use copy_split in freeze

Removes the need for PageVersionMeta struct.

.circleci/config.yml

@@ -254,7 +254,7 @@ 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" ! -name "*.filediff" -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

.dockerignore

@@ -2,12 +2,13 @@
 **/__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

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"
@@ -1179,10 +1199,12 @@ dependencies = [
  "bytes",
  "chrono",
  "clap",
+ "const_format",
  "crc32c",
  "daemonize",
  "futures",
  "hex",
+ "hex-literal",
  "humantime",
  "hyper",
  "lazy_static",
@@ -1406,6 +1428,7 @@ dependencies = [
  "hex",
  "md5",
  "rand",
+ "reqwest",
  "rustls",
  "serde",
  "serde_json",
@@ -2330,6 +2353,7 @@ dependencies = [
  "regex",
  "rust-s3",
  "serde",
+ "serde_json",
  "tokio",
  "tokio-stream",
  "walkdir",
@@ -2554,6 +2578,7 @@ version = "0.1.0"
 dependencies = [
  "lazy_static",
  "libc",
+ "once_cell",
  "prometheus",
 ]
 
@@ -2583,6 +2608,7 @@ dependencies = [
  "slog-scope",
  "slog-stdlog",
  "slog-term",
+ "tempfile",
  "thiserror",
  "tokio",
  "webpki",

Dockerfile

@@ -11,38 +11,19 @@ WORKDIR /zenith
 COPY ./vendor/postgres vendor/postgres
 COPY ./Makefile Makefile
 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 +32,7 @@ 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

README.md

@@ -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

control_plane/src/compute.rs

@@ -1,17 +1,16 @@
-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::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;
@@ -19,6 +18,7 @@ use zenith_utils::zid::ZTenantId;
 use zenith_utils::zid::ZTimelineId;
 
 use crate::local_env::LocalEnv;
+use crate::postgresql_conf::PostgresConf;
 use crate::storage::PageServerNode;
 
 //
@@ -144,76 +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 = config.contains("wal_acceptors");
+        let uses_wal_proposer = conf.get("wal_acceptors").is_some();
 
         // ok now
         Ok(PostgresNode {
@@ -308,74 +257,58 @@ impl PostgresNode {
     // 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<()> {
-        File::create(self.pgdata().join("postgresql.conf").to_str().unwrap())?;
-
+        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\
-                 zenith.file_cache_size = 4096\n\
-                 zenith.file_cache_path = '/tmp/file.cache'\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"
-        } else {
-            ""
+        // 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)
         };
-
-        // 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(),
-        )?;
+        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
-        self.append_conf(
-            "postgresql.conf",
-            format!(
-                concat!(
-                    "synchronous_standby_names = 'pageserver'\n", // TODO: add a new function arg?
-                    "zenith.callmemaybe_connstring = '{}'\n",     // FIXME escaping
-                ),
-                self.connstr(),
-            )
-            .as_str(),
-        )?;
+        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(())
     }
@@ -418,14 +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);
@@ -527,9 +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/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(())
+}

docs/README.md

@@ -10,5 +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

pageserver/Cargo.toml

@@ -34,8 +34,12 @@ 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/bin/pageserver.rs

@@ -9,22 +9,28 @@ use std::{
     env,
     net::TcpListener,
     path::{Path, PathBuf},
-    process::exit,
     str::FromStr,
     thread,
 };
 use zenith_utils::{auth::JwtAuth, logging, postgres_backend::AuthType};
 
-use anyhow::{bail, ensure, Result};
+use anyhow::{bail, ensure, Context, Result};
 use clap::{App, Arg, ArgMatches};
 use daemonize::Daemonize;
 
 use pageserver::{
-    branches, http, page_service, tenant_mgr, PageServerConf, RelishStorageConfig, S3Config,
-    LOG_FILE_NAME,
+    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;
 
+use const_format::formatcp;
+
 /// String arguments that can be declared via CLI or config file
 #[derive(Serialize, Deserialize)]
 struct CfgFileParams {
@@ -39,6 +45,7 @@ struct CfgFileParams {
     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)]
@@ -89,6 +96,7 @@ impl CfgFileParams {
             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"),
         }
     }
 
@@ -108,6 +116,9 @@ impl CfgFileParams {
                 .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),
         }
     }
 
@@ -176,25 +187,34 @@ impl CfgFileParams {
             );
         }
 
-        let relish_storage_config =
-            self.relish_storage
-                .as_ref()
-                .map(|storage_params| match storage_params.clone() {
-                    RelishStorage::Local { local_path } => {
-                        RelishStorageConfig::LocalFs(PathBuf::from(local_path))
-                    }
-                    RelishStorage::AwsS3 {
-                        bucket_name,
-                        bucket_region,
-                        access_key_id,
-                        secret_access_key,
-                    } => RelishStorageConfig::AwsS3(S3Config {
-                        bucket_name,
-                        bucket_region,
-                        access_key_id,
-                        secret_access_key,
-                    }),
-                });
+        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,
@@ -220,6 +240,7 @@ impl CfgFileParams {
 }
 
 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(
@@ -228,14 +249,14 @@ fn main() -> Result<()> {
                 .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("http endpoint address for for metrics and management API calls ip:port (default: 127.0.0.1:5430)"),
+                .help(formatcp!("http endpoint address for metrics and management API calls on ip:port (default: {DEFAULT_HTTP_LISTEN_ADDR})")),
         )
         .arg(
             Arg::with_name("daemonize")
@@ -343,10 +364,19 @@ fn main() -> Result<()> {
                 .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);
 
@@ -358,22 +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
@@ -383,16 +428,21 @@ 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<()> {
@@ -430,16 +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);
 
-    // keep join handles for spawned threads
-    let mut join_handles = vec![];
-
     // initialize authentication for incoming connections
     let auth = match &conf.auth_type {
         AuthType::Trust | AuthType::MD5 => None,

pageserver/src/branches.rs

@@ -17,6 +17,7 @@ use std::{
 use zenith_utils::zid::{ZTenantId, ZTimelineId};
 
 use log::*;
+use zenith_utils::crashsafe_dir;
 use zenith_utils::logging;
 use zenith_utils::lsn::Lsn;
 
@@ -118,7 +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(())
@@ -135,12 +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()))?;
 
-    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());
 
@@ -150,12 +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)
 }
@@ -221,7 +223,11 @@ fn bootstrap_timeline(
     // 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, lsn)?;
+    restore_local_repo::import_timeline_from_postgres_datadir(
+        &pgdata_path,
+        timeline.as_ref(),
+        lsn,
+    )?;
     timeline.checkpoint()?;
 
     println!(

pageserver/src/layered_repository.rs

@@ -11,7 +11,7 @@
 //! parent timeline, and the last LSN that has been written to disk.
 //!
 
-use anyhow::{bail, Context, Result};
+use anyhow::{anyhow, bail, ensure, Context, Result};
 use bookfile::Book;
 use bytes::Bytes;
 use lazy_static::lazy_static;
@@ -22,7 +22,8 @@ use serde::{Deserialize, Serialize};
 use std::collections::hash_map::Entry;
 use std::collections::HashMap;
 use std::collections::{BTreeSet, HashSet};
-use std::fs::File;
+use std::convert::TryInto;
+use std::fs::{File, OpenOptions};
 use std::io::Write;
 use std::ops::Bound::Included;
 use std::path::{Path, PathBuf};
@@ -33,8 +34,9 @@ use std::{fs, thread};
 
 use crate::layered_repository::inmemory_layer::FreezeLayers;
 use crate::relish::*;
-use crate::relish_storage::storage_uploader::QueueBasedRelishUploader;
+use crate::relish_storage::schedule_timeline_upload;
 use crate::repository::{GcResult, Repository, Timeline, WALRecord};
+use crate::walreceiver::IS_WAL_RECEIVER;
 use crate::walredo::WalRedoManager;
 use crate::PageServerConf;
 use crate::{ZTenantId, ZTimelineId};
@@ -44,6 +46,7 @@ use zenith_metrics::{
 };
 use zenith_metrics::{register_histogram_vec, HistogramVec};
 use zenith_utils::bin_ser::BeSer;
+use zenith_utils::crashsafe_dir;
 use zenith_utils::lsn::{AtomicLsn, Lsn, RecordLsn};
 use zenith_utils::seqwait::SeqWait;
 
@@ -52,6 +55,7 @@ mod delta_layer;
 mod filename;
 mod image_layer;
 mod inmemory_layer;
+mod interval_tree;
 mod layer_map;
 mod storage_layer;
 
@@ -71,6 +75,11 @@ static ZERO_PAGE: Bytes = Bytes::from_static(&[0u8; 8192]);
 // Timeout when waiting for WAL receiver to catch up to an LSN given in a GetPage@LSN call.
 static TIMEOUT: Duration = Duration::from_secs(60);
 
+// Taken from PG_CONTROL_MAX_SAFE_SIZE
+const METADATA_MAX_SAFE_SIZE: usize = 512;
+const METADATA_CHECKSUM_SIZE: usize = std::mem::size_of::<u32>();
+const METADATA_MAX_DATA_SIZE: usize = METADATA_MAX_SAFE_SIZE - METADATA_CHECKSUM_SIZE;
+
 // Metrics collected on operations on the storage repository.
 lazy_static! {
     static ref STORAGE_TIME: HistogramVec = register_histogram_vec!(
@@ -110,7 +119,9 @@ pub struct LayeredRepository {
     timelines: Mutex<HashMap<ZTimelineId, Arc<LayeredTimeline>>>,
 
     walredo_mgr: Arc<dyn WalRedoManager + Send + Sync>,
-    relish_uploader: Option<Arc<QueueBasedRelishUploader>>,
+    /// Makes evey repo's timelines to backup their files to remote storage,
+    /// when they get frozen.
+    upload_relishes: bool,
 }
 
 /// Public interface
@@ -125,7 +136,7 @@ impl Repository for LayeredRepository {
         let mut timelines = self.timelines.lock().unwrap();
 
         // Create the timeline directory, and write initial metadata to file.
-        std::fs::create_dir_all(self.conf.timeline_path(&timelineid, &self.tenantid))?;
+        crashsafe_dir::create_dir_all(self.conf.timeline_path(&timelineid, &self.tenantid))?;
 
         let metadata = TimelineMetadata {
             disk_consistent_lsn: Lsn(0),
@@ -133,7 +144,7 @@ impl Repository for LayeredRepository {
             ancestor_timeline: None,
             ancestor_lsn: Lsn(0),
         };
-        Self::save_metadata(self.conf, timelineid, self.tenantid, &metadata)?;
+        Self::save_metadata(self.conf, timelineid, self.tenantid, &metadata, true)?;
 
         let timeline = LayeredTimeline::new(
             self.conf,
@@ -142,8 +153,8 @@ impl Repository for LayeredRepository {
             timelineid,
             self.tenantid,
             Arc::clone(&self.walredo_mgr),
-            self.relish_uploader.as_ref().map(Arc::clone),
             0,
+            false,
         )?;
 
         let timeline_rc = Arc::new(timeline);
@@ -177,8 +188,8 @@ impl Repository for LayeredRepository {
             ancestor_timeline: Some(src),
             ancestor_lsn: start_lsn,
         };
-        std::fs::create_dir_all(self.conf.timeline_path(&dst, &self.tenantid))?;
-        Self::save_metadata(self.conf, dst, self.tenantid, &metadata)?;
+        crashsafe_dir::create_dir_all(self.conf.timeline_path(&dst, &self.tenantid))?;
+        Self::save_metadata(self.conf, dst, self.tenantid, &metadata, true)?;
 
         info!("branched timeline {} from {} at {}", dst, src, start_lsn);
 
@@ -192,12 +203,12 @@ impl Repository for LayeredRepository {
         &self,
         target_timelineid: Option<ZTimelineId>,
         horizon: u64,
-        compact: bool,
+        checkpoint_before_gc: bool,
     ) -> Result<GcResult> {
         STORAGE_TIME
             .with_label_values(&["gc"])
             .observe_closure_duration(|| {
-                self.gc_iteration_internal(target_timelineid, horizon, compact)
+                self.gc_iteration_internal(target_timelineid, horizon, checkpoint_before_gc)
             })
     }
 }
@@ -215,6 +226,7 @@ impl LayeredRepository {
             Some(timeline) => Ok(timeline.clone()),
             None => {
                 let metadata = Self::load_metadata(self.conf, timelineid, self.tenantid)?;
+                let disk_consistent_lsn = metadata.disk_consistent_lsn;
 
                 // Recurse to look up the ancestor timeline.
                 //
@@ -234,12 +246,12 @@ impl LayeredRepository {
                     timelineid,
                     self.tenantid,
                     Arc::clone(&self.walredo_mgr),
-                    self.relish_uploader.as_ref().map(Arc::clone),
-                    0, // init with 0 and update after layers are loaded
+                    0, // init with 0 and update after layers are loaded,
+                    self.upload_relishes,
                 )?;
 
                 // List the layers on disk, and load them into the layer map
-                timeline.load_layer_map()?;
+                timeline.load_layer_map(disk_consistent_lsn)?;
 
                 // needs to be after load_layer_map
                 timeline.init_current_logical_size()?;
@@ -268,15 +280,14 @@ impl LayeredRepository {
         conf: &'static PageServerConf,
         walredo_mgr: Arc<dyn WalRedoManager + Send + Sync>,
         tenantid: ZTenantId,
+        upload_relishes: bool,
     ) -> LayeredRepository {
         LayeredRepository {
             tenantid,
             conf,
             timelines: Mutex::new(HashMap::new()),
             walredo_mgr,
-            relish_uploader: conf.relish_storage_config.as_ref().map(|config| {
-                Arc::new(QueueBasedRelishUploader::new(config, &conf.workdir).unwrap())
-            }),
+            upload_relishes,
         }
     }
 
@@ -351,13 +362,36 @@ impl LayeredRepository {
         timelineid: ZTimelineId,
         tenantid: ZTenantId,
         data: &TimelineMetadata,
+        first_save: bool,
     ) -> Result<PathBuf> {
-        let path = conf.timeline_path(&timelineid, &tenantid).join("metadata");
-        let mut file = File::create(&path)?;
+        let timeline_path = conf.timeline_path(&timelineid, &tenantid);
+        let path = timeline_path.join("metadata");
+        // use OpenOptions to ensure file presence is consistent with first_save
+        let mut file = OpenOptions::new()
+            .write(true)
+            .create_new(first_save)
+            .open(&path)?;
 
         info!("saving metadata {}", path.display());
 
-        file.write_all(&TimelineMetadata::ser(data)?)?;
+        let mut metadata_bytes = TimelineMetadata::ser(data)?;
+
+        assert!(metadata_bytes.len() <= METADATA_MAX_DATA_SIZE);
+        metadata_bytes.resize(METADATA_MAX_SAFE_SIZE, 0u8);
+
+        let checksum = crc32c::crc32c(&metadata_bytes[..METADATA_MAX_DATA_SIZE]);
+        metadata_bytes[METADATA_MAX_DATA_SIZE..].copy_from_slice(&u32::to_le_bytes(checksum));
+
+        if file.write(&metadata_bytes)? != metadata_bytes.len() {
+            bail!("Could not write all the metadata bytes in a single call");
+        }
+        file.sync_all()?;
+
+        // fsync the parent directory to ensure the directory entry is durable
+        if first_save {
+            let timeline_dir = File::open(&timeline_path)?;
+            timeline_dir.sync_all()?;
+        }
 
         Ok(path)
     }
@@ -368,9 +402,18 @@ impl LayeredRepository {
         tenantid: ZTenantId,
     ) -> Result<TimelineMetadata> {
         let path = conf.timeline_path(&timelineid, &tenantid).join("metadata");
-        let data = std::fs::read(&path)?;
+        let metadata_bytes = std::fs::read(&path)?;
+        ensure!(metadata_bytes.len() == METADATA_MAX_SAFE_SIZE);
 
-        let data = TimelineMetadata::des(&data)?;
+        let data = &metadata_bytes[..METADATA_MAX_DATA_SIZE];
+        let calculated_checksum = crc32c::crc32c(data);
+
+        let checksum_bytes: &[u8; METADATA_CHECKSUM_SIZE] =
+            metadata_bytes[METADATA_MAX_DATA_SIZE..].try_into()?;
+        let expected_checksum = u32::from_le_bytes(*checksum_bytes);
+        ensure!(calculated_checksum == expected_checksum);
+
+        let data = TimelineMetadata::des_prefix(data)?;
         assert!(data.disk_consistent_lsn.is_aligned());
 
         Ok(data)
@@ -397,14 +440,14 @@ impl LayeredRepository {
     //    don't cover any branch point LSNs.
     //
     // TODO:
-    // - if a relation has been modified on a child branch, then we
+    // - if a relation has a non-incremental persistent layer on a child branch, then we
     //   don't need to keep that in the parent anymore. But currently
     //   we do.
     fn gc_iteration_internal(
         &self,
         target_timelineid: Option<ZTimelineId>,
         horizon: u64,
-        compact: bool,
+        checkpoint_before_gc: bool,
     ) -> Result<GcResult> {
         let mut totals: GcResult = Default::default();
         let now = Instant::now();
@@ -416,63 +459,71 @@ impl LayeredRepository {
         // Scan all timelines. For each timeline, remember the timeline ID and
         // the branch point where it was created.
         //
+        let mut timelineids: Vec<ZTimelineId> = Vec::new();
+
         // We scan the directory, not the in-memory hash table, because the hash
         // table only contains entries for timelines that have been accessed. We
         // need to take all timelines into account, not only the active ones.
-        let mut timelineids: Vec<ZTimelineId> = Vec::new();
-        let mut all_branchpoints: BTreeSet<(ZTimelineId, Lsn)> = BTreeSet::new();
         let timelines_path = self.conf.timelines_path(&self.tenantid);
+
         for direntry in fs::read_dir(timelines_path)? {
             let direntry = direntry?;
             if let Some(fname) = direntry.file_name().to_str() {
                 if let Ok(timelineid) = fname.parse::<ZTimelineId>() {
                     timelineids.push(timelineid);
-
-                    // Read the metadata of this timeline to get its parent timeline.
-                    //
-                    // We read the ancestor information directly from the file, instead
-                    // of calling get_timeline(). We don't want to load the timeline
-                    // into memory just for GC.
-                    //
-                    // FIXME: we open the timeline in the loop below with
-                    // get_timeline_locked() anyway, so maybe we should just do it
-                    // here, too.
-                    let metadata = Self::load_metadata(self.conf, timelineid, self.tenantid)?;
-                    if let Some(ancestor_timeline) = metadata.ancestor_timeline {
-                        all_branchpoints.insert((ancestor_timeline, metadata.ancestor_lsn));
-                    }
                 }
             }
         }
 
-        // Ok, we now know all the branch points. Iterate through them.
+        //Now collect info about branchpoints
+        let mut all_branchpoints: BTreeSet<(ZTimelineId, Lsn)> = BTreeSet::new();
+        for timelineid in &timelineids {
+            let timeline = self.get_timeline_locked(*timelineid, &mut *timelines)?;
+
+            if let Some(ancestor_timeline) = &timeline.ancestor_timeline {
+                // If target_timeline is specified, we only need to know branchpoints of its childs
+                if let Some(timelineid) = target_timelineid {
+                    if ancestor_timeline.timelineid == timelineid {
+                        all_branchpoints
+                            .insert((ancestor_timeline.timelineid, timeline.ancestor_lsn));
+                    }
+                }
+                // Collect branchpoints for all timelines
+                else {
+                    all_branchpoints.insert((ancestor_timeline.timelineid, timeline.ancestor_lsn));
+                }
+            }
+        }
+
+        // Ok, we now know all the branch points.
+        // Perform GC for each timeline.
         for timelineid in timelineids {
-            // If a target timeline was specified, leave the other timelines alone.
-            // This is a bit inefficient, because we still collect the information for
-            // all the timelines above.
-            if let Some(x) = target_timelineid {
-                if x != timelineid {
+            // We have already loaded all timelines above
+            // so this operation is just a quick map lookup.
+            let timeline = self.get_timeline_locked(timelineid, &mut *timelines)?;
+
+            // If target_timeline is specified, only GC it
+            if let Some(target_timelineid) = target_timelineid {
+                if timelineid != target_timelineid {
                     continue;
                 }
             }
 
-            let branchpoints: Vec<Lsn> = all_branchpoints
-                .range((
-                    Included((timelineid, Lsn(0))),
-                    Included((timelineid, Lsn(u64::MAX))),
-                ))
-                .map(|&x| x.1)
-                .collect();
+            if let Some(cutoff) = timeline.get_last_record_lsn().checked_sub(horizon) {
+                let branchpoints: Vec<Lsn> = all_branchpoints
+                    .range((
+                        Included((timelineid, Lsn(0))),
+                        Included((timelineid, Lsn(u64::MAX))),
+                    ))
+                    .map(|&x| x.1)
+                    .collect();
 
-            let timeline = self.get_timeline_locked(timelineid, &mut *timelines)?;
-            let last_lsn = timeline.get_last_record_lsn();
-
-            if let Some(cutoff) = last_lsn.checked_sub(horizon) {
-                // If GC was explicitly requested by the admin, force flush all in-memory
-                // layers to disk first, so that they too can be garbage collected. That's
+                // If requested, force flush all in-memory layers to disk first,
+                // so that they too can be garbage collected. That's
                 // used in tests, so we want as deterministic results as possible.
-                if compact {
+                if checkpoint_before_gc {
                     timeline.checkpoint()?;
+                    info!("timeline {} checkpoint_before_gc done", timelineid);
                 }
 
                 let result = timeline.gc_timeline(branchpoints, cutoff)?;
@@ -492,7 +543,7 @@ impl LayeredRepository {
                     error!("timeline size calculation diverged, incremental doesn't match non incremental. incremental={} non_incremental={}", incremental, non_incremental);
                 }
             }
-            Err(e) => error!("failed to calculate non incremental timeline size: {}", e),
+            Err(e) => error!("failed to calculate non incremental timeline size: {:#}", e),
         }
     }
 
@@ -538,8 +589,6 @@ pub struct LayeredTimeline {
     // WAL redo manager
     walredo_mgr: Arc<dyn WalRedoManager + Sync + Send>,
 
-    relish_uploader: Option<Arc<QueueBasedRelishUploader>>,
-
     // What page versions do we hold in the repository? If we get a
     // request > last_record_lsn, we need to wait until we receive all
     // the WAL up to the request. The SeqWait provides functions for
@@ -587,6 +636,9 @@ pub struct LayeredTimeline {
     // TODO: it is possible to combine these two fields into single one using custom metric which uses SeqCst
     // ordering for its operations, but involves private modules, and macro trickery
     current_logical_size_gauge: IntGauge,
+
+    /// If `true`, will backup its timeline files to remote storage after freezing.
+    upload_relishes: bool,
 }
 
 /// Public interface functions
@@ -594,8 +646,11 @@ impl Timeline for LayeredTimeline {
     /// Wait until WAL has been received up to the given LSN.
     fn wait_lsn(&self, lsn: Lsn) -> Result<()> {
         // This should never be called from the WAL receiver thread, because that could lead
-        // to a deadlock. FIXME: Is there a less hacky way to check that?
-        assert_ne!(thread::current().name(), Some("WAL receiver thread"));
+        // to a deadlock.
+        assert!(
+            !IS_WAL_RECEIVER.with(|c| c.get()),
+            "wait_lsn called by WAL receiver thread"
+        );
 
         self.last_record_lsn
             .wait_for_timeout(lsn, TIMEOUT)
@@ -769,6 +824,7 @@ impl Timeline for LayeredTimeline {
                 rel
             );
         }
+        ensure!(rec.lsn.is_aligned(), "unaligned record LSN");
 
         let seg = SegmentTag::from_blknum(rel, blknum);
         let delta_size = self.perform_write_op(seg, rec.lsn, |layer| {
@@ -782,42 +838,51 @@ impl Timeline for LayeredTimeline {
         if !rel.is_blocky() {
             bail!("invalid truncation for non-blocky relish {}", rel);
         }
+        ensure!(lsn.is_aligned(), "unaligned record LSN");
 
         debug!("put_truncation: {} to {} blocks at {}", rel, relsize, lsn);
 
-        if let Some(oldsize) = self.get_relish_size(rel, self.get_last_record_lsn())? {
-            if oldsize <= relsize {
-                return Ok(());
-            }
-            let old_last_seg = (oldsize - 1) / RELISH_SEG_SIZE;
-
-            let last_remain_seg = if relsize == 0 {
-                0
-            } else {
-                (relsize - 1) / RELISH_SEG_SIZE
-            };
-
-            // Drop segments beyond the last remaining segment.
-            for remove_segno in (last_remain_seg + 1)..=old_last_seg {
-                let seg = SegmentTag {
+        let oldsize = self
+            .get_relish_size(rel, self.get_last_record_lsn())?
+            .ok_or_else(|| {
+                anyhow!(
+                    "attempted to truncate non-existent relish {} at {}",
                     rel,
-                    segno: remove_segno,
-                };
-                self.perform_write_op(seg, lsn, |layer| layer.drop_segment(lsn))?;
-            }
+                    lsn
+                )
+            })?;
 
-            // Truncate the last remaining segment to the specified size
-            if relsize == 0 || relsize % RELISH_SEG_SIZE != 0 {
-                let seg = SegmentTag {
-                    rel,
-                    segno: last_remain_seg,
-                };
-                self.perform_write_op(seg, lsn, |layer| {
-                    layer.put_truncation(lsn, relsize % RELISH_SEG_SIZE)
-                })?;
-            }
-            self.decrease_current_logical_size((oldsize - relsize) * BLCKSZ as u32);
+        if oldsize <= relsize {
+            return Ok(());
         }
+        let old_last_seg = (oldsize - 1) / RELISH_SEG_SIZE;
+
+        let last_remain_seg = if relsize == 0 {
+            0
+        } else {
+            (relsize - 1) / RELISH_SEG_SIZE
+        };
+
+        // Drop segments beyond the last remaining segment.
+        for remove_segno in (last_remain_seg + 1)..=old_last_seg {
+            let seg = SegmentTag {
+                rel,
+                segno: remove_segno,
+            };
+            self.perform_write_op(seg, lsn, |layer| layer.drop_segment(lsn))?;
+        }
+
+        // Truncate the last remaining segment to the specified size
+        if relsize == 0 || relsize % RELISH_SEG_SIZE != 0 {
+            let seg = SegmentTag {
+                rel,
+                segno: last_remain_seg,
+            };
+            self.perform_write_op(seg, lsn, |layer| {
+                layer.put_truncation(lsn, relsize % RELISH_SEG_SIZE)
+            })?;
+        }
+        self.decrease_current_logical_size((oldsize - relsize) * BLCKSZ as u32);
         Ok(())
     }
 
@@ -864,6 +929,7 @@ impl Timeline for LayeredTimeline {
                 rel
             );
         }
+        ensure!(lsn.is_aligned(), "unaligned record LSN");
 
         let seg = SegmentTag::from_blknum(rel, blknum);
 
@@ -956,8 +1022,8 @@ impl LayeredTimeline {
         timelineid: ZTimelineId,
         tenantid: ZTenantId,
         walredo_mgr: Arc<dyn WalRedoManager + Send + Sync>,
-        relish_uploader: Option<Arc<QueueBasedRelishUploader>>,
         current_logical_size: usize,
+        upload_relishes: bool,
     ) -> Result<LayeredTimeline> {
         let current_logical_size_gauge = LOGICAL_TIMELINE_SIZE
             .get_metric_with_label_values(&[&tenantid.to_string(), &timelineid.to_string()])
@@ -969,7 +1035,6 @@ impl LayeredTimeline {
             layers: Mutex::new(LayerMap::default()),
 
             walredo_mgr,
-            relish_uploader,
 
             // initialize in-memory 'last_record_lsn' from 'disk_consistent_lsn'.
             last_record_lsn: SeqWait::new(RecordLsn {
@@ -982,6 +1047,7 @@ impl LayeredTimeline {
             ancestor_lsn: metadata.ancestor_lsn,
             current_logical_size: AtomicUsize::new(current_logical_size),
             current_logical_size_gauge,
+            upload_relishes,
         };
         Ok(timeline)
     }
@@ -989,7 +1055,7 @@ impl LayeredTimeline {
     ///
     /// Scan the timeline directory to populate the layer map
     ///
-    fn load_layer_map(&self) -> anyhow::Result<()> {
+    fn load_layer_map(&self, disk_consistent_lsn: Lsn) -> anyhow::Result<()> {
         info!(
             "loading layer map for timeline {} into memory",
             self.timelineid
@@ -998,8 +1064,20 @@ impl LayeredTimeline {
         let (imgfilenames, mut deltafilenames) =
             filename::list_files(self.conf, self.timelineid, self.tenantid)?;
 
+        let timeline_path = self.conf.timeline_path(&self.timelineid, &self.tenantid);
+
         // First create ImageLayer structs for each image file.
         for filename in imgfilenames.iter() {
+            if filename.lsn > disk_consistent_lsn {
+                warn!(
+                    "found future image layer {} on timeline {}",
+                    filename, self.timelineid
+                );
+
+                rename_to_backup(timeline_path.join(filename.to_string()))?;
+                continue;
+            }
+
             let layer = ImageLayer::new(self.conf, self.timelineid, self.tenantid, filename);
 
             info!(
@@ -1017,6 +1095,17 @@ impl LayeredTimeline {
         deltafilenames.sort();
 
         for filename in deltafilenames.iter() {
+            ensure!(filename.start_lsn < filename.end_lsn);
+            if filename.end_lsn > disk_consistent_lsn {
+                warn!(
+                    "found future delta layer {} on timeline {}",
+                    filename, self.timelineid
+                );
+
+                rename_to_backup(timeline_path.join(filename.to_string()))?;
+                continue;
+            }
+
             let predecessor = layers.get(&filename.seg, filename.start_lsn);
 
             let predecessor_str: String = if let Some(prec) = &predecessor {
@@ -1164,36 +1253,57 @@ impl LayeredTimeline {
         assert!(lsn.is_aligned());
 
         let last_record_lsn = self.get_last_record_lsn();
-        if lsn <= last_record_lsn {
-            panic!(
-                "cannot modify relation after advancing last_record_lsn (incoming_lsn={}, last_record_lsn={})",
-                lsn,
-                last_record_lsn
-            );
-        }
+        assert!(
+            lsn > last_record_lsn,
+            "cannot modify relation after advancing last_record_lsn (incoming_lsn={}, last_record_lsn={})",
+            lsn,
+            last_record_lsn,
+        );
 
         // Do we have a layer open for writing already?
-        if let Some(layer) = layers.get_open(&seg) {
-            if layer.get_start_lsn() > lsn {
+        let layer;
+        if let Some(open_layer) = layers.get_open(&seg) {
+            if open_layer.get_start_lsn() > lsn {
                 bail!("unexpected open layer in the future");
             }
-            return Ok(layer);
-        }
 
-        // No (writeable) layer for this relation yet. Create one.
+            // Open layer exists, but it is dropped, so create a new one.
+            if open_layer.is_dropped() {
+                assert!(!open_layer.is_writeable());
+                // Layer that is created after dropped one represents a new relish segment.
+                trace!(
+                    "creating layer for write for new relish segment after dropped layer {} at {}/{}",
+                    seg,
+                    self.timelineid,
+                    lsn
+                );
+
+                layer = InMemoryLayer::create(
+                    self.conf,
+                    self.timelineid,
+                    self.tenantid,
+                    seg,
+                    lsn,
+                    lsn,
+                )?;
+            } else {
+                return Ok(open_layer);
+            }
+        }
+        // No writeable layer for this relation. Create one.
         //
         // Is this a completely new relation? Or the first modification after branching?
         //
-
-        let layer;
-        if let Some((prev_layer, _prev_lsn)) = self.get_layer_for_read_locked(seg, lsn, &layers)? {
+        else if let Some((prev_layer, _prev_lsn)) =
+            self.get_layer_for_read_locked(seg, lsn, &layers)?
+        {
             // Create new entry after the previous one.
             let start_lsn;
             if prev_layer.get_timeline_id() != self.timelineid {
                 // First modification on this timeline
                 start_lsn = self.ancestor_lsn;
                 trace!(
-                    "creating file for write for {} at branch point {}/{}",
+                    "creating layer for write for {} at branch point {}/{}",
                     seg,
                     self.timelineid,
                     start_lsn
@@ -1201,7 +1311,7 @@ impl LayeredTimeline {
             } else {
                 start_lsn = prev_layer.get_end_lsn();
                 trace!(
-                    "creating file for write for {} after previous layer {}/{}",
+                    "creating layer for write for {} after previous layer {}/{}",
                     seg,
                     self.timelineid,
                     start_lsn
@@ -1268,6 +1378,8 @@ impl LayeredTimeline {
             last_record_lsn
         );
 
+        let timeline_dir = File::open(self.conf.timeline_path(&self.timelineid, &self.tenantid))?;
+
         // Take the in-memory layer with the oldest WAL record. If it's older
         // than the threshold, write it out to disk as a new image and delta file.
         // Repeat until all remaining in-memory layers are within the threshold.
@@ -1279,6 +1391,8 @@ impl LayeredTimeline {
         // a lot of memory and/or aren't receiving much updates anymore.
         let mut disk_consistent_lsn = last_record_lsn;
 
+        let mut created_historics = false;
+
         while let Some((oldest_layer, oldest_generation)) = layers.peek_oldest_open() {
             let oldest_pending_lsn = oldest_layer.get_oldest_pending_lsn();
 
@@ -1323,21 +1437,25 @@ impl LayeredTimeline {
                 layers.insert_open(new_open);
             }
 
+            // We temporarily insert InMemory layer into historic list here.
+            // TODO: check that all possible concurrent users of 'historic' treat it right
             layers.insert_historic(frozen.clone());
 
             // Write the now-frozen layer to disk. That could take a while, so release the lock while do it
             drop(layers);
             let new_historics = frozen.write_to_disk(self)?;
             layers = self.layers.lock().unwrap();
-            if let Some(relish_uploader) = &self.relish_uploader {
-                for label_path in new_historics.iter().filter_map(|layer| layer.path()) {
-                    relish_uploader.schedule_upload(self.timelineid, label_path);
-                }
+
+            if !new_historics.is_empty() {
+                created_historics = true;
             }
 
             // Finally, replace the frozen in-memory layer with the new on-disk layers
-            layers.remove_historic(frozen.as_ref());
+            layers.remove_historic(frozen.clone());
 
+            // If we created a successor InMemoryLayer, its predecessor is
+            // currently the frozen layer. We need to update the predecessor
+            // to be the latest on-disk layer.
             if let Some(last_historic) = new_historics.last() {
                 if let Some(new_open) = &maybe_new_open {
                     let maybe_old_predecessor =
@@ -1348,6 +1466,7 @@ impl LayeredTimeline {
                 }
             }
 
+            // Add the historics to the LayerMap
             for n in new_historics {
                 layers.insert_historic(n);
             }
@@ -1360,6 +1479,14 @@ impl LayeredTimeline {
             layer.unload()?;
         }
 
+        drop(layers);
+
+        if created_historics {
+            // We must fsync the timeline dir to ensure the directory entries for
+            // new layer files are durable
+            timeline_dir.sync_all()?;
+        }
+
         // Save the metadata, with updated 'disk_consistent_lsn', to a
         // file in the timeline dir. After crash, we will restart WAL
         // streaming and processing from that point.
@@ -1384,10 +1511,23 @@ impl LayeredTimeline {
             ancestor_timeline: ancestor_timelineid,
             ancestor_lsn: self.ancestor_lsn,
         };
-        let metadata_path =
-            LayeredRepository::save_metadata(self.conf, self.timelineid, self.tenantid, &metadata)?;
-        if let Some(relish_uploader) = &self.relish_uploader {
-            relish_uploader.schedule_upload(self.timelineid, metadata_path);
+        let _metadata_path = LayeredRepository::save_metadata(
+            self.conf,
+            self.timelineid,
+            self.tenantid,
+            &metadata,
+            false,
+        )?;
+        if self.upload_relishes {
+            schedule_timeline_upload(())
+            // schedule_timeline_upload(LocalTimeline {
+            //     tenant_id: self.tenantid,
+            //     timeline_id: self.timelineid,
+            //     metadata_path,
+            //     image_layers: image_layer_uploads,
+            //     delta_layers: delta_layer_uploads,
+            //     disk_consistent_lsn,
+            // });
         }
 
         // Also update the in-memory copy
@@ -1426,15 +1566,18 @@ impl LayeredTimeline {
             "running GC on timeline {}, cutoff {}",
             self.timelineid, cutoff
         );
+        info!("retain_lsns:  {:?}", retain_lsns);
 
         let mut layers_to_remove: Vec<Arc<dyn Layer>> = Vec::new();
 
-        // Scan all layer files in the directory. For each file, if a newer file
-        // exists, we can remove the old one.
+        // Scan all on-disk layers in the timeline.
+        //
+        // Garbage collect the layer if all conditions are satisfied:
+        // 1. it is older than cutoff LSN;
+        // 2. it doesn't need to be retained for 'retain_lsns';
+        // 3. newer on-disk layer exists (only for non-dropped segments);
+        // 4. this layer doesn't serve as a tombstone for some older layer;
         //
-        // Determine for each file if it needs to be retained
-        // FIXME: also scan open in-memory layers. Normally we cannot remove the
-        // latest layer of any seg, but if it was dropped it's possible
         let mut layers = self.layers.lock().unwrap();
         'outer: for l in layers.iter_historic_layers() {
             let seg = l.get_seg_tag();
@@ -1445,7 +1588,7 @@ impl LayeredTimeline {
                 result.ondisk_nonrelfiles_total += 1;
             }
 
-            // Is it newer than cutoff point?
+            // 1. Is it newer than cutoff point?
             if l.get_end_lsn() > cutoff {
                 info!(
                     "keeping {} {}-{} because it's newer than cutoff {}",
@@ -1462,10 +1605,10 @@ impl LayeredTimeline {
                 continue 'outer;
             }
 
-            // Is it needed by a child branch?
+            // 2. Is it needed by a child branch?
             for retain_lsn in &retain_lsns {
-                // FIXME: are the bounds inclusive or exclusive?
-                if l.get_start_lsn() <= *retain_lsn && *retain_lsn <= l.get_end_lsn() {
+                // start_lsn is inclusive and end_lsn is exclusive
+                if l.get_start_lsn() <= *retain_lsn && *retain_lsn < l.get_end_lsn() {
                     info!(
                         "keeping {} {}-{} because it's needed by branch point {}",
                         seg,
@@ -1482,9 +1625,15 @@ impl LayeredTimeline {
                 }
             }
 
-            // Unless the relation was dropped, is there a later image file for this relation?
+            // 3. Is there a later on-disk layer for this relation?
             if !l.is_dropped() && !layers.newer_image_layer_exists(l.get_seg_tag(), l.get_end_lsn())
             {
+                info!(
+                    "keeping {} {}-{} because it is the latest layer",
+                    seg,
+                    l.get_start_lsn(),
+                    l.get_end_lsn()
+                );
                 if seg.rel.is_relation() {
                     result.ondisk_relfiles_not_updated += 1;
                 } else {
@@ -1493,6 +1642,77 @@ impl LayeredTimeline {
                 continue 'outer;
             }
 
+            // 4. Does this layer serve as a tombstome for some older layer?
+            if l.is_dropped() {
+                let prior_lsn = l.get_start_lsn().checked_sub(1u64).unwrap();
+
+                // Check if this layer serves as a tombstone for this timeline
+                // We have to do this separately from timeline check below,
+                // because LayerMap of this timeline is already locked.
+                let mut is_tombstone = layers.layer_exists_at_lsn(l.get_seg_tag(), prior_lsn)?;
+                if is_tombstone {
+                    info!(
+                        "earlier layer exists at {} in {}",
+                        prior_lsn, self.timelineid
+                    );
+                }
+                // Now check ancestor timelines, if any
+                else if let Some(ancestor) = &self.ancestor_timeline {
+                    let prior_lsn = ancestor.get_last_record_lsn();
+                    if seg.rel.is_blocky() {
+                        info!(
+                            "check blocky relish size {} at {} in {} for layer {}-{}",
+                            seg,
+                            prior_lsn,
+                            ancestor.timelineid,
+                            l.get_start_lsn(),
+                            l.get_end_lsn()
+                        );
+                        match ancestor.get_relish_size(seg.rel, prior_lsn).unwrap() {
+                            Some(size) => {
+                                let last_live_seg = SegmentTag::from_blknum(seg.rel, size - 1);
+                                info!(
+                                    "blocky rel size is {} last_live_seg.segno {} seg.segno {}",
+                                    size, last_live_seg.segno, seg.segno
+                                );
+                                if last_live_seg.segno >= seg.segno {
+                                    is_tombstone = true;
+                                }
+                            }
+                            _ => {
+                                info!("blocky rel doesn't exist");
+                            }
+                        }
+                    } else {
+                        info!(
+                            "check non-blocky relish existence {} at {} in {} for layer {}-{}",
+                            seg,
+                            prior_lsn,
+                            ancestor.timelineid,
+                            l.get_start_lsn(),
+                            l.get_end_lsn()
+                        );
+                        is_tombstone = ancestor.get_rel_exists(seg.rel, prior_lsn).unwrap_or(false);
+                    }
+                }
+
+                if is_tombstone {
+                    info!(
+                        "keeping {} {}-{} because this layer servers as a tombstome for older layer",
+                        seg,
+                        l.get_start_lsn(),
+                        l.get_end_lsn()
+                    );
+
+                    if seg.rel.is_relation() {
+                        result.ondisk_relfiles_needed_as_tombstone += 1;
+                    } else {
+                        result.ondisk_nonrelfiles_needed_as_tombstone += 1;
+                    }
+                    continue 'outer;
+                }
+            }
+
             // We didn't find any reason to keep this file, so remove it.
             info!(
                 "garbage collecting {} {}-{} {}",
@@ -1509,7 +1729,7 @@ impl LayeredTimeline {
         // while iterating it. BTreeMap::retain() would be another option)
         for doomed_layer in layers_to_remove {
             doomed_layer.delete()?;
-            layers.remove_historic(&*doomed_layer);
+            layers.remove_historic(doomed_layer.clone());
 
             match (
                 doomed_layer.is_dropped(),
@@ -1740,3 +1960,23 @@ fn layer_ptr_eq(l1: &dyn Layer, l2: &dyn Layer) -> bool {
     // see here for more https://github.com/rust-lang/rust/issues/46139
     std::ptr::eq(l1_ptr as *const (), l2_ptr as *const ())
 }
+
+/// Add a suffix to a layer file's name: .{num}.old
+/// Uses the first available num (starts at 0)
+fn rename_to_backup(path: PathBuf) -> anyhow::Result<()> {
+    let filename = path.file_name().unwrap().to_str().unwrap();
+    let mut new_path = path.clone();
+
+    for i in 0u32.. {
+        new_path.set_file_name(format!("{}.{}.old", filename, i));
+        if !new_path.exists() {
+            std::fs::rename(&path, &new_path)?;
+            return Ok(());
+        }
+    }
+
+    Err(anyhow!(
+        "couldn't find an unused backup number for {:?}",
+        path
+    ))
+}

pageserver/src/layered_repository/README.md

@@ -25,11 +25,13 @@ OnDisk layers can be Image or Delta:
 Dropped segments are always represented on disk by DeltaLayer.
 
 LSN range defined by start_lsn and end_lsn:
-- start_lsn is always inclusive.
-- end_lsn depends on layer kind:
-	- InMemoryLayer is either unbounded (end_lsn = MAX_LSN) or dropped (end_lsn = drop_lsn)
-    - ImageLayer represents snapshot at one LSN, so end_lsn = lsn.
-    - DeltaLayer has explicit end_lsn, which represents end of incremental layer.
+- 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.

pageserver/src/layered_repository/delta_layer.rs

@@ -42,15 +42,12 @@ 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 log::*;
 use serde::{Deserialize, Serialize};
-use std::collections::BTreeMap;
 // avoid binding to Write (conflicts with std::io::Write)
 // while being able to use std::fmt::Write's methods
 use std::fmt::Write as _;
@@ -65,6 +62,7 @@ use bookfile::{Book, BookWriter};
 
 use zenith_utils::bin_ser::BeSer;
 use zenith_utils::lsn::Lsn;
+use zenith_utils::ordered_vec::OrderedVec;
 
 use super::blob::{read_blob, BlobRange};
 
@@ -109,12 +107,6 @@ impl From<&DeltaLayer> for Summary {
     }
 }
 
-#[derive(Serialize, Deserialize)]
-struct PageVersionMeta {
-    page_image_range: Option<BlobRange>,
-    record_range: Option<BlobRange>,
-}
-
 ///
 /// DeltaLayer is the in-memory data structure associated with an
 /// on-disk delta file.  We keep a DeltaLayer in memory for each
@@ -152,10 +144,10 @@ 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: OrderedVec<(u32, Lsn), BlobRange>,
 
     /// `relsizes` tracks the size of the relation at different points in time.
-    relsizes: BTreeMap<Lsn, u32>,
+    relsizes: OrderedVec<Lsn, u32>,
 }
 
 impl Layer for DeltaLayer {
@@ -228,16 +220,17 @@ impl Layer for DeltaLayer {
             let maxkey = (blknum, lsn);
             let mut 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 {
+                .range((Included(&minkey), Included(&maxkey)))
+                .iter();
+            while let Some(((_blknum, _entry_lsn), blob_range)) = iter.next_back() {
+                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);
                     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 {
@@ -276,10 +269,10 @@ impl Layer for DeltaLayer {
 
         // 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.range((Included(&Lsn(0)), Included(&lsn)));
 
         let result;
-        if let Some((_entry_lsn, entry)) = iter.next_back() {
+        if let Some((_entry_lsn, entry)) = slice.last() {
             result = *entry;
         // Use the base image if needed
         } else if let Some(predecessor) = &self.predecessor {
@@ -307,8 +300,8 @@ 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 = OrderedVec::default();
+        inner.relsizes = OrderedVec::default();
         inner.loaded = false;
         Ok(())
     }
@@ -340,16 +333,16 @@ impl Layer for DeltaLayer {
         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.iter() {
             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,
@@ -359,7 +352,7 @@ impl Layer for DeltaLayer {
                     wal_desc
                 )?;
             }
-            println!("  blk {} at {}: {}", k.0, k.1, desc);
+            println!("  blk {} at {}: {}", blk, lsn, desc);
         }
 
         Ok(())
@@ -381,14 +374,15 @@ 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(
+    pub fn create<'a>(
         conf: &'static PageServerConf,
         timelineid: ZTimelineId,
         tenantid: ZTenantId,
@@ -397,8 +391,8 @@ impl DeltaLayer {
         end_lsn: Lsn,
         dropped: bool,
         predecessor: Option<Arc<dyn Layer>>,
-        page_versions: BTreeMap<(u32, Lsn), PageVersion>,
-        relsizes: BTreeMap<Lsn, u32>,
+        page_versions: impl Iterator<Item = (u32, Lsn, &'a PageVersion)>,
+        relsizes: OrderedVec<Lsn, u32>,
     ) -> Result<DeltaLayer> {
         let delta_layer = DeltaLayer {
             path_or_conf: PathOrConf::Conf(conf),
@@ -410,7 +404,7 @@ impl DeltaLayer {
             dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: true,
-                page_version_metas: BTreeMap::new(),
+                page_version_metas: OrderedVec::default(), // TODO create with a size estimate
                 relsizes,
             }),
             predecessor,
@@ -430,42 +424,24 @@ impl DeltaLayer {
 
         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, lsn, page_version) in page_versions {
+            let buf = PageVersion::ser(page_version)?;
+            let blob_range = page_version_writer.write_blob(&buf)?;
 
-            let record_range = page_version
-                .record
-                .map(|record| {
-                    let buf = WALRecord::ser(&record)?;
-                    page_version_writer.write_blob(&buf)
-                })
-                .transpose()?;
-
-            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);
         }
 
         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 = OrderedVec::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 = OrderedVec::ser(&inner.relsizes)?;
         chapter.write_all(&buf)?;
         let book = chapter.close()?;
 
@@ -484,7 +460,8 @@ impl DeltaLayer {
         let book = chapter.close()?;
 
         // This flushes the underlying 'buf_writer'.
-        book.close()?;
+        let writer = book.close()?;
+        writer.get_ref().sync_all()?;
 
         trace!("saved {}", &path.display());
 
@@ -551,10 +528,10 @@ impl DeltaLayer {
         }
 
         let chapter = book.read_chapter(PAGE_VERSION_METAS_CHAPTER)?;
-        let page_version_metas = BTreeMap::des(&chapter)?;
+        let page_version_metas = OrderedVec::des(&chapter)?;
 
         let chapter = book.read_chapter(REL_SIZES_CHAPTER)?;
-        let relsizes = BTreeMap::des(&chapter)?;
+        let relsizes = OrderedVec::des(&chapter)?;
 
         debug!("loaded from {}", &path.display());
 
@@ -585,8 +562,8 @@ impl DeltaLayer {
             dropped: filename.dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: false,
-                page_version_metas: BTreeMap::new(),
-                relsizes: BTreeMap::new(),
+                page_version_metas: OrderedVec::default(),
+                relsizes: OrderedVec::default(),
             }),
             predecessor,
         }
@@ -609,8 +586,8 @@ impl DeltaLayer {
             dropped: summary.dropped,
             inner: Mutex::new(DeltaLayerInner {
                 loaded: false,
-                page_version_metas: BTreeMap::new(),
-                relsizes: BTreeMap::new(),
+                page_version_metas: OrderedVec::default(),
+                relsizes: OrderedVec::default(),
             }),
             predecessor: None,
         })

pageserver/src/layered_repository/filename.rs

@@ -290,7 +290,11 @@ 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 == "wal"
+            || fname == "metadata"
+            || fname == "ancestor"
+            || fname.ends_with(".old")
+        {
             // ignore these
         } else {
             warn!("unrecognized filename in timeline dir: {}", fname);

pageserver/src/layered_repository/image_layer.rs

@@ -152,7 +152,8 @@ impl Layer for ImageLayer {
     }
 
     fn get_end_lsn(&self) -> Lsn {
-        self.lsn
+        // End-bound is exclusive
+        self.lsn + 1
     }
 
     /// Look up given page in the file
@@ -336,7 +337,8 @@ impl ImageLayer {
         let book = chapter.close()?;
 
         // This flushes the underlying 'buf_writer'.
-        book.close()?;
+        let writer = book.close()?;
+        writer.get_ref().sync_all()?;
 
         trace!("saved {}", &path.display());
 

pageserver/src/layered_repository/inmemory_layer.rs

@@ -15,11 +15,15 @@ use crate::{ZTenantId, ZTimelineId};
 use anyhow::{bail, Result};
 use bytes::Bytes;
 use log::*;
-use std::collections::BTreeMap;
+use std::cmp::min;
+use std::collections::HashMap;
 use std::ops::Bound::Included;
+use std::ops::RangeBounds;
 use std::path::PathBuf;
-use std::sync::{Arc, Mutex};
+use std::sync::{Arc, RwLock};
+use zenith_utils::ordered_vec::OrderedVec;
 
+use zenith_utils::accum::Accum;
 use zenith_utils::lsn::Lsn;
 
 pub struct InMemoryLayer {
@@ -42,7 +46,84 @@ pub struct InMemoryLayer {
 
     /// The above fields never change. The parts that do change are in 'inner',
     /// and protected by mutex.
-    inner: Mutex<InMemoryLayerInner>,
+    inner: RwLock<InMemoryLayerInner>,
+}
+
+#[derive(Default)]
+struct PageVersions(HashMap<u32, OrderedVec<Lsn, PageVersion>>);
+
+impl PageVersions {
+    fn range<R: RangeBounds<Lsn>>(&self, blknum: u32, lsn_range: R) -> &[(Lsn, PageVersion)] {
+        match self.0.get(&blknum) {
+            Some(ov) => ov.range(lsn_range),
+            None => &[],
+        }
+    }
+
+    fn update(&mut self, blknum: u32, lsn: Lsn, page_version: PageVersion) {
+        let ordered_vec = self.0.entry(blknum).or_insert_with(OrderedVec::default);
+        ordered_vec.append_update(lsn, page_version);
+    }
+
+    fn ordered_iter(&self, cutoff_lsn: Option<Lsn>) -> OrderedBlockIter {
+        let mut block_numbers: Vec<u32> = self.0.keys().cloned().collect();
+        // TODO consider counting sort given the small size of the key space
+        block_numbers.sort_unstable();
+
+        let cur_idx = 0;
+        let ordered_vec_iter = block_numbers
+            .get(cur_idx)
+            .map(|blk_num| self.0.get(blk_num).unwrap().iter())
+            .unwrap_or_else(|| [].iter());
+
+        OrderedBlockIter {
+            page_versions: self,
+            cutoff_lsn,
+
+            block_numbers,
+            cur_idx,
+
+            ordered_vec_iter,
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+}
+
+struct OrderedBlockIter<'a> {
+    page_versions: &'a PageVersions,
+    cutoff_lsn: Option<Lsn>,
+
+    block_numbers: Vec<u32>,
+    cur_idx: usize,
+
+    ordered_vec_iter: std::slice::Iter<'a, (Lsn, PageVersion)>,
+}
+
+impl<'a> Iterator for OrderedBlockIter<'a> {
+    type Item = (u32, Lsn, &'a PageVersion);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        loop {
+            if let Some((lsn, page_version)) = self.ordered_vec_iter.next() {
+                if self
+                    .cutoff_lsn
+                    .as_ref()
+                    .map(|cutoff| lsn < cutoff)
+                    .unwrap_or(true)
+                {
+                    let blk_num = self.block_numbers[self.cur_idx];
+                    return Some((blk_num, *lsn, page_version));
+                }
+            }
+
+            let blk_num = self.block_numbers.get(self.cur_idx + 1)?;
+            self.cur_idx += 1;
+            self.ordered_vec_iter = self.page_versions.0.get(blk_num).unwrap().iter();
+        }
+    }
 }
 
 pub struct InMemoryLayerInner {
@@ -53,12 +134,12 @@ 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>,
+    segsizes: OrderedVec<Lsn, u32>,
 
     /// Writes are only allowed when true.
     /// Set to false when this layer is in the process of being replaced.
@@ -79,9 +160,9 @@ impl InMemoryLayerInner {
 
     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.range((Included(&Lsn(0)), Included(&lsn)));
 
-        if let Some((_entry_lsn, entry)) = iter.next_back() {
+        if let Some((_entry_lsn, entry)) = slice.last() {
             *entry
         } else {
             0
@@ -93,7 +174,7 @@ 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;
@@ -137,7 +218,7 @@ impl Layer for InMemoryLayer {
             return Lsn(end_lsn.0 + 1);
         }
 
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
 
         if let Some(drop_lsn) = inner.drop_lsn {
             drop_lsn
@@ -147,7 +228,7 @@ 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()
     }
 
@@ -165,15 +246,11 @@ impl Layer for InMemoryLayer {
         let predecessor: Option<Arc<dyn Layer>>;
 
         {
-            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
-                .page_versions
-                .range((Included(&minkey), Included(&maxkey)));
-            while let Some(((_blknum, _entry_lsn), entry)) = iter.next_back() {
+            let mut iter = inner.page_versions.range(blknum, ..=lsn).iter();
+            while let Some((_entry_lsn, entry)) = iter.next_back() {
                 if let Some(img) = &entry.page_image {
                     reconstruct_data.page_img = Some(img.clone());
                     need_image = false;
@@ -212,13 +289,13 @@ impl Layer for InMemoryLayer {
     fn get_seg_size(&self, lsn: Lsn) -> Result<u32> {
         assert!(lsn >= self.start_lsn);
 
-        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
@@ -250,13 +327,13 @@ impl Layer for InMemoryLayer {
     }
 
     fn is_incremental(&self) -> bool {
-        let inner = self.inner.lock().unwrap();
+        let inner = self.inner.read().unwrap();
         inner.predecessor.is_some()
     }
 
     /// 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
@@ -273,11 +350,11 @@ impl Layer for InMemoryLayer {
             println!("segsizes {}: {}", k, v);
         }
 
-        for (k, v) in inner.page_versions.iter() {
+        for (blknum, lsn, v) in inner.page_versions.ordered_iter(None) {
             println!(
                 "blk {} at {}: {}/{}\n",
-                k.0,
-                k.1,
+                blknum,
+                lsn,
                 v.page_image.is_some(),
                 v.record.is_some()
             );
@@ -338,10 +415,10 @@ impl InMemoryLayer {
             start_lsn,
             end_lsn: None,
             oldest_pending_lsn,
-            inner: Mutex::new(InMemoryLayerInner {
+            inner: RwLock::new(InMemoryLayerInner {
                 drop_lsn: None,
-                page_versions: BTreeMap::new(),
-                segsizes: BTreeMap::new(),
+                page_versions: PageVersions::default(),
+                segsizes: OrderedVec::default(),
                 writeable: true,
                 predecessor: None,
             }),
@@ -387,12 +464,13 @@ impl InMemoryLayer {
             self.timelineid,
             lsn
         );
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.write().unwrap();
 
         inner.check_writeable()?;
 
-        let old = inner.page_versions.insert((blknum, lsn), pv);
+        inner.page_versions.update(blknum, lsn, pv);
 
+        /*
         if old.is_some() {
             // We already had an entry for this LSN. That's odd..
             warn!(
@@ -400,12 +478,13 @@ impl InMemoryLayer {
                 self.seg.rel, blknum, lsn
             );
         }
+        */
 
         // Also update the relation size, if this extended the relation.
         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 {
@@ -436,18 +515,20 @@ impl InMemoryLayer {
                         gapblknum,
                         blknum
                     );
-                    let old = inner.page_versions.insert((gapblknum, lsn), zeropv);
+                    inner.page_versions.update(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.insert(lsn, newsize);
+                inner.segsizes.append_update(lsn, newsize);
                 return Ok(newsize - oldsize);
             }
         }
@@ -458,19 +539,14 @@ impl InMemoryLayer {
     pub fn put_truncation(&self, lsn: Lsn, segsize: u32) -> WriteResult<()> {
         self.assert_not_frozen();
 
-        let mut inner = self.inner.lock().unwrap();
+        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.insert(lsn, segsize);
-
-        if old.is_some() {
-            // We already had an entry for this LSN. That's odd..
-            warn!("Inserting truncation, but had an entry for the LSN already");
-        }
+        inner.segsizes.append_update(lsn, segsize);
 
         Ok(())
     }
@@ -479,14 +555,15 @@ impl InMemoryLayer {
     pub fn drop_segment(&self, lsn: Lsn) -> WriteResult<()> {
         self.assert_not_frozen();
 
-        let mut inner = self.inner.lock().unwrap();
+        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(())
     }
@@ -505,6 +582,9 @@ 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,
@@ -513,10 +593,10 @@ impl InMemoryLayer {
         );
 
         // For convenience, copy the segment size from the predecessor layer
-        let mut segsizes = BTreeMap::new();
+        let mut segsizes = OrderedVec::default();
         if seg.rel.is_blocky() {
             let size = src.get_seg_size(start_lsn)?;
-            segsizes.insert(start_lsn, size);
+            segsizes.append(start_lsn, size);
         }
 
         Ok(InMemoryLayer {
@@ -527,9 +607,9 @@ impl InMemoryLayer {
             start_lsn,
             end_lsn: None,
             oldest_pending_lsn,
-            inner: Mutex::new(InMemoryLayerInner {
+            inner: RwLock::new(InMemoryLayerInner {
                 drop_lsn: None,
-                page_versions: BTreeMap::new(),
+                page_versions: PageVersions::default(),
                 segsizes,
                 writeable: true,
                 predecessor: Some(src),
@@ -537,65 +617,74 @@ impl 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` (or the drop LSN, if dropped)
+    /// 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, cutoff_lsn: Lsn) -> Result<FreezeLayers> {
+    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
         );
 
         self.assert_not_frozen();
 
-        let mut inner = self.inner.lock().unwrap();
+        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()
+            );
+
+            // 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;
 
-        // 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
-        };
+        // Divide all the page versions into old and new
+        // at the 'cutoff_lsn' point.
+        let (before_segsizes, after_segsizes) = inner.segsizes.copy_split(&Lsn(cutoff_lsn.0 + 1));
 
-        // 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);
-                }
+        // The iterator is in Lsn order, so the first element will have the smallest Lsn
+        let mut after_oldest_lsn: Accum<Lsn> =
+            Accum(after_segsizes.iter().next().map(|(lsn, _size)| *lsn));
+
+        let mut before_page_versions = PageVersions::default();
+        let mut after_page_versions = PageVersions::default();
+        for (blknum, ordered_vec) in inner.page_versions.0.iter() {
+            let (before_ov, after_ov) = ordered_vec.copy_split(&Lsn(cutoff_lsn.0 + 1));
+
+            if let Some((lsn, _pv)) = after_ov.iter().next() {
+                after_oldest_lsn.accum(min, *lsn);
             }
 
-            before_page_versions = BTreeMap::new();
-            after_page_versions = BTreeMap::new();
-            for ((blknum, lsn), pv) in inner.page_versions.iter() {
-                if *lsn > end_lsn {
-                    after_page_versions.insert((*blknum, *lsn), pv.clone());
-                } else {
-                    before_page_versions.insert((*blknum, *lsn), pv.clone());
-                }
+            if !before_ov.is_empty() {
+                before_page_versions.0.insert(*blknum, before_ov);
+            }
+
+            if !after_ov.is_empty() {
+                after_page_versions.0.insert(*blknum, after_ov);
             }
-        } else {
-            before_page_versions = inner.page_versions.clone();
-            before_segsizes = inner.segsizes.clone();
-            after_segsizes = BTreeMap::new();
-            after_page_versions = BTreeMap::new();
         }
 
         let frozen = Arc::new(InMemoryLayer {
@@ -604,9 +693,9 @@ impl InMemoryLayer {
             timelineid: self.timelineid,
             seg: self.seg,
             start_lsn: self.start_lsn,
-            end_lsn: Some(end_lsn),
+            end_lsn: Some(cutoff_lsn),
             oldest_pending_lsn: self.start_lsn,
-            inner: Mutex::new(InMemoryLayerInner {
+            inner: RwLock::new(InMemoryLayerInner {
                 drop_lsn: inner.drop_lsn,
                 page_versions: before_page_versions,
                 segsizes: before_segsizes,
@@ -615,26 +704,25 @@ impl InMemoryLayer {
             }),
         });
 
-        let open = if !dropped && (!after_segsizes.is_empty() || !after_page_versions.is_empty()) {
+        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,
-                end_lsn,
-                end_lsn,
+                cutoff_lsn + 1,
+                after_oldest_lsn.0.unwrap(),
             )?;
 
             let new_inner = new_open.inner.get_mut().unwrap();
-            new_inner.page_versions.append(&mut after_page_versions);
-            new_inner.segsizes.append(&mut after_segsizes);
+            new_inner.page_versions = after_page_versions;
+            new_inner.segsizes.extend(after_segsizes);
 
             Some(Arc::new(new_open))
         } else {
             None
         };
 
-        // TODO could we avoid creating the `frozen` if it contains no data
         Ok(FreezeLayers { frozen, open })
     }
 
@@ -647,35 +735,53 @@ impl InMemoryLayer {
     /// 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>>> {
-        let end_lsn = self.end_lsn.expect("can only write frozen layers to disk");
+        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()
+        );
 
-        let inner = self.inner.lock().unwrap();
+        // 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);
 
-        let drop_lsn = inner.drop_lsn;
         let predecessor = inner.predecessor.clone();
 
-        let mut before_page_versions;
-        let mut before_segsizes;
-        if inner.drop_lsn.is_none() {
-            before_segsizes = BTreeMap::new();
-            for (lsn, size) in inner.segsizes.iter() {
-                if *lsn <= end_lsn {
-                    before_segsizes.insert(*lsn, *size);
-                }
-            }
-
-            before_page_versions = BTreeMap::new();
-            for ((blknum, lsn), pv) in inner.page_versions.iter() {
-                if *lsn < end_lsn {
-                    before_page_versions.insert((*blknum, *lsn), pv.clone());
-                }
-            }
-        } else {
-            before_page_versions = inner.page_versions.clone();
-            before_segsizes = inner.segsizes.clone();
+        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,
+                predecessor,
+                inner.page_versions.ordered_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)]);
         }
 
-        drop(inner);
+        let end_lsn = self.end_lsn.unwrap();
+
+        let before_segsizes = inner.segsizes.copy_prefix(&Lsn(end_lsn.0 + 1));
+        let mut before_page_versions = inner.page_versions.ordered_iter(Some(end_lsn));
 
         let mut frozen_layers: Vec<Arc<dyn Layer>> = Vec::new();
 
@@ -688,7 +794,7 @@ impl InMemoryLayer {
                 self.seg,
                 self.start_lsn,
                 end_lsn,
-                drop_lsn.is_some(),
+                false,
                 predecessor,
                 before_page_versions,
                 before_segsizes,
@@ -701,21 +807,21 @@ impl InMemoryLayer {
                 end_lsn
             );
         } else {
-            assert!(before_page_versions.is_empty());
+            assert!(before_page_versions.next().is_none());
         }
 
-        if drop_lsn.is_none() {
-            // 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);
-        }
+        drop(inner);
+
+        // 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);
 
         Ok(frozen_layers)
     }
 
     pub fn update_predecessor(&self, predecessor: Arc<dyn Layer>) -> Option<Arc<dyn Layer>> {
-        let mut inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.write().unwrap();
         inner.predecessor.replace(predecessor)
     }
 }

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

@@ -9,13 +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 std::cmp::Ordering;
-use std::collections::{BTreeMap, BinaryHeap, HashMap};
+use std::collections::{BinaryHeap, HashMap};
 use std::sync::Arc;
 use zenith_metrics::{register_int_gauge, IntGauge};
 use zenith_utils::lsn::Lsn;
@@ -76,7 +77,14 @@ impl LayerMap {
     pub fn insert_open(&mut self, layer: Arc<InMemoryLayer>) {
         let segentry = self.segs.entry(layer.get_seg_tag()).or_default();
 
-        segentry.insert_open(Arc::clone(&layer));
+        segentry.update_open(Arc::clone(&layer));
+
+        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 {
@@ -97,11 +105,14 @@ impl LayerMap {
 
         // Also remove it from the SegEntry of this segment
         let mut segentry = self.segs.get_mut(&segtag).unwrap();
-        assert!(Arc::ptr_eq(
-            segentry.open.as_ref().unwrap(),
-            &oldest_entry.layer
-        ));
-        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();
     }
@@ -121,12 +132,11 @@ 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();
     }
@@ -144,7 +154,7 @@ impl LayerMap {
                         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) {
+                            if let Some(exists) = segentry.exists_at_lsn(lsn)? {
                                 rels.insert(seg.rel, exists);
                             }
                         }
@@ -152,7 +162,7 @@ impl LayerMap {
                 }
                 _ => {
                     if tag == None {
-                        if let Some(exists) = segentry.exists_at_lsn(lsn) {
+                        if let Some(exists) = segentry.exists_at_lsn(lsn)? {
                             rels.insert(seg.rel, exists);
                         }
                     }
@@ -174,6 +184,20 @@ impl LayerMap {
         }
     }
 
+    /// 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 {
+            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
@@ -191,7 +215,7 @@ impl LayerMap {
 
     pub fn iter_historic_layers(&self) -> HistoricLayerIter {
         HistoricLayerIter {
-            segiter: self.segs.iter(),
+            seg_iter: self.segs.iter(),
             iter: None,
         }
     }
@@ -205,7 +229,7 @@ impl LayerMap {
                 open.dump()?;
             }
 
-            for (_, layer) in segentry.historic.iter() {
+            for layer in segentry.historic.iter() {
                 layer.dump()?;
             }
         }
@@ -214,34 +238,40 @@ impl LayerMap {
     }
 }
 
+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 a
-/// BTreeMap keyed by the layer's start LSN.
+/// each segment. The older layers, stored on disk, are kept in an
+/// IntervalTree.
 #[derive(Default)]
 struct SegEntry {
-    pub open: Option<Arc<InMemoryLayer>>,
-    pub historic: BTreeMap<Lsn, Arc<dyn Layer>>,
+    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) -> Option<bool> {
-        if let Some(layer) = &self.open {
-            if layer.get_start_lsn() <= lsn && lsn <= layer.get_end_lsn() {
-                let exists = layer.get_seg_exists(lsn).ok()?;
-                return Some(exists);
-            }
-        } else if let Some((_, layer)) = self.historic.range(..=lsn).next_back() {
-            let exists = layer.get_seg_exists(lsn).ok()?;
-            return Some(exists);
+    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)
         }
-        None
     }
 
     pub fn get(&self, lsn: Lsn) -> Option<Arc<dyn Layer>> {
@@ -252,40 +282,30 @@ impl SegEntry {
             }
         }
 
-        if let Some((_start_lsn, layer)) = self.historic.range(..=lsn).next_back() {
-            Some(Arc::clone(layer))
-        } else {
-            None
-        }
+        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
 
-        for (_newer_lsn, layer) in self.historic.range(lsn..) {
-            // Ignore incremental layers.
-            if layer.is_incremental() {
-                continue;
-            }
-            if layer.get_end_lsn() > lsn {
-                return true;
-            } else {
-                continue;
-            }
-        }
-        false
+        self.historic
+            .iter_newer(lsn)
+            .any(|layer| !layer.is_incremental())
     }
 
-    pub fn insert_open(&mut self, layer: Arc<InMemoryLayer>) {
-        assert!(self.open.is_none());
+    // 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>) {
-        let start_lsn = layer.get_start_lsn();
-
-        self.historic.insert(start_lsn, layer);
+        self.historic.insert(layer);
     }
 }
 
@@ -324,8 +344,8 @@ 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> {
@@ -335,11 +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;
@@ -394,14 +414,14 @@ mod tests {
         let mut layers = LayerMap::default();
 
         let gen1 = layers.increment_generation();
-        layers.insert_open(dummy_inmem_layer(conf, 0, Lsn(100), Lsn(100)));
-        layers.insert_open(dummy_inmem_layer(conf, 1, Lsn(100), Lsn(200)));
-        layers.insert_open(dummy_inmem_layer(conf, 2, Lsn(100), Lsn(120)));
-        layers.insert_open(dummy_inmem_layer(conf, 3, Lsn(100), Lsn(110)));
+        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(100), Lsn(110)));
-        layers.insert_open(dummy_inmem_layer(conf, 5, Lsn(100), Lsn(100)));
+        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
@@ -412,12 +432,12 @@ mod tests {
             layers.pop_oldest_open();
         };
 
-        assert_pop_layer(0, gen1); // 100
-        assert_pop_layer(5, gen2); // 100
-        assert_pop_layer(3, gen1); // 110
-        assert_pop_layer(4, gen2); // 110
-        assert_pop_layer(2, gen1); // 120
-        assert_pop_layer(1, gen1); // 200
+        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/storage_layer.rs

@@ -111,15 +111,14 @@ pub trait Layer: Send + Sync {
     /// Identify the relish segment
     fn get_seg_tag(&self) -> SegmentTag;
 
-    /// Inclusive start bound of the LSN range that this layer hold
+    /// Inclusive start bound of the LSN range that this layer holds
     fn get_start_lsn(&self) -> Lsn;
 
-    /// 'end_lsn' meaning depends on the layer kind:
-    /// - in-memory layer is either unbounded (end_lsn = MAX_LSN) or dropped (end_lsn = drop_lsn)
-    /// - image layer represents snapshot at one LSN, so end_lsn = lsn
-    /// - delta layer has end_lsn
+    /// Exclusive end bound of the LSN range that this layer holds.
     ///
-    /// TODO Is end_lsn always exclusive for all layer kinds?
+    /// - 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?

pageserver/src/lib.rs

@@ -13,7 +13,7 @@ pub mod http;
 pub mod layered_repository;
 pub mod page_service;
 pub mod relish;
-mod relish_storage;
+pub mod relish_storage;
 pub mod repository;
 pub mod restore_local_repo;
 pub mod tenant_mgr;
@@ -22,12 +22,13 @@ 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 = "127.0.0.1:64000"; // can't format! const yet...
+    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 = "127.0.0.1:9898";
+    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,
@@ -39,6 +40,7 @@ pub mod defaults {
     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! {
@@ -153,8 +155,8 @@ impl PageServerConf {
             checkpoint_period: Duration::from_secs(10),
             gc_horizon: defaults::DEFAULT_GC_HORIZON,
             gc_period: Duration::from_secs(10),
-            listen_pg_addr: "127.0.0.1:5430".to_string(),
-            listen_http_addr: "127.0.0.1:9898".to_string(),
+            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(),
@@ -167,18 +169,37 @@ impl PageServerConf {
 
 /// External relish storage configuration, enough for creating a client for that storage.
 #[derive(Debug, Clone)]
-pub enum RelishStorageConfig {
-    /// Root folder to place all stored relish data into.
+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>,
 }
 

pageserver/src/page_service.rs

@@ -194,7 +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);
             }
         });
     }
@@ -293,7 +293,9 @@ impl PageServerHandler {
             };
 
             let response = response.unwrap_or_else(|e| {
-                error!("error reading relation or page version: {}", 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(),
                 })
@@ -654,12 +656,14 @@ impl postgres_backend::Handler for PageServerHandler {
                 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"),
@@ -679,6 +683,12 @@ impl postgres_backend::Handler for PageServerHandler {
                         .as_bytes(),
                 ),
                 Some(result.ondisk_relfiles_not_updated.to_string().as_bytes()),
+                Some(
+                    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()),
@@ -695,6 +705,12 @@ impl postgres_backend::Handler for PageServerHandler {
                         .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()),

pageserver/src/relish_storage.rs

@@ -8,14 +8,43 @@
 
 mod local_fs;
 mod rust_s3;
-/// A queue and the background machinery behind it to upload
-/// local page server layer files to external storage.
-pub mod storage_uploader;
+/// 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 {

pageserver/src/relish_storage/storage_uploader.rs

@@ -1,116 +0,0 @@
-use std::{
-    collections::VecDeque,
-    path::{Path, PathBuf},
-    sync::{Arc, Mutex},
-    thread,
-};
-
-use zenith_utils::zid::ZTimelineId;
-
-use crate::{relish_storage::RelishStorage, RelishStorageConfig};
-
-use super::{local_fs::LocalFs, rust_s3::RustS3};
-
-pub struct QueueBasedRelishUploader {
-    upload_queue: Arc<Mutex<VecDeque<(ZTimelineId, PathBuf)>>>,
-}
-
-impl QueueBasedRelishUploader {
-    pub fn new(
-        config: &RelishStorageConfig,
-        page_server_workdir: &'static Path,
-    ) -> anyhow::Result<Self> {
-        let upload_queue = Arc::new(Mutex::new(VecDeque::new()));
-        let _handle = match config {
-            RelishStorageConfig::LocalFs(root) => {
-                let relish_storage = LocalFs::new(root.clone())?;
-                create_upload_thread(
-                    Arc::clone(&upload_queue),
-                    relish_storage,
-                    page_server_workdir,
-                )?
-            }
-            RelishStorageConfig::AwsS3(s3_config) => {
-                let relish_storage = RustS3::new(s3_config)?;
-                create_upload_thread(
-                    Arc::clone(&upload_queue),
-                    relish_storage,
-                    page_server_workdir,
-                )?
-            }
-        };
-
-        Ok(Self { upload_queue })
-    }
-
-    pub fn schedule_upload(&self, timeline_id: ZTimelineId, relish_path: PathBuf) {
-        self.upload_queue
-            .lock()
-            .unwrap()
-            .push_back((timeline_id, relish_path))
-    }
-}
-
-fn create_upload_thread<P, S: 'static + RelishStorage<RelishStoragePath = P>>(
-    upload_queue: Arc<Mutex<VecDeque<(ZTimelineId, PathBuf)>>>,
-    relish_storage: S,
-    page_server_workdir: &'static Path,
-) -> std::io::Result<thread::JoinHandle<()>> {
-    let runtime = tokio::runtime::Builder::new_current_thread()
-        .enable_all()
-        .build()?;
-    thread::Builder::new()
-        .name("Queue based relish uploader".to_string())
-        .spawn(move || loop {
-            runtime.block_on(async {
-                upload_loop_step(&upload_queue, &relish_storage, page_server_workdir).await;
-            })
-        })
-}
-
-async fn upload_loop_step<P, S: 'static + RelishStorage<RelishStoragePath = P>>(
-    upload_queue: &Mutex<VecDeque<(ZTimelineId, PathBuf)>>,
-    relish_storage: &S,
-    page_server_workdir: &Path,
-) {
-    let mut queue_accessor = upload_queue.lock().unwrap();
-    log::debug!("current upload queue length: {}", queue_accessor.len());
-    let next_upload = queue_accessor.pop_front();
-    drop(queue_accessor);
-
-    let (relish_timeline_id, relish_local_path) = match next_upload {
-        Some(data) => data,
-        None => {
-            // Don't spin and allow others to use the queue.
-            // In future, could be improved to be more clever about delays depending on relish upload stats
-            thread::sleep(std::time::Duration::from_secs(1));
-            return;
-        }
-    };
-
-    if let Err(e) = upload_relish(relish_storage, page_server_workdir, &relish_local_path).await {
-        log::error!(
-            "Failed to upload relish '{}' for timeline {}, reason: {}",
-            relish_local_path.display(),
-            relish_timeline_id,
-            e
-        );
-        upload_queue
-            .lock()
-            .unwrap()
-            .push_back((relish_timeline_id, relish_local_path))
-    } else {
-        log::debug!("Relish successfully uploaded");
-    }
-}
-
-async fn upload_relish<P, S: RelishStorage<RelishStoragePath = P>>(
-    relish_storage: &S,
-    page_server_workdir: &Path,
-    relish_local_path: &Path,
-) -> anyhow::Result<()> {
-    let destination = S::derive_destination(page_server_workdir, relish_local_path)?;
-    relish_storage
-        .upload_relish(relish_local_path, &destination)
-        .await
-}

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

@@ -28,18 +28,14 @@ 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>;
 }
 
@@ -52,6 +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
 
@@ -59,6 +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
 
@@ -71,6 +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;
 
@@ -78,6 +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;
 
@@ -212,12 +212,18 @@ mod tests {
     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::str::FromStr;
+    use std::path::PathBuf;
     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,
@@ -253,39 +259,53 @@ mod tests {
     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 = 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"))?;
+    struct RepoHarness {
+        conf: &'static PageServerConf,
+        tenant_id: ZTenantId,
+    }
 
-        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 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)?;
+        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"))?;
@@ -395,13 +415,148 @@ mod tests {
         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(())
+    }
+
     /// Test get_relsize() and truncation with a file larger than 1 GB, so that it's
     /// 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)?;
+        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 {
@@ -461,13 +616,9 @@ mod tests {
     /// Test list_rels() function, with branches and dropped relations
     ///
     #[test]
-    // FIXME: The last assertion in this test is currently failing, see
-    // https://github.com/zenithdb/zenith/issues/502. Ignore the failure until that's fixed.
-    #[ignore]
     fn test_list_rels_drop() -> Result<()> {
-        let repo = get_test_repo("test_list_rels_drop")?;
-        let timelineid = ZTimelineId::from_str("11223344556677881122334455667788").unwrap();
-        let tline = repo.create_empty_timeline(timelineid)?;
+        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
@@ -485,9 +636,8 @@ mod tests {
         assert!(tline.list_rels(0, TESTDB, Lsn(0x30))?.contains(&TESTREL_A));
 
         // Create a branch, check that the relation is visible there
-        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)?;
 
         assert!(newtline
             .list_rels(0, TESTDB, Lsn(0x30))?
@@ -507,9 +657,8 @@ mod tests {
 
         // Run checkpoint and garbage collection and check that it's still not visible
         newtline.checkpoint()?;
-        repo.gc_iteration(Some(newtimelineid), 0, true)?;
+        repo.gc_iteration(Some(NEW_TIMELINE_ID), 0, true)?;
 
-        // FIXME: this is currently failing
         assert!(!newtline
             .list_rels(0, TESTDB, Lsn(0x40))?
             .contains(&TESTREL_A));
@@ -522,9 +671,8 @@ 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)?;
+        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
@@ -542,9 +690,8 @@ mod tests {
         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));
@@ -572,8 +719,89 @@ mod tests {
         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

@@ -11,7 +11,7 @@ use std::fs::File;
 use std::io::Read;
 use std::path::Path;
 
-use anyhow::Result;
+use anyhow::{bail, Result};
 use bytes::{Buf, Bytes};
 
 use crate::relish::*;
@@ -173,8 +173,7 @@ fn import_relfile(
                     break;
                 }
                 _ => {
-                    error!("error reading file: {:?} ({})", path, e);
-                    break;
+                    bail!("error reading file {}: {:#}", path.display(), e);
                 }
             },
         };
@@ -268,8 +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);
                 }
             },
         };

pageserver/src/tenant_mgr.rs

@@ -9,46 +9,84 @@ use crate::PageServerConf;
 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 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());
-        LayeredRepository::launch_gc_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() {
@@ -63,14 +101,13 @@ pub fn create_repository_for_tenant(
 }
 
 pub fn insert_repository_for_tenant(tenantid: ZTenantId, repo: Arc<dyn Repository>) {
-    let o = &mut REPOSITORY.lock().unwrap();
-    o.insert(tenantid, repo);
+    access_repository().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))
+    access_repository()
+        .get(&tenantid)
+        .map(Arc::clone)
         .ok_or_else(|| anyhow!("repository not found for tenant name {}", tenantid))
 }
 

pageserver/src/walreceiver.rs

@@ -10,7 +10,7 @@ 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;
@@ -20,6 +20,7 @@ use postgres_ffi::xlog_utils::*;
 use postgres_ffi::*;
 use postgres_protocol::message::backend::ReplicationMessage;
 use postgres_types::PgLsn;
+use std::cell::Cell;
 use std::cmp::{max, min};
 use std::collections::HashMap;
 use std::fs;
@@ -27,6 +28,7 @@ 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;
@@ -44,6 +46,13 @@ 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,
@@ -64,12 +73,10 @@ pub fn launch_wal_receiver(
             receivers.insert(timelineid, receiver);
 
             // Also launch a new thread to handle this connection
-            //
-            // NOTE: This thread name is checked in the assertion in wait_lsn. If you change
-            // this, make sure you update the assertion too.
             let _walreceiver_thread = thread::Builder::new()
                 .name("WAL receiver thread".into())
                 .spawn(move || {
+                    IS_WAL_RECEIVER.with(|c| c.set(true));
                     thread_main(conf, timelineid, tenantid);
                 })
                 .unwrap();
@@ -158,7 +165,7 @@ 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.

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,
@@ -206,7 +205,7 @@ 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))
@@ -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),
@@ -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 {
@@ -459,7 +460,7 @@ impl PostgresRedoProcess {
         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

proxy/Cargo.toml

@@ -18,5 +18,6 @@ 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 {

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)?;

test_runner/batch_others/test_old_request_lsn.py

@@ -46,7 +46,7 @@ def test_old_request_lsn(zenith_cli, pageserver: ZenithPageserver, postgres: Pos
         from pg_settings where name = 'shared_buffers'
     ''')
     row = cur.fetchone()
-    print("shared_buffers is {}, table size {}", row[0], row[1]);
+    print(f'shared_buffers is {row[0]}, table size {row[1]}');
     assert int(row[0]) < int(row[1])
 
     cur.execute('VACUUM foo');

test_runner/batch_others/test_pgbench.py

@@ -12,5 +12,5 @@ def test_pgbench(postgres: PostgresFactory, pg_bin, zenith_cli):
 
     connstr = pg.connstr()
 
-    pg_bin.run_capture(['pgbench', '-i', '-s', '100', connstr])
-    pg_bin.run_capture(['pgbench'] + '-c 1 -N -T 100 -P 1 -M prepared'.split() + [connstr])
+    pg_bin.run_capture(['pgbench', '-i', connstr])
+    pg_bin.run_capture(['pgbench'] + '-c 10 -T 5 -P 1 -M prepared'.split() + [connstr])

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

@@ -6,8 +6,8 @@ pytest_plugins = ("fixtures.zenith_fixtures")
 
 def print_gc_result(row):
     print("GC duration {elapsed} ms".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}, 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}, removed: {layer_nonrelfiles_removed}, dropped: {layer_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))
 
 
 #
@@ -58,19 +58,21 @@ def test_layerfiles_gc(zenith_cli, pageserver, postgres, pg_bin):
                     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['layer_relfiles_total'] == layer_relfiles_remain + 1
-                    assert row['layer_relfiles_removed'] == 1
+                    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 layer 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_layerfiles_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['layer_relfiles_total'] == layer_relfiles_remain + 1
-                    assert row['layer_relfiles_removed'] == 1
+                    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 layer 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)")
@@ -90,8 +92,8 @@ def test_layerfiles_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['layer_relfiles_total'] == layer_relfiles_remain + 1
-                    assert row['layer_relfiles_removed'] == 1
+                    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.
@@ -113,12 +115,19 @@ def test_layerfiles_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['layer_relfiles_dropped'] == 3
+                    assert row['layer_relfiles_needed_as_tombstone'] == 3
 
                     # The catalog updates also create new layer files of the catalogs, which
                     # are counted as 'removed'
                     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_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

@@ -118,9 +118,14 @@ async def run_restarts_under_load(pg: Postgres, acceptors: List[WalAcceptor], n_
         victim = acceptors[it % len(acceptors)]
         victim.stop()
 
-        # wait for transactions that could have started and finished before
-        # victim acceptor was stopped
-        await asyncio.sleep(1)
+        # 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)

test_runner/fixtures/benchmark_fixture.py

@@ -136,7 +136,8 @@ class ZenithBenchmarker:
         # 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)
+        matches = re.search(r'^pageserver_disk_io_bytes{io_operation="write"} (\S+)$', all_metrics,
+                            re.MULTILINE)
         return int(round(float(matches.group(1))))
 
     @contextmanager

test_runner/fixtures/utils.py

@@ -21,7 +21,7 @@ def mkdir_if_needed(path: str) -> None:
     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"
@@ -29,6 +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())
@@ -41,6 +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
 
@@ -62,3 +65,7 @@ def debug_print(*args, **kwargs) -> None:
     """
     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

@@ -5,6 +5,7 @@ import os
 import pathlib
 import uuid
 import jwt
+import json
 import psycopg2
 import pytest
 import shutil
@@ -70,7 +71,9 @@ def pytest_configure(config):
         # 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')
+        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:
@@ -485,17 +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
@@ -854,6 +859,27 @@ 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. """

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')

walkeeper/Cargo.toml

@@ -13,6 +13,7 @@ bytes = "1.0.1"
 byteorder = "1.4.3"
 fs2 = "0.4.3"
 lazy_static = "1.4.0"
+serde_json = "1"
 log = "0.4.14"
 clap = "2.33.0"
 daemonize = "0.4.1"

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/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/safekeeper.rs

@@ -28,7 +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];
@@ -111,7 +111,7 @@ impl Default for SafeKeeperState {
 // protocol messages
 
 /// Initial Proposer -> Acceptor message
-#[derive(Debug, Serialize, Deserialize)]
+#[derive(Debug, Deserialize)]
 pub struct ProposerGreeting {
     /// proposer-acceptor protocol version
     pub protocol_version: u32,
@@ -128,19 +128,19 @@ 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
@@ -152,26 +152,26 @@ pub struct VoteResponse {
 
 /// 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,
+    pub commit_lsn: Lsn,
     /// minimal LSN which may be needed by proposer to perform recovery of some safekeeper
-    truncate_lsn: Lsn,
+    pub truncate_lsn: Lsn,
     // only for logging/debugging
-    proposer_uuid: PgUuid,
+    pub proposer_uuid: PgUuid,
 }
 
 /// Report safekeeper state to proposer
@@ -275,8 +275,8 @@ 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
@@ -423,7 +423,7 @@ where
         let mut last_rec_lsn = Lsn(0);
         if !msg.wal_data.is_empty() {
             self.storage
-                .write_wal(&self.s, msg.h.begin_lsn, &msg.wal_data)?;
+                .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)
@@ -546,7 +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(())
         }
     }

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};
@@ -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};
@@ -32,7 +32,7 @@ struct SharedState {
     sk: SafeKeeper<FileStorage>,
     /// 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,
 }
@@ -72,7 +72,7 @@ impl SharedState {
         };
 
         Ok(Self {
-            commit_lsn: Lsn(0),
+            notified_commit_lsn: Lsn(0),
             sk: SafeKeeper::new(Lsn(flush_lsn), tli, storage, state),
             hs_feedback: HotStandbyFeedback {
                 ts: 0,
@@ -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();
         }
     }
@@ -337,14 +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;
@@ -365,7 +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

zenith_metrics/Cargo.toml

@@ -7,3 +7,4 @@ edition = "2018"
 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};
@@ -24,9 +25,29 @@ pub fn gather() -> Vec<prometheus::proto::MetricFamily> {
     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) {
+    COMMON_METRICS_PREFIX.set(prefix.into()).unwrap();
+}
+
+/// 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 {
+    format!(
+        "{}_{}",
+        COMMON_METRICS_PREFIX.get().unwrap(),
+        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"]
     )

zenith_utils/Cargo.toml

@@ -38,3 +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/bin_ser.rs

@@ -94,9 +94,12 @@ pub fn le_coder() -> impl Options {
 
 /// 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.
@@ -107,19 +110,28 @@ 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 the full contents of a byte slice
     ///
     /// See also: [`BeSer::des_prefix`]
-    fn des(buf: &[u8]) -> Result<Self, DeserializeError> {
+    fn des(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         be_coder()
             .deserialize(buf)
             .or(Err(DeserializeError::BadInput))
@@ -131,7 +143,10 @@ pub trait BeSer: Serialize + DeserializeOwned {
     /// type, but does not guarantee that the entire slice is used.
     ///
     /// See also: [`BeSer::des`]
-    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError> {
+    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         be_coder()
             .allow_trailing_bytes()
             .deserialize(buf)
@@ -139,7 +154,10 @@ pub trait BeSer: Serialize + DeserializeOwned {
     }
 
     /// 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())
     }
 
@@ -147,16 +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.
@@ -167,19 +191,28 @@ 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 the full contents of a byte slice
     ///
     /// See also: [`LeSer::des_prefix`]
-    fn des(buf: &[u8]) -> Result<Self, DeserializeError> {
+    fn des(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         le_coder()
             .deserialize(buf)
             .or(Err(DeserializeError::BadInput))
@@ -191,7 +224,10 @@ pub trait LeSer: Serialize + DeserializeOwned {
     /// type, but does not guarantee that the entire slice is used.
     ///
     /// See also: [`LeSer::des`]
-    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError> {
+    fn des_prefix(buf: &[u8]) -> Result<Self, DeserializeError>
+    where
+        Self: DeserializeOwned,
+    {
         le_coder()
             .allow_trailing_bytes()
             .deserialize(buf)
@@ -199,7 +235,10 @@ pub trait LeSer: Serialize + DeserializeOwned {
     }
 
     /// 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())
     }
 
@@ -207,14 +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 {

zenith_utils/src/crashsafe_dir.rs

@@ -0,0 +1,125 @@
+use std::{
+    fs::{self, File},
+    io,
+    path::Path,
+};
+
+/// Similar to [`std::fs::create_dir`], except we fsync the
+/// created directory and its parent.
+pub fn create_dir(path: impl AsRef<Path>) -> io::Result<()> {
+    let path = path.as_ref();
+
+    fs::create_dir(path)?;
+    File::open(path)?.sync_all()?;
+
+    if let Some(parent) = path.parent() {
+        File::open(parent)?.sync_all()
+    } else {
+        Err(io::Error::new(
+            io::ErrorKind::InvalidInput,
+            "can't find parent",
+        ))
+    }
+}
+
+/// Similar to [`std::fs::create_dir_all`], except we fsync all
+/// newly created directories and the pre-existing parent.
+pub fn create_dir_all(path: impl AsRef<Path>) -> io::Result<()> {
+    let mut path = path.as_ref();
+
+    let mut dirs_to_create = Vec::new();
+
+    // Figure out which directories we need to create.
+    loop {
+        match path.metadata() {
+            Ok(metadata) if metadata.is_dir() => break,
+            Ok(_) => {
+                return Err(io::Error::new(
+                    io::ErrorKind::AlreadyExists,
+                    format!("non-directory found in path: {:?}", path),
+                ));
+            }
+            Err(ref e) if e.kind() == io::ErrorKind::NotFound => {}
+            Err(e) => return Err(e),
+        }
+
+        dirs_to_create.push(path);
+
+        match path.parent() {
+            Some(parent) => path = parent,
+            None => {
+                return Err(io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    "can't find parent",
+                ))
+            }
+        }
+    }
+
+    // Create directories from parent to child.
+    for &path in dirs_to_create.iter().rev() {
+        fs::create_dir(path)?;
+    }
+
+    // Fsync the created directories from child to parent.
+    for &path in dirs_to_create.iter() {
+        File::open(path)?.sync_all()?;
+    }
+
+    // If we created any new directories, fsync the parent.
+    if !dirs_to_create.is_empty() {
+        File::open(path)?.sync_all()?;
+    }
+
+    Ok(())
+}
+
+#[cfg(test)]
+mod tests {
+    use tempfile::tempdir;
+
+    use super::*;
+
+    #[test]
+    fn test_create_dir_fsyncd() {
+        let dir = tempdir().unwrap();
+
+        let existing_dir_path = dir.path();
+        let err = create_dir(existing_dir_path).unwrap_err();
+        assert_eq!(err.kind(), io::ErrorKind::AlreadyExists);
+
+        let child_dir = existing_dir_path.join("child");
+        create_dir(child_dir).unwrap();
+
+        let nested_child_dir = existing_dir_path.join("child1").join("child2");
+        let err = create_dir(nested_child_dir).unwrap_err();
+        assert_eq!(err.kind(), io::ErrorKind::NotFound);
+    }
+
+    #[test]
+    fn test_create_dir_all_fsyncd() {
+        let dir = tempdir().unwrap();
+
+        let existing_dir_path = dir.path();
+        create_dir_all(existing_dir_path).unwrap();
+
+        let child_dir = existing_dir_path.join("child");
+        assert!(!child_dir.exists());
+        create_dir_all(&child_dir).unwrap();
+        assert!(child_dir.exists());
+
+        let nested_child_dir = existing_dir_path.join("child1").join("child2");
+        assert!(!nested_child_dir.exists());
+        create_dir_all(&nested_child_dir).unwrap();
+        assert!(nested_child_dir.exists());
+
+        let file_path = existing_dir_path.join("file");
+        std::fs::write(&file_path, b"").unwrap();
+
+        let err = create_dir_all(&file_path).unwrap_err();
+        assert_eq!(err.kind(), io::ErrorKind::AlreadyExists);
+
+        let invalid_dir_path = file_path.join("folder");
+        create_dir_all(&invalid_dir_path).unwrap_err();
+    }
+}

zenith_utils/src/http/endpoint.rs

@@ -9,14 +9,14 @@ use routerify::ext::RequestExt;
 use routerify::RequestInfo;
 use routerify::{Middleware, Router, RouterBuilder, RouterService};
 use std::net::TcpListener;
-use zenith_metrics::{register_int_counter, IntCounter};
+use zenith_metrics::{new_common_metric_name, register_int_counter, IntCounter};
 use zenith_metrics::{Encoder, TextEncoder};
 
 use super::error::ApiError;
 
 lazy_static! {
     static ref SERVE_METRICS_COUNT: IntCounter = register_int_counter!(
-        "pageserver_serve_metrics_count",
+        new_common_metric_name("serve_metrics_count"),
         "Number of metric requests made"
     )
     .expect("failed to define a metric");

zenith_utils/src/lib.rs

@@ -8,6 +8,8 @@ pub mod lsn;
 /// SeqWait allows waiting for a future sequence number to arrive
 pub mod seqwait;
 
+pub mod ordered_vec;
+
 // Async version of SeqWait. Currently unused.
 // pub mod seqwait_async;
 
@@ -18,6 +20,9 @@ pub mod pq_proto;
 // dealing with connstring parsing and handy access to it's parts
 pub mod connstring;
 
+// helper functions for creating and fsyncing directories/trees
+pub mod crashsafe_dir;
+
 // common authentication routines
 pub mod auth;
 
@@ -31,3 +36,6 @@ pub mod sock_split;
 
 // common log initialisation routine
 pub mod logging;
+
+// Misc
+pub mod accum;

zenith_utils/src/lsn.rs

@@ -192,9 +192,7 @@ impl AtomicLsn {
     /// This operation will panic on overflow.
     pub fn fetch_add(&self, val: u64) -> Lsn {
         let prev = self.inner.fetch_add(val, Ordering::AcqRel);
-        if prev.checked_add(val).is_none() {
-            panic!("AtomicLsn overflow");
-        }
+        assert!(prev.checked_add(val).is_some(), "AtomicLsn overflow");
         Lsn(prev)
     }
 

zenith_utils/src/ordered_vec.rs

@@ -0,0 +1,273 @@
+use std::{
+    collections::BTreeMap,
+    ops::{Bound, RangeBounds},
+};
+
+use serde::{Deserialize, Serialize};
+
+#[derive(Clone, Debug, Serialize, Deserialize)]
+pub struct OrderedVec<K, V>(Vec<(K, V)>);
+
+impl<K, V> Default for OrderedVec<K, V> {
+    fn default() -> Self {
+        Self(Default::default())
+    }
+}
+
+impl<K: Ord + Copy, V> OrderedVec<K, V> {
+    pub fn iter(&self) -> std::slice::Iter<'_, (K, V)> {
+        self.0.iter()
+    }
+
+    pub fn range<R: RangeBounds<K>>(&self, range: R) -> &[(K, V)] {
+        match (range.start_bound(), range.end_bound()) {
+            (Bound::Excluded(l), Bound::Excluded(u)) if l == u => panic!("Invalid excluded"),
+            // TODO check for l <= x with or patterns
+            _ => {}
+        }
+
+        let start_idx = match range.start_bound() {
+            Bound::Included(key) => match self.0.binary_search_by_key(key, extract_key) {
+                Ok(idx) => idx,
+                Err(idx) => idx,
+            },
+            Bound::Excluded(key) => match self.0.binary_search_by_key(key, extract_key) {
+                Ok(idx) => idx + 1,
+                Err(idx) => idx,
+            },
+            Bound::Unbounded => 0,
+        };
+
+        let end_idx = match range.end_bound() {
+            Bound::Included(key) => match self.0.binary_search_by_key(key, extract_key) {
+                Ok(idx) => idx + 1,
+                Err(idx) => idx,
+            },
+            Bound::Excluded(key) => match self.0.binary_search_by_key(key, extract_key) {
+                Ok(idx) => idx,
+                Err(idx) => idx,
+            },
+            Bound::Unbounded => self.0.len(),
+        };
+
+        &self.0[start_idx..end_idx]
+    }
+
+    pub fn append(&mut self, key: K, value: V) {
+        if let Some((last_key, _last_value)) = self.0.last() {
+            debug_assert!(last_key < &key);
+        }
+
+        self.0.push((key, value));
+    }
+
+    pub fn append_update(&mut self, key: K, value: V) {
+        if let Some((last_key, this_value)) = self.0.last_mut() {
+            use std::cmp::Ordering;
+            match (*last_key).cmp(&key) {
+                Ordering::Less => {}
+                Ordering::Equal => {
+                    *this_value = value;
+                    return;
+                }
+                Ordering::Greater => {
+                    panic!();
+                }
+            }
+        }
+
+        self.0.push((key, value));
+    }
+
+    pub fn extend(&mut self, other: OrderedVec<K, V>) {
+        if let (Some((last, _)), Some((first, _))) = (self.0.last(), other.0.first()) {
+            assert!(last < first);
+        }
+
+        self.0.extend(other.0);
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.0.is_empty()
+    }
+
+    pub fn copy_prefix(&self, key: &K) -> Self
+    where
+        K: Clone,
+        V: Clone,
+    {
+        let idx = match self.0.binary_search_by_key(key, extract_key) {
+            Ok(idx) => idx,
+            Err(idx) => idx,
+        };
+
+        OrderedVec(Vec::from(&self.0[..idx]))
+    }
+
+    pub fn copy_split(&self, key: &K) -> (Self, Self)
+    where
+        K: Clone,
+        V: Clone,
+    {
+        let idx = match self.0.binary_search_by_key(key, extract_key) {
+            Ok(idx) => idx,
+            Err(idx) => idx,
+        };
+
+        (
+            OrderedVec(Vec::from(&self.0[..idx])),
+            OrderedVec(Vec::from(&self.0[idx..])),
+        )
+    }
+}
+
+impl<K: Ord, V> From<BTreeMap<K, V>> for OrderedVec<K, V> {
+    fn from(map: BTreeMap<K, V>) -> Self {
+        let vec: Vec<(K, V)> = map.into_iter().collect();
+
+        // TODO probably change this
+        for windows in vec.windows(2) {
+            let (k1, _data1) = &windows[0];
+            let (k2, _data2) = &windows[1];
+            debug_assert!(k1 < k2);
+        }
+
+        OrderedVec(vec)
+    }
+}
+
+fn extract_key<K: Copy, V>(pair: &(K, V)) -> K {
+    pair.0
+}
+
+#[cfg(test)]
+mod tests {
+    use std::{
+        collections::BTreeMap,
+        ops::{Bound, RangeBounds},
+    };
+
+    use super::OrderedVec;
+
+    #[test]
+    #[should_panic]
+    fn invalid_range() {
+        let mut map = BTreeMap::new();
+        map.insert(0, ());
+
+        let vec: OrderedVec<i32, ()> = OrderedVec::from(map);
+        struct InvalidRange;
+        impl RangeBounds<i32> for InvalidRange {
+            fn start_bound(&self) -> Bound<&i32> {
+                Bound::Excluded(&0)
+            }
+
+            fn end_bound(&self) -> Bound<&i32> {
+                Bound::Excluded(&0)
+            }
+        }
+
+        vec.range(InvalidRange);
+    }
+
+    #[test]
+    fn range_tests() {
+        let mut map = BTreeMap::new();
+        map.insert(0, ());
+        map.insert(2, ());
+        map.insert(4, ());
+        let vec = OrderedVec::from(map);
+
+        assert_eq!(vec.range(0..0), &[]);
+        assert_eq!(vec.range(0..1), &[(0, ())]);
+        assert_eq!(vec.range(0..2), &[(0, ())]);
+        assert_eq!(vec.range(0..3), &[(0, ()), (2, ())]);
+
+        assert_eq!(vec.range(..0), &[]);
+        assert_eq!(vec.range(..1), &[(0, ())]);
+
+        assert_eq!(vec.range(..3), &[(0, ()), (2, ())]);
+        assert_eq!(vec.range(..3), &[(0, ()), (2, ())]);
+
+        assert_eq!(vec.range(0..=0), &[(0, ())]);
+        assert_eq!(vec.range(0..=1), &[(0, ())]);
+        assert_eq!(vec.range(0..=2), &[(0, ()), (2, ())]);
+        assert_eq!(vec.range(0..=3), &[(0, ()), (2, ())]);
+
+        assert_eq!(vec.range(..=0), &[(0, ())]);
+        assert_eq!(vec.range(..=1), &[(0, ())]);
+        assert_eq!(vec.range(..=2), &[(0, ()), (2, ())]);
+        assert_eq!(vec.range(..=3), &[(0, ()), (2, ())]);
+    }
+
+    struct BoundIter {
+        min: i32,
+        max: i32,
+
+        next: Option<Bound<i32>>,
+    }
+
+    impl BoundIter {
+        fn new(min: i32, max: i32) -> Self {
+            Self {
+                min,
+                max,
+
+                next: Some(Bound::Unbounded),
+            }
+        }
+    }
+
+    impl Iterator for BoundIter {
+        type Item = Bound<i32>;
+
+        fn next(&mut self) -> Option<Self::Item> {
+            let cur = self.next?;
+
+            self.next = match &cur {
+                Bound::Unbounded => Some(Bound::Included(self.min)),
+                Bound::Included(x) => {
+                    if *x >= self.max {
+                        Some(Bound::Excluded(self.min))
+                    } else {
+                        Some(Bound::Included(x + 1))
+                    }
+                }
+                Bound::Excluded(x) => {
+                    if *x >= self.max {
+                        None
+                    } else {
+                        Some(Bound::Excluded(x + 1))
+                    }
+                }
+            };
+
+            Some(cur)
+        }
+    }
+
+    #[test]
+    fn range_exhaustive() {
+        let map: BTreeMap<i32, ()> = (1..=7).step_by(2).map(|x| (x, ())).collect();
+        let vec = OrderedVec::from(map.clone());
+
+        const RANGE_MIN: i32 = 0;
+        const RANGE_MAX: i32 = 8;
+        for lower_bound in BoundIter::new(RANGE_MIN, RANGE_MAX) {
+            let ub_min = match lower_bound {
+                Bound::Unbounded => RANGE_MIN,
+                Bound::Included(x) => x,
+                Bound::Excluded(x) => x + 1,
+            };
+            for upper_bound in BoundIter::new(ub_min, RANGE_MAX) {
+                let map_range: Vec<(i32, ())> = map
+                    .range((lower_bound, upper_bound))
+                    .map(|(&x, _)| (x, ()))
+                    .collect();
+                let vec_slice = vec.range((lower_bound, upper_bound));
+
+                assert_eq!(map_range, vec_slice);
+            }
+        }
+    }
+}

zenith_utils/src/pq_proto.rs

@@ -652,7 +652,7 @@ impl<'a> BeMessage<'a> {
             }
 
             BeMessage::EncryptionResponse(should_negotiate) => {
-                let response = if *should_negotiate { b'Y' } else { b'N' };
+                let response = if *should_negotiate { b'S' } else { b'N' };
                 buf.put_u8(response);
             }
 

zenith_utils/src/zid.rs

@@ -78,6 +78,10 @@ macro_rules! zid_newtype {
             pub fn generate() -> Self {
                 $t(ZId::generate())
             }
+
+            pub const fn from_array(b: [u8; 16]) -> Self {
+                $t(ZId(b))
+            }
         }
 
         impl FromStr for $t {

zenith_utils/tests/bin_ser_test.rs

@@ -1,10 +1,10 @@
 use bytes::{Buf, BytesMut};
 use hex_literal::hex;
-use serde::{Deserialize, Serialize};
+use serde::Deserialize;
 use std::io::Read;
 use zenith_utils::bin_ser::LeSer;
 
-#[derive(Debug, PartialEq, Serialize, Deserialize)]
+#[derive(Debug, PartialEq, Deserialize)]
 pub struct HeaderData {
     magic: u16,
     info: u16,

zenith_utils/tests/ssl_test.rs

@@ -43,7 +43,7 @@ fn ssl() {
         client_sock.write_u32::<BigEndian>(80877103).unwrap();
 
         let ssl_response = client_sock.read_u8().unwrap();
-        assert_eq!(b'Y', ssl_response);
+        assert_eq!(b'S', ssl_response);
 
         let mut cfg = rustls::ClientConfig::new();
         cfg.root_store.add(&CERT).unwrap();