in rels {
+        if let RelishTag::Relation(src_rel) = rel {
+            assert_eq!(src_rel.spcnode, src_tablespace_id);
+            assert_eq!(src_rel.dbnode, src_db_id);
 
-        let nblocks = timeline
-            .get_relish_size(RelishTag::Relation(src_rel), req_lsn)?
-            .unwrap_or(0);
-        let dst_rel = RelTag {
-            spcnode: tablespace_id,
-            dbnode: db_id,
-            relnode: src_rel.relnode,
-            forknum: src_rel.forknum,
-        };
+            let nblocks = timeline.get_relish_size(rel, req_lsn)?.unwrap_or(0);
+            let dst_rel = RelTag {
+                spcnode: tablespace_id,
+                dbnode: db_id,
+                relnode: src_rel.relnode,
+                forknum: src_rel.forknum,
+            };
 
-        // Copy content
-        for blknum in 0..nblocks {
-            let content =
-                timeline.get_page_at_lsn_nowait(RelishTag::Relation(src_rel), blknum, req_lsn)?;
+            // Copy content
+            for blknum in 0..nblocks {
+                let content = timeline.get_page_at_lsn(rel, blknum, req_lsn)?;
 
-            debug!("copying block {} from {} to {}", blknum, src_rel, dst_rel);
+                debug!("copying block {} from {} to {}", blknum, src_rel, dst_rel);
 
-            timeline.put_page_image(RelishTag::Relation(dst_rel), blknum, lsn, content)?;
-            num_blocks_copied += 1;
+                timeline.put_page_image(RelishTag::Relation(dst_rel), blknum, lsn, content)?;
+                num_blocks_copied += 1;
+            }
+
+            if nblocks == 0 {
+                // make sure we have some trace of the relation, even if it's empty
+                timeline.put_truncation(RelishTag::Relation(dst_rel), lsn, 0)?;
+            }
+
+            num_rels_copied += 1;
         }
-
-        if nblocks == 0 {
-            // make sure we have some trace of the relation, even if it's empty
-            timeline.put_truncation(RelishTag::Relation(dst_rel), lsn, 0)?;
-        }
-
-        num_rels_copied += 1;
     }
 
     // Copy relfilemap
     // TODO This implementation is very inefficient -
     // it scans all non-rels only to find FileNodeMaps
     for tag in timeline.list_nonrels(req_lsn)? {
-        match tag {
-            RelishTag::FileNodeMap { spcnode, dbnode } => {
-                if spcnode == src_tablespace_id && dbnode == src_db_id {
-                    let img = timeline.get_page_at_lsn_nowait(tag, 0, req_lsn)?;
-                    let new_tag = RelishTag::FileNodeMap {
-                        spcnode: tablespace_id,
-                        dbnode: db_id,
-                    };
-                    timeline.put_page_image(new_tag, 0, lsn, img)?;
-                    break;
-                }
+        if let RelishTag::FileNodeMap { spcnode, dbnode } = tag {
+            if spcnode == src_tablespace_id && dbnode == src_db_id {
+                let img = timeline.get_page_at_lsn(tag, 0, req_lsn)?;
+                let new_tag = RelishTag::FileNodeMap {
+                    spcnode: tablespace_id,
+                    dbnode: db_id,
+                };
+                timeline.put_page_image(new_tag, 0, lsn, img)?;
+                break;
             }
-            _ => {} // do nothing
         }
     }
     info!(
@@ -733,7 +666,7 @@ fn save_xact_record(
                 dbnode: xnode.dbnode,
                 relnode: xnode.relnode,
             };
-            timeline.put_unlink(RelishTag::Relation(rel), lsn)?;
+            timeline.drop_relish(RelishTag::Relation(rel), lsn)?;
         }
     }
     Ok(())
@@ -775,7 +708,7 @@ fn save_clog_truncate_record(
         return Ok(());
     }
 
-    // Iterate via SLRU CLOG segments and unlink segments that we're ready to truncate
+    // Iterate via SLRU CLOG segments and drop segments that we're ready to truncate
     // TODO This implementation is very inefficient -
     // it scans all non-rels only to find Clog
     //
@@ -785,17 +718,14 @@ fn save_clog_truncate_record(
     // instead.
     let req_lsn = min(timeline.get_last_record_lsn(), lsn);
     for obj in timeline.list_nonrels(req_lsn)? {
-        match obj {
-            RelishTag::Slru { slru, segno } => {
-                if slru == SlruKind::Clog {
-                    let segpage = segno * pg_constants::SLRU_PAGES_PER_SEGMENT;
-                    if slru_may_delete_clogsegment(segpage, xlrec.pageno) {
-                        timeline.put_unlink(RelishTag::Slru { slru, segno }, lsn)?;
-                        trace!("unlink CLOG segment {:>04X} at lsn {}", segno, lsn);
-                    }
+        if let RelishTag::Slru { slru, segno } = obj {
+            if slru == SlruKind::Clog {
+                let segpage = segno * pg_constants::SLRU_PAGES_PER_SEGMENT;
+                if slru_may_delete_clogsegment(segpage, xlrec.pageno) {
+                    timeline.drop_relish(RelishTag::Slru { slru, segno }, lsn)?;
+                    trace!("Drop CLOG segment {:>04X} at lsn {}", segno, lsn);
                 }
             }
-            _ => {}
         }
     }
 
@@ -894,7 +824,7 @@ fn save_multixact_truncate_record(
     // Delete all the segments except the last one. The last segment can still
     // contain, possibly partially, valid data.
     while segment != endsegment {
-        timeline.put_unlink(
+        timeline.drop_relish(
             RelishTag::Slru {
                 slru: SlruKind::MultiXactMembers,
                 segno: segment as u32,

pageserver/src/tenant_mgr.rs

@@ -3,51 +3,90 @@
 
 use crate::branches;
 use crate::layered_repository::LayeredRepository;
-use crate::repository::Repository;
+use crate::repository::{Repository, Timeline};
 use crate::walredo::PostgresRedoManager;
 use crate::PageServerConf;
-use anyhow::{anyhow, bail, Result};
+use anyhow::{anyhow, bail, Context, Result};
 use lazy_static::lazy_static;
 use log::info;
+use std::collections::hash_map::Entry;
 use std::collections::HashMap;
 use std::fs;
 use std::str::FromStr;
-use std::sync::{Arc, Mutex};
-use zenith_utils::zid::ZTenantId;
+use std::sync::{Arc, Mutex, MutexGuard};
+use zenith_utils::zid::{ZTenantId, ZTimelineId};
 
 lazy_static! {
-    pub static ref REPOSITORY: Mutex<HashMap<ZTenantId, Arc<dyn Repository>>> =
+    static ref REPOSITORY: Mutex<HashMap<ZTenantId, Arc<dyn Repository>>> =
         Mutex::new(HashMap::new());
 }
 
-pub fn init(conf: &'static PageServerConf) {
-    let mut m = REPOSITORY.lock().unwrap();
+fn access_repository() -> MutexGuard<'static, HashMap<ZTenantId, Arc<dyn Repository>>> {
+    REPOSITORY.lock().unwrap()
+}
 
+pub fn init(conf: &'static PageServerConf) {
+    let mut m = access_repository();
     for dir_entry in fs::read_dir(conf.tenants_path()).unwrap() {
         let tenantid =
             ZTenantId::from_str(dir_entry.unwrap().file_name().to_str().unwrap()).unwrap();
-
-        // Set up a WAL redo manager, for applying WAL records.
-        let walredo_mgr = PostgresRedoManager::new(conf, tenantid);
-
-        // Set up an object repository, for actual data storage.
-        let repo = Arc::new(LayeredRepository::new(
-            conf,
-            Arc::new(walredo_mgr),
-            tenantid,
-        ));
-        LayeredRepository::launch_checkpointer_thread(conf, repo.clone());
-
+        let repo = init_repo(conf, tenantid);
         info!("initialized storage for tenant: {}", &tenantid);
         m.insert(tenantid, repo);
     }
 }
 
+fn init_repo(conf: &'static PageServerConf, tenant_id: ZTenantId) -> Arc<LayeredRepository> {
+    // Set up a WAL redo manager, for applying WAL records.
+    let walredo_mgr = PostgresRedoManager::new(conf, tenant_id);
+
+    // Set up an object repository, for actual data storage.
+    let repo = Arc::new(LayeredRepository::new(
+        conf,
+        Arc::new(walredo_mgr),
+        tenant_id,
+        true,
+    ));
+    LayeredRepository::launch_checkpointer_thread(conf, repo.clone());
+    LayeredRepository::launch_gc_thread(conf, repo.clone());
+    repo
+}
+
+// TODO kb Currently unused function, will later be used when the relish storage downloads a new layer.
+// Relevant PR: https://github.com/zenithdb/zenith/pull/686
+pub fn register_relish_download(
+    conf: &'static PageServerConf,
+    tenant_id: ZTenantId,
+    timeline_id: ZTimelineId,
+) {
+    log::info!(
+        "Registering new download, tenant id {}, timeline id: {}",
+        tenant_id,
+        timeline_id
+    );
+    match access_repository().entry(tenant_id) {
+        Entry::Occupied(o) => init_timeline(o.get().as_ref(), timeline_id),
+        Entry::Vacant(v) => {
+            log::info!("New repo initialized");
+            let new_repo = init_repo(conf, tenant_id);
+            init_timeline(new_repo.as_ref(), timeline_id);
+            v.insert(new_repo);
+        }
+    }
+}
+
+fn init_timeline(repo: &dyn Repository, timeline_id: ZTimelineId) {
+    match repo.get_timeline(timeline_id) {
+        Ok(_timeline) => log::info!("Successfully initialized timeline {}", timeline_id),
+        Err(e) => log::error!("Failed to init timeline {}, reason: {:#}", timeline_id, e),
+    }
+}
+
 pub fn create_repository_for_tenant(
     conf: &'static PageServerConf,
     tenantid: ZTenantId,
 ) -> Result<()> {
-    let mut m = REPOSITORY.lock().unwrap();
+    let mut m = access_repository();
 
     // First check that the tenant doesn't exist already
     if m.get(&tenantid).is_some() {
@@ -61,14 +100,18 @@ pub fn create_repository_for_tenant(
     Ok(())
 }
 
-pub fn insert_repository_for_tenant(tenantid: ZTenantId, repo: Arc<dyn Repository>) {
-    let o = &mut REPOSITORY.lock().unwrap();
-    o.insert(tenantid, repo);
-}
-
-pub fn get_repository_for_tenant(tenantid: &ZTenantId) -> Result<Arc<dyn Repository>> {
-    let o = &REPOSITORY.lock().unwrap();
-    o.get(tenantid)
-        .map(|repo| Arc::clone(repo))
+pub fn get_repository_for_tenant(tenantid: ZTenantId) -> Result<Arc<dyn Repository>> {
+    access_repository()
+        .get(&tenantid)
+        .map(Arc::clone)
         .ok_or_else(|| anyhow!("repository not found for tenant name {}", tenantid))
 }
+
+pub fn get_timeline_for_tenant(
+    tenantid: ZTenantId,
+    timelineid: ZTimelineId,
+) -> Result<Arc<dyn Timeline>> {
+    get_repository_for_tenant(tenantid)?
+        .get_timeline(timelineid)
+        .with_context(|| format!("cannot fetch timeline {}", timelineid))
+}

pageserver/src/waldecoder.rs

@@ -54,6 +54,11 @@ impl WalStreamDecoder {
         }
     }
 
+    // The latest LSN position fed to the decoder.
+    pub fn available(&self) -> Lsn {
+        self.lsn + self.inputbuf.remaining() as u64
+    }
+
     pub fn feed_bytes(&mut self, buf: &[u8]) {
         self.inputbuf.extend_from_slice(buf);
     }
@@ -159,17 +164,10 @@ impl WalStreamDecoder {
                     let recordbuf = recordbuf.freeze();
                     let mut buf = recordbuf.clone();
 
+                    let xlogrec = XLogRecord::from_bytes(&mut buf);
+
                     // XLOG_SWITCH records are special. If we see one, we need to skip
                     // to the next WAL segment.
-                    let xlogrec = XLogRecord::from_bytes(&mut buf);
-                    let mut crc = crc32c_append(0, &recordbuf[XLOG_RECORD_CRC_OFFS + 4..]);
-                    crc = crc32c_append(crc, &recordbuf[0..XLOG_RECORD_CRC_OFFS]);
-                    if crc != xlogrec.xl_crc {
-                        return Err(WalDecodeError {
-                            msg: "WAL record crc mismatch".into(),
-                            lsn: self.lsn,
-                        });
-                    }
                     if xlogrec.is_xlog_switch_record() {
                         trace!("saw xlog switch record at {}", self.lsn);
                         self.padlen =
@@ -179,6 +177,15 @@ impl WalStreamDecoder {
                         self.padlen = self.lsn.calc_padding(8u32) as u32;
                     }
 
+                    let mut crc = crc32c_append(0, &recordbuf[XLOG_RECORD_CRC_OFFS + 4..]);
+                    crc = crc32c_append(crc, &recordbuf[0..XLOG_RECORD_CRC_OFFS]);
+                    if crc != xlogrec.xl_crc {
+                        return Err(WalDecodeError {
+                            msg: "WAL record crc mismatch".into(),
+                            lsn: self.lsn,
+                        });
+                    }
+
                     // Always align resulting LSN on 0x8 boundary -- that is important for getPage()
                     // and WalReceiver integration. Since this code is used both for WalReceiver and
                     // initial WAL import let's force alignment right here.
@@ -197,6 +204,7 @@ impl WalStreamDecoder {
 }
 
 #[allow(dead_code)]
+#[derive(Default)]
 pub struct DecodedBkpBlock {
     /* Is this block ref in use? */
     //in_use: bool,
@@ -229,25 +237,7 @@ pub struct DecodedBkpBlock {
 
 impl DecodedBkpBlock {
     pub fn new() -> DecodedBkpBlock {
-        DecodedBkpBlock {
-            rnode_spcnode: 0,
-            rnode_dbnode: 0,
-            rnode_relnode: 0,
-            forknum: 0,
-            blkno: 0,
-
-            flags: 0,
-            has_image: false,
-            apply_image: false,
-            will_init: false,
-            hole_offset: 0,
-            hole_length: 0,
-            bimg_len: 0,
-            bimg_info: 0,
-
-            has_data: false,
-            data_len: 0,
-        }
+        Default::default()
     }
 }
 

pageserver/src/walreceiver.rs

@@ -10,25 +10,22 @@ use crate::restore_local_repo;
 use crate::tenant_mgr;
 use crate::waldecoder::*;
 use crate::PageServerConf;
-use anyhow::{Error, Result};
+use anyhow::{bail, Error, Result};
 use lazy_static::lazy_static;
 use log::*;
 use postgres::fallible_iterator::FallibleIterator;
 use postgres::replication::ReplicationIter;
 use postgres::{Client, NoTls, SimpleQueryMessage, SimpleQueryRow};
-use postgres_ffi::xlog_utils::*;
 use postgres_ffi::*;
 use postgres_protocol::message::backend::ReplicationMessage;
 use postgres_types::PgLsn;
-use std::cmp::{max, min};
+use std::cell::Cell;
 use std::collections::HashMap;
-use std::fs;
-use std::fs::{File, OpenOptions};
-use std::io::{Seek, SeekFrom, Write};
 use std::str::FromStr;
 use std::sync::Mutex;
 use std::thread;
 use std::thread::sleep;
+use std::thread_local;
 use std::time::{Duration, SystemTime};
 use zenith_utils::lsn::Lsn;
 use zenith_utils::zid::ZTenantId;
@@ -46,6 +43,13 @@ lazy_static! {
         Mutex::new(HashMap::new());
 }
 
+thread_local! {
+    // Boolean that is true only for WAL receiver threads
+    //
+    // This is used in `wait_lsn` to guard against usage that might lead to a deadlock.
+    pub(crate) static IS_WAL_RECEIVER: Cell<bool> = Cell::new(false);
+}
+
 // Launch a new WAL receiver, or tell one that's running about change in connection string
 pub fn launch_wal_receiver(
     conf: &'static PageServerConf,
@@ -69,7 +73,8 @@ pub fn launch_wal_receiver(
             let _walreceiver_thread = thread::Builder::new()
                 .name("WAL receiver thread".into())
                 .spawn(move || {
-                    thread_main(conf, timelineid, &tenantid);
+                    IS_WAL_RECEIVER.with(|c| c.set(true));
+                    thread_main(conf, timelineid, tenantid);
                 })
                 .unwrap();
         }
@@ -90,7 +95,7 @@ fn get_wal_producer_connstr(timelineid: ZTimelineId) -> String {
 //
 // This is the entry point for the WAL receiver thread.
 //
-fn thread_main(conf: &'static PageServerConf, timelineid: ZTimelineId, tenantid: &ZTenantId) {
+fn thread_main(conf: &'static PageServerConf, timelineid: ZTimelineId, tenantid: ZTenantId) {
     info!(
         "WAL receiver thread started for timeline : '{}'",
         timelineid
@@ -117,10 +122,10 @@ fn thread_main(conf: &'static PageServerConf, timelineid: ZTimelineId, tenantid:
 }
 
 fn walreceiver_main(
-    conf: &PageServerConf,
+    _conf: &PageServerConf,
     timelineid: ZTimelineId,
     wal_producer_connstr: &str,
-    tenantid: &ZTenantId,
+    tenantid: ZTenantId,
 ) -> Result<(), Error> {
     // Connect to the database in replication mode.
     info!("connecting to {:?}", wal_producer_connstr);
@@ -146,8 +151,7 @@ fn walreceiver_main(
     let end_of_wal = Lsn::from(u64::from(identify.xlogpos));
     let mut caught_up = false;
 
-    let repository = tenant_mgr::get_repository_for_tenant(tenantid)?;
-    let timeline = repository.get_timeline(timelineid).unwrap();
+    let timeline = tenant_mgr::get_timeline_for_tenant(tenantid, timelineid)?;
 
     //
     // Start streaming the WAL, from where we left off previously.
@@ -158,13 +162,13 @@ fn walreceiver_main(
     let mut startpoint = last_rec_lsn;
 
     if startpoint == Lsn(0) {
-        error!("No previous WAL position");
+        bail!("No previous WAL position");
     }
 
     // There might be some padding after the last full record, skip it.
     startpoint += startpoint.calc_padding(8u32);
 
-    debug!(
+    info!(
         "last_record_lsn {} starting replication from {} for timeline {}, server is at {}...",
         last_rec_lsn, startpoint, timelineid, end_of_wal
     );
@@ -176,7 +180,7 @@ fn walreceiver_main(
 
     let mut waldecoder = WalStreamDecoder::new(startpoint);
 
-    let checkpoint_bytes = timeline.get_page_at_lsn_nowait(RelishTag::Checkpoint, 0, startpoint)?;
+    let checkpoint_bytes = timeline.get_page_at_lsn(RelishTag::Checkpoint, 0, startpoint)?;
     let mut checkpoint = CheckPoint::decode(&checkpoint_bytes)?;
     trace!("CheckPoint.nextXid = {}", checkpoint.nextXid.value);
 
@@ -188,16 +192,6 @@ fn walreceiver_main(
                 let data = xlog_data.data();
                 let startlsn = Lsn::from(xlog_data.wal_start());
                 let endlsn = startlsn + data.len() as u64;
-                let prev_last_rec_lsn = last_rec_lsn;
-
-                write_wal_file(
-                    conf,
-                    startlsn,
-                    &timelineid,
-                    pg_constants::WAL_SEGMENT_SIZE,
-                    data,
-                    tenantid,
-                )?;
 
                 trace!("received XLogData between {} and {}", startlsn, endlsn);
 
@@ -220,7 +214,6 @@ fn walreceiver_main(
                         recdata,
                         lsn,
                     )?;
-                    last_rec_lsn = lsn;
 
                     let new_checkpoint_bytes = checkpoint.encode();
                     // Check if checkpoint data was updated by save_decoded_record
@@ -232,34 +225,11 @@ fn walreceiver_main(
                             new_checkpoint_bytes,
                         )?;
                     }
-                }
 
-                // Somewhat arbitrarily, if we have at least 10 complete wal segments (16 MB each),
-                // "checkpoint" the repository to flush all the changes from WAL we've processed
-                // so far to disk. After this, we don't need the original WAL anymore, and it
-                // can be removed. This is probably too aggressive for production, but it's useful
-                // to expose bugs now.
-                //
-                // TODO: We don't actually dare to remove the WAL. It's useful for debugging,
-                // and we might it for logical decoding other things in the future. Although
-                // we should also be able to fetch it back from the WAL safekeepers or S3 if
-                // needed.
-                if prev_last_rec_lsn.segment_number(pg_constants::WAL_SEGMENT_SIZE)
-                    != last_rec_lsn.segment_number(pg_constants::WAL_SEGMENT_SIZE)
-                {
-                    info!("switched segment {} to {}", prev_last_rec_lsn, last_rec_lsn);
-                    let (oldest_segno, newest_segno) = find_wal_file_range(
-                        conf,
-                        &timelineid,
-                        pg_constants::WAL_SEGMENT_SIZE,
-                        last_rec_lsn,
-                        tenantid,
-                    )?;
-
-                    if newest_segno - oldest_segno >= 10 {
-                        // TODO: This is where we could remove WAL older than last_rec_lsn.
-                        //remove_wal_files(timelineid, pg_constants::WAL_SEGMENT_SIZE, last_rec_lsn)?;
-                    }
+                    // Now that this record has been fully handled, including updating the
+                    // checkpoint data, let the repository know that it is up-to-date to this LSN
+                    timeline.advance_last_record_lsn(lsn);
+                    last_rec_lsn = lsn;
                 }
 
                 if !caught_up && endlsn >= end_of_wal {
@@ -283,7 +253,7 @@ fn walreceiver_main(
                 );
 
                 if reply_requested {
-                    Some(timeline.get_last_record_lsn())
+                    Some(last_rec_lsn)
                 } else {
                     None
                 }
@@ -307,53 +277,15 @@ fn walreceiver_main(
     Ok(())
 }
 
-fn find_wal_file_range(
-    conf: &PageServerConf,
-    timeline: &ZTimelineId,
-    wal_seg_size: usize,
-    written_upto: Lsn,
-    tenant: &ZTenantId,
-) -> Result<(u64, u64)> {
-    let written_upto_segno = written_upto.segment_number(wal_seg_size);
-
-    let mut oldest_segno = written_upto_segno;
-    let mut newest_segno = written_upto_segno;
-    // Scan the wal directory, and count how many WAL filed we could remove
-    let wal_dir = conf.wal_dir_path(timeline, tenant);
-    for entry in fs::read_dir(wal_dir)? {
-        let entry = entry?;
-        let path = entry.path();
-
-        if path.is_dir() {
-            continue;
-        }
-
-        let filename = path.file_name().unwrap().to_str().unwrap();
-
-        if IsXLogFileName(filename) {
-            let (segno, _tli) = XLogFromFileName(filename, wal_seg_size);
-
-            if segno > written_upto_segno {
-                // that's strange.
-                warn!("there is a WAL file from future at {}", path.display());
-                continue;
-            }
-
-            oldest_segno = min(oldest_segno, segno);
-            newest_segno = max(newest_segno, segno);
-        }
-    }
-    // FIXME: would be good to assert that there are no gaps in the WAL files
-
-    Ok((oldest_segno, newest_segno))
-}
-
 /// Data returned from the postgres `IDENTIFY_SYSTEM` command
 ///
 /// See the [postgres docs] for more details.
 ///
 /// [postgres docs]: https://www.postgresql.org/docs/current/protocol-replication.html
 #[derive(Debug)]
+// As of nightly 2021-09-11, fields that are only read by the type's `Debug` impl still count as
+// unused. Relevant issue: https://github.com/rust-lang/rust/issues/88900
+#[allow(dead_code)]
 pub struct IdentifySystem {
     systemid: u64,
     timeline: u32,
@@ -394,98 +326,3 @@ pub fn identify_system(client: &mut Client) -> Result<IdentifySystem, Error> {
         Err(IdentifyError.into())
     }
 }
-
-fn write_wal_file(
-    conf: &PageServerConf,
-    startpos: Lsn,
-    timelineid: &ZTimelineId,
-    wal_seg_size: usize,
-    buf: &[u8],
-    tenantid: &ZTenantId,
-) -> anyhow::Result<()> {
-    let mut bytes_left: usize = buf.len();
-    let mut bytes_written: usize = 0;
-    let mut partial;
-    let mut start_pos = startpos;
-    const ZERO_BLOCK: &[u8] = &[0u8; XLOG_BLCKSZ];
-
-    let wal_dir = conf.wal_dir_path(timelineid, tenantid);
-
-    /* Extract WAL location for this block */
-    let mut xlogoff = start_pos.segment_offset(wal_seg_size);
-
-    while bytes_left != 0 {
-        let bytes_to_write;
-
-        /*
-         * If crossing a WAL boundary, only write up until we reach wal
-         * segment size.
-         */
-        if xlogoff + bytes_left > wal_seg_size {
-            bytes_to_write = wal_seg_size - xlogoff;
-        } else {
-            bytes_to_write = bytes_left;
-        }
-
-        /* Open file */
-        let segno = start_pos.segment_number(wal_seg_size);
-        let wal_file_name = XLogFileName(
-            1, // FIXME: always use Postgres timeline 1
-            segno,
-            wal_seg_size,
-        );
-        let wal_file_path = wal_dir.join(wal_file_name.clone());
-        let wal_file_partial_path = wal_dir.join(wal_file_name.clone() + ".partial");
-
-        {
-            let mut wal_file: File;
-            /* Try to open already completed segment */
-            if let Ok(file) = OpenOptions::new().write(true).open(&wal_file_path) {
-                wal_file = file;
-                partial = false;
-            } else if let Ok(file) = OpenOptions::new().write(true).open(&wal_file_partial_path) {
-                /* Try to open existed partial file */
-                wal_file = file;
-                partial = true;
-            } else {
-                /* Create and fill new partial file */
-                partial = true;
-                match OpenOptions::new()
-                    .create(true)
-                    .write(true)
-                    .open(&wal_file_partial_path)
-                {
-                    Ok(mut file) => {
-                        for _ in 0..(wal_seg_size / XLOG_BLCKSZ) {
-                            file.write_all(&ZERO_BLOCK)?;
-                        }
-                        wal_file = file;
-                    }
-                    Err(e) => {
-                        error!("Failed to open log file {:?}: {}", &wal_file_path, e);
-                        return Err(e.into());
-                    }
-                }
-            }
-            wal_file.seek(SeekFrom::Start(xlogoff as u64))?;
-            wal_file.write_all(&buf[bytes_written..(bytes_written + bytes_to_write)])?;
-
-            // FIXME: Flush the file
-            //wal_file.sync_all()?;
-        }
-        /* Write was successful, advance our position */
-        bytes_written += bytes_to_write;
-        bytes_left -= bytes_to_write;
-        start_pos += bytes_to_write as u64;
-        xlogoff += bytes_to_write;
-
-        /* Did we reach the end of a WAL segment? */
-        if start_pos.segment_offset(wal_seg_size) == 0 {
-            xlogoff = 0;
-            if partial {
-                fs::rename(&wal_file_partial_path, &wal_file_path)?;
-            }
-        }
-    }
-    Ok(())
-}

pageserver/src/walredo.rs

@@ -22,8 +22,7 @@ use byteorder::{ByteOrder, LittleEndian};
 use bytes::{Buf, BufMut, Bytes, BytesMut};
 use lazy_static::lazy_static;
 use log::*;
-use serde::{Deserialize, Serialize};
-use std::cell::RefCell;
+use serde::Serialize;
 use std::fs;
 use std::fs::OpenOptions;
 use std::io::prelude::*;
@@ -60,7 +59,7 @@ use postgres_ffi::XLogRecord;
 /// In Postgres `BufferTag` structure is used for exactly the same purpose.
 /// [See more related comments here](https://github.com/postgres/postgres/blob/99c5852e20a0987eca1c38ba0c09329d4076b6a0/src/include/storage/buf_internals.h#L91).
 ///
-#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Serialize, Deserialize)]
+#[derive(Debug, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Serialize)]
 pub struct BufferTag {
     pub rel: RelTag,
     pub blknum: u32,
@@ -206,10 +205,10 @@ impl WalRedoManager for PostgresRedoManager {
                     .block_on(PostgresRedoProcess::launch(self.conf, &self.tenantid))?;
                 *process_guard = Some(p);
             }
-            let process = (*process_guard).as_ref().unwrap();
+            let process = process_guard.as_mut().unwrap();
 
             self.runtime
-                .block_on(self.handle_apply_request(&process, &request))
+                .block_on(self.handle_apply_request(process, &request))
         };
         end_time = Instant::now();
 
@@ -247,7 +246,7 @@ impl PostgresRedoManager {
     ///
     async fn handle_apply_request(
         &self,
-        process: &PostgresRedoProcess,
+        process: &mut PostgresRedoProcess,
         request: &WalRedoRequest,
     ) -> Result<Bytes, WalRedoError> {
         let rel = request.rel;
@@ -299,9 +298,11 @@ impl PostgresRedoManager {
                     // Transaction manager stuff
                     let rec_segno = match rel {
                         RelishTag::Slru { slru, segno } => {
-                            if slru != SlruKind::Clog {
-                                panic!("Not valid XACT relish tag {:?}", rel);
-                            }
+                            assert!(
+                                slru == SlruKind::Clog,
+                                "Not valid XACT relish tag {:?}",
+                                rel
+                            );
                             segno
                         }
                         _ => panic!("Not valid XACT relish tag {:?}", rel),
@@ -324,7 +325,7 @@ impl PostgresRedoManager {
                             if rec_segno == segno && blknum == rpageno {
                                 transaction_id_set_status(
                                     *subxact,
-                                    pg_constants::TRANSACTION_STATUS_SUB_COMMITTED,
+                                    pg_constants::TRANSACTION_STATUS_COMMITTED,
                                     &mut page,
                                 );
                             }
@@ -421,7 +422,7 @@ impl PostgresRedoManager {
         );
 
         if let Err(e) = apply_result {
-            error!("could not apply WAL records: {}", e);
+            error!("could not apply WAL records: {:#}", e);
             result = Err(WalRedoError::IoError(e));
         } else {
             let img = apply_result.unwrap();
@@ -438,8 +439,8 @@ impl PostgresRedoManager {
 /// Handle to the Postgres WAL redo process
 ///
 struct PostgresRedoProcess {
-    stdin: RefCell<ChildStdin>,
-    stdout: RefCell<ChildStdout>,
+    stdin: ChildStdin,
+    stdout: ChildStdout,
 }
 
 impl PostgresRedoProcess {
@@ -453,13 +454,13 @@ impl PostgresRedoProcess {
         // FIXME: We need a dummy Postgres cluster to run the process in. Currently, we
         // just create one with constant name. That fails if you try to launch more than
         // one WAL redo manager concurrently.
-        let datadir = conf.tenant_path(&tenantid).join("wal-redo-datadir");
+        let datadir = conf.tenant_path(tenantid).join("wal-redo-datadir");
 
         // Create empty data directory for wal-redo postgres, deleting old one first.
         if datadir.exists() {
             info!("directory {:?} exists, removing", &datadir);
             if let Err(e) = fs::remove_dir_all(&datadir) {
-                error!("could not remove old wal-redo-datadir: {:?}", e);
+                error!("could not remove old wal-redo-datadir: {:#}", e);
             }
         }
         info!("running initdb in {:?}", datadir.display());
@@ -532,10 +533,7 @@ impl PostgresRedoProcess {
         };
         tokio::spawn(f_stderr);
 
-        Ok(PostgresRedoProcess {
-            stdin: RefCell::new(stdin),
-            stdout: RefCell::new(stdout),
-        })
+        Ok(PostgresRedoProcess { stdin, stdout })
     }
 
     //
@@ -543,13 +541,14 @@ impl PostgresRedoProcess {
     // new page image.
     //
     async fn apply_wal_records(
-        &self,
+        &mut self,
         tag: BufferTag,
         base_img: Option<Bytes>,
         records: &[WALRecord],
     ) -> Result<Bytes, std::io::Error> {
-        let mut stdin = self.stdin.borrow_mut();
-        let mut stdout = self.stdout.borrow_mut();
+        let stdout = &mut self.stdout;
+        // Buffer the writes to avoid a lot of small syscalls.
+        let mut stdin = tokio::io::BufWriter::new(&mut self.stdin);
 
         // We do three things simultaneously: send the old base image and WAL records to
         // the child process's stdin, read the result from child's stdout, and forward any logging

postgres_ffi/src/controlfile_utils.rs

@@ -11,7 +11,7 @@
 //! data directory is compatible with a postgres binary. That includes
 //! a version number, configuration options that can be set at
 //! compilation time like the block size, and the platform's alignment
-//! and endianess information. (The PostgreSQL on-disk file format is
+//! and endianness information. (The PostgreSQL on-disk file format is
 //! not portable across platforms.)
 //!
 //! The control file is stored in the PostgreSQL data directory, as
@@ -58,7 +58,7 @@ impl ControlFileData {
         let expectedcrc = crc32c::crc32c(&buf[0..OFFSETOF_CRC]);
 
         // Use serde to deserialize the input as a ControlFileData struct.
-        let controlfile = ControlFileData::des(buf)?;
+        let controlfile = ControlFileData::des_prefix(buf)?;
 
         // Check the CRC
         if expectedcrc != controlfile.crc {

postgres_ffi/src/lib.rs

@@ -32,5 +32,5 @@ pub const fn transaction_id_precedes(id1: TransactionId, id2: TransactionId) ->
     }
 
     let diff = id1.wrapping_sub(id2) as i32;
-    return diff < 0;
+    diff < 0
 }

postgres_ffi/src/pg_constants.rs

@@ -189,11 +189,11 @@ pub const XLOG_CHECKPOINT_SHUTDOWN: u8 = 0x00;
 pub const XLOG_CHECKPOINT_ONLINE: u8 = 0x10;
 pub const XLP_LONG_HEADER: u16 = 0x0002;
 
-pub const PG_MAJORVERSION: &'static str = "14";
+pub const PG_MAJORVERSION: &str = "14";
 
 // List of subdirectories inside pgdata.
 // Copied from src/bin/initdb/initdb.c
-pub const PGDATA_SUBDIRS: [&'static str; 22] = [
+pub const PGDATA_SUBDIRS: [&str; 22] = [
     "global",
     "pg_wal/archive_status",
     "pg_commit_ts",
@@ -218,11 +218,11 @@ pub const PGDATA_SUBDIRS: [&'static str; 22] = [
     "pg_logical/mappings",
 ];
 
-pub const PGDATA_SPECIAL_FILES: [&'static str; 4] = [
-    "pg_hba.conf",
-    "pg_ident.conf",
-    "postgresql.conf",
-    "postgresql.auto.conf",
-];
+// Don't include postgresql.conf as it is inconvenient on node start:
+// we need postgresql.conf before basebackup to synchronize safekeepers
+// so no point in overwriting it during backup restore. Rest of the files
+// here are not needed before backup so it is okay to edit them after.
+pub const PGDATA_SPECIAL_FILES: [&str; 3] =
+    ["pg_hba.conf", "pg_ident.conf", "postgresql.auto.conf"];
 
-pub static PG_HBA: &'static str = include_str!("../samples/pg_hba.conf");
+pub static PG_HBA: &str = include_str!("../samples/pg_hba.conf");

postgres_ffi/src/xlog_utils.rs

@@ -16,16 +16,20 @@ use crate::XLogPageHeaderData;
 use crate::XLogRecord;
 use crate::XLOG_PAGE_MAGIC;
 
+use anyhow::{bail, Result};
 use byteorder::{ByteOrder, LittleEndian};
 use bytes::{Buf, Bytes};
 use bytes::{BufMut, BytesMut};
 use crc32c::*;
 use log::*;
+use std::cmp::max;
 use std::cmp::min;
 use std::fs::{self, File};
 use std::io::prelude::*;
+use std::io::SeekFrom;
 use std::path::{Path, PathBuf};
 use std::time::SystemTime;
+use zenith_utils::lsn::Lsn;
 
 pub const XLOG_FNAME_LEN: usize = 24;
 pub const XLOG_BLCKSZ: usize = 8192;
@@ -37,6 +41,7 @@ pub const MAX_SEND_SIZE: usize = XLOG_BLCKSZ * 16;
 pub const XLOG_SIZE_OF_XLOG_SHORT_PHD: usize = std::mem::size_of::<XLogPageHeaderData>();
 pub const XLOG_SIZE_OF_XLOG_LONG_PHD: usize = std::mem::size_of::<XLogLongPageHeaderData>();
 pub const XLOG_SIZE_OF_XLOG_RECORD: usize = std::mem::size_of::<XLogRecord>();
+#[allow(clippy::identity_op)]
 pub const SIZE_OF_XLOG_RECORD_DATA_HEADER_SHORT: usize = 1 * 2;
 
 pub type XLogRecPtr = u64;
@@ -88,6 +93,21 @@ pub fn IsPartialXLogFileName(fname: &str) -> bool {
     fname.ends_with(".partial") && IsXLogFileName(&fname[0..fname.len() - 8])
 }
 
+/// If LSN points to the beginning of the page, then shift it to first record,
+/// otherwise align on 8-bytes boundary (required for WAL records)
+pub fn normalize_lsn(lsn: Lsn, seg_sz: usize) -> Lsn {
+    if lsn.0 % XLOG_BLCKSZ as u64 == 0 {
+        let hdr_size = if lsn.0 % seg_sz as u64 == 0 {
+            XLOG_SIZE_OF_XLOG_LONG_PHD
+        } else {
+            XLOG_SIZE_OF_XLOG_SHORT_PHD
+        };
+        lsn + hdr_size as u64
+    } else {
+        lsn.align()
+    }
+}
+
 pub fn get_current_timestamp() -> TimestampTz {
     const UNIX_EPOCH_JDATE: u64 = 2440588; /* == date2j(1970, 1, 1) */
     const POSTGRES_EPOCH_JDATE: u64 = 2451545; /* == date2j(2000, 1, 1) */
@@ -108,8 +128,10 @@ fn find_end_of_wal_segment(
     segno: XLogSegNo,
     tli: TimeLineID,
     wal_seg_size: usize,
-) -> u32 {
-    let mut offs: usize = 0;
+    start_offset: usize, // start reading at this point
+) -> Result<u32> {
+    // step back to the beginning of the page to read it in...
+    let mut offs: usize = start_offset - start_offset % XLOG_BLCKSZ;
     let mut contlen: usize = 0;
     let mut wal_crc: u32 = 0;
     let mut crc: u32 = 0;
@@ -118,24 +140,33 @@ fn find_end_of_wal_segment(
     let file_name = XLogFileName(tli, segno, wal_seg_size);
     let mut last_valid_rec_pos: usize = 0;
     let mut file = File::open(data_dir.join(file_name.clone() + ".partial")).unwrap();
+    file.seek(SeekFrom::Start(offs as u64))?;
     let mut rec_hdr = [0u8; XLOG_RECORD_CRC_OFFS];
 
     while offs < wal_seg_size {
         // we are at the beginning of the page; read it in
         if offs % XLOG_BLCKSZ == 0 {
-            if let Ok(bytes_read) = file.read(&mut buf) {
-                if bytes_read != buf.len() {
-                    break;
-                }
-            } else {
-                break;
+            let bytes_read = file.read(&mut buf)?;
+            if bytes_read != buf.len() {
+                bail!(
+                    "failed to read {} bytes from {} at {}",
+                    XLOG_BLCKSZ,
+                    file_name,
+                    offs
+                );
             }
+
             let xlp_magic = LittleEndian::read_u16(&buf[0..2]);
             let xlp_info = LittleEndian::read_u16(&buf[2..4]);
             let xlp_rem_len = LittleEndian::read_u32(&buf[XLP_REM_LEN_OFFS..XLP_REM_LEN_OFFS + 4]);
+            // this is expected in current usage when valid WAL starts after page header
             if xlp_magic != XLOG_PAGE_MAGIC as u16 {
-                info!("Invalid WAL file {}.partial magic {}", file_name, xlp_magic);
-                break;
+                trace!(
+                    "invalid WAL file {}.partial magic {} at {:?}",
+                    file_name,
+                    xlp_magic,
+                    Lsn(XLogSegNoOffsetToRecPtr(segno, offs as u32, wal_seg_size)),
+                );
             }
             if offs == 0 {
                 offs = XLOG_SIZE_OF_XLOG_LONG_PHD;
@@ -145,11 +176,18 @@ fn find_end_of_wal_segment(
             } else {
                 offs += XLOG_SIZE_OF_XLOG_SHORT_PHD;
             }
+            // ... and step forward again if asked
+            offs = max(offs, start_offset);
+
         // beginning of the next record
         } else if contlen == 0 {
             let page_offs = offs % XLOG_BLCKSZ;
             let xl_tot_len = LittleEndian::read_u32(&buf[page_offs..page_offs + 4]) as usize;
             if xl_tot_len == 0 {
+                info!(
+                    "find_end_of_wal_segment reached zeros at {:?}",
+                    Lsn(XLogSegNoOffsetToRecPtr(segno, offs as u32, wal_seg_size))
+                );
                 break; // zeros, reached the end
             }
             last_valid_rec_pos = offs;
@@ -173,12 +211,11 @@ fn find_end_of_wal_segment(
                 let crc_offs = page_offs - rec_offs + XLOG_RECORD_CRC_OFFS;
                 wal_crc = LittleEndian::read_u32(&buf[crc_offs..crc_offs + 4]);
                 crc = crc32c_append(0, &buf[crc_offs + 4..page_offs + n]);
-                crc = !crc;
             } else {
                 crc ^= 0xFFFFFFFFu32;
                 crc = crc32c_append(crc, &buf[page_offs..page_offs + n]);
-                crc = !crc;
             }
+            crc = !crc;
             rec_offs += n;
             offs += n;
             contlen -= n;
@@ -201,7 +238,7 @@ fn find_end_of_wal_segment(
             }
         }
     }
-    last_valid_rec_pos as u32
+    Ok(last_valid_rec_pos as u32)
 }
 
 ///
@@ -214,7 +251,8 @@ pub fn find_end_of_wal(
     data_dir: &Path,
     wal_seg_size: usize,
     precise: bool,
-) -> (XLogRecPtr, TimeLineID) {
+    start_lsn: Lsn, // start reading WAL at this point or later
+) -> Result<(XLogRecPtr, TimeLineID)> {
     let mut high_segno: XLogSegNo = 0;
     let mut high_tli: TimeLineID = 0;
     let mut high_ispartial = false;
@@ -256,19 +294,32 @@ pub fn find_end_of_wal(
             high_segno += 1;
         } else if precise {
             /* otherwise locate last record in last partial segment */
-            high_offs = find_end_of_wal_segment(data_dir, high_segno, high_tli, wal_seg_size);
+            if start_lsn.segment_number(wal_seg_size) > high_segno {
+                bail!(
+                    "provided start_lsn {:?} is beyond highest segno {:?} available",
+                    start_lsn,
+                    high_segno,
+                );
+            }
+            high_offs = find_end_of_wal_segment(
+                data_dir,
+                high_segno,
+                high_tli,
+                wal_seg_size,
+                start_lsn.segment_offset(wal_seg_size),
+            )?;
         }
         let high_ptr = XLogSegNoOffsetToRecPtr(high_segno, high_offs, wal_seg_size);
-        return (high_ptr, high_tli);
+        return Ok((high_ptr, high_tli));
     }
-    (0, 0)
+    Ok((0, 0))
 }
 
 pub fn main() {
     let mut data_dir = PathBuf::new();
     data_dir.push(".");
     let wal_seg_size = 16 * 1024 * 1024;
-    let (wal_end, tli) = find_end_of_wal(&data_dir, wal_seg_size, true);
+    let (wal_end, tli) = find_end_of_wal(&data_dir, wal_seg_size, true, Lsn(0)).unwrap();
     println!(
         "wal_end={:>08X}{:>08X}, tli={}",
         (wal_end >> 32) as u32,
@@ -416,7 +467,6 @@ mod tests {
     use super::*;
     use regex::Regex;
     use std::{env, process::Command, str::FromStr};
-    use zenith_utils::lsn::Lsn;
 
     // Run find_end_of_wal against file in test_wal dir
     // Ensure that it finds last record correctly
@@ -448,7 +498,7 @@ mod tests {
         let wal_seg_size = 16 * 1024 * 1024;
 
         // 3. Check end_of_wal on non-partial WAL segment (we treat it as fully populated)
-        let (wal_end, tli) = find_end_of_wal(&wal_dir, wal_seg_size, true);
+        let (wal_end, tli) = find_end_of_wal(&wal_dir, wal_seg_size, true, Lsn(0)).unwrap();
         let wal_end = Lsn(wal_end);
         println!("wal_end={}, tli={}", wal_end, tli);
         assert_eq!(wal_end, "0/2000000".parse::<Lsn>().unwrap());
@@ -465,7 +515,7 @@ mod tests {
         let waldump_output = std::str::from_utf8(&waldump_output.stderr).unwrap();
         println!("waldump_output = '{}'", &waldump_output);
         let re = Regex::new(r"invalid record length at (.+):").unwrap();
-        let caps = re.captures(&waldump_output).unwrap();
+        let caps = re.captures(waldump_output).unwrap();
         let waldump_wal_end = Lsn::from_str(caps.get(1).unwrap().as_str()).unwrap();
 
         // 5. Rename file to partial to actually find last valid lsn
@@ -474,7 +524,7 @@ mod tests {
             wal_dir.join("000000010000000000000001.partial"),
         )
         .unwrap();
-        let (wal_end, tli) = find_end_of_wal(&wal_dir, wal_seg_size, true);
+        let (wal_end, tli) = find_end_of_wal(&wal_dir, wal_seg_size, true, Lsn(0)).unwrap();
         let wal_end = Lsn(wal_end);
         println!("wal_end={}, tli={}", wal_end, tli);
         assert_eq!(wal_end, waldump_wal_end);

proxy/Cargo.toml

@@ -14,9 +14,10 @@ rand = "0.8.3"
 hex = "0.4.3"
 serde = "1"
 serde_json = "1"
-tokio = { version = "1.7.1", features = ["full"] }
-tokio-postgres = "0.7.2"
+tokio = "1.11"
+tokio-postgres = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }
 clap = "2.33.0"
 rustls = "0.19.1"
+reqwest = { version = "0.11", features = ["blocking", "json"] }
 
 zenith_utils = { path = "../zenith_utils" }

proxy/src/cplane_api.rs

@@ -1,17 +1,14 @@
-use anyhow::{bail, Result};
+use anyhow::{bail, Context, Result};
 use serde::{Deserialize, Serialize};
-use std::{
-    collections::HashMap,
-    net::{IpAddr, SocketAddr},
-};
+use std::net::{SocketAddr, ToSocketAddrs};
 
 pub struct CPlaneApi {
-    // address: SocketAddr,
+    auth_endpoint: &'static str,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Serialize, Deserialize, Debug)]
 pub struct DatabaseInfo {
-    pub host: IpAddr, // TODO: allow host name here too
+    pub host: String,
     pub port: u16,
     pub dbname: String,
     pub user: String,
@@ -19,8 +16,13 @@ pub struct DatabaseInfo {
 }
 
 impl DatabaseInfo {
-    pub fn socket_addr(&self) -> SocketAddr {
-        SocketAddr::new(self.host, self.port)
+    pub fn socket_addr(&self) -> Result<SocketAddr> {
+        let host_port = format!("{}:{}", self.host, self.port);
+        host_port
+            .to_socket_addrs()
+            .with_context(|| format!("cannot resolve {} to SocketAddr", host_port))?
+            .next()
+            .ok_or_else(|| anyhow::Error::msg("cannot resolve at least one SocketAddr"))
     }
 
     pub fn conn_string(&self) -> String {
@@ -31,62 +33,35 @@ impl DatabaseInfo {
     }
 }
 
-// mock cplane api
 impl CPlaneApi {
-    pub fn new(_address: &SocketAddr) -> CPlaneApi {
-        CPlaneApi {
-            // address: address.clone(),
-        }
+    pub fn new(auth_endpoint: &'static str) -> CPlaneApi {
+        CPlaneApi { auth_endpoint }
     }
 
-    pub fn check_auth(&self, user: &str, md5_response: &[u8], salt: &[u8; 4]) -> Result<()> {
-        // passwords for both is "mypass"
-        let auth_map: HashMap<_, &str> = vec![
-            ("stas@zenith", "716ee6e1c4a9364d66285452c47402b1"),
-            ("stas2@zenith", "3996f75df64c16a8bfaf01301b61d582"),
-        ]
-        .into_iter()
-        .collect();
+    pub fn authenticate_proxy_request(
+        &self,
+        user: &str,
+        database: &str,
+        md5_response: &[u8],
+        salt: &[u8; 4],
+    ) -> Result<DatabaseInfo> {
+        let mut url = reqwest::Url::parse(self.auth_endpoint)?;
+        url.query_pairs_mut()
+            .append_pair("login", user)
+            .append_pair("database", database)
+            .append_pair("md5response", std::str::from_utf8(md5_response)?)
+            .append_pair("salt", &hex::encode(salt));
 
-        let stored_hash = auth_map
-            .get(&user)
-            .ok_or_else(|| anyhow::Error::msg("user not found"))?;
-        let salted_stored_hash = format!(
-            "md5{:x}",
-            md5::compute([stored_hash.as_bytes(), salt].concat())
-        );
+        println!("cplane request: {}", url.as_str());
 
-        let received_hash = std::str::from_utf8(&md5_response)?;
+        let resp = reqwest::blocking::get(url)?;
 
-        println!(
-            "auth: {} rh={} sh={} ssh={} {:?}",
-            user, received_hash, stored_hash, salted_stored_hash, salt
-        );
-
-        if received_hash == salted_stored_hash {
-            Ok(())
+        if resp.status().is_success() {
+            let conn_info: DatabaseInfo = serde_json::from_str(resp.text()?.as_str())?;
+            println!("got conn info: #{:?}", conn_info);
+            Ok(conn_info)
         } else {
             bail!("Auth failed")
         }
     }
-
-    pub fn get_database_uri(&self, _user: &str, _database: &str) -> Result<DatabaseInfo> {
-        Ok(DatabaseInfo {
-            host: "127.0.0.1".parse()?,
-            port: 5432,
-            dbname: "stas".to_string(),
-            user: "stas".to_string(),
-            password: "mypass".to_string(),
-        })
-    }
-
-    // pub fn create_database(&self, _user: &String, _database: &String) -> Result<DatabaseInfo> {
-    //     Ok(DatabaseInfo {
-    //         host: "127.0.0.1".parse()?,
-    //         port: 5432,
-    //         dbname: "stas".to_string(),
-    //         user: "stas".to_string(),
-    //         password: "mypass".to_string(),
-    //     })
-    // }
 }

proxy/src/main.rs

@@ -34,7 +34,7 @@ pub struct ProxyConf {
     pub redirect_uri: String,
 
     /// control plane address where we would check auth.
-    pub cplane_address: SocketAddr,
+    pub auth_endpoint: String,
 
     pub ssl_config: Option<Arc<ServerConfig>>,
 }
@@ -56,8 +56,7 @@ fn configure_ssl(arg_matches: &ArgMatches) -> anyhow::Result<Option<Arc<ServerCo
 
     let key = {
         let key_bytes = std::fs::read(key_path).context("SSL key file")?;
-        let mut keys = pemfile::rsa_private_keys(&mut &key_bytes[..])
-            .or_else(|_| pemfile::pkcs8_private_keys(&mut &key_bytes[..]))
+        let mut keys = pemfile::pkcs8_private_keys(&mut &key_bytes[..])
             .map_err(|_| anyhow!("couldn't read TLS keys"))?;
         ensure!(keys.len() == 1, "keys.len() = {} (should be 1)", keys.len());
         keys.pop().unwrap()
@@ -102,6 +101,14 @@ fn main() -> anyhow::Result<()> {
                 .help("redirect unauthenticated users to given uri")
                 .default_value("http://localhost:3000/psql_session/"),
         )
+        .arg(
+            Arg::with_name("auth-endpoint")
+                .short("a")
+                .long("auth-endpoint")
+                .takes_value(true)
+                .help("redirect unauthenticated users to given uri")
+                .default_value("http://localhost:3000/authenticate_proxy_request/"),
+        )
         .arg(
             Arg::with_name("ssl-key")
                 .short("k")
@@ -122,7 +129,7 @@ fn main() -> anyhow::Result<()> {
         proxy_address: arg_matches.value_of("proxy").unwrap().parse()?,
         mgmt_address: arg_matches.value_of("mgmt").unwrap().parse()?,
         redirect_uri: arg_matches.value_of("uri").unwrap().parse()?,
-        cplane_address: "127.0.0.1:3000".parse()?,
+        auth_endpoint: arg_matches.value_of("auth-endpoint").unwrap().parse()?,
         ssl_config: configure_ssl(&arg_matches)?,
     };
     let state = ProxyState {
@@ -143,10 +150,10 @@ fn main() -> anyhow::Result<()> {
         // for each connection.
         thread::Builder::new()
             .name("Proxy thread".into())
-            .spawn(move || proxy::thread_main(&state, pageserver_listener))?,
+            .spawn(move || proxy::thread_main(state, pageserver_listener))?,
         thread::Builder::new()
             .name("Mgmt thread".into())
-            .spawn(move || mgmt::thread_main(&state, mgmt_listener))?,
+            .spawn(move || mgmt::thread_main(state, mgmt_listener))?,
     ];
 
     for t in threads.into_iter() {

proxy/src/mgmt.rs

@@ -5,7 +5,7 @@ use std::{
 
 use anyhow::bail;
 use bytes::Bytes;
-use serde::{Deserialize, Serialize};
+use serde::Deserialize;
 use zenith_utils::{
     postgres_backend::{self, query_from_cstring, AuthType, PostgresBackend},
     pq_proto::{BeMessage, SINGLE_COL_ROWDESC},
@@ -49,7 +49,7 @@ struct MgmtHandler {
 //             "host": "127.0.0.1",
 //             "port": 5432,
 //             "dbname": "stas",
-//             "user": "stas"
+//             "user": "stas",
 //             "password": "mypass"
 //         }
 //     }
@@ -60,13 +60,16 @@ struct MgmtHandler {
 //         "Failure": "oops"
 //     }
 // }
-#[derive(Serialize, Deserialize)]
+//
+// // to test manually by sending a query to mgmt interface:
+// psql -h 127.0.0.1 -p 9999 -c '{"session_id":"4f10dde522e14739","result":{"Success":{"host":"127.0.0.1","port":5432,"dbname":"stas","user":"stas","password":"stas"}}}'
+#[derive(Deserialize)]
 pub struct PsqlSessionResponse {
     session_id: String,
     result: PsqlSessionResult,
 }
 
-#[derive(Serialize, Deserialize)]
+#[derive(Deserialize)]
 pub enum PsqlSessionResult {
     Success(DatabaseInfo),
     Failure(String),
@@ -78,34 +81,47 @@ impl postgres_backend::Handler for MgmtHandler {
         pgb: &mut PostgresBackend,
         query_string: Bytes,
     ) -> anyhow::Result<()> {
-        let query_string = query_from_cstring(query_string);
+        let res = try_process_query(self, pgb, query_string);
+        // intercept and log error message
+        if res.is_err() {
+            println!("Mgmt query failed: #{:?}", res);
+        }
+        res
+    }
+}
 
-        println!("Got mgmt query: '{}'", std::str::from_utf8(&query_string)?);
+fn try_process_query(
+    mgmt: &mut MgmtHandler,
+    pgb: &mut PostgresBackend,
+    query_string: Bytes,
+) -> anyhow::Result<()> {
+    let query_string = query_from_cstring(query_string);
 
-        let resp: PsqlSessionResponse = serde_json::from_slice(&query_string)?;
+    println!("Got mgmt query: '{}'", std::str::from_utf8(&query_string)?);
 
-        let waiters = self.state.waiters.lock().unwrap();
+    let resp: PsqlSessionResponse = serde_json::from_slice(&query_string)?;
 
-        let sender = waiters
-            .get(&resp.session_id)
-            .ok_or_else(|| anyhow::Error::msg("psql_session_id is not found"))?;
+    let waiters = mgmt.state.waiters.lock().unwrap();
 
-        match resp.result {
-            PsqlSessionResult::Success(db_info) => {
-                sender.send(Ok(db_info))?;
+    let sender = waiters
+        .get(&resp.session_id)
+        .ok_or_else(|| anyhow::Error::msg("psql_session_id is not found"))?;
 
-                pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
-                    .write_message_noflush(&BeMessage::DataRow(&[Some(b"ok")]))?
-                    .write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
-                pgb.flush()?;
-                Ok(())
-            }
+    match resp.result {
+        PsqlSessionResult::Success(db_info) => {
+            sender.send(Ok(db_info))?;
 
-            PsqlSessionResult::Failure(message) => {
-                sender.send(Err(anyhow::Error::msg(message.clone())))?;
+            pgb.write_message_noflush(&SINGLE_COL_ROWDESC)?
+                .write_message_noflush(&BeMessage::DataRow(&[Some(b"ok")]))?
+                .write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
+            pgb.flush()?;
+            Ok(())
+        }
 
-                bail!("psql session request failed: {}", message)
-            }
+        PsqlSessionResult::Failure(message) => {
+            sender.send(Err(anyhow::Error::msg(message.clone())))?;
+
+            bail!("psql session request failed: {}", message)
         }
     }
 }

proxy/src/proxy.rs

@@ -57,7 +57,7 @@ pub fn proxy_conn_main(
 ) -> anyhow::Result<()> {
     let mut conn = ProxyConnection {
         state,
-        cplane: CPlaneApi::new(&state.conf.cplane_address),
+        cplane: CPlaneApi::new(&state.conf.auth_endpoint),
         user: "".into(),
         database: "".into(),
         pgb: PostgresBackend::new(
@@ -80,6 +80,8 @@ pub fn proxy_conn_main(
         conn.handle_new_user()?
     };
 
+    // XXX: move that inside handle_new_user/handle_existing_user to be able to
+    // report wrong connection error.
     proxy_pass(conn.pgb, db_info)
 }
 
@@ -172,21 +174,31 @@ impl ProxyConnection {
                 .split_last()
                 .ok_or_else(|| anyhow::Error::msg("unexpected password message"))?;
 
-            if let Err(e) = self.check_auth_md5(md5_response) {
-                self.pgb
-                    .write_message(&BeMessage::ErrorResponse(format!("{}", e)))?;
-                bail!("auth failed: {}", e);
-            } else {
-                self.pgb
-                    .write_message_noflush(&BeMessage::AuthenticationOk)?;
-                self.pgb
-                    .write_message_noflush(&BeMessage::ParameterStatus)?;
-                self.pgb.write_message(&BeMessage::ReadyForQuery)?;
-            }
-        }
+            match self.cplane.authenticate_proxy_request(
+                self.user.as_str(),
+                self.database.as_str(),
+                md5_response,
+                &self.md5_salt,
+            ) {
+                Err(e) => {
+                    self.pgb
+                        .write_message(&BeMessage::ErrorResponse(format!("{}", e)))?;
 
-        // ok, we are authorized
-        self.cplane.get_database_uri(&self.user, &self.database)
+                    bail!("auth failed: {}", e);
+                }
+                Ok(conn_info) => {
+                    self.pgb
+                        .write_message_noflush(&BeMessage::AuthenticationOk)?;
+                    self.pgb
+                        .write_message_noflush(&BeMessage::ParameterStatus)?;
+                    self.pgb.write_message(&BeMessage::ReadyForQuery)?;
+
+                    Ok(conn_info)
+                }
+            }
+        } else {
+            bail!("protocol violation");
+        }
     }
 
     fn handle_new_user(&mut self) -> anyhow::Result<DatabaseInfo> {
@@ -232,17 +244,11 @@ databases without opening the browser.
 
         Ok(dbinfo)
     }
-
-    fn check_auth_md5(&self, md5_response: &[u8]) -> anyhow::Result<()> {
-        assert!(self.is_existing_user());
-        self.cplane
-            .check_auth(self.user.as_str(), md5_response, &self.md5_salt)
-    }
 }
 
 /// Create a TCP connection to a postgres database, authenticate with it, and receive the ReadyForQuery message
 async fn connect_to_db(db_info: DatabaseInfo) -> anyhow::Result<tokio::net::TcpStream> {
-    let mut socket = tokio::net::TcpStream::connect(db_info.socket_addr()).await?;
+    let mut socket = tokio::net::TcpStream::connect(db_info.socket_addr()?).await?;
     let config = db_info.conn_string().parse::<tokio_postgres::Config>()?;
     let _ = config.connect_raw(&mut socket, NoTls).await?;
     Ok(socket)
@@ -273,7 +279,9 @@ fn proxy(
 
 /// Proxy a client connection to a postgres database
 fn proxy_pass(pgb: PostgresBackend, db_info: DatabaseInfo) -> anyhow::Result<()> {
-    let runtime = tokio::runtime::Builder::new_current_thread().build()?;
+    let runtime = tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()?;
     let db_stream = runtime.block_on(connect_to_db(db_info))?;
     let db_stream = db_stream.into_std()?;
     db_stream.set_nonblocking(false)?;

run_clippy.sh

@@ -8,4 +8,8 @@
 # warnings and errors right in the editor.
 # In vscode, this setting is Rust-analyzer>Check On Save:Command
 
-cargo clippy "${@:2}" -- -A clippy::new_without_default -A clippy::manual_range_contains -A clippy::comparison_chain
+
+# * `-A unknown_lints` – do not warn about unknown lint suppressions
+#                        that people with newer toolchains might use
+# * `-D warnings`      - fail on any warnings (`cargo` returns non-zero exit status)
+cargo clippy "${@:2}" --all-targets --all-features --all --tests -- -A unknown_lints -D warnings

test_runner/Pipfile

@@ -9,6 +9,8 @@ psycopg2 = "*"
 typing-extensions = "*"
 pyjwt = {extras = ["crypto"], version = "*"}
 requests = "*"
+pytest-xdist = "*"
+asyncpg = "*"
 
 [dev-packages]
 yapf = "*"

test_runner/Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "b666740289d9c82797e5c39b2a7f0074c865c9183ee878ce4fa5cda7928506ea"
+            "sha256": "3cdc048691824d0b93912b6b78a0aa01dc98f278212c1badb0cc2edbd2103c3a"
         },
         "pipfile-spec": 6,
         "requires": {
@@ -16,6 +16,25 @@
         ]
     },
     "default": {
+        "asyncpg": {
+            "hashes": [
+                "sha256:129d501f3d30616afd51eb8d3142ef51ba05374256bd5834cec3ef4956a9b317",
+                "sha256:29ef6ae0a617fc13cc2ac5dc8e9b367bb83cba220614b437af9b67766f4b6b20",
+                "sha256:41704c561d354bef01353835a7846e5606faabbeb846214dfcf666cf53319f18",
+                "sha256:556b0e92e2b75dc028b3c4bc9bd5162ddf0053b856437cf1f04c97f9c6837d03",
+                "sha256:8ff5073d4b654e34bd5eaadc01dc4d68b8a9609084d835acd364cd934190a08d",
+                "sha256:a458fc69051fbb67d995fdda46d75a012b5d6200f91e17d23d4751482640ed4c",
+                "sha256:a7095890c96ba36f9f668eb552bb020dddb44f8e73e932f8573efc613ee83843",
+                "sha256:a738f4807c853623d3f93f0fea11f61be6b0e5ca16ea8aeb42c2c7ee742aa853",
+                "sha256:c4fc0205fe4ddd5aeb3dfdc0f7bafd43411181e1f5650189608e5971cceacff1",
+                "sha256:dd2fa063c3344823487d9ddccb40802f02622ddf8bf8a6cc53885ee7a2c1c0c6",
+                "sha256:ddffcb85227bf39cd1bedd4603e0082b243cf3b14ced64dce506a15b05232b83",
+                "sha256:e36c6806883786b19551bb70a4882561f31135dc8105a59662e0376cf5b2cbc5",
+                "sha256:eed43abc6ccf1dc02e0d0efc06ce46a411362f3358847c6b0ec9a43426f91ece"
+            ],
+            "index": "pypi",
+            "version": "==0.24.0"
+        },
         "attrs": {
             "hashes": [
                 "sha256:149e90d6d8ac20db7a955ad60cf0e6881a3f20d37096140088356da6c716b0b1",
@@ -83,30 +102,43 @@
         },
         "charset-normalizer": {
             "hashes": [
-                "sha256:0c8911edd15d19223366a194a513099a302055a962bca2cec0f54b8b63175d8b",
-                "sha256:f23667ebe1084be45f6ae0538e4a5a865206544097e4e8bbcacf42cd02a348f3"
+                "sha256:5d209c0a931f215cee683b6445e2d77677e7e75e159f78def0db09d68fafcaa6",
+                "sha256:5ec46d183433dcbd0ab716f2d7f29d8dee50505b3fdb40c6b985c7c4f5a3591f"
             ],
             "markers": "python_version >= '3'",
-            "version": "==2.0.4"
+            "version": "==2.0.6"
         },
         "cryptography": {
             "hashes": [
-                "sha256:0f1212a66329c80d68aeeb39b8a16d54ef57071bf22ff4e521657b27372e327d",
-                "sha256:1e056c28420c072c5e3cb36e2b23ee55e260cb04eee08f702e0edfec3fb51959",
-                "sha256:240f5c21aef0b73f40bb9f78d2caff73186700bf1bc6b94285699aff98cc16c6",
-                "sha256:26965837447f9c82f1855e0bc8bc4fb910240b6e0d16a664bb722df3b5b06873",
-                "sha256:37340614f8a5d2fb9aeea67fd159bfe4f5f4ed535b1090ce8ec428b2f15a11f2",
-                "sha256:3d10de8116d25649631977cb37da6cbdd2d6fa0e0281d014a5b7d337255ca713",
-                "sha256:3d8427734c781ea5f1b41d6589c293089704d4759e34597dce91014ac125aad1",
-                "sha256:7ec5d3b029f5fa2b179325908b9cd93db28ab7b85bb6c1db56b10e0b54235177",
-                "sha256:8e56e16617872b0957d1c9742a3f94b43533447fd78321514abbe7db216aa250",
-                "sha256:b01fd6f2737816cb1e08ed4807ae194404790eac7ad030b34f2ce72b332f5586",
-                "sha256:bf40af59ca2465b24e54f671b2de2c59257ddc4f7e5706dbd6930e26823668d3",
-                "sha256:de4e5f7f68220d92b7637fc99847475b59154b7a1b3868fb7385337af54ac9ca",
-                "sha256:eb8cc2afe8b05acbd84a43905832ec78e7b3873fb124ca190f574dca7389a87d",
-                "sha256:ee77aa129f481be46f8d92a1a7db57269a2f23052d5f2433b4621bb457081cc9"
+                "sha256:0a7dcbcd3f1913f664aca35d47c1331fce738d44ec34b7be8b9d332151b0b01e",
+                "sha256:1eb7bb0df6f6f583dd8e054689def236255161ebbcf62b226454ab9ec663746b",
+                "sha256:21ca464b3a4b8d8e86ba0ee5045e103a1fcfac3b39319727bc0fc58c09c6aff7",
+                "sha256:34dae04a0dce5730d8eb7894eab617d8a70d0c97da76b905de9efb7128ad7085",
+                "sha256:3520667fda779eb788ea00080124875be18f2d8f0848ec00733c0ec3bb8219fc",
+                "sha256:3c4129fc3fdc0fa8e40861b5ac0c673315b3c902bbdc05fc176764815b43dd1d",
+                "sha256:3fa3a7ccf96e826affdf1a0a9432be74dc73423125c8f96a909e3835a5ef194a",
+                "sha256:5b0fbfae7ff7febdb74b574055c7466da334a5371f253732d7e2e7525d570498",
+                "sha256:695104a9223a7239d155d7627ad912953b540929ef97ae0c34c7b8bf30857e89",
+                "sha256:8695456444f277af73a4877db9fc979849cd3ee74c198d04fc0776ebc3db52b9",
+                "sha256:94cc5ed4ceaefcbe5bf38c8fba6a21fc1d365bb8fb826ea1688e3370b2e24a1c",
+                "sha256:94fff993ee9bc1b2440d3b7243d488c6a3d9724cc2b09cdb297f6a886d040ef7",
+                "sha256:9965c46c674ba8cc572bc09a03f4c649292ee73e1b683adb1ce81e82e9a6a0fb",
+                "sha256:a00cf305f07b26c351d8d4e1af84ad7501eca8a342dedf24a7acb0e7b7406e14",
+                "sha256:a305600e7a6b7b855cd798e00278161b681ad6e9b7eca94c721d5f588ab212af",
+                "sha256:cd65b60cfe004790c795cc35f272e41a3df4631e2fb6b35aa7ac6ef2859d554e",
+                "sha256:d2a6e5ef66503da51d2110edf6c403dc6b494cc0082f85db12f54e9c5d4c3ec5",
+                "sha256:d9ec0e67a14f9d1d48dd87a2531009a9b251c02ea42851c060b25c782516ff06",
+                "sha256:f44d141b8c4ea5eb4dbc9b3ad992d45580c1d22bf5e24363f2fbf50c2d7ae8a7"
             ],
-            "version": "==3.4.7"
+            "version": "==3.4.8"
+        },
+        "execnet": {
+            "hashes": [
+                "sha256:8f694f3ba9cc92cab508b152dcfe322153975c29bda272e2fd7f3f00f36e47c5",
+                "sha256:a295f7cc774947aac58dde7fdc85f4aa00c42adf5d8f5468fc630c1acf30a142"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
+            "version": "==1.9.0"
         },
         "idna": {
             "hashes": [
@@ -133,11 +165,11 @@
         },
         "pluggy": {
             "hashes": [
-                "sha256:15b2acde666561e1298d71b523007ed7364de07029219b604cf808bfa1c765b0",
-                "sha256:966c145cd83c96502c3c3868f50408687b38434af77734af1e9ca461a4081d2d"
+                "sha256:4224373bacce55f955a878bf9cfa763c1e360858e330072059e10bad68531159",
+                "sha256:74134bbf457f031a36d68416e1509f34bd5ccc019f0bcc952c7b909d06b37bd3"
             ],
-            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3'",
-            "version": "==0.13.1"
+            "markers": "python_version >= '3.6'",
+            "version": "==1.0.0"
         },
         "psycopg2": {
             "hashes": [
@@ -191,11 +223,27 @@
         },
         "pytest": {
             "hashes": [
-                "sha256:50bcad0a0b9c5a72c8e4e7c9855a3ad496ca6a881a3641b4260605450772c54b",
-                "sha256:91ef2131a9bd6be8f76f1f08eac5c5317221d6ad1e143ae03894b862e8976890"
+                "sha256:131b36680866a76e6781d13f101efb86cf674ebb9762eb70d3082b6f29889e89",
+                "sha256:7310f8d27bc79ced999e760ca304d69f6ba6c6649c0b60fb0e04a4a77cacc134"
             ],
             "index": "pypi",
-            "version": "==6.2.4"
+            "version": "==6.2.5"
+        },
+        "pytest-forked": {
+            "hashes": [
+                "sha256:6aa9ac7e00ad1a539c41bec6d21011332de671e938c7637378ec9710204e37ca",
+                "sha256:dc4147784048e70ef5d437951728825a131b81714b398d5d52f17c7c144d8815"
+            ],
+            "markers": "python_version >= '2.7' and python_version not in '3.0, 3.1, 3.2, 3.3, 3.4'",
+            "version": "==1.3.0"
+        },
+        "pytest-xdist": {
+            "hashes": [
+                "sha256:7b61ebb46997a0820a263553179d6d1e25a8c50d8a8620cd1aa1e20e3be99168",
+                "sha256:89b330316f7fc475f999c81b577c2b926c9569f3d397ae432c0c2e2496d61ff9"
+            ],
+            "index": "pypi",
+            "version": "==2.4.0"
         },
         "requests": {
             "hashes": [
@@ -215,12 +263,12 @@
         },
         "typing-extensions": {
             "hashes": [
-                "sha256:0ac0f89795dd19de6b97debb0c6af1c70987fd80a2d62d1958f7e56fcc31b497",
-                "sha256:50b6f157849174217d0656f99dc82fe932884fb250826c18350e159ec6cdf342",
-                "sha256:779383f6086d90c99ae41cf0ff39aac8a7937a9283ce0a414e5dd782f4c94a84"
+                "sha256:49f75d16ff11f1cd258e1b988ccff82a3ca5570217d7ad8c5f48205dd99a677e",
+                "sha256:d8226d10bc02a29bcc81df19a26e56a9647f8b0a6d4a83924139f4a8b01f17b7",
+                "sha256:f1d25edafde516b146ecd0613dabcc61409817af4766fbbcfb8d1ad4ec441a34"
             ],
             "index": "pypi",
-            "version": "==3.10.0.0"
+            "version": "==3.10.0.2"
         },
         "urllib3": {
             "hashes": [
@@ -309,12 +357,12 @@
         },
         "typing-extensions": {
             "hashes": [
-                "sha256:0ac0f89795dd19de6b97debb0c6af1c70987fd80a2d62d1958f7e56fcc31b497",
-                "sha256:50b6f157849174217d0656f99dc82fe932884fb250826c18350e159ec6cdf342",
-                "sha256:779383f6086d90c99ae41cf0ff39aac8a7937a9283ce0a414e5dd782f4c94a84"
+                "sha256:49f75d16ff11f1cd258e1b988ccff82a3ca5570217d7ad8c5f48205dd99a677e",
+                "sha256:d8226d10bc02a29bcc81df19a26e56a9647f8b0a6d4a83924139f4a8b01f17b7",
+                "sha256:f1d25edafde516b146ecd0613dabcc61409817af4766fbbcfb8d1ad4ec441a34"
             ],
             "index": "pypi",
-            "version": "==3.10.0.0"
+            "version": "==3.10.0.2"
         },
         "yapf": {
             "hashes": [

test_runner/batch_others/test_auth.py

@@ -1,11 +1,15 @@
 
 from contextlib import closing
+from typing import Iterator
 from uuid import uuid4
 import psycopg2
-from fixtures.zenith_fixtures import Postgres, ZenithCli, ZenithPageserver, PgBin
+from fixtures.zenith_fixtures import PortDistributor, Postgres, ZenithCli, ZenithPageserver, PgBin
 import pytest
 
 
+pytest_plugins = ("fixtures.zenith_fixtures")
+
+
 def test_pageserver_auth(pageserver_auth_enabled: ZenithPageserver):
     ps = pageserver_auth_enabled
 
@@ -42,7 +46,8 @@ def test_compute_auth_to_pageserver(
     pageserver_auth_enabled: ZenithPageserver,
     repo_dir: str,
     with_wal_acceptors: bool,
-    pg_bin: PgBin
+    pg_bin: PgBin,
+    port_distributor: PortDistributor,
 ):
     ps = pageserver_auth_enabled
     # since we are in progress of refactoring protocols between compute safekeeper and page server
@@ -59,7 +64,7 @@ def test_compute_auth_to_pageserver(
         repo_dir=repo_dir,
         pg_bin=pg_bin,
         tenant_id=ps.initial_tenant,
-        port=55432, # FIXME port distribution is hardcoded in tests and in cli
+        port=port_distributor.get_port(),
     ).create_start(
         branch,
         wal_acceptors=wa_factory.get_connstrs() if with_wal_acceptors else None,

test_runner/batch_others/test_branch_behind.py

@@ -1,3 +1,4 @@
+import subprocess
 from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
 
 
@@ -32,11 +33,11 @@ def test_branch_behind(zenith_cli, pageserver: ZenithPageserver, postgres: Postg
     main_cur.execute('''
         INSERT INTO foo
             SELECT 'long string to consume some space' || g
-            FROM generate_series(1, 100000) g
+            FROM generate_series(1, 200000) g
     ''')
     main_cur.execute('SELECT pg_current_wal_insert_lsn()')
     lsn_b = main_cur.fetchone()[0]
-    print('LSN after 100100 rows: ' + lsn_b)
+    print('LSN after 200100 rows: ' + lsn_b)
 
     # Branch at the point where only 100 rows were inserted
     zenith_cli.run(["branch", "test_branch_behind_hundred", "test_branch_behind@" + lsn_a])
@@ -45,15 +46,15 @@ def test_branch_behind(zenith_cli, pageserver: ZenithPageserver, postgres: Postg
     main_cur.execute('''
         INSERT INTO foo
             SELECT 'long string to consume some space' || g
-            FROM generate_series(1, 100000) g
+            FROM generate_series(1, 200000) g
     ''')
     main_cur.execute('SELECT pg_current_wal_insert_lsn()')
 
     main_cur.execute('SELECT pg_current_wal_insert_lsn()')
     lsn_c = main_cur.fetchone()[0]
-    print('LSN after 200100 rows: ' + lsn_c)
+    print('LSN after 400100 rows: ' + lsn_c)
 
-    # Branch at the point where only 200 rows were inserted
+    # Branch at the point where only 200100 rows were inserted
     zenith_cli.run(["branch", "test_branch_behind_more", "test_branch_behind@" + lsn_b])
 
     pg_hundred = postgres.create_start("test_branch_behind_hundred")
@@ -69,8 +70,23 @@ def test_branch_behind(zenith_cli, pageserver: ZenithPageserver, postgres: Postg
     more_pg_conn = pg_more.connect()
     more_cur = more_pg_conn.cursor()
     more_cur.execute('SELECT count(*) FROM foo')
-    assert more_cur.fetchone() == (100100, )
+    assert more_cur.fetchone() == (200100, )
 
     # All the rows are visible on the main branch
     main_cur.execute('SELECT count(*) FROM foo')
-    assert main_cur.fetchone() == (200100, )
+    assert main_cur.fetchone() == (400100, )
+
+    # Check bad lsn's for branching
+
+    # branch at segment boundary
+    zenith_cli.run(["branch", "test_branch_segment_boundary", "test_branch_behind@0/3000000"])
+    pg = postgres.create_start("test_branch_segment_boundary")
+    cur = pg.connect().cursor()
+    cur.execute('SELECT 1')
+    assert cur.fetchone() == (1, )
+
+    # branch at pre-initdb lsn
+    try:
+        zenith_cli.run(["branch", "test_branch_preinitdb", "test_branch_behind@0/42"])
+    except subprocess.CalledProcessError:
+        print("Branch creation with pre-initdb LSN failed (as expected)")

test_runner/batch_others/test_createdropdb.py

@@ -2,7 +2,7 @@ import os
 import pathlib
 
 from contextlib import closing
-from fixtures.zenith_fixtures import ZenithPageserver, PostgresFactory, ZenithCli
+from fixtures.zenith_fixtures import ZenithPageserver, PostgresFactory, ZenithCli, check_restored_datadir_content
 
 pytest_plugins = ("fixtures.zenith_fixtures")
 
@@ -48,6 +48,7 @@ def test_dropdb(
     pageserver: ZenithPageserver,
     postgres: PostgresFactory,
     pg_bin,
+    test_output_dir
 ):
     zenith_cli.run(["branch", "test_dropdb", "empty"])
 
@@ -69,6 +70,8 @@ def test_dropdb(
         with conn.cursor() as cur:
             cur.execute('DROP DATABASE foodb')
 
+            cur.execute('CHECKPOINT')
+
             cur.execute('SELECT pg_current_wal_insert_lsn()')
             lsn_after_drop = cur.fetchone()[0]
 
@@ -94,3 +97,6 @@ def test_dropdb(
     print(dbpath)
 
     assert os.path.isdir(dbpath) == False
+
+    # Check that we restore the content of the datadir correctly
+    check_restored_datadir_content(zenith_cli, test_output_dir, pg, pageserver.service_port.pg)

test_runner/batch_others/test_multixact.py

@@ -1,4 +1,4 @@
-from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver, check_restored_datadir_content
 
 pytest_plugins = ("fixtures.zenith_fixtures")
 
@@ -9,7 +9,8 @@ pytest_plugins = ("fixtures.zenith_fixtures")
 # it only checks next_multixact_id field in restored pg_control,
 # since we don't have functions to check multixact internals.
 #
-def test_multixact(pageserver: ZenithPageserver, postgres: PostgresFactory, pg_bin, zenith_cli, base_dir):
+def test_multixact(pageserver: ZenithPageserver, postgres: PostgresFactory,
+                    pg_bin, zenith_cli, base_dir, test_output_dir):
     # Create a branch for us
     zenith_cli.run(["branch", "test_multixact", "empty"])
     pg = postgres.create_start('test_multixact')
@@ -63,3 +64,6 @@ def test_multixact(pageserver: ZenithPageserver, postgres: PostgresFactory, pg_b
 
     # Check that we restored pg_controlfile correctly
     assert next_multixact_id_new == next_multixact_id
+
+    # Check that we restore the content of the datadir correctly
+    check_restored_datadir_content(zenith_cli, test_output_dir, pg_new, pageserver.service_port.pg)

test_runner/batch_others/test_old_request_lsn.py

@@ -0,0 +1,65 @@
+from contextlib import closing
+
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+
+pytest_plugins = ("fixtures.zenith_fixtures")
+
+#
+# Test where Postgres generates a lot of WAL, and it's garbage collected away, but
+# no pages are evicted so that Postgres uses an old LSN in a GetPage request.
+# We had a bug where the page server failed to find the page version because it
+# thought it was already garbage collected away, because the LSN in the GetPage
+# request was very old and the WAL from that time was indeed already removed.
+# In reality, the LSN on a GetPage request coming from a primary server is
+# just a hint that the page hasn't been modified since that LSN, and the page
+# server should return the latest page version regardless of the LSN.
+#
+def test_old_request_lsn(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFactory, pg_bin):
+    # Create a branch for us
+    zenith_cli.run(["branch", "test_old_request_lsn", "empty"])
+    pg = postgres.create_start('test_old_request_lsn')
+    print('postgres is running on test_old_request_lsn branch')
+
+    pg_conn = pg.connect()
+    cur = pg_conn.cursor()
+
+    # Get the timeline ID of our branch. We need it for the 'do_gc' command
+    cur.execute("SHOW zenith.zenith_timeline")
+    timeline = cur.fetchone()[0]
+
+    psconn = pageserver.connect()
+    pscur = psconn.cursor()
+
+    # Create table, and insert some rows. Make it big enough that it doesn't fit in
+    # shared_buffers.
+    cur.execute('CREATE TABLE foo (id int4 PRIMARY KEY, val int, t text)')
+    cur.execute('''
+        INSERT INTO foo
+            SELECT g, 1, 'long string to consume some space' || g
+            FROM generate_series(1, 100000) g
+    ''')
+
+    # Verify that the table is larger than shared_buffers, so that the SELECT below
+    # will cause GetPage requests.
+    cur.execute('''
+        select setting::int * pg_size_bytes(unit) as shared_buffers, pg_relation_size('foo') as tbl_ize
+        from pg_settings where name = 'shared_buffers'
+    ''')
+    row = cur.fetchone()
+    print(f'shared_buffers is {row[0]}, table size {row[1]}');
+    assert int(row[0]) < int(row[1])
+
+    cur.execute('VACUUM foo');
+
+    # Make a lot of updates on a single row, generating a lot of WAL. Trigger
+    # garbage collections so that the page server will remove old page versions.
+    for i in range(10):
+        pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
+        for j in range(100):
+            cur.execute('UPDATE foo SET val = val + 1 WHERE id = 1;');
+
+    # All (or at least most of) the updates should've been on the same page, so
+    # that we haven't had to evict any dirty pages for a long time. Now run
+    # a query that sends GetPage@LSN requests with the old LSN.
+    cur.execute("SELECT COUNT(*), SUM(val) FROM foo");
+    assert cur.fetchone() == (100000, 101000)

test_runner/batch_others/test_restart_compute.py

@@ -9,10 +9,7 @@ pytest_plugins = ("fixtures.zenith_fixtures")
 #
 # Test restarting and recreating a postgres instance
 #
-# XXX: with_wal_acceptors=True fails now, would be fixed with
-# `postgres --sync-walkeepers` patches.
-#
-@pytest.mark.parametrize('with_wal_acceptors', [False])
+@pytest.mark.parametrize('with_wal_acceptors', [False, True])
 def test_restart_compute(
         zenith_cli,
         pageserver: ZenithPageserver,

test_runner/batch_others/test_snapfiles_gc.py

@@ -6,19 +6,19 @@ pytest_plugins = ("fixtures.zenith_fixtures")
 
 def print_gc_result(row):
     print("GC duration {elapsed} ms".format_map(row));
-    print("  REL    total: {snapshot_relfiles_total}, needed_by_cutoff {snapshot_relfiles_needed_by_cutoff}, needed_by_branches: {snapshot_relfiles_needed_by_branches}, not_updated: {snapshot_relfiles_not_updated}, removed: {snapshot_relfiles_removed}, dropped: {snapshot_relfiles_dropped}".format_map(row))
-    print("  NONREL total: {snapshot_nonrelfiles_total}, needed_by_cutoff {snapshot_nonrelfiles_needed_by_cutoff}, needed_by_branches: {snapshot_nonrelfiles_needed_by_branches}, not_updated: {snapshot_nonrelfiles_not_updated}, removed: {snapshot_nonrelfiles_removed}, dropped: {snapshot_nonrelfiles_dropped}".format_map(row))
+    print("  REL    total: {layer_relfiles_total}, needed_by_cutoff {layer_relfiles_needed_by_cutoff}, needed_by_branches: {layer_relfiles_needed_by_branches}, not_updated: {layer_relfiles_not_updated}, needed_as_tombstone {layer_relfiles_needed_as_tombstone}, removed: {layer_relfiles_removed}, dropped: {layer_relfiles_dropped}".format_map(row))
+    print("  NONREL total: {layer_nonrelfiles_total}, needed_by_cutoff {layer_nonrelfiles_needed_by_cutoff}, needed_by_branches: {layer_nonrelfiles_needed_by_branches}, not_updated: {layer_nonrelfiles_not_updated}, needed_as_tombstone {layer_nonrelfiles_needed_as_tombstone}, removed: {layer_nonrelfiles_removed}, dropped: {layer_nonrelfiles_dropped}".format_map(row))
 
 
 #
-# Test Garbage Collection of old snapshot files
+# Test Garbage Collection of old layer files
 #
 # This test is pretty tightly coupled with the current implementation of layered
 # storage, in layered_repository.rs.
 #
-def test_snapfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
-    zenith_cli.run(["branch", "test_snapfiles_gc", "empty"])
-    pg = postgres.create_start('test_snapfiles_gc')
+def test_layerfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
+    zenith_cli.run(["branch", "test_layerfiles_gc", "empty"])
+    pg = postgres.create_start('test_layerfiles_gc')
 
     with closing(pg.connect()) as conn:
         with conn.cursor() as cur:
@@ -55,22 +55,24 @@ def test_snapfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
                     row = pscur.fetchone()
                     print_gc_result(row);
                     # remember the number of files
-                    snapshot_relfiles_remain = row['snapshot_relfiles_total'] - row['snapshot_relfiles_removed']
-                    assert snapshot_relfiles_remain > 0
+                    layer_relfiles_remain = row['layer_relfiles_total'] - row['layer_relfiles_removed']
+                    assert layer_relfiles_remain > 0
 
-                    # Insert a row.
+                    # Insert a row and run GC. Checkpoint should freeze the layer
+                    # so that there is only the most recent image layer left for the rel,
+                    # removing the old image and delta layer.
                     print("Inserting one row and running GC")
                     cur.execute("INSERT INTO foo VALUES (1)")
                     pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
                     row = pscur.fetchone()
                     print_gc_result(row);
-                    assert row['snapshot_relfiles_total'] == snapshot_relfiles_remain + 1
-                    assert row['snapshot_relfiles_removed'] == 1
-                    assert row['snapshot_relfiles_dropped'] == 0
+                    assert row['layer_relfiles_total'] == layer_relfiles_remain + 2
+                    assert row['layer_relfiles_removed'] == 2
+                    assert row['layer_relfiles_dropped'] == 0
 
                     # Insert two more rows and run GC.
-                    # This should create a new snapshot file with the new contents, and
-                    # remove the old one.
+                    # This should create new image and delta layer file with the new contents, and
+                    # then remove the old one image and the just-created delta layer.
                     print("Inserting two more rows and running GC")
                     cur.execute("INSERT INTO foo VALUES (2)")
                     cur.execute("INSERT INTO foo VALUES (3)")
@@ -78,11 +80,11 @@ def test_snapfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
                     pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
                     row = pscur.fetchone()
                     print_gc_result(row);
-                    assert row['snapshot_relfiles_total'] == snapshot_relfiles_remain + 1
-                    assert row['snapshot_relfiles_removed'] == 1
-                    assert row['snapshot_relfiles_dropped'] == 0
+                    assert row['layer_relfiles_total'] == layer_relfiles_remain + 2
+                    assert row['layer_relfiles_removed'] == 2
+                    assert row['layer_relfiles_dropped'] == 0
 
-                    # Do it again. Should again create a new snapshot file and remove old one.
+                    # Do it again. Should again create two new layer files and remove old ones.
                     print("Inserting two more rows and running GC")
                     cur.execute("INSERT INTO foo VALUES (2)")
                     cur.execute("INSERT INTO foo VALUES (3)")
@@ -90,18 +92,18 @@ def test_snapfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
                     pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
                     row = pscur.fetchone()
                     print_gc_result(row);
-                    assert row['snapshot_relfiles_total'] == snapshot_relfiles_remain + 1
-                    assert row['snapshot_relfiles_removed'] == 1
-                    assert row['snapshot_relfiles_dropped'] == 0
+                    assert row['layer_relfiles_total'] == layer_relfiles_remain + 2
+                    assert row['layer_relfiles_removed'] == 2
+                    assert row['layer_relfiles_dropped'] == 0
 
                     # Run GC again, with no changes in the database. Should not remove anything.
                     print("Run GC again, with nothing to do")
                     pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
                     row = pscur.fetchone()
                     print_gc_result(row);
-                    assert row['snapshot_relfiles_total'] == snapshot_relfiles_remain
-                    assert row['snapshot_relfiles_removed'] == 0
-                    assert row['snapshot_relfiles_dropped'] == 0
+                    assert row['layer_relfiles_total'] == layer_relfiles_remain
+                    assert row['layer_relfiles_removed'] == 0
+                    assert row['layer_relfiles_dropped'] == 0
 
                     #
                     # Test DROP TABLE checks that relation data and metadata was deleted by GC from object storage
@@ -113,12 +115,19 @@ def test_snapfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
                     row = pscur.fetchone()
                     print_gc_result(row);
 
+                    # We still cannot remove the latest layers
+                    # because they serve as tombstones for earlier layers.
+                    assert row['layer_relfiles_dropped'] == 0
                     # Each relation fork is counted separately, hence 3.
-                    assert row['snapshot_relfiles_dropped'] == 3
+                    assert row['layer_relfiles_needed_as_tombstone'] == 3
 
-                    # The catalog updates also create new snapshot files of the catalogs, which
+                    # The catalog updates also create new layer files of the catalogs, which
                     # are counted as 'removed'
-                    assert row['snapshot_relfiles_removed'] > 0
+                    assert row['layer_relfiles_removed'] > 0
+
+                    # TODO Change the test to check actual CG of dropped layers.
+                    # Each relation fork is counted separately, hence 3.
+                    #assert row['layer_relfiles_dropped'] == 3
 
                     # TODO: perhaps we should count catalog and user relations separately,
                     # to make this kind of testing more robust

test_runner/batch_others/test_timeline_size.py

@@ -0,0 +1,39 @@
+from contextlib import closing
+from uuid import UUID
+import psycopg2.extras
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+
+
+def test_timeline_size(
+    zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFactory, pg_bin
+):
+    # Branch at the point where only 100 rows were inserted
+    zenith_cli.run(["branch", "test_timeline_size", "empty"])
+
+    client = pageserver.http_client()
+    res = client.branch_detail(UUID(pageserver.initial_tenant), "test_timeline_size")
+    assert res["current_logical_size"] == res["current_logical_size_non_incremental"]
+
+    pgmain = postgres.create_start("test_timeline_size")
+    print("postgres is running on 'test_timeline_size' branch")
+
+    with closing(pgmain.connect()) as conn:
+        with conn.cursor() as cur:
+            cur.execute("SHOW zenith.zenith_timeline")
+
+            # Create table, and insert the first 100 rows
+            cur.execute("CREATE TABLE foo (t text)")
+            cur.execute(
+                """
+                INSERT INTO foo
+                    SELECT 'long string to consume some space' || g
+                    FROM generate_series(1, 10) g
+            """
+            )
+
+            res = client.branch_detail(UUID(pageserver.initial_tenant), "test_timeline_size")
+            assert res["current_logical_size"] == res["current_logical_size_non_incremental"]
+            cur.execute("TRUNCATE foo")
+
+            res = client.branch_detail(UUID(pageserver.initial_tenant), "test_timeline_size")
+            assert res["current_logical_size"] == res["current_logical_size_non_incremental"]

test_runner/batch_others/test_twophase.py

@@ -59,9 +59,8 @@ def test_twophase(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFa
     # Create a branch with the transaction in prepared state
     zenith_cli.run(["branch", "test_twophase_prepared", "test_twophase"])
 
-    # Create compute node, but don't start.
-    # We want to observe pgdata before postgres starts
-    pg2 = postgres.create(
+    # Start compute on the new branch
+    pg2 = postgres.create_start(
         'test_twophase_prepared',
         config_lines=['max_prepared_transactions=5'],
     )
@@ -71,7 +70,6 @@ def test_twophase(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFa
     print(twophase_files2)
     assert twophase_files2.sort() == twophase_files.sort()
 
-    pg2 = pg2.start()
     conn2 = pg2.connect()
     cur2 = conn2.cursor()
 

test_runner/batch_others/test_wal_acceptor.py

@@ -1,10 +1,14 @@
 import pytest
 import random
 import time
+import os
+import subprocess
+import uuid
 
 from contextlib import closing
 from multiprocessing import Process, Value
-from fixtures.zenith_fixtures import WalAcceptorFactory, ZenithPageserver, PostgresFactory
+from fixtures.zenith_fixtures import WalAcceptorFactory, ZenithPageserver, PostgresFactory, PgBin
+from fixtures.utils import lsn_to_hex, mkdir_if_needed
 
 pytest_plugins = ("fixtures.zenith_fixtures")
 
@@ -198,3 +202,92 @@ def test_race_conditions(zenith_cli, pageserver: ZenithPageserver, postgres: Pos
 
     stop_value.value = 1
     proc.join()
+
+class ProposerPostgres:
+    """Object for running safekeepers sync with walproposer"""
+    def __init__(self, pgdata_dir: str, pg_bin: PgBin, timeline_id: str, tenant_id: str):
+        self.pgdata_dir: str = pgdata_dir
+        self.pg_bin: PgBin = pg_bin
+        self.timeline_id: str = timeline_id
+        self.tenant_id: str = tenant_id
+
+    def pg_data_dir_path(self) -> str:
+        """ Path to data directory """
+        return self.pgdata_dir
+
+    def config_file_path(self) -> str:
+        """ Path to postgresql.conf """
+        return os.path.join(self.pgdata_dir, 'postgresql.conf')
+
+    def create_dir_config(self, wal_acceptors: str):
+        """ Create dir and config for running --sync-safekeepers """
+
+        mkdir_if_needed(self.pg_data_dir_path())
+        with open(self.config_file_path(), "w") as f:
+            f.writelines([
+                "synchronous_standby_names = 'walproposer'\n",
+                f"zenith.zenith_timeline = '{self.timeline_id}'\n",
+                f"zenith.zenith_tenant = '{self.tenant_id}'\n",
+                f"wal_acceptors = '{wal_acceptors}'\n",
+            ])
+
+    def sync_safekeepers(self) -> str:
+        """
+        Run 'postgres --sync-safekeepers'.
+        Returns execution result, which is commit_lsn after sync.
+        """
+
+        command = ["postgres", "--sync-safekeepers"]
+        env = {
+            "PGDATA": self.pg_data_dir_path(),
+        }
+
+        basepath = self.pg_bin.run_capture(command, env)
+        stdout_filename = basepath + '.stdout'
+
+        with open(stdout_filename, 'r') as stdout_f:
+            stdout = stdout_f.read()
+            return stdout.strip("\n ")
+
+
+# insert wal in all safekeepers and run sync on proposer
+def test_sync_safekeepers(repo_dir: str, pg_bin: PgBin, wa_factory: WalAcceptorFactory):
+    wa_factory.start_n_new(3)
+
+    timeline_id = uuid.uuid4().hex
+    tenant_id = uuid.uuid4().hex
+
+    # write config for proposer
+    pgdata_dir = os.path.join(repo_dir, "proposer_pgdata")
+    pg = ProposerPostgres(pgdata_dir, pg_bin, timeline_id, tenant_id)
+    pg.create_dir_config(wa_factory.get_connstrs())
+
+    # valid lsn, which is not in the segment start, nor in zero segment
+    epoch_start_lsn = 0x16B9188  # 0/16B9188
+    begin_lsn = epoch_start_lsn
+
+    # append and commit WAL
+    lsn_after_append = []
+    for i in range(3):
+        res = wa_factory.instances[i].append_logical_message(
+            tenant_id,
+            timeline_id,
+            {
+                "lm_prefix": "prefix",
+                "lm_message": "message",
+                "set_commit_lsn": True,
+                "term": 2,
+                "begin_lsn": begin_lsn,
+                "epoch_start_lsn": epoch_start_lsn,
+                "truncate_lsn": epoch_start_lsn,
+            },
+        )
+        lsn_hex = lsn_to_hex(res["inserted_wal"]["end_lsn"])
+        lsn_after_append.append(lsn_hex)
+        print(f"safekeeper[{i}] lsn after append: {lsn_hex}")
+
+    # run sync safekeepers
+    lsn_after_sync = pg.sync_safekeepers()
+    print(f"lsn after sync = {lsn_after_sync}")
+
+    assert all(lsn_after_sync == lsn for lsn in lsn_after_append)

test_runner/batch_others/test_wal_acceptor_async.py

@@ -0,0 +1,159 @@
+import asyncio
+import asyncpg
+import random
+
+from fixtures.zenith_fixtures import WalAcceptor, WalAcceptorFactory, ZenithPageserver, PostgresFactory, Postgres
+from typing import List
+from fixtures.utils import debug_print
+
+pytest_plugins = ("fixtures.zenith_fixtures")
+
+
+class BankClient(object):
+    def __init__(self, conn: asyncpg.Connection, n_accounts, init_amount):
+        self.conn: asyncpg.Connection = conn
+        self.n_accounts = n_accounts
+        self.init_amount = init_amount
+
+    async def initdb(self):
+        await self.conn.execute('DROP TABLE IF EXISTS bank_accs')
+        await self.conn.execute('CREATE TABLE bank_accs(uid int primary key, amount int)')
+        await self.conn.execute('''
+            INSERT INTO bank_accs
+            SELECT *, $1 FROM generate_series(0, $2)
+        ''', self.init_amount, self.n_accounts - 1)
+        await self.conn.execute('DROP TABLE IF EXISTS bank_log')
+        await self.conn.execute('CREATE TABLE bank_log(from_uid int, to_uid int, amount int)')
+        
+        # TODO: Remove when https://github.com/zenithdb/zenith/issues/644 is fixed
+        await self.conn.execute('ALTER TABLE bank_accs SET (autovacuum_enabled = false)')
+        await self.conn.execute('ALTER TABLE bank_log SET (autovacuum_enabled = false)')
+
+    async def check_invariant(self):
+        row = await self.conn.fetchrow('SELECT sum(amount) AS sum FROM bank_accs')
+        assert row['sum'] == self.n_accounts * self.init_amount
+
+async def bank_transfer(conn: asyncpg.Connection, from_uid, to_uid, amount):
+    # avoid deadlocks by sorting uids
+    if from_uid > to_uid:
+        from_uid, to_uid, amount = to_uid, from_uid, -amount
+
+    async with conn.transaction():
+        await conn.execute(
+            'UPDATE bank_accs SET amount = amount + ($1) WHERE uid = $2',
+            amount, to_uid,
+        )
+        await conn.execute(
+            'UPDATE bank_accs SET amount = amount - ($1) WHERE uid = $2',
+            amount, from_uid,
+        )
+        await conn.execute('INSERT INTO bank_log VALUES ($1, $2, $3)',
+            from_uid, to_uid, amount,
+        )
+
+class WorkerStats(object):
+    def __init__(self, n_workers):
+        self.counters = [0] * n_workers
+        self.running = True
+
+    def reset(self):
+        self.counters = [0] * len(self.counters)
+
+    def inc_progress(self, worker_id):
+        self.counters[worker_id] += 1
+
+    def check_progress(self):
+        debug_print("Workers progress: {}".format(self.counters))
+
+        # every worker should finish at least one tx
+        assert all(cnt > 0 for cnt in self.counters)
+
+        progress = sum(self.counters)
+        print('All workers made {} transactions'.format(progress))
+
+
+async def run_random_worker(stats: WorkerStats, pg: Postgres, worker_id, n_accounts, max_transfer):
+    pg_conn = await pg.connect_async()
+    debug_print('Started worker {}'.format(worker_id))
+
+    while stats.running:
+        from_uid = random.randint(0, n_accounts - 1)
+        to_uid = (from_uid + random.randint(1, n_accounts - 1)) % n_accounts
+        amount = random.randint(1, max_transfer)
+
+        await bank_transfer(pg_conn, from_uid, to_uid, amount)
+        stats.inc_progress(worker_id)
+
+        debug_print('Executed transfer({}) {} => {}'.format(amount, from_uid, to_uid))
+
+    debug_print('Finished worker {}'.format(worker_id))
+
+    await pg_conn.close()
+
+
+# This test will run several iterations and check progress in each of them.
+# On each iteration 1 acceptor is stopped, and 2 others should allow
+# background workers execute transactions. In the end, state should remain
+# consistent.
+async def run_restarts_under_load(pg: Postgres, acceptors: List[WalAcceptor], n_workers=10):
+    n_accounts = 100
+    init_amount = 100000
+    max_transfer = 100
+    period_time = 10
+    iterations = 6
+
+    pg_conn = await pg.connect_async()
+    bank = BankClient(pg_conn, n_accounts=n_accounts, init_amount=init_amount)
+    # create tables and initial balances
+    await bank.initdb()
+
+    stats = WorkerStats(n_workers)
+    workers = []
+    for worker_id in range(n_workers):
+        worker = run_random_worker(stats, pg, worker_id, bank.n_accounts, max_transfer)
+        workers.append(asyncio.create_task(worker))
+
+
+    for it in range(iterations):
+        victim = acceptors[it % len(acceptors)]
+        victim.stop()
+
+        # Wait till previous victim recovers so it is ready for the next
+        # iteration by making any writing xact.
+        conn = await pg.connect_async()
+        await conn.execute(
+            'UPDATE bank_accs SET amount = amount WHERE uid = 1',
+            timeout=120
+        )
+        await conn.close()
+
+        stats.reset()
+        await asyncio.sleep(period_time)
+        # assert that at least one transaction has completed in every worker
+        stats.check_progress()
+
+        victim.start()
+
+    print('Iterations are finished, exiting coroutines...')
+    stats.running = False
+    # await all workers
+    await asyncio.gather(*workers)
+    # assert balances sum hasn't changed
+    await bank.check_invariant()
+    await pg_conn.close()
+
+
+# restart acceptors one by one, while executing and validating bank transactions
+def test_restarts_under_load(zenith_cli, pageserver: ZenithPageserver, postgres: PostgresFactory,
+                             wa_factory: WalAcceptorFactory):
+
+    wa_factory.start_n_new(3)
+
+    zenith_cli.run(["branch", "test_wal_acceptors_restarts_under_load", "empty"])
+    pg = postgres.create_start('test_wal_acceptors_restarts_under_load',
+                               wal_acceptors=wa_factory.get_connstrs())
+
+    asyncio.run(run_restarts_under_load(pg, wa_factory.instances))
+
+    # TODO: Remove when https://github.com/zenithdb/zenith/issues/644 is fixed
+    pg.stop()

test_runner/batch_pg_regress/test_pg_regress.py

@@ -1,7 +1,7 @@
 import os
 
 from fixtures.utils import mkdir_if_needed
-from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver, check_restored_datadir_content
 
 pytest_plugins = ("fixtures.zenith_fixtures")
 
@@ -49,3 +49,10 @@ def test_pg_regress(pageserver: ZenithPageserver, postgres: PostgresFactory, pg_
     # logs the exact same data to `regression.out` anyway.
     with capsys.disabled():
         pg_bin.run(pg_regress_command, env=env, cwd=runpath)
+
+        # checkpoint one more time to ensure that the lsn we get is the latest one
+        pg.safe_psql('CHECKPOINT')
+        lsn = pg.safe_psql('select pg_current_wal_insert_lsn()')[0][0]
+
+        # Check that we restore the content of the datadir correctly
+        check_restored_datadir_content(zenith_cli, test_output_dir, pg, pageserver.service_port.pg)

test_runner/batch_pg_regress/test_zenith_regress.py

@@ -1,13 +1,13 @@
 import os
 
 from fixtures.utils import mkdir_if_needed
-from fixtures.zenith_fixtures import PostgresFactory
+from fixtures.zenith_fixtures import PageserverPort, PostgresFactory, check_restored_datadir_content
 
 pytest_plugins = ("fixtures.zenith_fixtures")
 
 
 def test_zenith_regress(postgres: PostgresFactory, pg_bin, zenith_cli, test_output_dir, pg_distrib_dir,
-                        base_dir, capsys):
+                        base_dir, capsys, pageserver_port: PageserverPort):
 
     # Create a branch for us
     zenith_cli.run(["branch", "test_zenith_regress", "empty"])
@@ -50,3 +50,10 @@ def test_zenith_regress(postgres: PostgresFactory, pg_bin, zenith_cli, test_outp
     # logs the exact same data to `regression.out` anyway.
     with capsys.disabled():
         pg_bin.run(pg_regress_command, env=env, cwd=runpath)
+
+        # checkpoint one more time to ensure that the lsn we get is the latest one
+        pg.safe_psql('CHECKPOINT')
+        lsn = pg.safe_psql('select pg_current_wal_insert_lsn()')[0][0]
+
+        # Check that we restore the content of the datadir correctly
+        check_restored_datadir_content(zenith_cli, test_output_dir, pg, pageserver_port.pg)

test_runner/fixtures/benchmark_fixture.py

@@ -1,6 +1,7 @@
 from pprint import pprint
 
 import os
+import re
 import timeit
 import pathlib
 import uuid
@@ -78,7 +79,7 @@ class ZenithBenchmarkResults:
 
         self.results.append((test_name, metric_name, metric_value, unit))
 
-# Sesssion scope fixture that initializes the results object
+# Session scope fixture that initializes the results object
 @pytest.fixture(autouse=True, scope='session')
 def zenbenchmark_global(request) -> Iterator[ZenithBenchmarkResults]:
     """
@@ -120,6 +121,60 @@ class ZenithBenchmarker:
 
         self.results.record(self.request.node.name, metric_name, end - start, 's')
 
+    def get_io_writes(self, pageserver) -> int:
+        """
+        Fetch the "cumulative # of bytes written" metric from the pageserver
+        """
+        # Fetch all the exposed prometheus metrics from page server
+        all_metrics = pageserver.http_client().get_metrics()
+        # Use a regular expression to extract the one we're interested in
+        #
+        # TODO: If we start to collect more of the prometheus metrics in the
+        # performance test suite like this, we should refactor this to load and
+        # parse all the metrics into a more convenient structure in one go.
+        #
+        # The metric should be an integer, as it's a number of bytes. But in general
+        # all prometheus metrics are floats. So to be pedantic, read it as a float
+        # and round to integer.
+        matches = re.search(r'^pageserver_disk_io_bytes{io_operation="write"} (\S+)$', all_metrics,
+                            re.MULTILINE)
+        return int(round(float(matches.group(1))))
+
+    def get_peak_mem(self, pageserver) -> int:
+        """
+        Fetch the "maxrss" metric from the pageserver
+        """
+        # Fetch all the exposed prometheus metrics from page server
+        all_metrics = pageserver.http_client().get_metrics()
+        # See comment in get_io_writes()
+        matches = re.search(r'^pageserver_maxrss_kb (\S+)$', all_metrics,
+                            re.MULTILINE)
+        return int(round(float(matches.group(1))))
+
+    def get_timeline_size(self, repo_dir: str, tenantid: str, timelineid: str):
+        """
+        Calculate the on-disk size of a timeline
+        """
+        path = "{}/tenants/{}/timelines/{}".format(repo_dir, tenantid, timelineid)
+
+        totalbytes = 0
+        for root, dirs, files in os.walk(path):
+            for name in files:
+                totalbytes += os.path.getsize(os.path.join(root, name))
+
+        return totalbytes
+
+    @contextmanager
+    def record_pageserver_writes(self, pageserver, metric_name):
+        """
+        Record bytes written by the pageserver during a test.
+        """
+        before = self.get_io_writes(pageserver)
+        yield
+        after = self.get_io_writes(pageserver)
+
+        self.results.record(self.request.node.name, metric_name, round((after - before) / (1024 * 1024)), 'MB')
+
 @pytest.fixture(scope='function')
 def zenbenchmark(zenbenchmark_global, request) -> Iterator[ZenithBenchmarker]:
     """

test_runner/fixtures/utils.py

@@ -14,13 +14,14 @@ def mkdir_if_needed(path: str) -> None:
 
     Note this won't try to create intermediate directories.
     """
-    if os.path.exists(path):
-        assert os.path.isdir(path)
-        return
-    os.mkdir(path)
+    try:
+        os.mkdir(path)
+    except FileExistsError:
+        pass
+    assert os.path.isdir(path)
 
 
-def subprocess_capture(capture_dir: str, cmd: List[str], **kwargs: Any) -> None:
+def subprocess_capture(capture_dir: str, cmd: List[str], **kwargs: Any) -> str:
     """ Run a process and capture its output
 
     Output will go to files named "cmd_NNN.stdout" and "cmd_NNN.stderr"
@@ -28,6 +29,7 @@ def subprocess_capture(capture_dir: str, cmd: List[str], **kwargs: Any) -> None:
     counter.
 
     If those files already exist, we will overwrite them.
+    Returns basepath for files with captured output.
     """
     assert type(cmd) is list
     base = os.path.basename(cmd[0]) + '_{}'.format(global_counter())
@@ -40,6 +42,8 @@ def subprocess_capture(capture_dir: str, cmd: List[str], **kwargs: Any) -> None:
             print('(capturing output to "{}.stdout")'.format(base))
             subprocess.run(cmd, **kwargs, stdout=stdout_f, stderr=stderr_f)
 
+    return basepath
+
 
 _global_counter = 0
 
@@ -53,3 +57,15 @@ def global_counter() -> int:
     global _global_counter
     _global_counter += 1
     return _global_counter
+
+def debug_print(*args, **kwargs) -> None:
+    """ Print to the console if TEST_DEBUG_PRINT is set in env.
+    
+    All parameters are passed to print().
+    """
+    if os.environ.get('TEST_DEBUG_PRINT') is not None:
+        print(*args, **kwargs)
+
+def lsn_to_hex(num: int) -> str:
+    """ Convert lsn from int to standard hex notation. """
+    return "{:X}/{:X}".format(num >> 32, num & 0xffffffff)

test_runner/fixtures/zenith_fixtures.py

@@ -1,15 +1,19 @@
 from dataclasses import dataclass
 from functools import cached_property
+import asyncpg
 import os
 import pathlib
 import uuid
 import jwt
+import json
 import psycopg2
 import pytest
 import shutil
 import signal
 import subprocess
 import time
+import filecmp
+import difflib
 
 from contextlib import closing
 from pathlib import Path
@@ -47,8 +51,29 @@ Fn = TypeVar('Fn', bound=Callable[..., Any])
 DEFAULT_OUTPUT_DIR = 'test_output'
 DEFAULT_POSTGRES_DIR = 'tmp_install'
 
-DEFAULT_PAGESERVER_PG_PORT = 64000
-DEFAULT_PAGESERVER_HTTP_PORT = 9898
+BASE_PORT = 15000
+WORKER_PORT_NUM = 100
+
+def pytest_configure(config):
+    """
+    Ensure that no unwanted daemons are running before we start testing.
+    Check that we do not owerflow available ports range.
+    """
+    numprocesses = config.getoption('numprocesses')
+    if numprocesses is not None and BASE_PORT + numprocesses * WORKER_PORT_NUM > 32768: # do not use ephemeral ports
+         raise Exception('Too many workers configured. Cannot distrubute ports for services.')
+
+    # does not use -c as it is not supported on macOS
+    cmd = ['pgrep', 'pageserver|postgres|wal_acceptor']
+    result = subprocess.run(cmd, stdout=subprocess.DEVNULL)
+    if result.returncode == 0:
+        # returncode of 0 means it found something.
+        # This is bad; we don't want any of those processes polluting the
+        # result of the test.
+        # NOTE this shows as an internal pytest error, there might be a better way
+        raise Exception(
+            'Found interfering processes running. Stop all Zenith pageservers, nodes, WALs, as well as stand-alone Postgres.'
+        )
 
 
 def determine_scope(fixture_name: str, config: Any) -> str:
@@ -73,20 +98,6 @@ def zenfixture(func: Fn) -> Fn:
     return pytest.fixture(func, scope=scope)
 
 
-@pytest.fixture(autouse=True, scope='session')
-def safety_check() -> None:
-    """ Ensure that no unwanted daemons are running before we start testing. """
-
-    # does not use -c as it is not supported on macOS
-    cmd = ['pgrep', 'pageserver|postgres|wal_acceptor']
-    result = subprocess.run(cmd, stdout=subprocess.DEVNULL)
-    if result.returncode == 0:
-        # returncode of 0 means it found something.
-        # This is bad; we don't want any of those processes polluting the
-        # result of the test.
-        raise Exception('found interfering processes running')
-
-
 class PgProtocol:
     """ Reusable connection logic """
     def __init__(self, host: str, port: int, username: Optional[str] = None):
@@ -122,6 +133,21 @@ class PgProtocol:
         conn.autocommit = autocommit
         return conn
 
+    async def connect_async(self, *, dbname: str = 'postgres', username: Optional[str] = None, password: Optional[str] = None) -> asyncpg.Connection:
+        """
+        Connect to the node from async python.
+        Returns asyncpg's connection object.
+        """
+
+        conn = await asyncpg.connect(
+            host=self.host,
+            port=self.port,
+            database=dbname,
+            user=username or self.username,
+            password=password,
+        )
+        return conn
+
     def safe_psql(self, query: str, **kwargs: Any) -> List[Any]:
         """
         Execute query against the node and return all rows.
@@ -169,12 +195,27 @@ class ZenithCli:
 
         args = [self.bin_zenith] + arguments
         print('Running command "{}"'.format(' '.join(args)))
-        return subprocess.run(args,
-                              env=self.env,
-                              check=True,
-                              universal_newlines=True,
-                              stdout=subprocess.PIPE,
-                              stderr=subprocess.PIPE)
+
+        # Interceipt CalledProcessError and print more info
+        try:
+            res = subprocess.run(args,
+                                env=self.env,
+                                check=True,
+                                universal_newlines=True,
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.PIPE)
+        except subprocess.CalledProcessError as exc:
+            # this way command output will be in recorded and shown in CI in failure message
+            msg = f"""\
+            Run failed: {exc}
+              stdout: {exc.stdout}
+              stderr: {exc.stderr}
+            """
+            print(msg)
+
+            raise Exception(msg) from exc
+
+        return res
 
 
 @zenfixture
@@ -211,6 +252,13 @@ class ZenithPageserverHttpClient(requests.Session):
         res.raise_for_status()
         return res.json()
 
+    def branch_detail(self, tenant_id: uuid.UUID, name: str) -> Dict:
+        res = self.get(
+            f"http://localhost:{self.port}/v1/branch/{tenant_id.hex}/{name}",
+        )
+        res.raise_for_status()
+        return res.json()
+
     def tenant_list(self) -> List[str]:
         res = self.get(f"http://localhost:{self.port}/v1/tenant")
         res.raise_for_status()
@@ -226,6 +274,11 @@ class ZenithPageserverHttpClient(requests.Session):
         res.raise_for_status()
         return res.json()
 
+    def get_metrics(self) -> str:
+        res = self.get(f"http://localhost:{self.port}/metrics")
+        res.raise_for_status()
+        return res.text
+
 
 @dataclass
 class AuthKeys:
@@ -252,24 +305,60 @@ class AuthKeys:
         return token
 
 
+@zenfixture
+def worker_seq_no(worker_id: str):
+    # worker_id is a pytest-xdist fixture
+    # it can be master or gw<number>
+    # parse it to always get a number
+    if worker_id == 'master':
+        return 0
+    assert worker_id.startswith('gw')
+    return int(worker_id[2:])
 
 
+@zenfixture
+def worker_base_port(worker_seq_no: int):
+    # so we divide ports in ranges of 100 ports
+    # so workers have disjoint set of ports for services
+    return BASE_PORT + worker_seq_no * WORKER_PORT_NUM
+
+class PortDistributor:
+    def __init__(self, base_port: int, port_number: int) -> None:
+        self.iterator = iter(range(base_port, base_port + port_number))
+
+    def get_port(self) -> int:
+        try:
+            return next(self.iterator)
+        except StopIteration:
+            raise RuntimeError('port range configured for test is exhausted, consider enlarging the range')
+
+
+@zenfixture
+def port_distributor(worker_base_port):
+    return PortDistributor(base_port=worker_base_port, port_number=WORKER_PORT_NUM)
+
+@dataclass
+class PageserverPort:
+    pg: int
+    http: int
+
 
 class ZenithPageserver(PgProtocol):
     """ An object representing a running pageserver. """
-    def __init__(self, zenith_cli: ZenithCli, repo_dir: str):
-        super().__init__(host='localhost', port=DEFAULT_PAGESERVER_PG_PORT)
+    def __init__(self, zenith_cli: ZenithCli, repo_dir: str, port: PageserverPort):
+        super().__init__(host='localhost', port=port.pg)
         self.zenith_cli = zenith_cli
         self.running = False
         self.initial_tenant = None
         self.repo_dir = repo_dir
+        self.service_port = port # do not shadow PgProtocol.port which is just int
 
     def init(self, enable_auth: bool = False) -> 'ZenithPageserver':
         """
         Initialize the repository, i.e. run "zenith init".
         Returns self.
         """
-        cmd = ['init']
+        cmd = ['init', f'--pageserver-pg-port={self.service_port.pg}', f'--pageserver-http-port={self.service_port.http}']
         if enable_auth:
             cmd.append('--enable-auth')
         self.zenith_cli.run(cmd)
@@ -319,13 +408,23 @@ class ZenithPageserver(PgProtocol):
 
     def http_client(self, auth_token: Optional[str] = None):
         return ZenithPageserverHttpClient(
-            port=DEFAULT_PAGESERVER_HTTP_PORT,
+            port=self.service_port.http,
             auth_token=auth_token,
         )
 
 
+
+
 @zenfixture
-def pageserver(zenith_cli: ZenithCli, repo_dir: str) -> Iterator[ZenithPageserver]:
+def pageserver_port(port_distributor: PortDistributor) -> PageserverPort:
+    pg = port_distributor.get_port()
+    http = port_distributor.get_port()
+    print(f"pageserver_port: pg={pg} http={http}")
+    return PageserverPort(pg=pg, http=http)
+
+
+@zenfixture
+def pageserver(zenith_cli: ZenithCli, repo_dir: str, pageserver_port: PageserverPort) -> Iterator[ZenithPageserver]:
     """
     The 'pageserver' fixture provides a Page Server that's up and running.
 
@@ -337,8 +436,7 @@ def pageserver(zenith_cli: ZenithCli, repo_dir: str) -> Iterator[ZenithPageserve
     By convention, the test branches are named after the tests. For example,
     test called 'test_foo' would create and use branches with the 'test_foo' prefix.
     """
-
-    ps = ZenithPageserver(zenith_cli, repo_dir).init().start()
+    ps = ZenithPageserver(zenith_cli=zenith_cli, repo_dir=repo_dir, port=pageserver_port).init().start()
     # For convenience in tests, create a branch from the freshly-initialized cluster.
     zenith_cli.run(["branch", "empty", "main"])
 
@@ -390,17 +488,19 @@ class PgBin:
     def run_capture(self,
                     command: List[str],
                     env: Optional[Env] = None,
-                    cwd: Optional[str] = None) -> None:
+                    cwd: Optional[str] = None,
+                    **kwargs: Any) -> None:
         """
         Run one of the postgres binaries, with stderr and stdout redirected to a file.
 
-        This is just like `run`, but for chatty programs.
+        This is just like `run`, but for chatty programs. Returns basepath for files
+        with captured output.
         """
 
         self._fixpath(command)
         print('Running command "{}"'.format(' '.join(command)))
         env = self._build_env(env)
-        subprocess_capture(self.log_dir, command, env=env, cwd=cwd, check=True)
+        return subprocess_capture(self.log_dir, command, env=env, cwd=cwd, check=True, **kwargs)
 
 
 @zenfixture
@@ -408,8 +508,8 @@ def pg_bin(test_output_dir: str, pg_distrib_dir: str) -> PgBin:
     return PgBin(test_output_dir, pg_distrib_dir)
 
 @pytest.fixture
-def pageserver_auth_enabled(zenith_cli: ZenithCli, repo_dir: str):
-    with ZenithPageserver(zenith_cli, repo_dir).init(enable_auth=True).start() as ps:
+def pageserver_auth_enabled(zenith_cli: ZenithCli, repo_dir: str, pageserver_port: PageserverPort):
+    with ZenithPageserver(zenith_cli=zenith_cli, repo_dir=repo_dir, port=pageserver_port).init(enable_auth=True).start() as ps:
         # For convenience in tests, create a branch from the freshly-initialized cluster.
         zenith_cli.run(["branch", "empty", "main"])
         yield ps
@@ -434,7 +534,6 @@ class Postgres(PgProtocol):
         branch: str,
         wal_acceptors: Optional[str] = None,
         config_lines: Optional[List[str]] = None,
-        config_only: bool = False,
     ) -> 'Postgres':
         """
         Create the pg data directory.
@@ -446,10 +545,7 @@ class Postgres(PgProtocol):
         if not config_lines:
             config_lines = []
 
-        if config_only:
-            self.zenith_cli.run(['pg', 'create', '--config-only', branch, f'--tenantid={self.tenant_id}'])
-        else:
-            self.zenith_cli.run(['pg', 'create', branch, f'--tenantid={self.tenant_id}'])
+        self.zenith_cli.run(['pg', 'create', branch, f'--tenantid={self.tenant_id}', f'--port={self.port}'])
         self.branch = branch
         path = pathlib.Path('pgdatadirs') / 'tenants' / self.tenant_id / self.branch
         self.pgdata_dir = os.path.join(self.repo_dir, path)
@@ -470,12 +566,12 @@ class Postgres(PgProtocol):
 
         assert self.branch is not None
 
-        print(f"Starting postgres on brach {self.branch}")
+        print(f"Starting postgres on branch {self.branch}")
 
-        self.zenith_cli.run(['pg', 'start', self.branch, f'--tenantid={self.tenant_id}'])
+        run_result = self.zenith_cli.run(['pg', 'start', self.branch, f'--tenantid={self.tenant_id}', f'--port={self.port}'])
         self.running = True
 
-        self.pg_bin.run(['pg_controldata', self.pg_data_dir_path()])
+        print(f"stdout: {run_result.stdout}")
 
         return self
 
@@ -572,7 +668,6 @@ class Postgres(PgProtocol):
             branch=branch,
             wal_acceptors=wal_acceptors,
             config_lines=config_lines,
-            config_only=True,
         ).start()
 
         return self
@@ -583,16 +678,15 @@ class Postgres(PgProtocol):
     def __exit__(self, exc_type, exc, tb):
         self.stop()
 
-
 class PostgresFactory:
     """ An object representing multiple running postgres daemons. """
-    def __init__(self, zenith_cli: ZenithCli, repo_dir: str, pg_bin: PgBin, initial_tenant: str, base_port: int = 55431):
+    def __init__(self, zenith_cli: ZenithCli, repo_dir: str, pg_bin: PgBin, initial_tenant: str, port_distributor: PortDistributor):
         self.zenith_cli = zenith_cli
         self.repo_dir = repo_dir
         self.num_instances = 0
         self.instances: List[Postgres] = []
         self.initial_tenant: str = initial_tenant
-        self.base_port = base_port
+        self.port_distributor = port_distributor
         self.pg_bin = pg_bin
 
     def create_start(
@@ -602,15 +696,13 @@ class PostgresFactory:
         wal_acceptors: Optional[str] = None,
         config_lines: Optional[List[str]] = None
     ) -> Postgres:
-
         pg = Postgres(
             zenith_cli=self.zenith_cli,
             repo_dir=self.repo_dir,
             pg_bin=self.pg_bin,
             tenant_id=tenant_id or self.initial_tenant,
-            port=self.base_port + self.num_instances + 1,
+            port=self.port_distributor.get_port(),
         )
-
         self.num_instances += 1
         self.instances.append(pg)
 
@@ -633,7 +725,7 @@ class PostgresFactory:
             repo_dir=self.repo_dir,
             pg_bin=self.pg_bin,
             tenant_id=tenant_id or self.initial_tenant,
-            port=self.base_port + self.num_instances + 1,
+            port=self.port_distributor.get_port(),
         )
 
         self.num_instances += 1
@@ -658,7 +750,7 @@ class PostgresFactory:
             repo_dir=self.repo_dir,
             pg_bin=self.pg_bin,
             tenant_id=tenant_id or self.initial_tenant,
-            port=self.base_port + self.num_instances + 1,
+            port=self.port_distributor.get_port(),
         )
 
         self.num_instances += 1
@@ -682,8 +774,14 @@ def initial_tenant(pageserver: ZenithPageserver):
 
 
 @zenfixture
-def postgres(zenith_cli: ZenithCli, initial_tenant: str, repo_dir: str, pg_bin: PgBin) -> Iterator[PostgresFactory]:
-    pgfactory = PostgresFactory(zenith_cli, repo_dir, pg_bin, initial_tenant=initial_tenant)
+def postgres(zenith_cli: ZenithCli, initial_tenant: str, repo_dir: str, pg_bin: PgBin, port_distributor: PortDistributor) -> Iterator[PostgresFactory]:
+    pgfactory = PostgresFactory(
+        zenith_cli=zenith_cli,
+        repo_dir=repo_dir,
+        pg_bin=pg_bin,
+        initial_tenant=initial_tenant,
+        port_distributor=port_distributor,
+    )
 
     yield pgfactory
 
@@ -699,10 +797,11 @@ def read_pid(path: Path):
 @dataclass
 class WalAcceptor:
     """ An object representing a running wal acceptor daemon. """
-    bin_path: Path
+    wa_bin_path: Path
     data_dir: Path
     port: int
     num: int # identifier for logging
+    pageserver_port: int
     auth_token: Optional[str] = None
 
     def start(self) -> 'WalAcceptor':
@@ -710,13 +809,13 @@ class WalAcceptor:
         self.data_dir.mkdir(parents=True, exist_ok=True)
         self.pidfile.unlink(missing_ok=True)
 
-        cmd = [str(self.bin_path)]
+        cmd = [str(self.wa_bin_path)]
         cmd.extend(["-D", str(self.data_dir)])
-        cmd.extend(["-l", "localhost:{}".format(self.port)])
+        cmd.extend(["-l", f"localhost:{self.port}"])
         cmd.append("--daemonize")
         cmd.append("--no-sync")
         # Tell page server it can receive WAL from this WAL safekeeper
-        cmd.extend(["--pageserver", "localhost:{}".format(DEFAULT_PAGESERVER_PG_PORT)])
+        cmd.extend(["--pageserver", f"localhost:{self.pageserver_port}"])
         cmd.extend(["--recall", "1 second"])
         print('Running command "{}"'.format(' '.join(cmd)))
         env = {'PAGESERVER_AUTH_TOKEN': self.auth_token} if self.auth_token else None
@@ -760,27 +859,49 @@ class WalAcceptor:
             pass # pidfile might be obsolete
         return self
 
+    def append_logical_message(self, tenant_id: str, timeline_id: str, request: Dict[str, Any]) -> Dict[str, Any]:
+        """
+        Send JSON_CTRL query to append LogicalMessage to WAL and modify 
+        safekeeper state. It will construct LogicalMessage from provided
+        prefix and message, and then will write it to WAL.
+        """
+
+        # "replication=0" hacks psycopg not to send additional queries
+        # on startup, see https://github.com/psycopg/psycopg2/pull/482
+        connstr = f"host=localhost port={self.port} replication=0 options='-c ztimelineid={timeline_id} ztenantid={tenant_id}'"
+
+        with closing(psycopg2.connect(connstr)) as conn:
+            # server doesn't support transactions
+            conn.autocommit = True
+            with conn.cursor() as cur:
+                request_json = json.dumps(request)
+                print(f"JSON_CTRL request on port {self.port}: {request_json}")
+                cur.execute("JSON_CTRL " + request_json)
+                all = cur.fetchall()
+                print(f"JSON_CTRL response: {all[0][0]}")
+                return json.loads(all[0][0])
 
 class WalAcceptorFactory:
     """ An object representing multiple running wal acceptors. """
-    def __init__(self, zenith_binpath: Path, data_dir: Path):
-        self.wa_binpath = zenith_binpath / 'wal_acceptor'
+    def __init__(self, zenith_binpath: Path, data_dir: Path, pageserver_port: int, port_distributor: PortDistributor):
+        self.wa_bin_path = zenith_binpath / 'wal_acceptor'
         self.data_dir = data_dir
         self.instances: List[WalAcceptor] = []
-        self.initial_port = 54321
+        self.port_distributor = port_distributor
+        self.pageserver_port = pageserver_port
 
     def start_new(self, auth_token: Optional[str] = None) -> WalAcceptor:
         """
         Start new wal acceptor.
         """
-
         wa_num = len(self.instances)
         wa = WalAcceptor(
-            self.wa_binpath,
-            self.data_dir / "wal_acceptor_{}".format(wa_num),
-            self.initial_port + wa_num,
-            wa_num,
-            auth_token,
+            wa_bin_path=self.wa_bin_path,
+            data_dir=self.data_dir / "wal_acceptor_{}".format(wa_num),
+            port=self.port_distributor.get_port(),
+            num=wa_num,
+            pageserver_port=self.pageserver_port,
+            auth_token=auth_token,
         )
         wa.start()
         self.instances.append(wa)
@@ -805,9 +926,14 @@ class WalAcceptorFactory:
 
 
 @zenfixture
-def wa_factory(zenith_binpath: str, repo_dir: str) -> Iterator[WalAcceptorFactory]:
+def wa_factory(zenith_binpath: str, repo_dir: str, pageserver_port: PageserverPort, port_distributor: PortDistributor) -> Iterator[WalAcceptorFactory]:
     """ Gives WalAcceptorFactory providing wal acceptors. """
-    wafactory = WalAcceptorFactory(Path(zenith_binpath), Path(repo_dir) / "wal_acceptors")
+    wafactory = WalAcceptorFactory(
+        zenith_binpath=Path(zenith_binpath),
+        data_dir=Path(repo_dir) / "wal_acceptors",
+        pageserver_port=pageserver_port.pg,
+        port_distributor=port_distributor,
+    )
     yield wafactory
     # After the yield comes any cleanup code we need.
     print('Starting wal acceptors cleanup')
@@ -911,3 +1037,85 @@ class TenantFactory:
 @zenfixture
 def tenant_factory(zenith_cli: ZenithCli):
     return TenantFactory(zenith_cli)
+
+#
+# Test helpers
+#
+def list_files_to_compare(pgdata_dir: str):
+    pgdata_files = []
+    for root, _file, filenames in os.walk(pgdata_dir):
+        for filename in filenames:
+            rel_dir = os.path.relpath(root, pgdata_dir)
+            # Skip some dirs and files we don't want to compare
+            skip_dirs = ['pg_wal', 'pg_stat', 'pg_stat_tmp', 'pg_subtrans', 'pg_logical']
+            skip_files = ['pg_internal.init', 'pg.log', 'zenith.signal', 'postgresql.conf',
+                        'postmaster.opts', 'postmaster.pid', 'pg_control']
+            if rel_dir not in skip_dirs and filename not in skip_files:
+                rel_file = os.path.join(rel_dir, filename)
+                pgdata_files.append(rel_file)
+
+    pgdata_files.sort()
+    print(pgdata_files)
+    return pgdata_files
+
+# pg is the existing and running compute node, that we want to compare with a basebackup
+def check_restored_datadir_content(zenith_cli: ZenithCli, test_output_dir: str, pg: Postgres, pageserver_pg_port: int):
+
+    # Get the timeline ID of our branch. We need it for the 'basebackup' command
+    with closing(pg.connect()) as conn:
+        with conn.cursor() as cur:
+            cur.execute("SHOW zenith.zenith_timeline")
+            timeline = cur.fetchone()[0]
+
+    # stop postgres to ensure that files won't change
+    pg.stop()
+
+    # Take a basebackup from pageserver
+    restored_dir_path = os.path.join(test_output_dir, f"{pg.branch}_restored_datadir")
+    mkdir_if_needed(restored_dir_path)
+
+    psql_path = os.path.join(pg.pg_bin.pg_bin_path, 'psql')
+
+    cmd = rf"""
+        {psql_path}                                    \
+            --no-psqlrc                                \
+            postgres://localhost:{pageserver_pg_port}  \
+            -c 'basebackup {pg.tenant_id} {timeline}'  \
+         | tar -x -C {restored_dir_path}
+    """
+
+    subprocess.check_call(cmd, shell=True)
+
+    # list files we're going to compare
+    pgdata_files = list_files_to_compare(pg.pgdata_dir)
+    restored_files = list_files_to_compare(restored_dir_path)
+
+    # check that file sets are equal
+    assert pgdata_files == restored_files
+
+    # compare content of the files
+    # filecmp returns (match, mismatch, error) lists
+    # We've already filtered all mismatching files in list_files_to_compare(),
+    # so here expect that the content is identical
+    (match, mismatch, error) = filecmp.cmpfiles(pg.pgdata_dir,
+                                                restored_dir_path,
+                                                pgdata_files,
+                                                shallow=False)
+    print('filecmp result mismatch and error lists:')
+    print(mismatch)
+    print(error)
+
+    for f in mismatch:
+
+        f1 = os.path.join(pg.pgdata_dir, f)
+        f2 = os.path.join(restored_dir_path, f)
+        stdout_filename = "{}.filediff".format(f2)
+
+        with open(stdout_filename, 'w') as stdout_f:
+            subprocess.run("xxd -b {} > {}.hex ".format(f1, f1), shell=True)
+            subprocess.run("xxd -b {} > {}.hex ".format(f2, f2), shell=True)
+
+            cmd = ['diff {}.hex {}.hex'.format(f1, f2)]
+            subprocess.run(cmd, stdout=stdout_f, shell=True)
+
+    assert (mismatch, error) == ([], [])

test_runner/performance/test_bulk_insert.py

@@ -0,0 +1,51 @@
+import os
+from contextlib import closing
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+
+pytest_plugins = ("fixtures.zenith_fixtures", "fixtures.benchmark_fixture")
+
+#
+# Run bulk INSERT test.
+#
+# Collects metrics:
+#
+# 1. Time to INSERT 5 million rows
+# 2. Disk writes
+# 3. Disk space used
+# 4. Peak memory usage
+#
+def test_bulk_insert(postgres: PostgresFactory, pageserver: ZenithPageserver, pg_bin, zenith_cli, zenbenchmark, repo_dir: str):
+    # Create a branch for us
+    zenith_cli.run(["branch", "test_bulk_insert", "empty"])
+
+    pg = postgres.create_start('test_bulk_insert')
+    print("postgres is running on 'test_bulk_insert' branch")
+
+    # Open a connection directly to the page server that we'll use to force
+    # flushing the layers to disk
+    psconn = pageserver.connect();
+    pscur = psconn.cursor()
+
+    # Get the timeline ID of our branch. We need it for the 'do_gc' command
+    with closing(pg.connect()) as conn:
+        with conn.cursor() as cur:
+            cur.execute("SHOW zenith.zenith_timeline")
+            timeline = cur.fetchone()[0]
+
+            cur.execute("create table huge (i int, j int);")
+
+            # Run INSERT, recording the time and I/O it takes
+            with zenbenchmark.record_pageserver_writes(pageserver, 'pageserver_writes'):
+                with zenbenchmark.record_duration('insert'):
+                    cur.execute("insert into huge values (generate_series(1, 5000000), 0);")
+
+                    # Flush the layers from memory to disk. This is included in the reported
+                    # time and I/O
+                    pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
+
+            # Record peak memory usage
+            zenbenchmark.record("peak_mem", zenbenchmark.get_peak_mem(pageserver) / 1024, 'MB')
+
+            # Report disk space used by the repository
+            timeline_size = zenbenchmark.get_timeline_size(repo_dir, pageserver.initial_tenant, timeline)
+            zenbenchmark.record('size', timeline_size / (1024*1024), 'MB')

test_runner/performance/test_bulk_tenant_create.py

@@ -0,0 +1,58 @@
+import timeit
+import pytest
+
+from fixtures.zenith_fixtures import (
+    TenantFactory,
+    ZenithCli,
+    PostgresFactory,
+)
+
+pytest_plugins = ("fixtures.benchmark_fixture")
+
+# Run bulk tenant creation test.
+#
+# Collects metrics:
+#
+# 1. Time to create {1,10,50} tenants
+# 2. Average creation time per tenant
+
+
+@pytest.mark.parametrize('tenants_count', [1, 5, 10])
+@pytest.mark.parametrize('use_wal_acceptors', ['with_wa', 'without_wa'])
+def test_bulk_tenant_create(
+    zenith_cli: ZenithCli,
+    tenant_factory: TenantFactory,
+    postgres: PostgresFactory,
+    wa_factory,
+    use_wal_acceptors: str,
+    tenants_count: int,
+    zenbenchmark,
+):
+    """Measure tenant creation time (with and without wal acceptors)"""
+
+    time_slices = []
+
+    for i in range(tenants_count):
+        start = timeit.default_timer()
+
+        tenant = tenant_factory.create()
+        zenith_cli.run([
+            "branch", f"test_bulk_tenant_create_{tenants_count}_{i}_{use_wal_acceptors}", "main",
+            f"--tenantid={tenant}"
+        ])
+
+        if use_wal_acceptors == 'with_wa':
+            wa_factory.start_n_new(3)
+
+        pg_tenant = postgres.create_start(
+            f"test_bulk_tenant_create_{tenants_count}_{i}_{use_wal_acceptors}",
+            tenant,
+            wal_acceptors=wa_factory.get_connstrs() if use_wal_acceptors == 'with_wa' else None,
+        )
+
+        end = timeit.default_timer()
+        time_slices.append(end - start)
+
+        pg_tenant.stop()
+
+    zenbenchmark.record('tenant_creation_time', sum(time_slices) / len(time_slices), 's')

test_runner/performance/test_perf_pgbench.py

@@ -4,19 +4,6 @@ from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
 
 pytest_plugins = ("fixtures.zenith_fixtures", "fixtures.benchmark_fixture")
 
-def get_timeline_size(repo_dir: str, tenantid: str, timelineid: str):
-    path = "{}/tenants/{}/timelines/{}".format(repo_dir, tenantid, timelineid)
-
-    totalbytes = 0
-    for root, dirs, files in os.walk(path):
-        for name in files:
-            totalbytes += os.path.getsize(os.path.join(root, name))
-
-        if 'wal' in dirs:
-            dirs.remove('wal')  # don't visit 'wal' subdirectory
-
-    return totalbytes
-
 #
 # Run a very short pgbench test.
 #
@@ -46,13 +33,14 @@ def test_pgbench(postgres: PostgresFactory, pageserver: ZenithPageserver, pg_bin
 
     connstr = pg.connstr()
 
-    # Initialize pgbench database
-    with zenbenchmark.record_duration('init'):
-        pg_bin.run_capture(['pgbench', '-s5', '-i', connstr])
+    # Initialize pgbench database, recording the time and I/O it takes
+    with zenbenchmark.record_pageserver_writes(pageserver, 'pageserver_writes'):
+        with zenbenchmark.record_duration('init'):
+            pg_bin.run_capture(['pgbench', '-s5', '-i', connstr])
 
-        # Flush the layers from memory to disk. The time to do that is included in the
-        # reported init time.
-        pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
+            # Flush the layers from memory to disk. This is included in the reported
+            # time and I/O
+            pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
 
     # Run pgbench for 5000 transactions
     with zenbenchmark.record_duration('5000_xacts'):
@@ -63,5 +51,5 @@ def test_pgbench(postgres: PostgresFactory, pageserver: ZenithPageserver, pg_bin
     pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
 
     # Report disk space used by the repository
-    timeline_size = get_timeline_size(repo_dir, pageserver.initial_tenant, timeline)
+    timeline_size = zenbenchmark.get_timeline_size(repo_dir, pageserver.initial_tenant, timeline)
     zenbenchmark.record('size', timeline_size / (1024*1024), 'MB')

test_runner/performance/test_write_amplification.py

@@ -0,0 +1,74 @@
+# Demonstrate Write Amplification with naive oldest-first layer checkpointing
+# algorithm.
+#
+# In each iteration of the test, we create a new table that's slightly under 10
+# MB in size (10 MB is the current "segment size" used by the page server). Then
+# we make a tiny update to all the tables already created. This creates a WAL
+# pattern where you have a lot of updates on one segment (the newly created
+# one), alternating with a small updates on all relations. This is the worst
+# case scenario for the naive checkpointing policy where we write out the layers
+# in LSN order, writing the oldest layer first. That creates a new 10 MB image
+# layer to be created for each of those small updates.  This is the Write
+# Amplification problem at its finest.
+import os
+from contextlib import closing
+from fixtures.zenith_fixtures import PostgresFactory, ZenithPageserver
+
+pytest_plugins = ("fixtures.zenith_fixtures", "fixtures.benchmark_fixture")
+
+def test_write_amplification(postgres: PostgresFactory, pageserver: ZenithPageserver, pg_bin, zenith_cli, zenbenchmark, repo_dir: str):
+    # Create a branch for us
+    zenith_cli.run(["branch", "test_write_amplification", "empty"])
+
+    pg = postgres.create_start('test_write_amplification')
+    print("postgres is running on 'test_write_amplification' branch")
+
+    # Open a connection directly to the page server that we'll use to force
+    # flushing the layers to disk
+    psconn = pageserver.connect();
+    pscur = psconn.cursor()
+
+    with closing(pg.connect()) as conn:
+        with conn.cursor() as cur:
+            # Get the timeline ID of our branch. We need it for the 'do_gc' command
+            cur.execute("SHOW zenith.zenith_timeline")
+            timeline = cur.fetchone()[0]
+
+            with zenbenchmark.record_pageserver_writes(pageserver, 'pageserver_writes'):
+                with zenbenchmark.record_duration('run'):
+
+                    # NOTE: Because each iteration updates every table already created,
+                    # the runtime and write amplification is O(n^2), where n is the
+                    # number of iterations.
+                    for i in range(25):
+                        cur.execute(f'''
+                        CREATE TABLE tbl{i} AS
+                            SELECT g as i, 'long string to consume some space' || g as t
+                            FROM generate_series(1, 100000) g
+                        ''')
+                        cur.execute(f"create index on tbl{i} (i);")
+                        for j in range(1, i):
+                            cur.execute(f"delete from tbl{j} where i = {i}")
+
+                        # Force checkpointing. As of this writing, we don't have
+                        # a back-pressure mechanism, and the page server cannot
+                        # keep up digesting and checkpointing the WAL at the
+                        # rate that it is generated. If we don't force a
+                        # checkpoint, the WAL will just accumulate in memory
+                        # until you hit OOM error. So in effect, we use much
+                        # more memory to hold the incoming WAL, and write them
+                        # out in larger batches than we'd really want. Using
+                        # more memory hides the write amplification problem this
+                        # test tries to demonstrate.
+                        #
+                        # The write amplification problem is real, and using
+                        # more memory isn't the right solution. We could
+                        # demonstrate the effect also by generating the WAL
+                        # slower, adding some delays in this loop.  But forcing
+                        # the the checkpointing and GC makes the test go faster,
+                        # with the same total I/O effect.
+                        pscur.execute(f"do_gc {pageserver.initial_tenant} {timeline} 0")
+
+            # Report disk space used by the repository
+            timeline_size = zenbenchmark.get_timeline_size(repo_dir, pageserver.initial_tenant, timeline)
+            zenbenchmark.record('size', timeline_size / (1024*1024), 'MB')

walkeeper/Cargo.toml

@@ -13,16 +13,12 @@ bytes = "1.0.1"
 byteorder = "1.4.3"
 fs2 = "0.4.3"
 lazy_static = "1.4.0"
-slog-stdlog = "4.1.0"
-slog-async = "2.6.0"
-slog-scope = "4.4.0"
-slog-term = "2.8.0"
-slog = "2.7.0"
+serde_json = "1"
 log = "0.4.14"
 clap = "2.33.0"
 daemonize = "0.4.1"
 rust-s3 = { version = "0.27.0-rc4", features = ["no-verify-ssl"] }
-tokio = { version = "1.3.0", features = ["full"] }
+tokio = "1.11"
 tokio-stream = { version = "0.1.4" }
 postgres-protocol = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }
 postgres = { git = "https://github.com/zenithdb/rust-postgres.git", rev="9eb0dbfbeb6a6c1b79099b9f7ae4a8c021877858" }

walkeeper/README

@@ -76,6 +76,43 @@ safekeepers.
 See README_PROTO.md for a more detailed desription of the consensus
 protocol. spec/ contains TLA+ specification of it.
 
+# Q&A
+
+Q: Why have a separate service instead of connecting Page Server directly to a
+   primary PostgreSQL node?
+A: Page Server is a single server which can be lost. As our primary
+   fault-tolerant storage is S3, we do not want to wait for it before
+   committing a transaction. The WAL service acts as a temporary fault-tolerant
+   storage for recent data before it gets to the Page Server and then finally
+   to S3. Whenever WALs and pages are committed to S3, WAL's storage can be
+   trimmed.
+
+Q: What if the compute node evicts a page, needs it back, but the page is yet
+   to reach the Page Server?
+A: If the compute node has evicted a page, all changes from that page are
+   already committed, i.e. they are saved on majority of WAL safekeepers. These
+   WAL records will eventually reach the Page Server. The Page Server notes
+   that the compute note requests pages with a very recent LSN and will not
+   respond to the compute node until it a corresponding WAL is received from WAL
+   safekeepers.
+
+Q: How long may Page Server wait for?
+A: Not too long, hopefully. If a page is evicted, it probably was not used for
+   a while, so the WAL service have had enough time to push changes to the Page
+   Server. There may be issues if there is no backpressure and compute node with
+   WAL service run ahead of Page Server, though.
+   There is no backpressure right now, so you may even see some spurious
+   timeouts in tests.
+
+Q: How do WAL safekeepers communicate with each other?
+A: They may only send each other messages via the compute node, they never
+   communicate directly with each other.
+
+Q: Why have a consensus algorithm if there is only a single compute node?
+A: Actually there may be moments with multiple PostgreSQL nodes running at the
+   same time. E.g. we are bringing one up and one down. We would like to avoid
+   simultaneous writes from different nodes, so there should be a consensus on
+   who is the primary node.
 
 # Terminology
 

walkeeper/src/bin/wal_acceptor.rs

@@ -1,15 +1,14 @@
 //
 // Main entry point for the wal_acceptor executable
 //
-use anyhow::{Context, Result};
+use anyhow::Result;
 use clap::{App, Arg};
 use daemonize::Daemonize;
 use log::*;
-use slog::Drain;
+use std::env;
 use std::path::{Path, PathBuf};
 use std::thread;
-use std::{env, io};
-use std::{fs::File, fs::OpenOptions};
+use zenith_utils::logging;
 
 use walkeeper::s3_offload;
 use walkeeper::wal_service;
@@ -113,20 +112,7 @@ fn main() -> Result<()> {
 
 fn start_wal_acceptor(conf: WalAcceptorConf) -> Result<()> {
     let log_filename = conf.data_dir.join("wal_acceptor.log");
-    // Don't open the same file for output multiple times;
-    // the different fds could overwrite each other's output.
-    let log_file = OpenOptions::new()
-        .create(true)
-        .append(true)
-        .open(&log_filename)
-        .with_context(|| format!("failed to open {:?}", &log_filename))?;
-
-    // Initialize logger
-    let logger_file = log_file.try_clone().unwrap();
-    let _scope_guard = init_logging(&conf, logger_file)?;
-    let _log_guard = slog_stdlog::init().unwrap();
-    // Note: this `info!(...)` macro comes from `log` crate
-    info!("standard logging redirected to slog");
+    let (_scope_guard, log_file) = logging::init(log_filename, conf.daemonize)?;
 
     if conf.daemonize {
         info!("daemonizing...");
@@ -179,29 +165,3 @@ fn start_wal_acceptor(conf: WalAcceptorConf) -> Result<()> {
     }
     Ok(())
 }
-
-fn init_logging(
-    conf: &WalAcceptorConf,
-    log_file: File,
-) -> Result<slog_scope::GlobalLoggerGuard, io::Error> {
-    if conf.daemonize {
-        let decorator = slog_term::PlainSyncDecorator::new(log_file);
-        let drain = slog_term::CompactFormat::new(decorator).build();
-        let drain = slog::Filter::new(drain, |record: &slog::Record| {
-            record.level().is_at_least(slog::Level::Info)
-        });
-        let drain = std::sync::Mutex::new(drain).fuse();
-        let logger = slog::Logger::root(drain, slog::o!());
-        Ok(slog_scope::set_global_logger(logger))
-    } else {
-        let decorator = slog_term::TermDecorator::new().build();
-        let drain = slog_term::FullFormat::new(decorator).build().fuse();
-        let drain = slog::Filter::new(drain, |record: &slog::Record| {
-            record.level().is_at_least(slog::Level::Info)
-        })
-        .fuse();
-        let drain = slog_async::Async::new(drain).chan_size(1000).build().fuse();
-        let logger = slog::Logger::root(drain, slog::o!());
-        Ok(slog_scope::set_global_logger(logger))
-    }
-}

walkeeper/src/json_ctrl.rs

@@ -0,0 +1,249 @@
+//!
+//! This module implements JSON_CTRL protocol, which allows exchange
+//! JSON messages over psql for testing purposes.
+//!
+//! Currently supports AppendLogicalMessage, which is used for WAL
+//! modifications in tests.
+//!
+
+use anyhow::{anyhow, Result};
+use bytes::{BufMut, Bytes, BytesMut};
+use crc32c::crc32c_append;
+use log::*;
+use serde::{Deserialize, Serialize};
+
+use crate::safekeeper::{AcceptorProposerMessage, AppendResponse};
+use crate::safekeeper::{
+    AppendRequest, AppendRequestHeader, ProposerAcceptorMessage, ProposerGreeting,
+};
+use crate::safekeeper::{SafeKeeperState, Term};
+use crate::send_wal::SendWalHandler;
+use crate::timeline::TimelineTools;
+use postgres_ffi::pg_constants;
+use postgres_ffi::xlog_utils;
+use postgres_ffi::{uint32, uint64, Oid, XLogRecord};
+use zenith_utils::lsn::Lsn;
+use zenith_utils::postgres_backend::PostgresBackend;
+use zenith_utils::pq_proto::{BeMessage, RowDescriptor, TEXT_OID};
+
+#[derive(Serialize, Deserialize, Debug)]
+struct AppendLogicalMessage {
+    // prefix and message to build LogicalMessage
+    lm_prefix: String,
+    lm_message: String,
+
+    // if true, commit_lsn will match flush_lsn after append
+    set_commit_lsn: bool,
+
+    // fields from AppendRequestHeader
+    term: Term,
+    epoch_start_lsn: Lsn,
+    begin_lsn: Lsn,
+    truncate_lsn: Lsn,
+}
+
+#[derive(Serialize, Deserialize)]
+struct AppendResult {
+    // safekeeper state after append
+    state: SafeKeeperState,
+    // info about new record in the WAL
+    inserted_wal: InsertedWAL,
+}
+
+/// Handles command to craft logical message WAL record with given
+/// content, and then append it with specified term and lsn. This
+/// function is used to test safekeepers in different scenarios.
+pub fn handle_json_ctrl(
+    swh: &mut SendWalHandler,
+    pgb: &mut PostgresBackend,
+    cmd: &Bytes,
+) -> Result<()> {
+    let cmd = cmd
+        .strip_prefix(b"JSON_CTRL")
+        .ok_or_else(|| anyhow!("invalid prefix"))?;
+    // trim zeroes in the end
+    let cmd = cmd.strip_suffix(&[0u8]).unwrap_or(cmd);
+
+    let append_request: AppendLogicalMessage = serde_json::from_slice(cmd)?;
+    info!("JSON_CTRL request: {:?}", append_request);
+
+    // need to init safekeeper state before AppendRequest
+    prepare_safekeeper(swh)?;
+
+    let inserted_wal = append_logical_message(swh, append_request)?;
+    let response = AppendResult {
+        state: swh.timeline.get().get_info(),
+        inserted_wal,
+    };
+    let response_data = serde_json::to_vec(&response)?;
+
+    pgb.write_message_noflush(&BeMessage::RowDescription(&[RowDescriptor {
+        name: b"json",
+        typoid: TEXT_OID,
+        typlen: -1,
+        ..Default::default()
+    }]))?
+    .write_message_noflush(&BeMessage::DataRow(&[Some(&response_data)]))?
+    .write_message(&BeMessage::CommandComplete(b"JSON_CTRL"))?;
+    Ok(())
+}
+
+/// Prepare safekeeper to process append requests without crashes,
+/// by sending ProposerGreeting with default server.wal_seg_size.
+fn prepare_safekeeper(swh: &mut SendWalHandler) -> Result<()> {
+    let greeting_request = ProposerAcceptorMessage::Greeting(ProposerGreeting {
+        protocol_version: 1, // current protocol
+        pg_version: 0,       // unknown
+        proposer_id: [0u8; 16],
+        system_id: 0,
+        ztli: swh.timelineid.unwrap(),
+        tenant_id: swh.tenantid.unwrap(),
+        tli: 0,
+        wal_seg_size: pg_constants::WAL_SEGMENT_SIZE as u32, // 16MB, default for tests
+    });
+
+    let response = swh.timeline.get().process_msg(&greeting_request)?;
+    match response {
+        AcceptorProposerMessage::Greeting(_) => Ok(()),
+        _ => anyhow::bail!("not GreetingResponse"),
+    }
+}
+
+#[derive(Serialize, Deserialize)]
+struct InsertedWAL {
+    begin_lsn: Lsn,
+    end_lsn: Lsn,
+    append_response: AppendResponse,
+}
+
+/// Extend local WAL with new LogicalMessage record. To do that,
+/// create AppendRequest with new WAL and pass it to safekeeper.
+fn append_logical_message(
+    swh: &mut SendWalHandler,
+    msg: AppendLogicalMessage,
+) -> Result<InsertedWAL> {
+    let wal_data = encode_logical_message(msg.lm_prefix, msg.lm_message);
+    let sk_state = swh.timeline.get().get_info();
+
+    let begin_lsn = msg.begin_lsn;
+    let end_lsn = begin_lsn + wal_data.len() as u64;
+
+    let commit_lsn = if msg.set_commit_lsn {
+        end_lsn
+    } else {
+        sk_state.commit_lsn
+    };
+
+    let append_request = ProposerAcceptorMessage::AppendRequest(AppendRequest {
+        h: AppendRequestHeader {
+            term: msg.term,
+            epoch_start_lsn: begin_lsn,
+            begin_lsn,
+            end_lsn,
+            commit_lsn,
+            truncate_lsn: msg.truncate_lsn,
+            proposer_uuid: [0u8; 16],
+        },
+        wal_data: Bytes::from(wal_data),
+    });
+
+    let response = swh.timeline.get().process_msg(&append_request)?;
+
+    let append_response = match response {
+        AcceptorProposerMessage::AppendResponse(resp) => resp,
+        _ => anyhow::bail!("not AppendResponse"),
+    };
+
+    Ok(InsertedWAL {
+        begin_lsn,
+        end_lsn,
+        append_response,
+    })
+}
+
+#[repr(C)]
+#[derive(Debug, Clone, Default, Serialize, Deserialize)]
+struct XlLogicalMessage {
+    db_id: Oid,
+    transactional: uint32, // bool, takes 4 bytes due to alignment in C structures
+    prefix_size: uint64,
+    message_size: uint64,
+}
+
+impl XlLogicalMessage {
+    pub fn encode(&self) -> Bytes {
+        use zenith_utils::bin_ser::LeSer;
+        self.ser().unwrap().into()
+    }
+}
+
+/// Create new WAL record for non-transactional logical message.
+/// Used for creating artificial WAL for tests, as LogicalMessage
+/// record is basically no-op.
+fn encode_logical_message(prefix: String, message: String) -> Vec<u8> {
+    let mut prefix_bytes = BytesMut::with_capacity(prefix.len() + 1);
+    prefix_bytes.put(prefix.as_bytes());
+    prefix_bytes.put_u8(0);
+
+    let message_bytes = message.as_bytes();
+
+    let logical_message = XlLogicalMessage {
+        db_id: 0,
+        transactional: 0,
+        prefix_size: prefix_bytes.len() as u64,
+        message_size: message_bytes.len() as u64,
+    };
+
+    let mainrdata = logical_message.encode();
+    let mainrdata_len: usize = mainrdata.len() + prefix_bytes.len() + message_bytes.len();
+    // only short mainrdata is supported for now
+    assert!(mainrdata_len <= 255);
+    let mainrdata_len = mainrdata_len as u8;
+
+    let mut data: Vec<u8> = vec![pg_constants::XLR_BLOCK_ID_DATA_SHORT, mainrdata_len];
+    data.extend_from_slice(&mainrdata);
+    data.extend_from_slice(&prefix_bytes);
+    data.extend_from_slice(message_bytes);
+
+    let total_len = xlog_utils::XLOG_SIZE_OF_XLOG_RECORD + data.len();
+
+    let mut header = XLogRecord {
+        xl_tot_len: total_len as u32,
+        xl_xid: 0,
+        xl_prev: 0,
+        xl_info: 0,
+        xl_rmid: 21,
+        __bindgen_padding_0: [0u8; 2usize],
+        xl_crc: 0, // crc will be calculated later
+    };
+
+    let header_bytes = header.encode();
+    let crc = crc32c_append(0, &data);
+    let crc = crc32c_append(crc, &header_bytes[0..xlog_utils::XLOG_RECORD_CRC_OFFS]);
+    header.xl_crc = crc;
+
+    let mut wal: Vec<u8> = Vec::new();
+    wal.extend_from_slice(&header.encode());
+    wal.extend_from_slice(&data);
+
+    // WAL start position must be aligned at 8 bytes,
+    // this will add padding for the next WAL record.
+    const PADDING: usize = 8;
+    let padding_rem = wal.len() % PADDING;
+    if padding_rem != 0 {
+        wal.resize(wal.len() + PADDING - padding_rem, 0);
+    }
+
+    wal
+}
+
+#[test]
+fn test_encode_logical_message() {
+    let expected = [
+        64, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 21, 0, 0, 170, 34, 166, 227, 255, 38,
+        0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 0, 0, 0, 112, 114, 101, 102,
+        105, 120, 0, 109, 101, 115, 115, 97, 103, 101,
+    ];
+    let actual = encode_logical_message("prefix".to_string(), "message".to_string());
+    assert_eq!(expected, actual[..]);
+}

walkeeper/src/lib.rs

@@ -2,6 +2,7 @@
 use std::path::PathBuf;
 use std::time::Duration;
 
+pub mod json_ctrl;
 pub mod receive_wal;
 pub mod replication;
 pub mod s3_offload;

walkeeper/src/receive_wal.rs

@@ -74,7 +74,7 @@ fn request_callback(conf: WalAcceptorConf, timelineid: ZTimelineId, tenantid: ZT
 
 impl<'pg> ReceiveWalConn<'pg> {
     pub fn new(pg: &'pg mut PostgresBackend) -> Result<ReceiveWalConn<'pg>> {
-        let peer_addr = pg.get_peer_addr().clone();
+        let peer_addr = *pg.get_peer_addr();
         Ok(ReceiveWalConn {
             pg_backend: pg,
             peer_addr,

walkeeper/src/replication.rs

@@ -3,7 +3,7 @@
 
 use crate::send_wal::SendWalHandler;
 use crate::timeline::{Timeline, TimelineTools};
-use anyhow::{anyhow, Result};
+use anyhow::{anyhow, Context, Result};
 use bytes::Bytes;
 use log::*;
 use postgres_ffi::xlog_utils::{get_current_timestamp, TimestampTz, XLogFileName, MAX_SEND_SIZE};
@@ -25,6 +25,10 @@ use zenith_utils::sock_split::ReadStream;
 
 pub const END_REPLICATION_MARKER: Lsn = Lsn::MAX;
 
+// See: https://www.postgresql.org/docs/13/protocol-replication.html
+const HOT_STANDBY_FEEDBACK_TAG_BYTE: u8 = b'h';
+const STANDBY_STATUS_UPDATE_TAG_BYTE: u8 = b'r';
+
 type FullTransactionId = u64;
 
 /// Hot standby feedback received from replica
@@ -81,10 +85,22 @@ impl ReplicationConn {
     ) -> Result<()> {
         // Wait for replica's feedback.
         while let Some(msg) = FeMessage::read(&mut stream_in)? {
-            match msg {
+            match &msg {
                 FeMessage::CopyData(m) => {
-                    let feedback = HotStandbyFeedback::des(&m)?;
-                    subscriber.add_hs_feedback(feedback);
+                    // There's two possible data messages that the client is supposed to send here:
+                    // `HotStandbyFeedback` and `StandbyStatusUpdate`. We only handle hot standby
+                    // feedback.
+
+                    match m.first().cloned() {
+                        Some(HOT_STANDBY_FEEDBACK_TAG_BYTE) => {
+                            // Note: deserializing is on m[1..] because we skip the tag byte.
+                            let feedback = HotStandbyFeedback::des(&m[1..])
+                                .context("failed to deserialize HotStandbyFeedback")?;
+                            subscriber.add_hs_feedback(feedback);
+                        }
+                        Some(STANDBY_STATUS_UPDATE_TAG_BYTE) => (),
+                        _ => warn!("unexpected message {:?}", msg),
+                    }
                 }
                 FeMessage::Sync => {}
                 FeMessage::CopyFail => return Err(anyhow!("Copy failed")),
@@ -105,7 +121,7 @@ impl ReplicationConn {
         let mut lsns = caps.map(|cap| cap[1].parse::<Lsn>());
         let start_pos = lsns
             .next()
-            .ok_or_else(|| anyhow!("failed to find start LSN"))??;
+            .ok_or_else(|| anyhow!("Failed to parse start LSN from command"))??;
         let stop_pos = lsns.next().transpose()?.unwrap_or(Lsn(0));
         Ok((start_pos, stop_pos))
     }
@@ -120,13 +136,12 @@ impl ReplicationConn {
         }
 
         // If that failed, try it without the .partial extension.
-        match File::open(&wal_file_path) {
-            Ok(opened_file) => Ok(opened_file),
-            Err(e) => {
-                error!("Failed to open log file {:?}: {}", &wal_file_path, e);
-                Err(e.into())
-            }
-        }
+        File::open(&wal_file_path)
+            .with_context(|| format!("Failed to open WAL file {:?}", wal_file_path))
+            .map_err(|e| {
+                error!("{}", e);
+                e
+            })
     }
 
     ///
@@ -144,17 +159,17 @@ impl ReplicationConn {
 
         thread::spawn(move || {
             if let Err(err) = Self::background_thread(bg_stream_in, bg_timeline) {
-                error!("socket error: {}", err);
+                error!("Replication background thread failed: {}", err);
             }
         });
 
-        let (mut start_pos, mut stop_pos) = Self::parse_start_stop(&cmd)?;
+        let (mut start_pos, mut stop_pos) = Self::parse_start_stop(cmd)?;
 
         let mut wal_seg_size: usize;
         loop {
             wal_seg_size = swh.timeline.get().get_info().server.wal_seg_size as usize;
             if wal_seg_size == 0 {
-                error!("Can not start replication before connecting to wal_proposer");
+                error!("Cannot start replication before connecting to wal_proposer");
                 sleep(Duration::from_secs(1));
             } else {
                 break;
@@ -216,8 +231,9 @@ impl ReplicationConn {
 
             // Read some data from the file.
             let mut file_buf = vec![0u8; send_size];
-            file.seek(SeekFrom::Start(xlogoff as u64))?;
-            file.read_exact(&mut file_buf)?;
+            file.seek(SeekFrom::Start(xlogoff as u64))
+                .and_then(|_| file.read_exact(&mut file_buf))
+                .context("Failed to read data from WAL file")?;
 
             // Write some data to the network socket.
             pgb.write_message(&BeMessage::XLogData(XLogDataBody {
@@ -225,11 +241,12 @@ impl ReplicationConn {
                 wal_end: end_pos.0,
                 timestamp: get_current_timestamp(),
                 data: &file_buf,
-            }))?;
+            }))
+            .context("Failed to send XLogData")?;
 
             start_pos += send_size as u64;
 
-            debug!("Sent WAL to page server up to {}", end_pos);
+            debug!("sent WAL up to {}", end_pos);
 
             // Decide whether to reuse this file. If we don't set wal_file here
             // a new file will be opened next time.

walkeeper/src/safekeeper.rs

@@ -7,9 +7,11 @@ use byteorder::WriteBytesExt;
 use bytes::Buf;
 use bytes::Bytes;
 use log::*;
+use pageserver::waldecoder::WalStreamDecoder;
 use postgres_ffi::xlog_utils::TimeLineID;
 use serde::{Deserialize, Serialize};
 use std::cmp::max;
+use std::cmp::min;
 use std::io;
 use std::io::Read;
 
@@ -26,7 +28,7 @@ const SK_PROTOCOL_VERSION: u32 = 1;
 const UNKNOWN_SERVER_VERSION: u32 = 0;
 
 /// Consensus logical timestamp.
-type Term = u64;
+pub type Term = u64;
 
 /// Unique id of proposer. Not needed for correctness, used for monitoring.
 type PgUuid = [u8; 16];
@@ -47,6 +49,7 @@ pub struct ServerInfo {
     /// Postgres server version
     pub pg_version: u32,
     pub system_id: SystemId,
+    pub tenant_id: ZTenantId,
     /// Zenith timelineid
     pub ztli: ZTimelineId,
     pub tli: TimeLineID,
@@ -65,14 +68,16 @@ pub struct SafeKeeperState {
     /// information about server
     pub server: ServerInfo,
     /// Unique id of the last *elected* proposer we dealed with. Not needed
-    /// correctness, exists for monitoring purposes.
+    /// for correctness, exists for monitoring purposes.
     pub proposer_uuid: PgUuid,
-    /// part of WAL acknowledged by quorum (note that we might not have wal to
-    /// up this point locally)
+    /// part of WAL acknowledged by quorum and available locally
     pub commit_lsn: Lsn,
-    /// minimal LSN which may be needed for recovery of some safekeeper (end lsn
-    /// + 1 of last record streamed to everyone)
+    /// minimal LSN which may be needed for recovery of some safekeeper (end_lsn
+    /// of last record streamed to everyone)
     pub truncate_lsn: Lsn,
+    // Safekeeper starts receiving WAL from this LSN, zeros before it ought to
+    // be skipped during decoding.
+    pub wal_start_lsn: Lsn,
 }
 
 impl SafeKeeperState {
@@ -84,6 +89,7 @@ impl SafeKeeperState {
             server: ServerInfo {
                 pg_version: UNKNOWN_SERVER_VERSION, /* Postgres server version */
                 system_id: 0,                       /* Postgres system identifier */
+                tenant_id: ZTenantId::from([0u8; 16]),
                 ztli: ZTimelineId::from([0u8; 16]),
                 tli: 0,
                 wal_seg_size: 0,
@@ -91,14 +97,21 @@ impl SafeKeeperState {
             proposer_uuid: [0; 16],
             commit_lsn: Lsn(0),   /* part of WAL acknowledged by quorum */
             truncate_lsn: Lsn(0), /* minimal LSN which may be needed for recovery of some safekeeper */
+            wal_start_lsn: Lsn(0),
         }
     }
 }
 
+impl Default for SafeKeeperState {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 // protocol messages
 
 /// Initial Proposer -> Acceptor message
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Deserialize)]
 pub struct ProposerGreeting {
     /// proposer-acceptor protocol version
     pub protocol_version: u32,
@@ -115,50 +128,50 @@ pub struct ProposerGreeting {
 
 /// Acceptor -> Proposer initial response: the highest term known to me
 /// (acceptor voted for).
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Serialize)]
 pub struct AcceptorGreeting {
     term: u64,
 }
 
 /// Vote request sent from proposer to safekeepers
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Deserialize)]
 pub struct VoteRequest {
     term: Term,
 }
 
 /// Vote itself, sent from safekeeper to proposer
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Serialize)]
 pub struct VoteResponse {
     term: Term,      // not really needed, just a sanity check
     vote_given: u64, // fixme u64 due to padding
     /// Safekeeper's log position, to let proposer choose the most advanced one
     epoch: Term,
     flush_lsn: Lsn,
-    restart_lsn: Lsn,
+    truncate_lsn: Lsn,
 }
 
 /// Request with WAL message sent from proposer to safekeeper. Along the way it
 /// announces 1) successful election (with epoch_start_lsn); 2) commit_lsn.
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug)]
 pub struct AppendRequest {
-    h: AppendRequestHeader,
-    wal_data: Bytes,
+    pub h: AppendRequestHeader,
+    pub wal_data: Bytes,
 }
-#[derive(Debug, Clone, Serialize, Deserialize)]
+#[derive(Debug, Clone, Deserialize)]
 pub struct AppendRequestHeader {
-    term: Term,
+    pub term: Term,
     // LSN since the proposer appends WAL; determines epoch switch point.
-    epoch_start_lsn: Lsn,
+    pub epoch_start_lsn: Lsn,
     /// start position of message in WAL
-    begin_lsn: Lsn,
+    pub begin_lsn: Lsn,
     /// end position of message in WAL
-    end_lsn: Lsn,
+    pub end_lsn: Lsn,
     /// LSN committed by quorum of safekeepers
-    commit_lsn: Lsn,
-    /// restart LSN position  (minimal LSN which may be needed by proposer to perform recovery)
-    restart_lsn: Lsn,
+    pub commit_lsn: Lsn,
+    /// minimal LSN which may be needed by proposer to perform recovery of some safekeeper
+    pub truncate_lsn: Lsn,
     // only for logging/debugging
-    proposer_uuid: PgUuid,
+    pub proposer_uuid: PgUuid,
 }
 
 /// Report safekeeper state to proposer
@@ -172,6 +185,9 @@ pub struct AppendResponse {
     // make much sense without taking epoch into account, as history can be
     // diverged.
     pub flush_lsn: Lsn,
+    // We report back our awareness about which WAL is committed, as this is
+    // a criterion for walproposer --sync mode exit
+    pub commit_lsn: Lsn,
     pub hs_feedback: HotStandbyFeedback,
 }
 
@@ -205,7 +221,7 @@ impl ProposerAcceptorMessage {
                 let rec_size = hdr
                     .end_lsn
                     .checked_sub(hdr.begin_lsn)
-                    .ok_or(anyhow!("begin_lsn > end_lsn in AppendRequest"))?
+                    .ok_or_else(|| anyhow!("begin_lsn > end_lsn in AppendRequest"))?
                     .0 as usize;
                 if rec_size > MAX_SEND_SIZE {
                     bail!(
@@ -217,10 +233,7 @@ impl ProposerAcceptorMessage {
                 let mut wal_data_vec: Vec<u8> = vec![0; rec_size];
                 stream.read_exact(&mut wal_data_vec)?;
                 let wal_data = Bytes::from(wal_data_vec);
-                let msg = AppendRequest {
-                    h: hdr,
-                    wal_data: wal_data,
-                };
+                let msg = AppendRequest { h: hdr, wal_data };
 
                 Ok(ProposerAcceptorMessage::AppendRequest(msg))
             }
@@ -262,22 +275,24 @@ impl AcceptorProposerMessage {
 pub trait Storage {
     /// Persist safekeeper state on disk, optionally syncing it.
     fn persist(&mut self, s: &SafeKeeperState, sync: bool) -> Result<()>;
-    /// Write piece of wal in buf to disk.
-    fn write_wal(&mut self, s: &SafeKeeperState, startpos: Lsn, buf: &[u8]) -> Result<()>;
+    /// Write piece of wal in buf to disk and sync it.
+    fn write_wal(&mut self, server: &ServerInfo, startpos: Lsn, buf: &[u8]) -> Result<()>;
 }
 
 /// SafeKeeper which consumes events (messages from compute) and provides
 /// replies.
-#[derive(Debug)]
 pub struct SafeKeeper<ST: Storage> {
-    /// Locally flushed part of WAL (end_lsn of last record). Established by
-    /// reading wal.
+    /// Locally flushed part of WAL with full records (end_lsn of last record).
+    /// Established by reading wal.
     pub flush_lsn: Lsn,
     pub tli: u32,
-    pub flushed_truncate_lsn: Lsn,
+    /// not-yet-flushed pairs of same named fields in s.*
+    pub commit_lsn: Lsn,
+    pub truncate_lsn: Lsn,
     pub storage: ST,
     pub s: SafeKeeperState,          // persistent part
     pub elected_proposer_term: Term, // for monitoring/debugging
+    decoder: WalStreamDecoder,
 }
 
 impl<ST> SafeKeeper<ST>
@@ -289,10 +304,12 @@ where
         SafeKeeper {
             flush_lsn,
             tli,
-            flushed_truncate_lsn: Lsn(0),
+            commit_lsn: state.commit_lsn,
+            truncate_lsn: state.truncate_lsn,
             storage,
             s: state,
             elected_proposer_term: 0,
+            decoder: WalStreamDecoder::new(Lsn(0)),
         }
     }
 
@@ -320,13 +337,6 @@ where
                 SK_PROTOCOL_VERSION
             );
         }
-        if self.s.server.system_id != 0 && self.s.server.system_id != msg.system_id {
-            bail!(
-                "system identifier changed: got {}, expected {}",
-                msg.system_id,
-                self.s.server.system_id,
-            );
-        }
         /* Postgres upgrade is not treated as fatal error */
         if msg.pg_version != self.s.server.pg_version
             && self.s.server.pg_version != UNKNOWN_SERVER_VERSION
@@ -339,10 +349,10 @@ where
 
         // set basic info about server, if not yet
         self.s.server.system_id = msg.system_id;
+        self.s.server.tenant_id = msg.tenant_id;
         self.s.server.ztli = msg.ztli;
         self.s.server.tli = msg.tli;
         self.s.server.wal_seg_size = msg.wal_seg_size;
-        self.s.proposer_uuid = msg.proposer_id;
         self.storage.persist(&self.s, true)?;
 
         info!(
@@ -362,7 +372,7 @@ where
             vote_given: false as u64,
             epoch: 0,
             flush_lsn: Lsn(0),
-            restart_lsn: Lsn(0),
+            truncate_lsn: Lsn(0),
         };
         if self.s.acceptor_state.term < msg.term {
             self.s.acceptor_state.term = msg.term;
@@ -371,19 +381,20 @@ where
             resp.vote_given = true as u64;
             resp.epoch = self.s.acceptor_state.epoch;
             resp.flush_lsn = self.flush_lsn;
-            resp.restart_lsn = self.s.truncate_lsn;
+            resp.truncate_lsn = self.s.truncate_lsn;
         }
         info!("processed VoteRequest for term {}: {:?}", msg.term, &resp);
         Ok(AcceptorProposerMessage::VoteResponse(resp))
     }
 
     /// Handle request to append WAL.
+    #[allow(clippy::comparison_chain)]
     fn handle_append_request(&mut self, msg: &AppendRequest) -> Result<AcceptorProposerMessage> {
         // log first AppendRequest from this proposer
         if self.elected_proposer_term < msg.h.term {
             info!(
-                "start receiving WAL from timeline {} term {}",
-                self.s.server.ztli, msg.h.term,
+                "start accepting WAL from timeline {}, tenant {}, term {}, epochStartLsn {:?}",
+                self.s.server.ztli, self.s.server.tenant_id, msg.h.term, msg.h.epoch_start_lsn,
             );
             self.elected_proposer_term = msg.h.term;
         }
@@ -398,62 +409,122 @@ where
             let resp = AppendResponse {
                 term: self.s.acceptor_state.term,
                 epoch: self.s.acceptor_state.epoch,
+                commit_lsn: Lsn(0),
                 flush_lsn: Lsn(0),
                 hs_feedback: HotStandbyFeedback::empty(),
             };
             return Ok(AcceptorProposerMessage::AppendResponse(resp));
         }
 
-        // do the job
-        self.storage
-            .write_wal(&self.s, msg.h.begin_lsn, &msg.wal_data)?;
+        self.s.proposer_uuid = msg.h.proposer_uuid;
         let mut sync_control_file = false;
+
+        // do the job
+        let mut last_rec_lsn = Lsn(0);
+        if !msg.wal_data.is_empty() {
+            self.storage
+                .write_wal(&self.s.server, msg.h.begin_lsn, &msg.wal_data)?;
+
+            // figure out last record's end lsn for reporting (if we got the
+            // whole record)
+            if self.decoder.available() != msg.h.begin_lsn {
+                info!(
+                    "restart decoder from {} to {}",
+                    self.decoder.available(),
+                    msg.h.begin_lsn,
+                );
+                self.decoder = WalStreamDecoder::new(msg.h.begin_lsn);
+            }
+            self.decoder.feed_bytes(&msg.wal_data);
+            loop {
+                match self.decoder.poll_decode()? {
+                    None => break, // no full record yet
+                    Some((lsn, _rec)) => {
+                        last_rec_lsn = lsn;
+                    }
+                }
+            }
+
+            // If this was the first record we ever receieved, remember LSN to help
+            // find_end_of_wal skip the hole in the beginning.
+            if self.s.wal_start_lsn == Lsn(0) {
+                self.s.wal_start_lsn = msg.h.begin_lsn;
+                sync_control_file = true;
+            }
+        }
+
         /*
          * Epoch switch happen when written WAL record cross the boundary.
          * The boundary is maximum of last WAL position at this node (FlushLSN) and global
          * maximum (vcl) determined by WAL proposer during handshake.
          * Switching epoch means that node completes recovery and start writing in the WAL new data.
          * XXX: this is wrong, we must actively truncate not matching part of log.
+         *
+         * The non-strict inequality is important for us, as proposer in --sync mode doesn't
+         * generate new records, but to advance commit_lsn epoch switch must happen on majority.
+         * We can regard this as commit of empty entry in new epoch, this should be safe.
          */
         if self.s.acceptor_state.epoch < msg.h.term
-            && msg.h.end_lsn > max(self.flush_lsn, msg.h.epoch_start_lsn)
+            && msg.h.end_lsn >= max(self.flush_lsn, msg.h.epoch_start_lsn)
         {
-            info!("switched to new epoch {}", msg.h.term);
+            info!(
+                "switched to new epoch {} on receival of request end_lsn={:?}, len={:?}",
+                msg.h.term,
+                msg.h.end_lsn,
+                msg.wal_data.len(),
+            );
             self.s.acceptor_state.epoch = msg.h.term; /* bump epoch */
             sync_control_file = true;
         }
-        if msg.h.end_lsn > self.flush_lsn {
-            self.flush_lsn = msg.h.end_lsn;
+        if last_rec_lsn > self.flush_lsn {
+            self.flush_lsn = last_rec_lsn;
         }
 
-        self.s.proposer_uuid = msg.h.proposer_uuid;
-        self.s.commit_lsn = msg.h.commit_lsn;
-        self.s.truncate_lsn = msg.h.restart_lsn;
+        // Advance commit_lsn taking into account what we have locally. xxx this
+        // is wrapped into epoch check because we overwrite wal instead of
+        // truncating it, so without it commit_lsn might include wrong part.
+        // Anyway, nobody is much interested in our commit_lsn while epoch
+        // switch hasn't happened, right?
+        //
+        // commit_lsn can be 0, being unknown to new walproposer while he hasn't
+        // collected majority of its epoch acks yet, ignore it in this case.
+        if self.s.acceptor_state.epoch == msg.h.term && msg.h.commit_lsn != Lsn(0) {
+            let commit_lsn = min(msg.h.commit_lsn, self.flush_lsn);
+            // If new commit_lsn reached epoch switch, force sync of control file:
+            // walproposer in sync mode is very interested when this happens.
+            sync_control_file |=
+                commit_lsn >= msg.h.epoch_start_lsn && self.s.commit_lsn < msg.h.epoch_start_lsn;
+            self.commit_lsn = commit_lsn;
+        }
 
+        self.truncate_lsn = msg.h.truncate_lsn;
         /*
-         * Update restart LSN in control file.
+         * Update truncate and commit LSN in control file.
          * To avoid negative impact on performance of extra fsync, do it only
          * when restart_lsn delta exceeds WAL segment size.
          */
         sync_control_file |=
-            self.flushed_truncate_lsn + (self.s.server.wal_seg_size as u64) < self.s.truncate_lsn;
-        self.storage.persist(&self.s, sync_control_file)?;
+            self.s.truncate_lsn + (self.s.server.wal_seg_size as u64) < self.truncate_lsn;
         if sync_control_file {
-            self.flushed_truncate_lsn = self.s.truncate_lsn;
+            self.s.commit_lsn = self.commit_lsn;
+            self.s.truncate_lsn = self.truncate_lsn;
         }
+        self.storage.persist(&self.s, sync_control_file)?;
 
         let resp = AppendResponse {
             term: self.s.acceptor_state.term,
             epoch: self.s.acceptor_state.epoch,
             flush_lsn: self.flush_lsn,
+            commit_lsn: self.s.commit_lsn,
             // will be filled by caller code to avoid bothering safekeeper
             hs_feedback: HotStandbyFeedback::empty(),
         };
-        trace!(
-            "processed AppendRequest of len {}, flush_lsn={:X}/{:>08X}, resp {:?}",
+        info!(
+            "processed AppendRequest of len {}, end_lsn={:?}, commit_lsn={:?}, truncate_lsn={:?}, resp {:?}",
             msg.wal_data.len(),
-            (self.flush_lsn.0 >> 32) as u32,
-            self.flush_lsn.0 as u32,
+            msg.h.end_lsn,
+            msg.h.commit_lsn,
+            msg.h.truncate_lsn,
             &resp,
         );
         Ok(AcceptorProposerMessage::AppendResponse(resp))
@@ -475,7 +546,7 @@ mod tests {
             Ok(())
         }
 
-        fn write_wal(&mut self, _s: &SafeKeeperState, _startpos: Lsn, _buf: &[u8]) -> Result<()> {
+        fn write_wal(&mut self, _server: &ServerInfo, _startpos: Lsn, _buf: &[u8]) -> Result<()> {
             Ok(())
         }
     }
@@ -492,7 +563,7 @@ mod tests {
         let mut vote_resp = sk.process_msg(&vote_request);
         match vote_resp.unwrap() {
             AcceptorProposerMessage::VoteResponse(resp) => assert!(resp.vote_given != 0),
-            _ => assert!(false),
+            r => panic!("unexpected response: {:?}", r),
         }
 
         // reboot...
@@ -506,7 +577,7 @@ mod tests {
         vote_resp = sk.process_msg(&vote_request);
         match vote_resp.unwrap() {
             AcceptorProposerMessage::VoteResponse(resp) => assert!(resp.vote_given == 0),
-            _ => assert!(false),
+            r => panic!("unexpected response: {:?}", r),
         }
     }
 
@@ -519,11 +590,11 @@ mod tests {
 
         let mut ar_hdr = AppendRequestHeader {
             term: 1,
-            epoch_start_lsn: Lsn(2),
+            epoch_start_lsn: Lsn(3),
             begin_lsn: Lsn(1),
             end_lsn: Lsn(2),
             commit_lsn: Lsn(0),
-            restart_lsn: Lsn(0),
+            truncate_lsn: Lsn(0),
             proposer_uuid: [0; 16],
         };
         let mut append_request = AppendRequest {
@@ -531,20 +602,20 @@ mod tests {
             wal_data: Bytes::from_static(b"b"),
         };
 
-        // check that AppendRequest before VCL doesn't switch epoch
+        // check that AppendRequest before epochStartLsn doesn't switch epoch
         let resp = sk.process_msg(&ProposerAcceptorMessage::AppendRequest(append_request));
         assert!(resp.is_ok());
-        assert!(sk.storage.persisted_state.acceptor_state.epoch == 0);
+        assert_eq!(sk.storage.persisted_state.acceptor_state.epoch, 0);
 
-        // but record after VCL does the switch
+        // but record at epochStartLsn does the switch
         ar_hdr.begin_lsn = Lsn(2);
         ar_hdr.end_lsn = Lsn(3);
         append_request = AppendRequest {
-            h: ar_hdr.clone(),
+            h: ar_hdr,
             wal_data: Bytes::from_static(b"b"),
         };
         let resp = sk.process_msg(&ProposerAcceptorMessage::AppendRequest(append_request));
         assert!(resp.is_ok());
-        assert!(sk.storage.persisted_state.acceptor_state.epoch == 1);
+        assert_eq!(sk.storage.persisted_state.acceptor_state.epoch, 1);
     }
 }

walkeeper/src/send_wal.rs

@@ -2,6 +2,7 @@
 //! pageserver/any other consumer.
 //!
 
+use crate::json_ctrl::handle_json_ctrl;
 use crate::receive_wal::ReceiveWalConn;
 use crate::replication::ReplicationConn;
 use crate::timeline::{Timeline, TimelineTools};
@@ -33,13 +34,13 @@ impl postgres_backend::Handler for SendWalHandler {
         let ztimelineid = sm
             .params
             .get("ztimelineid")
-            .ok_or(anyhow!("timelineid is required"))?;
+            .ok_or_else(|| anyhow!("timelineid is required"))?;
         self.timelineid = Some(ZTimelineId::from_str(ztimelineid)?);
 
         let ztenantid = sm
             .params
             .get("ztenantid")
-            .ok_or(anyhow!("tenantid is required"))?;
+            .ok_or_else(|| anyhow!("tenantid is required"))?;
         self.tenantid = Some(ZTenantId::from_str(ztenantid)?);
 
         if let Some(app_name) = sm.params.get("application_name") {
@@ -49,9 +50,11 @@ impl postgres_backend::Handler for SendWalHandler {
     }
 
     fn process_query(&mut self, pgb: &mut PostgresBackend, query_string: Bytes) -> Result<()> {
-        // START_WAL_PUSH is the only command that initializes the timeline
+        // START_WAL_PUSH is the only command that initializes the timeline in production.
+        // There is also JSON_CTRL command, which should initialize the timeline for testing.
         if self.timeline.is_none() {
-            if query_string.starts_with(b"START_WAL_PUSH") {
+            if query_string.starts_with(b"START_WAL_PUSH") || query_string.starts_with(b"JSON_CTRL")
+            {
                 self.timeline.set(
                     &self.conf,
                     self.tenantid.unwrap(),
@@ -76,6 +79,9 @@ impl postgres_backend::Handler for SendWalHandler {
         } else if query_string.starts_with(b"START_WAL_PUSH") {
             ReceiveWalConn::new(pgb)?.run(self)?;
             Ok(())
+        } else if query_string.starts_with(b"JSON_CTRL") {
+            handle_json_ctrl(self, pgb, &query_string)?;
+            Ok(())
         } else {
             bail!("Unexpected command {:?}", query_string);
         }

walkeeper/src/timeline.rs

@@ -18,8 +18,8 @@ use zenith_utils::zid::{ZTenantId, ZTimelineId};
 
 use crate::replication::{HotStandbyFeedback, END_REPLICATION_MARKER};
 use crate::safekeeper::{
-    AcceptorProposerMessage, ProposerAcceptorMessage, SafeKeeper, SafeKeeperState, Storage,
-    SK_FORMAT_VERSION, SK_MAGIC,
+    AcceptorProposerMessage, ProposerAcceptorMessage, SafeKeeper, SafeKeeperState, ServerInfo,
+    Storage, SK_FORMAT_VERSION, SK_MAGIC,
 };
 use crate::WalAcceptorConf;
 use postgres_ffi::xlog_utils::{XLogFileName, XLOG_BLCKSZ};
@@ -27,15 +27,12 @@ use postgres_ffi::xlog_utils::{XLogFileName, XLOG_BLCKSZ};
 const CONTROL_FILE_NAME: &str = "safekeeper.control";
 
 /// Shared state associated with database instance (tenant)
-#[derive(Debug)]
 struct SharedState {
     /// Safekeeper object
     sk: SafeKeeper<FileStorage>,
-    /// opened file control file handle (needed to hold exlusive file lock)
-    control_file: File,
     /// For receiving-sending wal cooperation
     /// quorum commit LSN we've notified walsenders about
-    commit_lsn: Lsn,
+    notified_commit_lsn: Lsn,
     /// combined hot standby feedback from all replicas
     hs_feedback: HotStandbyFeedback,
 }
@@ -59,20 +56,24 @@ impl SharedState {
     ) -> Result<Self> {
         let (cf, state) = SharedState::load_control_file(conf, timelineid, create)?;
         let storage = FileStorage {
-            control_file: cf.try_clone()?,
+            control_file: cf,
             conf: conf.clone(),
         };
         let (flush_lsn, tli) = if state.server.wal_seg_size != 0 {
             let wal_dir = conf.data_dir.join(format!("{}", timelineid));
-            find_end_of_wal(&wal_dir, state.server.wal_seg_size as usize, true)
+            find_end_of_wal(
+                &wal_dir,
+                state.server.wal_seg_size as usize,
+                true,
+                state.wal_start_lsn,
+            )?
         } else {
             (0, 0)
         };
 
         Ok(Self {
-            commit_lsn: Lsn(0),
+            notified_commit_lsn: Lsn(0),
             sk: SafeKeeper::new(Lsn(flush_lsn), tli, storage, state),
-            control_file: cf,
             hs_feedback: HotStandbyFeedback {
                 ts: 0,
                 xmin: u64::MAX,
@@ -127,7 +128,7 @@ impl SharedState {
                     if let CreateControlFile::False = create {
                         bail!("control file is empty");
                     }
-                    return Ok((file, SafeKeeperState::new()));
+                    Ok((file, SafeKeeperState::new()))
                 } else {
                     match SafeKeeperState::des_from(&mut file) {
                         Err(e) => {
@@ -144,7 +145,7 @@ impl SharedState {
                                     SK_FORMAT_VERSION
                                 );
                             }
-                            return Ok((file, s));
+                            Ok((file, s))
                         }
                     }
                 }
@@ -161,7 +162,6 @@ impl SharedState {
 }
 
 /// Database instance (tenant)
-#[derive(Debug)]
 pub struct Timeline {
     pub timelineid: ZTimelineId,
     mutex: Mutex<SharedState>,
@@ -186,7 +186,7 @@ impl Timeline {
     pub fn wait_for_lsn(&self, lsn: Lsn) -> Lsn {
         let mut shared_state = self.mutex.lock().unwrap();
         loop {
-            let commit_lsn = shared_state.commit_lsn;
+            let commit_lsn = shared_state.notified_commit_lsn;
             // This must be `>`, not `>=`.
             if commit_lsn > lsn {
                 return commit_lsn;
@@ -198,8 +198,8 @@ impl Timeline {
     // Notify caught-up WAL senders about new WAL data received
     pub fn notify_wal_senders(&self, commit_lsn: Lsn) {
         let mut shared_state = self.mutex.lock().unwrap();
-        if shared_state.commit_lsn < commit_lsn {
-            shared_state.commit_lsn = commit_lsn;
+        if shared_state.notified_commit_lsn < commit_lsn {
+            shared_state.notified_commit_lsn = commit_lsn;
             self.cond.notify_all();
         }
     }
@@ -217,14 +217,11 @@ impl Timeline {
             rmsg = shared_state.sk.process_msg(msg)?;
             // locally available commit lsn. flush_lsn can be smaller than
             // commit_lsn if we are catching up safekeeper.
-            commit_lsn = min(shared_state.sk.flush_lsn, shared_state.sk.s.commit_lsn);
+            commit_lsn = shared_state.sk.commit_lsn;
 
             // if this is AppendResponse, fill in proper hot standby feedback
-            match rmsg {
-                AcceptorProposerMessage::AppendResponse(ref mut resp) => {
-                    resp.hs_feedback = shared_state.hs_feedback.clone();
-                }
-                _ => (),
+            if let AcceptorProposerMessage::AppendResponse(ref mut resp) = rmsg {
+                resp.hs_feedback = shared_state.hs_feedback.clone();
             }
         }
         // Ping wal sender that new data might be available.
@@ -340,14 +337,14 @@ impl Storage for FileStorage {
         Ok(())
     }
 
-    fn write_wal(&mut self, s: &SafeKeeperState, startpos: Lsn, buf: &[u8]) -> Result<()> {
+    fn write_wal(&mut self, server: &ServerInfo, startpos: Lsn, buf: &[u8]) -> Result<()> {
         let mut bytes_left: usize = buf.len();
         let mut bytes_written: usize = 0;
         let mut partial;
         let mut start_pos = startpos;
         const ZERO_BLOCK: &[u8] = &[0u8; XLOG_BLCKSZ];
-        let wal_seg_size = s.server.wal_seg_size as usize;
-        let ztli = s.server.ztli;
+        let wal_seg_size = server.wal_seg_size as usize;
+        let ztli = server.ztli;
 
         /* Extract WAL location for this block */
         let mut xlogoff = start_pos.segment_offset(wal_seg_size) as usize;
@@ -368,7 +365,7 @@ impl Storage for FileStorage {
             /* Open file */
             let segno = start_pos.segment_number(wal_seg_size);
             // note: we basically don't support changing pg timeline
-            let wal_file_name = XLogFileName(s.server.tli, segno, wal_seg_size);
+            let wal_file_name = XLogFileName(server.tli, segno, wal_seg_size);
             let wal_file_path = self
                 .conf
                 .data_dir
@@ -401,7 +398,7 @@ impl Storage for FileStorage {
                     {
                         Ok(mut file) => {
                             for _ in 0..(wal_seg_size / XLOG_BLCKSZ) {
-                                file.write_all(&ZERO_BLOCK)?;
+                                file.write_all(ZERO_BLOCK)?;
                             }
                             wal_file = file;
                         }

zenith/src/main.rs

@@ -1,10 +1,10 @@
-use anyhow::{anyhow, bail};
+use anyhow::anyhow;
 use anyhow::{Context, Result};
 use clap::{App, AppSettings, Arg, ArgMatches, SubCommand};
 use control_plane::compute::ComputeControlPlane;
-use control_plane::local_env::{self, LocalEnv};
+use control_plane::local_env;
 use control_plane::storage::PageServerNode;
-use std::collections::btree_map::Entry;
+use pageserver::defaults::{DEFAULT_HTTP_LISTEN_PORT, DEFAULT_PG_LISTEN_PORT};
 use std::collections::HashMap;
 use std::process::exit;
 use std::str::FromStr;
@@ -13,7 +13,6 @@ use zenith_utils::postgres_backend::AuthType;
 use zenith_utils::zid::{ZTenantId, ZTimelineId};
 
 use pageserver::branches::BranchInfo;
-use zenith_utils::lsn::Lsn;
 
 ///
 /// Branches tree element used as a value in the HashMap.
@@ -30,7 +29,7 @@ struct BranchTreeEl {
 // This utility helps to manage zenith installation. That includes following:
 //   * Management of local postgres installations running on top of the
 //     pageserver.
-//   * Providing CLI api to the pageserver (local or remote)
+//   * Providing CLI api to the pageserver
 //   * TODO: export/import to/from usual postgres
 fn main() -> Result<()> {
     let timeline_arg = Arg::with_name("timeline")
@@ -45,16 +44,27 @@ fn main() -> Result<()> {
         .takes_value(true)
         .required(false);
 
+    let port_arg = Arg::with_name("port")
+        .long("port")
+        .required(false)
+        .value_name("port");
+
     let matches = App::new("Zenith CLI")
         .setting(AppSettings::ArgRequiredElseHelp)
         .subcommand(
             SubCommand::with_name("init")
                 .about("Initialize a new Zenith repository")
                 .arg(
-                    Arg::with_name("remote-pageserver")
-                        .long("remote-pageserver")
+                    Arg::with_name("pageserver-pg-port")
+                        .long("pageserver-pg-port")
                         .required(false)
-                        .value_name("pageserver-url"),
+                        .value_name("pageserver-pg-port"),
+                )
+                .arg(
+                    Arg::with_name("pageserver-http-port")
+                        .long("pageserver-http-port")
+                        .required(false)
+                        .value_name("pageserver-http-port"),
                 )
                 .arg(
                     Arg::with_name("enable-auth")
@@ -87,7 +97,7 @@ fn main() -> Result<()> {
                 .subcommand(SubCommand::with_name("list").arg(tenantid_arg.clone()))
                 .subcommand(SubCommand::with_name("create")
                     .about("Create a postgres compute node")
-                    .arg(timeline_arg.clone()).arg(tenantid_arg.clone())
+                    .arg(timeline_arg.clone()).arg(tenantid_arg.clone()).arg(port_arg.clone())
                     .arg(
                         Arg::with_name("config-only")
                             .help("Don't do basebackup, create compute node with only config files")
@@ -95,8 +105,12 @@ fn main() -> Result<()> {
                             .required(false)
                     ))
                 .subcommand(SubCommand::with_name("start")
-                    .about("Start a postrges compute node.\n This command actually creates new node from scrath, but preserves existing config files")
-                    .arg(timeline_arg.clone()).arg(tenantid_arg.clone()))
+                    .about("Start a postgres compute node.\n This command actually creates new node from scratch, but preserves existing config files")
+                    .arg(
+                        timeline_arg.clone()
+                    ).arg(
+                        tenantid_arg.clone()
+                    ).arg(port_arg.clone()))
                 .subcommand(
                     SubCommand::with_name("stop")
                         .arg(timeline_arg.clone())
@@ -107,36 +121,36 @@ fn main() -> Result<()> {
                                 .long("destroy")
                                 .required(false)
                         )
-                )
-        )
-        .subcommand(
-            SubCommand::with_name("remote")
-                .setting(AppSettings::ArgRequiredElseHelp)
-                .about("Manage remote pagerservers")
-                .subcommand(
-                    SubCommand::with_name("add")
-                        .about("Add a new remote pageserver")
-                        .arg(Arg::with_name("name").required(true))
-                        .arg(
-                            Arg::with_name("url")
-                                .help("PostgreSQL connection URI")
-                                .required(true),
-                        ),
-                ),
+                    )
+
         )
         .get_matches();
 
     // Create config file
     if let ("init", Some(init_match)) = matches.subcommand() {
         let tenantid = ZTenantId::generate();
-        let pageserver_uri = init_match.value_of("pageserver-url");
+        let pageserver_pg_port = match init_match.value_of("pageserver-pg-port") {
+            Some(v) => v.parse()?,
+            None => DEFAULT_PG_LISTEN_PORT,
+        };
+        let pageserver_http_port = match init_match.value_of("pageserver-http-port") {
+            Some(v) => v.parse()?,
+            None => DEFAULT_HTTP_LISTEN_PORT,
+        };
+
         let auth_type = if init_match.is_present("enable-auth") {
             AuthType::ZenithJWT
         } else {
             AuthType::Trust
         };
-        local_env::init(pageserver_uri, tenantid, auth_type)
-            .with_context(|| "Failed to create config file")?;
+
+        local_env::init(
+            pageserver_pg_port,
+            pageserver_http_port,
+            tenantid,
+            auth_type,
+        )
+        .with_context(|| "Failed to create config file")?;
     }
 
     // all other commands would need config
@@ -214,13 +228,6 @@ fn main() -> Result<()> {
             }
         }
 
-        ("remote", Some(remote_match)) => {
-            if let Err(e) = handle_remote(remote_match, &env) {
-                eprintln!("remote operation failed: {}", e);
-                exit(1);
-            }
-        }
-
         _ => {}
     };
 
@@ -359,7 +366,7 @@ fn get_branch_infos(
 }
 
 fn handle_tenant(tenant_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
-    let pageserver = PageServerNode::from_env(&env);
+    let pageserver = PageServerNode::from_env(env);
     match tenant_match.subcommand() {
         ("list", Some(_)) => {
             for tenant in pageserver.tenant_list()? {
@@ -381,21 +388,19 @@ fn handle_tenant(tenant_match: &ArgMatches, env: &local_env::LocalEnv) -> Result
 }
 
 fn handle_branch(branch_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
-    let pageserver = PageServerNode::from_env(&env);
+    let pageserver = PageServerNode::from_env(env);
 
     if let Some(branchname) = branch_match.value_of("branchname") {
         let startpoint_str = branch_match
             .value_of("start-point")
-            .ok_or(anyhow!("Missing start-point"))?;
+            .ok_or_else(|| anyhow!("Missing start-point"))?;
         let tenantid: ZTenantId = branch_match
             .value_of("tenantid")
             .map_or(Ok(env.tenantid), |value| value.parse())?;
         let branch = pageserver.branch_create(branchname, startpoint_str, &tenantid)?;
         println!(
             "Created branch '{}' at {:?} for tenant: {}",
-            branch.name,
-            branch.latest_valid_lsn.unwrap_or(Lsn(0)),
-            tenantid,
+            branch.name, branch.latest_valid_lsn, tenantid,
         );
     } else {
         let tenantid: ZTenantId = branch_match
@@ -434,9 +439,7 @@ fn handle_pg(pg_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
                     node.address,
                     branch_infos
                         .get(&node.timelineid)
-                        .map(|bi| bi
-                            .latest_valid_lsn
-                            .map_or("?".to_string(), |lsn| lsn.to_string()))
+                        .map(|bi| bi.latest_valid_lsn.to_string())
                         .unwrap_or_else(|| "?".to_string()),
                     node.status(),
                 );
@@ -447,9 +450,12 @@ fn handle_pg(pg_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
                 .value_of("tenantid")
                 .map_or(Ok(env.tenantid), |value| value.parse())?;
             let timeline_name = create_match.value_of("timeline").unwrap_or("main");
-            let config_only = create_match.is_present("config-only");
 
-            cplane.new_node(tenantid, timeline_name, config_only)?;
+            let port: Option<u16> = match create_match.value_of("port") {
+                Some(p) => Some(p.parse()?),
+                None => None,
+            };
+            cplane.new_node(tenantid, timeline_name, port)?;
         }
         ("start", Some(start_match)) => {
             let tenantid: ZTenantId = start_match
@@ -457,6 +463,11 @@ fn handle_pg(pg_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
                 .map_or(Ok(env.tenantid), |value| value.parse())?;
             let timeline_name = start_match.value_of("timeline").unwrap_or("main");
 
+            let port: Option<u16> = match start_match.value_of("port") {
+                Some(p) => Some(p.parse()?),
+                None => None,
+            };
+
             let node = cplane.nodes.get(&(tenantid, timeline_name.to_owned()));
 
             let auth_token = if matches!(env.auth_type, AuthType::ZenithJWT) {
@@ -466,11 +477,20 @@ fn handle_pg(pg_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
                 None
             };
 
-            println!("Starting postgres on timeline {}...", timeline_name);
+            println!(
+                "Starting {} postgres on timeline {}...",
+                if node.is_some() { "existing" } else { "new" },
+                timeline_name
+            );
             if let Some(node) = node {
                 node.start(&auth_token)?;
             } else {
-                let node = cplane.new_node(tenantid, timeline_name, false)?;
+                // when used with custom port this results in non obvious behaviour
+                // port is remembered from first start command, i e
+                // start --port X
+                // stop
+                // start <-- will also use port X even without explicit port argument
+                let node = cplane.new_node(tenantid, timeline_name, port)?;
                 node.start(&auth_token)?;
             }
         }
@@ -493,29 +513,3 @@ fn handle_pg(pg_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<()> {
 
     Ok(())
 }
-
-fn handle_remote(remote_match: &ArgMatches, local_env: &LocalEnv) -> Result<()> {
-    match remote_match.subcommand() {
-        ("add", Some(args)) => {
-            let name = args.value_of("name").unwrap();
-            let url = args.value_of("url").unwrap();
-
-            // validate the URL
-            postgres::Config::from_str(url)?;
-
-            let mut new_local_env = local_env.clone();
-
-            match new_local_env.remotes.entry(name.to_string()) {
-                Entry::Vacant(vacant) => {
-                    vacant.insert(url.to_string());
-                }
-                Entry::Occupied(_) => bail!("origin '{}' already exists", name),
-            }
-
-            local_env::save_config(&new_local_env)?;
-        }
-        _ => bail!("unknown command"),
-    }
-
-    Ok(())
-}

zenith_metrics/Cargo.toml

@@ -4,6 +4,7 @@ version = "0.1.0"
 edition = "2018"
 
 [dependencies]
-prometheus = "0.12"
+prometheus = {version = "0.12", default_features=false} # removes protobuf dependency
 libc = "0.2"
 lazy_static = "1.4"
+once_cell = "1.8.0"

zenith_metrics/src/lib.rs

@@ -3,6 +3,7 @@
 //! Otherwise, we might not see all metrics registered via
 //! a default registry.
 use lazy_static::lazy_static;
+use once_cell::race::OnceBox;
 pub use prometheus::{exponential_buckets, linear_buckets};
 pub use prometheus::{register_histogram, Histogram};
 pub use prometheus::{register_histogram_vec, HistogramVec};
@@ -13,7 +14,6 @@ pub use prometheus::{register_int_gauge_vec, IntGaugeVec};
 pub use prometheus::{Encoder, TextEncoder};
 
 mod wrappers;
-use libc::{c_long, getrusage, rusage, suseconds_t, time_t, timeval, RUSAGE_SELF};
 pub use wrappers::{CountedReader, CountedWriter};
 
 /// Gathers all Prometheus metrics and records the I/O stats just before that.
@@ -21,61 +21,86 @@ pub use wrappers::{CountedReader, CountedWriter};
 /// Metrics gathering is a relatively simple and standalone operation, so
 /// it might be fine to do it this way to keep things simple.
 pub fn gather() -> Vec<prometheus::proto::MetricFamily> {
-    update_io_metrics();
+    update_rusage_metrics();
     prometheus::gather()
 }
 
+static COMMON_METRICS_PREFIX: OnceBox<&str> = OnceBox::new();
+
+/// Sets a prefix which will be used for all common metrics, typically a service
+/// name like 'pageserver'. Should be executed exactly once in the beginning of
+/// any executable which uses common metrics.
+pub fn set_common_metrics_prefix(prefix: &'static str) {
+    // Not unwrap() because metrics may be initialized after multiple threads have been started.
+    COMMON_METRICS_PREFIX
+        .set(prefix.into())
+        .unwrap_or_else(|_| {
+            eprintln!(
+                "set_common_metrics_prefix() was called second time with '{}', exiting",
+                prefix
+            );
+            std::process::exit(1);
+        });
+}
+
+/// Prepends a prefix to a common metric name so they are distinguished between
+/// different services, see https://github.com/zenithdb/zenith/pull/681
+/// A call to set_common_metrics_prefix() is necessary prior to calling this.
+pub fn new_common_metric_name(unprefixed_metric_name: &str) -> String {
+    // Not unwrap() because metrics may be initialized after multiple threads have been started.
+    format!(
+        "{}_{}",
+        COMMON_METRICS_PREFIX.get().unwrap_or_else(|| {
+            eprintln!("set_common_metrics_prefix() was not called, but metrics are used, exiting");
+            std::process::exit(1);
+        }),
+        unprefixed_metric_name
+    )
+}
+
 lazy_static! {
     static ref DISK_IO_BYTES: IntGaugeVec = register_int_gauge_vec!(
-        "pageserver_disk_io_bytes",
+        new_common_metric_name("disk_io_bytes"),
         "Bytes written and read from disk, grouped by the operation (read|write)",
         &["io_operation"]
     )
     .expect("Failed to register disk i/o bytes int gauge vec");
+    static ref MAXRSS_KB: IntGauge = register_int_gauge!(
+        new_common_metric_name("maxrss_kb"),
+        "Memory usage (Maximum Resident Set Size)"
+    )
+    .expect("Failed to register maxrss_kb int gauge");
 }
 
 // Records I/O stats in a "cross-platform" way.
-// Compiles both on macOs and Linux, but current macOs implementation always returns 0 as values for I/O stats.
-// An alternative is to read procfs (`/proc/[pid]/io`) which does not work under macOs at all, hence abandoned.
+// Compiles both on macOS and Linux, but current macOS implementation always returns 0 as values for I/O stats.
+// An alternative is to read procfs (`/proc/[pid]/io`) which does not work under macOS at all, hence abandoned.
 //
 // Uses https://www.freebsd.org/cgi/man.cgi?query=getrusage to retrieve the number of block operations
 // performed by the process.
-// We know the the size of the block, so we can determine the I/O bytes out of it.
+// We know the size of the block, so we can determine the I/O bytes out of it.
 // The value might be not 100% exact, but should be fine for Prometheus metrics in this case.
-fn update_io_metrics() {
-    let mut usage = rusage {
-        ru_utime: timeval {
-            tv_sec: 0 as time_t,
-            tv_usec: 0 as suseconds_t,
-        },
-        ru_stime: timeval {
-            tv_sec: 0 as time_t,
-            tv_usec: 0 as suseconds_t,
-        },
-        ru_maxrss: 0 as c_long,
-        ru_ixrss: 0 as c_long,
-        ru_idrss: 0 as c_long,
-        ru_isrss: 0 as c_long,
-        ru_minflt: 0 as c_long,
-        ru_majflt: 0 as c_long,
-        ru_nswap: 0 as c_long,
-        ru_inblock: 0 as c_long,
-        ru_oublock: 0 as c_long,
-        ru_msgsnd: 0 as c_long,
-        ru_msgrcv: 0 as c_long,
-        ru_nsignals: 0 as c_long,
-        ru_nvcsw: 0 as c_long,
-        ru_nivcsw: 0 as c_long,
-    };
-    unsafe {
-        getrusage(RUSAGE_SELF, (&mut usage) as *mut rusage);
-    }
+#[allow(clippy::unnecessary_cast)]
+fn update_rusage_metrics() {
+    let rusage_stats = get_rusage_stats();
 
     const BYTES_IN_BLOCK: i64 = 512;
     DISK_IO_BYTES
         .with_label_values(&["read"])
-        .set(usage.ru_inblock * BYTES_IN_BLOCK);
+        .set(rusage_stats.ru_inblock * BYTES_IN_BLOCK);
     DISK_IO_BYTES
         .with_label_values(&["write"])
-        .set(usage.ru_oublock * BYTES_IN_BLOCK);
+        .set(rusage_stats.ru_oublock * BYTES_IN_BLOCK);
+    MAXRSS_KB.set(rusage_stats.ru_maxrss);
+}
+
+fn get_rusage_stats() -> libc::rusage {
+    let mut rusage = std::mem::MaybeUninit::uninit();
+
+    // SAFETY: kernel will initialize the struct for us
+    unsafe {
+        let ret = libc::getrusage(libc::RUSAGE_SELF, rusage.as_mut_ptr());
+        assert!(ret == 0, "getrusage failed: bad args");
+        rusage.assume_init()
+    }
 }

zenith_metrics/src/wrappers.rs

@@ -186,7 +186,7 @@ mod tests {
         assert_eq!(total, stream.len());
     }
 
-    // This mimicks the constraints of std::thread::spawn
+    // This mimics the constraints of std::thread::spawn
     fn assert_send_sync(_x: impl Sync + Send + 'static) {}
 
     #[test]

zenith_utils/Cargo.toml

@@ -17,7 +17,13 @@ routerify = "2"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
 thiserror = "1.0"
-tokio = { version = "1.5.0", features = ["full"] }
+tokio = "1.11"
+
+slog-async = "2.6.0"
+slog-stdlog = "4.1.0"
+slog-scope = "4.4.0"
+slog-term = "2.8.0"
+slog = "2.7.0"
 
 zenith_metrics = { path = "../zenith_metrics" }
 workspace_hack = { path = "../workspace_hack" }
@@ -32,3 +38,4 @@ rustls-split = "0.2.1"
 hex-literal = "0.3"
 bytes = "1.0"
 webpki = "0.21"
+tempfile = "3.2"

zenith_utils/src/accum.rs

@@ -0,0 +1,33 @@
+/// A helper to "accumulate" a value similar to `Iterator::reduce`, but lets you
+/// feed the accumulated values by calling the 'accum' function, instead of having an
+/// iterator.
+///
+/// For example, to calculate the smallest value among some integers:
+///
+/// ```
+/// use zenith_utils::accum::Accum;
+///
+/// let values = [1, 2, 3];
+///
+/// let mut min_value: Accum<u32> = Accum(None);
+/// for new_value in &values {
+///     min_value.accum(std::cmp::min, *new_value);
+/// }
+///
+/// assert_eq!(min_value.0.unwrap(), 1);
+/// ```
+pub struct Accum<T>(pub Option<T>);
+impl<T: Copy> Accum<T> {
+    pub fn accum<F>(&mut self, func: F, new_value: T)
+    where
+        F: FnOnce(T, T) -> T,
+    {
+        // If there is no previous value, just store the new value.
+        // Otherwise call the function to decide which one to keep.
+        self.0 = Some(if let Some(accum) = self.0 {
+            func(accum, new_value)
+        } else {
+            new_value
+        });
+    }
+}

zenith_utils/src/auth.rs

@@ -1,6 +1,6 @@
 // For details about authentication see docs/authentication.md
 // TODO there are two issues for our use case in jsonwebtoken library which will be resolved in next release
-// The fisrt one is that there is no way to disable expiration claim, but it can be excluded from validation, so use this as a workaround for now.
+// The first one is that there is no way to disable expiration claim, but it can be excluded from validation, so use this as a workaround for now.
 // Relevant issue: https://github.com/Keats/jsonwebtoken/issues/190
 // The second one is that we wanted to use ed25519 keys, but they are also not supported until next version. So we go with RSA keys for now.
 // Relevant issue: https://github.com/Keats/jsonwebtoken/issues/162
@@ -8,7 +8,8 @@
 use hex::{self, FromHex};
 use serde::de::Error;
 use serde::{self, Deserializer, Serializer};
-use std::{fs, path::PathBuf};
+use std::fs;
+use std::path::Path;
 
 use anyhow::{bail, Result};
 use jsonwebtoken::{
@@ -43,8 +44,8 @@ where
 {
     let opt: Option<String> = Option::deserialize(deserializer)?;
     match opt {
-        Some(tid) => return Ok(Some(ZTenantId::from_hex(tid).map_err(Error::custom)?)),
-        None => return Ok(None),
+        Some(tid) => Ok(Some(ZTenantId::from_hex(tid).map_err(Error::custom)?)),
+        None => Ok(None),
     }
 }
 
@@ -91,7 +92,7 @@ pub struct JwtAuth {
 }
 
 impl JwtAuth {
-    pub fn new<'a>(decoding_key: DecodingKey<'a>) -> Self {
+    pub fn new(decoding_key: DecodingKey<'_>) -> Self {
         Self {
             decoding_key: decoding_key.into_static(),
             validation: Validation {
@@ -102,7 +103,7 @@ impl JwtAuth {
         }
     }
 
-    pub fn from_key_path(key_path: &PathBuf) -> Result<Self> {
+    pub fn from_key_path(key_path: &Path) -> Result<Self> {
         let public_key = fs::read_to_string(key_path)?;
         Ok(Self::new(DecodingKey::from_rsa_pem(public_key.as_bytes())?))
     }
@@ -113,8 +114,8 @@ impl JwtAuth {
 }
 
 // this function is used only for testing purposes in CLI e g generate tokens during init
-pub fn encode_from_key_path(claims: &Claims, key_path: &PathBuf) -> Result<String> {
+pub fn encode_from_key_path(claims: &Claims, key_path: &Path) -> Result<String> {
     let key_data = fs::read_to_string(key_path)?;
-    let key = EncodingKey::from_rsa_pem(&key_data.as_bytes())?;
+    let key = EncodingKey::from_rsa_pem(key_data.as_bytes())?;
     Ok(encode(&Header::new(JWT_ALGORITHM), claims, &key)?)
 }

zenith_utils/src/bin_ser.rs

@@ -6,7 +6,7 @@
 //!
 //! The [`LeSer`] trait does the same thing, in little-endian form.
 //!
-//! Note: you will get a compile error if you try to `use` both trais
+//! Note: you will get a compile error if you try to `use` both traits
 //! in the same module or scope. This is intended to be a safety
 //! mechanism: mixing big-endian and little-endian encoding in the same file
 //! is error-prone.
@@ -69,14 +69,13 @@ impl From<bincode::Error> for SerializeError {
 /// Properties:
 /// - Big endian
 /// - Fixed integer encoding (i.e. 1u32 is 00000001 not 01)
-/// - Allow trailing bytes: this means we don't throw an error
-///   if the deserializer is passed a buffer with more data
-///   past the end.
+///
+/// Does not allow trailing bytes in deserialization. If this is desired, you
+/// may set [`Options::allow_trailing_bytes`] to explicitly accomodate this.
 pub fn be_coder() -> impl Options {
     bincode::DefaultOptions::new()
         .with_big_endian()
         .with_fixint_encoding()
-        .allow_trailing_bytes()
 }
 
 /// A shortcut that configures little-ending binary serialization
@@ -84,21 +83,23 @@ pub fn be_coder() -> impl Options {
 /// Properties:
 /// - Little endian
 /// - Fixed integer encoding (i.e. 1u32 is 00000001 not 01)
-/// - Allow trailing bytes: this means we don't throw an error
-///   if the deserializer is passed a buffer with more data
-///   past the end.
+///
+/// Does not allow trailing bytes in deserialization. If this is desired, you
+/// may set [`Options::allow_trailing_bytes`] to explicitly accomodate this.
 pub fn le_coder() -> impl Options {
     bincode::DefaultOptions::new()
         .with_little_endian()
         .with_fixint_encoding()
-        .allow_trailing_bytes()
 }
 
 /// Binary serialize/deserialize helper functions (Big Endian)
 ///
-pub trait BeSer: Serialize + DeserializeOwned {
+pub trait BeSer {
     /// Serialize into a byte slice
-    fn ser_into_slice(&self, mut b: &mut [u8]) -> Result<(), SerializeError> {
+    fn ser_into_slice(&self, mut b: &mut [u8]) -> Result<(), SerializeError>
+    where
+        Self: Serialize,
+    {
         // &mut [u8] implements Write, but `ser_into` needs a mutable
         // reference to that. So we need the slightly awkward "mutable
         // reference to a mutable reference.
@@ -109,24 +110,54 @@ pub trait BeSer: Serialize + DeserializeOwned {
     ///
     /// This is useful for most `Write` types except `&mut [u8]`, which
     /// can more easily use [`ser_into_slice`](Self::ser_into_slice).
-    fn ser_into<W: Write>(&self, w: &mut W) -> Result<(), SerializeError> {
+    fn ser_into<W: Write>(&self, w: &mut W) -> Result<(), SerializeError>
+    where
+        Self: Serialize,
+    {
         be_coder().serialize_into(w, &self).map_err(|e| e.into())
     }
 
     /// Serialize into a new heap-allocated buffer
-    fn ser(&self) -> Result<Vec<u8>, SerializeError> {
+    fn ser(&self) -> Result<Vec<u8>, SerializeError>
+    where
+        Self: Serialize,
+    {
         be_coder().serialize(&self).map_err(|e| e.into())
     }
 
-    /// Deserialize from a byte slice
-    fn des(buf: &[u8]) -> Result<Self, DeserializeError> {
+    /// Deserialize from the full contents of a byte slice
+    ///
+    /// See also: [`BeSer::des_prefix`]
+    fn des(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         be_coder()
             .deserialize(buf)
             .or(Err(DeserializeError::BadInput))
     }
 
+    /// Deserialize from a prefix of the byte slice
+    ///
+    /// Uses as much of the byte slice as is necessary to deserialize the
+    /// type, but does not guarantee that the entire slice is used.
+    ///
+    /// See also: [`BeSer::des`]
+    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
+        be_coder()
+            .allow_trailing_bytes()
+            .deserialize(buf)
+            .or(Err(DeserializeError::BadInput))
+    }
+
     /// Deserialize from a reader
-    fn des_from<R: Read>(r: &mut R) -> Result<Self, DeserializeError> {
+    fn des_from<R: Read>(r: &mut R) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         be_coder().deserialize_from(r).map_err(|e| e.into())
     }
 
@@ -134,16 +165,22 @@ pub trait BeSer: Serialize + DeserializeOwned {
     ///
     /// Note: it may be faster to serialize to a buffer and then measure the
     /// buffer length, than to call `serialized_size` and then `ser_into`.
-    fn serialized_size(&self) -> Result<u64, SerializeError> {
+    fn serialized_size(&self) -> Result<u64, SerializeError>
+    where
+        Self: Serialize,
+    {
         be_coder().serialized_size(self).map_err(|e| e.into())
     }
 }
 
 /// Binary serialize/deserialize helper functions (Little Endian)
 ///
-pub trait LeSer: Serialize + DeserializeOwned {
+pub trait LeSer {
     /// Serialize into a byte slice
-    fn ser_into_slice(&self, mut b: &mut [u8]) -> Result<(), SerializeError> {
+    fn ser_into_slice(&self, mut b: &mut [u8]) -> Result<(), SerializeError>
+    where
+        Self: Serialize,
+    {
         // &mut [u8] implements Write, but `ser_into` needs a mutable
         // reference to that. So we need the slightly awkward "mutable
         // reference to a mutable reference.
@@ -154,24 +191,54 @@ pub trait LeSer: Serialize + DeserializeOwned {
     ///
     /// This is useful for most `Write` types except `&mut [u8]`, which
     /// can more easily use [`ser_into_slice`](Self::ser_into_slice).
-    fn ser_into<W: Write>(&self, w: &mut W) -> Result<(), SerializeError> {
+    fn ser_into<W: Write>(&self, w: &mut W) -> Result<(), SerializeError>
+    where
+        Self: Serialize,
+    {
         le_coder().serialize_into(w, &self).map_err(|e| e.into())
     }
 
     /// Serialize into a new heap-allocated buffer
-    fn ser(&self) -> Result<Vec<u8>, SerializeError> {
+    fn ser(&self) -> Result<Vec<u8>, SerializeError>
+    where
+        Self: Serialize,
+    {
         le_coder().serialize(&self).map_err(|e| e.into())
     }
 
-    /// Deserialize from a byte slice
-    fn des(buf: &[u8]) -> Result<Self, DeserializeError> {
+    /// Deserialize from the full contents of a byte slice
+    ///
+    /// See also: [`LeSer::des_prefix`]
+    fn des(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         le_coder()
             .deserialize(buf)
             .or(Err(DeserializeError::BadInput))
     }
 
+    /// Deserialize from a prefix of the byte slice
+    ///
+    /// Uses as much of the byte slice as is necessary to deserialize the
+    /// type, but does not guarantee that the entire slice is used.
+    ///
+    /// See also: [`LeSer::des`]
+    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
+        le_coder()
+            .allow_trailing_bytes()
+            .deserialize(buf)
+            .or(Err(DeserializeError::BadInput))
+    }
+
     /// Deserialize from a reader
-    fn des_from<R: Read>(r: &mut R) -> Result<Self, DeserializeError> {
+    fn des_from<R: Read>(r: &mut R) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         le_coder().deserialize_from(r).map_err(|e| e.into())
     }
 
@@ -179,14 +246,18 @@ pub trait LeSer: Serialize + DeserializeOwned {
     ///
     /// Note: it may be faster to serialize to a buffer and then measure the
     /// buffer length, than to call `serialized_size` and then `ser_into`.
-    fn serialized_size(&self) -> Result<u64, SerializeError> {
+    fn serialized_size(&self) -> Result<u64, SerializeError>
+    where
+        Self: Serialize,
+    {
         le_coder().serialized_size(self).map_err(|e| e.into())
     }
 }
 
-impl<T> BeSer for T where T: Serialize + DeserializeOwned {}
-
-impl<T> LeSer for T where T: Serialize + DeserializeOwned {}
+// Because usage of `BeSer` or `LeSer` can be done with *either* a Serialize or
+// DeserializeOwned implementation, the blanket implementation has to be for every type.
+impl<T> BeSer for T {}
+impl<T> LeSer for T {}
 
 #[cfg(test)]
 mod tests {
@@ -247,8 +318,10 @@ mod tests {
         assert_eq!(decoded, SHORT2);
 
         // with trailing data
-        let decoded = ShortStruct::des(SHORT2_ENC_BE_TRAILING).unwrap();
+        let decoded = ShortStruct::des_prefix(SHORT2_ENC_BE_TRAILING).unwrap();
         assert_eq!(decoded, SHORT2);
+        let err = ShortStruct::des(SHORT2_ENC_BE_TRAILING).unwrap_err();
+        assert!(matches!(err, DeserializeError::BadInput));
 
         // serialize into a `Write` sink.
         let mut buf = Cursor::new(vec![0xFF; 8]);
@@ -279,8 +352,10 @@ mod tests {
         assert_eq!(decoded, SHORT2);
 
         // with trailing data
-        let decoded = ShortStruct::des(SHORT2_ENC_LE_TRAILING).unwrap();
+        let decoded = ShortStruct::des_prefix(SHORT2_ENC_LE_TRAILING).unwrap();
         assert_eq!(decoded, SHORT2);
+        let err = ShortStruct::des(SHORT2_ENC_LE_TRAILING).unwrap_err();
+        assert!(matches!(err, DeserializeError::BadInput));
 
         // serialize into a `Write` sink.
         let mut buf = Cursor::new(vec![0xFF; 8]);