wip

## Problem
For the Private Access POC we want users to be able to disable access
from the public proxy. To limit the number of changes this can be done
by configuring an IP allowlist [ "255.255.255.255" ]. For the Private
Access proxy a new commandline flag allows to disable IP allowlist
completely.

See
https://www.notion.so/neondatabase/Neon-Private-Access-POC-Proposal-8f707754e1ab4190ad5709da7832f020?d=887495c15e884aa4973f973a8a0a582a#7ac6ec249b524a74adbeddc4b84b8f5f
for details about the POC.,

## Summary of changes
- Adding the commandline flag is_private_access_proxy=true will disable
IP allowlist

.devcontainer/Dockerfile.devcontainer

@@ -0,0 +1 @@
+FROM neondatabase/build-tools:pinned

.devcontainer/devcontainer.json

@@ -0,0 +1,23 @@
+// https://containers.dev/implementors/json_reference/
+{
+  "name": "Neon",
+  "build": {
+    "context": "..",
+    "dockerfile": "Dockerfile.devcontainer"
+  },
+
+  "postCreateCommand": {
+    "build neon": "BUILD_TYPE=debug CARGO_BUILD_FLAGS='--features=testing' mold -run make -s -j`nproc`",
+    "install python deps": "./scripts/pysync"
+  },
+
+  "customizations": {
+    "vscode": {
+      "extensions": [
+        "charliermarsh.ruff",
+        "github.vscode-github-actions",
+        "rust-lang.rust-analyzer"
+      ]
+    }
+  }
+}

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,6 @@
+
+blank_issues_enabled: true
+contact_links:
+  - name: Feature request
+    url: https://console.neon.tech/app/projects?modal=feedback
+    about: For feature requests in the Neon product, please submit via the feedback form on `https://console.neon.tech`

.github/actionlint.yml

@@ -7,6 +7,13 @@ self-hosted-runner:
     - small-arm64
     - us-east-2
 config-variables:
+  - AZURE_DEV_CLIENT_ID
+  - AZURE_DEV_REGISTRY_NAME
+  - AZURE_DEV_SUBSCRIPTION_ID
+  - AZURE_PROD_CLIENT_ID
+  - AZURE_PROD_REGISTRY_NAME
+  - AZURE_PROD_SUBSCRIPTION_ID
+  - AZURE_TENANT_ID
   - BENCHMARK_PROJECT_ID_PUB
   - BENCHMARK_PROJECT_ID_SUB
   - REMOTE_STORAGE_AZURE_CONTAINER

.github/actions/run-python-test-set/action.yml

@@ -71,7 +71,7 @@ runs:
       if: inputs.build_type != 'remote'
       uses: ./.github/actions/download
       with:
-        name: compatibility-snapshot-${{ inputs.build_type }}-pg${{ inputs.pg_version }}
+        name: compatibility-snapshot-${{ runner.arch }}-${{ inputs.build_type }}-pg${{ inputs.pg_version }}
         path: /tmp/compatibility_snapshot_pg${{ inputs.pg_version }}
         prefix: latest
         # The lack of compatibility snapshot (for example, for the new Postgres version)
@@ -211,13 +211,13 @@ runs:
         fi
 
     - name: Upload compatibility snapshot
-      if: github.ref_name == 'release'
+      # Note, that we use `github.base_ref` which is a target branch for a PR
+      if: github.event_name == 'pull_request' && github.base_ref == 'release'
       uses: ./.github/actions/upload
       with:
-        name: compatibility-snapshot-${{ inputs.build_type }}-pg${{ inputs.pg_version }}-${{ github.run_id }}
+        name: compatibility-snapshot-${{ runner.arch }}-${{ inputs.build_type }}-pg${{ inputs.pg_version }}
         # Directory is created by test_compatibility.py::test_create_snapshot, keep the path in sync with the test
         path: /tmp/test_output/compatibility_snapshot_pg${{ inputs.pg_version }}/
-        prefix: latest
 
     - name: Upload test results
       if: ${{ !cancelled() }}

.github/workflows/_build-and-test-locally.yml

@@ -216,8 +216,14 @@ jobs:
           #nextest does not yet support running doctests
           ${cov_prefix} cargo test --doc $CARGO_FLAGS $CARGO_FEATURES
 
+          # run all non-pageserver tests
+          ${cov_prefix} cargo nextest run $CARGO_FLAGS $CARGO_FEATURES -E '!package(pageserver)'
+
+          # run pageserver tests with different settings
           for io_engine in std-fs tokio-epoll-uring ; do
-            NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IOENGINE=$io_engine ${cov_prefix} cargo nextest run $CARGO_FLAGS $CARGO_FEATURES
+            for io_buffer_alignment in 0 1 512 ; do
+              NEON_PAGESERVER_UNIT_TEST_VIRTUAL_FILE_IOENGINE=$io_engine NEON_PAGESERVER_UNIT_TEST_IO_BUFFER_ALIGNMENT=$io_buffer_alignment ${cov_prefix} cargo nextest run $CARGO_FLAGS $CARGO_FEATURES  -E 'package(pageserver)'
+            done
           done
 
           # Run separate tests for real S3

.github/workflows/_push-to-acr.yml

@@ -0,0 +1,56 @@
+name: Push images to ACR
+on:
+  workflow_call:
+    inputs:
+      client_id:
+        description: Client ID of Azure managed identity or Entra app
+        required: true
+        type: string
+      image_tag:
+        description: Tag for the container image
+        required: true
+        type: string
+      images:
+        description: Images to push
+        required: true
+        type: string
+      registry_name:
+        description: Name of the container registry
+        required: true
+        type: string
+      subscription_id:
+        description: Azure subscription ID
+        required: true
+        type: string
+      tenant_id:
+        description: Azure tenant ID
+        required: true
+        type: string
+
+jobs:
+  push-to-acr:
+    runs-on: ubuntu-22.04
+    permissions:
+      contents: read  # This is required for actions/checkout
+      id-token: write # This is required for Azure Login to work.
+
+    steps:
+      - name: Azure login
+        uses: azure/login@6c251865b4e6290e7b78be643ea2d005bc51f69a  # @v2.1.1
+        with:
+          client-id: ${{ inputs.client_id }}
+          subscription-id: ${{ inputs.subscription_id }}
+          tenant-id: ${{ inputs.tenant_id }}
+
+      - name: Login to ACR
+        run: |
+          az acr login --name=${{ inputs.registry_name }}
+
+      - name: Copy docker images to ACR ${{ inputs.registry_name }}
+        run: |
+          images='${{ inputs.images }}'
+          for image in ${images}; do
+            docker buildx imagetools create \
+              -t ${{ inputs.registry_name }}.azurecr.io/neondatabase/${image}:${{ inputs.image_tag }} \
+                                        neondatabase/${image}:${{ inputs.image_tag }}
+          done

.github/workflows/build_and_test.yml

@@ -286,6 +286,7 @@ jobs:
           PERF_TEST_RESULT_CONNSTR: "${{ secrets.PERF_TEST_RESULT_CONNSTR }}"
           TEST_RESULT_CONNSTR: "${{ secrets.REGRESS_TEST_RESULT_CONNSTR_NEW }}"
           PAGESERVER_VIRTUAL_FILE_IO_ENGINE: tokio-epoll-uring
+          SYNC_AFTER_EACH_TEST: true
       # XXX: no coverage data handling here, since benchmarks are run on release builds,
       # while coverage is currently collected for the debug ones
 
@@ -793,9 +794,6 @@ jobs:
           docker compose -f ./docker-compose/docker-compose.yml down
 
   promote-images:
-    permissions:
-      contents: read  # This is required for actions/checkout
-      id-token: write # This is required for Azure Login to work.
     needs: [ check-permissions, tag, test-images, vm-compute-node-image ]
     runs-on: ubuntu-22.04
 
@@ -822,28 +820,6 @@ jobs:
                                                neondatabase/vm-compute-node-${version}:${{ needs.tag.outputs.build-tag }}
           done
 
-      - name: Azure login
-        if: github.ref_name == 'main'
-        uses: azure/login@6c251865b4e6290e7b78be643ea2d005bc51f69a  # @v2.1.1
-        with:
-          client-id: ${{ secrets.AZURE_DEV_CLIENT_ID }}
-          tenant-id: ${{ secrets.AZURE_TENANT_ID }}
-          subscription-id: ${{ secrets.AZURE_DEV_SUBSCRIPTION_ID }}
-
-      - name: Login to ACR
-        if: github.ref_name == 'main'
-        run: |
-          az acr login --name=neoneastus2
-
-      - name: Copy docker images to ACR-dev
-        if: github.ref_name == 'main'
-        run: |
-          for image in neon compute-tools {vm-,}compute-node-{v14,v15,v16}; do
-            docker buildx imagetools create \
-              -t neoneastus2.azurecr.io/neondatabase/${image}:${{ needs.tag.outputs.build-tag }} \
-                                        neondatabase/${image}:${{ needs.tag.outputs.build-tag }}
-          done
-
       - name: Add latest tag to images
         if: github.ref_name == 'main'
         run: |
@@ -881,6 +857,30 @@ jobs:
                                                369495373322.dkr.ecr.eu-central-1.amazonaws.com/${image}:${{ needs.tag.outputs.build-tag }}
           done
 
+  push-to-acr-dev:
+    if: github.ref_name == 'main'
+    needs: [ tag, promote-images ]
+    uses: ./.github/workflows/_push-to-acr.yml
+    with:
+      client_id: ${{ vars.AZURE_DEV_CLIENT_ID }}
+      image_tag: ${{ needs.tag.outputs.build-tag }}
+      images: neon compute-tools vm-compute-node-v14 vm-compute-node-v15 vm-compute-node-v16 compute-node-v14 compute-node-v15 compute-node-v16
+      registry_name: ${{ vars.AZURE_DEV_REGISTRY_NAME }}
+      subscription_id: ${{ vars.AZURE_DEV_SUBSCRIPTION_ID }}
+      tenant_id: ${{ vars.AZURE_TENANT_ID }}
+
+  push-to-acr-prod:
+    if: github.ref_name == 'release'|| github.ref_name == 'release-proxy'
+    needs: [ tag, promote-images ]
+    uses: ./.github/workflows/_push-to-acr.yml
+    with:
+      client_id: ${{ vars.AZURE_PROD_CLIENT_ID }}
+      image_tag: ${{ needs.tag.outputs.build-tag }}
+      images: neon compute-tools vm-compute-node-v14 vm-compute-node-v15 vm-compute-node-v16 compute-node-v14 compute-node-v15 compute-node-v16
+      registry_name: ${{ vars.AZURE_PROD_REGISTRY_NAME }}
+      subscription_id: ${{ vars.AZURE_PROD_SUBSCRIPTION_ID }}
+      tenant_id: ${{ vars.AZURE_TENANT_ID }}
+
   trigger-custom-extensions-build-and-wait:
     needs: [ check-permissions, tag ]
     runs-on: ubuntu-22.04
@@ -956,8 +956,8 @@ jobs:
           exit 1
 
   deploy:
-    needs: [ check-permissions, promote-images, tag, build-and-test-locally, trigger-custom-extensions-build-and-wait ]
+    needs: [ check-permissions, promote-images, tag, build-and-test-locally, trigger-custom-extensions-build-and-wait, push-to-acr-dev, push-to-acr-prod ]
-    if: github.ref_name == 'main' || github.ref_name == 'release'|| github.ref_name == 'release-proxy'
+    if: (github.ref_name == 'main' || github.ref_name == 'release' || github.ref_name == 'release-proxy') && !failure() && !cancelled()
 
     runs-on: [ self-hosted, small ]
     container: 369495373322.dkr.ecr.eu-central-1.amazonaws.com/ansible:latest
@@ -1055,43 +1055,88 @@ jobs:
               generate_release_notes: true,
             })
 
+  # The job runs on `release` branch and copies compatibility data and Neon artifact from the last *release PR* to the latest directory
   promote-compatibility-data:
-    needs: [ check-permissions, promote-images, tag, build-and-test-locally ]
+    needs: [ deploy ]
     if: github.ref_name == 'release'
 
-    runs-on: [ self-hosted, small ]
+    runs-on: ubuntu-22.04
-    container:
-      image: 369495373322.dkr.ecr.eu-central-1.amazonaws.com/base:pinned
-      options: --init
     steps:
-      - name: Promote compatibility snapshot for the release
+      - name: Fetch GITHUB_RUN_ID and COMMIT_SHA for the last merged release PR
+        id: fetch-last-release-pr-info
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          branch_name_and_pr_number=$(gh pr list \
+            --repo "${GITHUB_REPOSITORY}" \
+            --base release \
+            --state merged \
+            --limit 10 \
+            --json mergeCommit,headRefName,number \
+            --jq ".[] | select(.mergeCommit.oid==\"${GITHUB_SHA}\") | { branch_name: .headRefName, pr_number: .number }")
+          branch_name=$(echo "${branch_name_and_pr_number}" | jq -r '.branch_name')
+          pr_number=$(echo "${branch_name_and_pr_number}" | jq -r '.pr_number')
+
+          run_id=$(gh run list \
+            --repo "${GITHUB_REPOSITORY}" \
+            --workflow build_and_test.yml \
+            --branch "${branch_name}" \
+            --json databaseId \
+            --limit 1 \
+            --jq '.[].databaseId')
+
+          last_commit_sha=$(gh pr view "${pr_number}" \
+            --repo "${GITHUB_REPOSITORY}" \
+            --json commits \
+            --jq '.commits[-1].oid')
+
+          echo "run-id=${run_id}" | tee -a ${GITHUB_OUTPUT}
+          echo "commit-sha=${last_commit_sha}" | tee -a ${GITHUB_OUTPUT}
+
+      - name: Promote compatibility snapshot and Neon artifact
         env:
           BUCKET: neon-github-public-dev
-          PREFIX: artifacts/latest
+          AWS_REGION: eu-central-1
-          COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+          COMMIT_SHA: ${{ steps.fetch-last-release-pr-info.outputs.commit-sha }}
+          RUN_ID: ${{ steps.fetch-last-release-pr-info.outputs.run-id }}
         run: |
-          # Update compatibility snapshot for the release
+          old_prefix="artifacts/${COMMIT_SHA}/${RUN_ID}"
-          for pg_version in v14 v15 v16; do
+          new_prefix="artifacts/latest"
-            for build_type in debug release; do
-              OLD_FILENAME=compatibility-snapshot-${build_type}-pg${pg_version}-${GITHUB_RUN_ID}.tar.zst
-              NEW_FILENAME=compatibility-snapshot-${build_type}-pg${pg_version}.tar.zst
 
-              time aws s3 mv --only-show-errors s3://${BUCKET}/${PREFIX}/${OLD_FILENAME} s3://${BUCKET}/${PREFIX}/${NEW_FILENAME}
+          files_to_promote=()
+          files_on_s3=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${old_prefix} | jq -r '.Contents[]?.Key' || true)
+
+          for arch in X64 ARM64; do
+            for build_type in debug release; do
+              neon_artifact_filename="neon-Linux-${arch}-${build_type}-artifact.tar.zst"
+              s3_key=$(echo "${files_on_s3}" | grep ${neon_artifact_filename} | sort --version-sort | tail -1 || true)
+              if [ -z "${s3_key}" ]; then
+                echo >&2 "Neither s3://${BUCKET}/${old_prefix}/${neon_artifact_filename} nor its version from previous attempts exist"
+                exit 1
+              fi
+
+              files_to_promote+=("s3://${BUCKET}/${s3_key}")
+
+              for pg_version in v14 v15 v16; do
+                # We run less tests for debug builds, so we don't need to promote them
+                if [ "${build_type}" == "debug" ] && { [ "${arch}" == "ARM64" ] || [ "${pg_version}" != "v16" ] ; }; then
+                  continue
+                fi
+
+                compatibility_data_filename="compatibility-snapshot-${arch}-${build_type}-pg${pg_version}.tar.zst"
+                s3_key=$(echo "${files_on_s3}" | grep ${compatibility_data_filename} | sort --version-sort | tail -1 || true)
+                if [ -z "${s3_key}" ]; then
+                  echo >&2 "Neither s3://${BUCKET}/${old_prefix}/${compatibility_data_filename} nor its version from previous attempts exist"
+                  exit 1
+                fi
+
+                files_to_promote+=("s3://${BUCKET}/${s3_key}")
+              done
             done
           done
 
-          # Update Neon artifact for the release (reuse already uploaded artifact)
+          for f in "${files_to_promote[@]}"; do
-          for build_type in debug release; do
+            time aws s3 cp --only-show-errors ${f} s3://${BUCKET}/${new_prefix}/
-            OLD_PREFIX=artifacts/${COMMIT_SHA}/${GITHUB_RUN_ID}
-            FILENAME=neon-${{ runner.os }}-${{ runner.arch }}-${build_type}-artifact.tar.zst
-
-            S3_KEY=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${OLD_PREFIX} | jq -r '.Contents[]?.Key' | grep ${FILENAME} | sort --version-sort | tail -1 || true)
-            if [ -z "${S3_KEY}" ]; then
-              echo >&2 "Neither s3://${BUCKET}/${OLD_PREFIX}/${FILENAME} nor its version from previous attempts exist"
-              exit 1
-            fi
-
-            time aws s3 cp --only-show-errors s3://${BUCKET}/${S3_KEY} s3://${BUCKET}/${PREFIX}/${FILENAME}
           done
 
   pin-build-tools-image:

.github/workflows/label-for-external-users.yml

@@ -7,6 +7,11 @@ on:
   pull_request_target:
     types:
       - opened
+  workflow_dispatch:
+    inputs:
+      github-actor:
+        description: 'GitHub username. If empty, the username of the current user will be used'
+        required: false
 
 # No permission for GITHUB_TOKEN by default; the **minimal required** set of permissions should be granted in each job.
 permissions: {}
@@ -26,12 +31,31 @@ jobs:
       id: check-user
       env:
         GH_TOKEN: ${{ secrets.CI_ACCESS_TOKEN }}
+        ACTOR: ${{ inputs.github-actor || github.actor }}
       run: |
-        if gh api -H "Accept: application/vnd.github+json" -H "X-GitHub-Api-Version: 2022-11-28" "/orgs/${GITHUB_REPOSITORY_OWNER}/members/${GITHUB_ACTOR}"; then
+        expected_error="User does not exist or is not a member of the organization"
-          is_member=true
+        output_file=output.txt
-        else
+
-          is_member=false
+        for i in $(seq 1 10); do
-        fi
+          if gh api "/orgs/${GITHUB_REPOSITORY_OWNER}/members/${ACTOR}" \
+              -H "Accept: application/vnd.github+json" \
+              -H "X-GitHub-Api-Version: 2022-11-28" > ${output_file}; then
+
+            is_member=true
+            break
+          elif grep -q "${expected_error}" ${output_file}; then
+            is_member=false
+            break
+          elif [ $i -eq 10 ]; then
+            title="Failed to get memmbership status for ${ACTOR}"
+            message="The latest GitHub API error message: '$(cat ${output_file})'"
+            echo "::error file=.github/workflows/label-for-external-users.yml,title=${title}::${message}"
+
+            exit 1
+          fi
+
+          sleep 1
+        done
 
         echo "is-member=${is_member}" | tee -a ${GITHUB_OUTPUT}
 

Cargo.lock

@@ -915,27 +915,30 @@ dependencies = [
 
 [[package]]
 name = "bindgen"
-version = "0.65.1"
+version = "0.70.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cfdf7b466f9a4903edc73f95d6d2bcd5baf8ae620638762244d3f60143643cc5"
+checksum = "f49d8fed880d473ea71efb9bf597651e77201bdd4893efe54c9e5d65ae04ce6f"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.4.1",
  "cexpr",
  "clang-sys",
- "lazy_static",
+ "itertools 0.12.1",
- "lazycell",
  "log",
- "peeking_take_while",
+ "prettyplease 0.2.17",
- "prettyplease 0.2.6",
  "proc-macro2",
  "quote",
  "regex",
  "rustc-hash",
  "shlex",
  "syn 2.0.52",
- "which",
 ]
 
+[[package]]
+name = "bit_field"
+version = "0.10.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dc827186963e592360843fb5ba4b973e145841266c1357f7180c43526f2e5b61"
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -1186,9 +1189,9 @@ dependencies = [
 
 [[package]]
 name = "comfy-table"
-version = "6.1.4"
+version = "7.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6e7b787b0dc42e8111badfdbe4c3059158ccb2db8780352fa1b01e8ccf45cc4d"
+checksum = "b34115915337defe99b2aff5c2ce6771e5fbc4079f4b506301f5cf394c8452f7"
 dependencies = [
  "crossterm",
  "strum",
@@ -1243,7 +1246,7 @@ dependencies = [
  "tokio-postgres",
  "tokio-stream",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "tracing-opentelemetry",
  "tracing-subscriber",
@@ -1327,7 +1330,6 @@ name = "control_plane"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "async-trait",
  "camino",
  "clap",
  "comfy-table",
@@ -1358,8 +1360,8 @@ dependencies = [
  "tokio",
  "tokio-postgres",
  "tokio-util",
- "toml 0.7.4",
+ "toml",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "url",
  "utils",
@@ -1483,25 +1485,22 @@ checksum = "248e3bacc7dc6baa3b21e405ee045c3047101a49145e7e9eca583ab4c2ca5345"
 
 [[package]]
 name = "crossterm"
-version = "0.25.0"
+version = "0.27.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e64e6c0fbe2c17357405f7c758c1ef960fce08bdfb2c03d88d2a18d7e09c4b67"
+checksum = "f476fe445d41c9e991fd07515a6f463074b782242ccf4a5b7b1d1012e70824df"
 dependencies = [
- "bitflags 1.3.2",
+ "bitflags 2.4.1",
  "crossterm_winapi",
  "libc",
- "mio",
  "parking_lot 0.12.1",
- "signal-hook",
- "signal-hook-mio",
  "winapi",
 ]
 
 [[package]]
 name = "crossterm_winapi"
-version = "0.9.0"
+version = "0.9.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2ae1b35a484aa10e07fe0638d02301c5ad24de82d310ccbd2f3693da5f09bf1c"
+checksum = "acdd7c62a3665c7f6830a51635d9ac9b23ed385797f70a83bb8bafe9c572ab2b"
 dependencies = [
  "winapi",
 ]
@@ -1672,9 +1671,9 @@ dependencies = [
 
 [[package]]
 name = "diesel"
-version = "2.2.1"
+version = "2.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "62d6dcd069e7b5fe49a302411f759d4cf1cf2c27fe798ef46fb8baefc053dd2b"
+checksum = "65e13bab2796f412722112327f3e575601a3e9cdcbe426f0d30dbf43f3f5dc71"
 dependencies = [
  "bitflags 2.4.1",
  "byteorder",
@@ -2722,6 +2721,12 @@ dependencies = [
  "hashbrown 0.14.5",
 ]
 
+[[package]]
+name = "indoc"
+version = "2.0.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b248f5224d1d606005e02c97f5aa4e88eeb230488bcc03bc9ca4d7991399f2b5"
+
 [[package]]
 name = "infer"
 version = "0.2.3"
@@ -2938,23 +2943,6 @@ dependencies = [
  "spin 0.5.2",
 ]
 
-[[package]]
-name = "lazycell"
-version = "1.3.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
-
-[[package]]
-name = "leaky-bucket"
-version = "1.0.1"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8eb491abd89e9794d50f93c8db610a29509123e3fbbc9c8c67a528e9391cd853"
-dependencies = [
- "parking_lot 0.12.1",
- "tokio",
- "tracing",
-]
-
 [[package]]
 name = "libc"
 version = "0.2.150"
@@ -3153,7 +3141,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "fd01039851e82f8799046eabbb354056283fb265c8ec0996af940f4e85a380ff"
 dependencies = [
  "serde",
- "toml 0.8.14",
+ "toml",
 ]
 
 [[package]]
@@ -3669,7 +3657,7 @@ dependencies = [
  "thiserror",
  "tokio",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "utils",
  "workspace_hack",
 ]
@@ -3683,6 +3671,7 @@ dependencies = [
  "async-compression",
  "async-stream",
  "async-trait",
+ "bit_field",
  "byteorder",
  "bytes",
  "camino",
@@ -3706,8 +3695,8 @@ dependencies = [
  "humantime",
  "humantime-serde",
  "hyper 0.14.26",
+ "indoc",
  "itertools 0.10.5",
- "leaky-bucket",
  "md5",
  "metrics",
  "nix 0.27.1",
@@ -3732,6 +3721,7 @@ dependencies = [
  "reqwest 0.12.4",
  "rpds",
  "scopeguard",
+ "send-future",
  "serde",
  "serde_json",
  "serde_path_to_error",
@@ -3754,7 +3744,7 @@ dependencies = [
  "tokio-stream",
  "tokio-tar",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "twox-hash",
  "url",
@@ -3771,6 +3761,7 @@ dependencies = [
  "bincode",
  "byteorder",
  "bytes",
+ "camino",
  "chrono",
  "const_format",
  "enum-map",
@@ -3778,11 +3769,16 @@ dependencies = [
  "humantime",
  "humantime-serde",
  "itertools 0.10.5",
+ "nix 0.27.1",
+ "postgres_backend",
  "postgres_ffi",
  "rand 0.8.5",
+ "remote_storage",
+ "reqwest 0.12.4",
  "serde",
  "serde_json",
  "serde_with",
+ "storage_broker",
  "strum",
  "strum_macros",
  "thiserror",
@@ -3794,7 +3790,6 @@ name = "pageserver_client"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "async-trait",
  "bytes",
  "futures",
  "pageserver_api",
@@ -3912,8 +3907,9 @@ dependencies = [
 
 [[package]]
 name = "parquet"
-version = "51.0.0"
+version = "53.0.0"
-source = "git+https://github.com/apache/arrow-rs?branch=master#2534976a564be3d2d56312dc88fb1b6ed4cef829"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f0fbf928021131daaa57d334ca8e3904fe9ae22f73c56244fc7db9b04eedc3d8"
 dependencies = [
  "ahash",
  "bytes",
@@ -3932,8 +3928,9 @@ dependencies = [
 
 [[package]]
 name = "parquet_derive"
-version = "51.0.0"
+version = "53.0.0"
-source = "git+https://github.com/apache/arrow-rs?branch=master#2534976a564be3d2d56312dc88fb1b6ed4cef829"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "86e9fcfae007533a06b580429a3f7e07cb833ec8aa37c041c16563e7918f057e"
 dependencies = [
  "parquet",
  "proc-macro2",
@@ -3970,12 +3967,6 @@ dependencies = [
  "sha2",
 ]
 
-[[package]]
-name = "peeking_take_while"
-version = "0.1.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "19b17cddbe7ec3f8bc800887bab5e717348c95ea2ca0b1bf0837fb964dc67099"
-
 [[package]]
 name = "pem"
 version = "3.0.3"
@@ -4129,7 +4120,7 @@ dependencies = [
 [[package]]
 name = "postgres"
 version = "0.19.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -4142,7 +4133,7 @@ dependencies = [
 [[package]]
 name = "postgres-protocol"
 version = "0.6.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
 dependencies = [
  "base64 0.20.0",
  "byteorder",
@@ -4161,7 +4152,7 @@ dependencies = [
 [[package]]
 name = "postgres-types"
 version = "0.2.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -4273,9 +4264,9 @@ dependencies = [
 
 [[package]]
 name = "prettyplease"
-version = "0.2.6"
+version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3b69d39aab54d069e7f2fe8cb970493e7834601ca2d8c65fd7bbd183578080d1"
+checksum = "8d3928fb5db768cb86f891ff014f0144589297e3c6a1aba6ed7cecfdace270c7"
 dependencies = [
  "proc-macro2",
  "syn 2.0.52",
@@ -4820,7 +4811,7 @@ dependencies = [
  "tokio",
  "tokio-stream",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "utils",
 ]
@@ -5330,7 +5321,7 @@ dependencies = [
  "tokio-stream",
  "tokio-tar",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "tracing-subscriber",
  "url",
@@ -5455,6 +5446,12 @@ version = "1.0.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bebd363326d05ec3e2f532ab7660680f3b02130d780c299bca73469d521bc0ed"
 
+[[package]]
+name = "send-future"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "224e328af6e080cddbab3c770b1cf50f0351ba0577091ef2410c3951d835ff87"
+
 [[package]]
 name = "sentry"
 version = "0.32.3"
@@ -5590,11 +5587,12 @@ dependencies = [
 
 [[package]]
 name = "serde_json"
-version = "1.0.96"
+version = "1.0.125"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "057d394a50403bcac12672b2b18fb387ab6d289d957dab67dd201875391e52f1"
+checksum = "83c8e735a073ccf5be70aa8066aa984eaf2fa000db6c8d0100ae605b366d31ed"
 dependencies = [
  "itoa",
+ "memchr",
  "ryu",
  "serde",
 ]
@@ -5732,17 +5730,6 @@ dependencies = [
  "signal-hook-registry",
 ]
 
-[[package]]
-name = "signal-hook-mio"
-version = "0.2.3"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "29ad2e15f37ec9a6cc544097b78a1ec90001e9f71b81338ca39f430adaca99af"
-dependencies = [
- "libc",
- "mio",
- "signal-hook",
-]
-
 [[package]]
 name = "signal-hook-registry"
 version = "1.4.1"
@@ -5949,7 +5936,6 @@ name = "storage_controller_client"
 version = "0.1.0"
 dependencies = [
  "anyhow",
- "async-trait",
  "bytes",
  "futures",
  "pageserver_api",
@@ -6056,21 +6042,21 @@ checksum = "73473c0e59e6d5812c5dfe2a064a6444949f089e20eec9a2e5506596494e4623"
 
 [[package]]
 name = "strum"
-version = "0.24.1"
+version = "0.26.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "063e6045c0e62079840579a7e47a355ae92f60eb74daaf156fb1e84ba164e63f"
+checksum = "8fec0f0aef304996cf250b31b5a10dee7980c85da9d759361292b8bca5a18f06"
 
 [[package]]
 name = "strum_macros"
-version = "0.24.3"
+version = "0.26.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1e385be0d24f186b4ce2f9982191e7101bb737312ad61c1f2f984f34bcf85d59"
+checksum = "4c6bee85a5a24955dc440386795aa378cd9cf82acd5f764469152d2270e581be"
 dependencies = [
- "heck 0.4.1",
+ "heck 0.5.0",
  "proc-macro2",
  "quote",
  "rustversion",
- "syn 1.0.109",
+ "syn 2.0.52",
 ]
 
 [[package]]
@@ -6081,8 +6067,9 @@ checksum = "81cdd64d312baedb58e21336b31bc043b77e01cc99033ce76ef539f78e965ebc"
 
 [[package]]
 name = "svg_fmt"
-version = "0.4.2"
+version = "0.4.3"
-source = "git+https://github.com/nical/rust_debug?rev=28a7d96eecff2f28e75b1ea09f2d499a60d0e3b4#28a7d96eecff2f28e75b1ea09f2d499a60d0e3b4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "20e16a0f46cf5fd675563ef54f26e83e20f2366bcf027bcb3cc3ed2b98aaf2ca"
 
 [[package]]
 name = "syn"
@@ -6410,7 +6397,7 @@ dependencies = [
 [[package]]
 name = "tokio-postgres"
 version = "0.7.7"
-source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
 dependencies = [
  "async-trait",
  "byteorder",
@@ -6521,18 +6508,6 @@ dependencies = [
  "tracing",
 ]
 
-[[package]]
-name = "toml"
-version = "0.7.4"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d6135d499e69981f9ff0ef2167955a5333c35e36f6937d382974566b3d5b94ec"
-dependencies = [
- "serde",
- "serde_spanned",
- "toml_datetime",
- "toml_edit 0.19.10",
-]
-
 [[package]]
 name = "toml"
 version = "0.8.14"
@@ -6542,7 +6517,7 @@ dependencies = [
  "serde",
  "serde_spanned",
  "toml_datetime",
- "toml_edit 0.22.14",
+ "toml_edit",
 ]
 
 [[package]]
@@ -6554,19 +6529,6 @@ dependencies = [
  "serde",
 ]
 
-[[package]]
-name = "toml_edit"
-version = "0.19.10"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2380d56e8670370eee6566b0bfd4265f65b3f432e8c6d85623f728d4fa31f739"
-dependencies = [
- "indexmap 1.9.3",
- "serde",
- "serde_spanned",
- "toml_datetime",
- "winnow 0.4.6",
-]
-
 [[package]]
 name = "toml_edit"
 version = "0.22.14"
@@ -6577,7 +6539,7 @@ dependencies = [
  "serde",
  "serde_spanned",
  "toml_datetime",
- "winnow 0.6.13",
+ "winnow",
 ]
 
 [[package]]
@@ -6952,7 +6914,6 @@ dependencies = [
  "anyhow",
  "arc-swap",
  "async-compression",
- "async-trait",
  "bincode",
  "byteorder",
  "bytes",
@@ -6968,7 +6929,6 @@ dependencies = [
  "humantime",
  "hyper 0.14.26",
  "jsonwebtoken",
- "leaky-bucket",
  "metrics",
  "nix 0.27.1",
  "once_cell",
@@ -6992,7 +6952,7 @@ dependencies = [
  "tokio-stream",
  "tokio-tar",
  "tokio-util",
- "toml_edit 0.19.10",
+ "toml_edit",
  "tracing",
  "tracing-error",
  "tracing-subscriber",
@@ -7538,15 +7498,6 @@ version = "0.52.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "32b752e52a2da0ddfbdbcc6fceadfeede4c939ed16d13e648833a61dfb611ed8"
 
-[[package]]
-name = "winnow"
-version = "0.4.6"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "61de7bac303dc551fe038e2b3cef0f571087a47571ea6e79a87692ac99b99699"
-dependencies = [
- "memchr",
-]
-
 [[package]]
 name = "winnow"
 version = "0.6.13"
@@ -7616,6 +7567,7 @@ dependencies = [
  "hyper 0.14.26",
  "indexmap 1.9.3",
  "itertools 0.10.5",
+ "itertools 0.12.1",
  "lazy_static",
  "libc",
  "log",
@@ -7653,6 +7605,7 @@ dependencies = [
  "tokio",
  "tokio-rustls 0.24.0",
  "tokio-util",
+ "toml_edit",
  "tonic",
  "tower",
  "tracing",

Cargo.toml

@@ -64,7 +64,8 @@ aws-types = "1.2.0"
 axum = { version = "0.6.20", features = ["ws"] }
 base64 = "0.13.0"
 bincode = "1.3"
-bindgen = "0.65"
+bindgen = "0.70"
+bit_field = "0.10.2"
 bstr = "1.0"
 byteorder = "1.4"
 bytes = "1.0"
@@ -72,7 +73,7 @@ camino = "1.1.6"
 cfg-if = "1.0.0"
 chrono = { version = "0.4", default-features = false, features = ["clock"] }
 clap = { version = "4.0", features = ["derive"] }
-comfy-table = "6.1"
+comfy-table = "7.1"
 const_format = "0.2"
 crc32c = "0.6"
 crossbeam-deque = "0.8.5"
@@ -102,18 +103,18 @@ humantime-serde = "1.1.1"
 hyper = "0.14"
 tokio-tungstenite = "0.20.0"
 indexmap = "2"
+indoc = "2"
 inotify = "0.10.2"
 ipnet = "2.9.0"
 itertools = "0.10"
 jsonwebtoken = "9"
 lasso = "0.7"
-leaky-bucket = "1.0.1"
 libc = "0.2"
 md5 = "0.7.0"
 measured = { version = "0.0.22", features=["lasso"] }
 measured-process = { version = "0.0.22" }
 memoffset = "0.8"
-nix = { version = "0.27", features = ["fs", "process", "socket", "signal", "poll"] }
+nix = { version = "0.27", features = ["dir", "fs", "process", "socket", "signal", "poll"] }
 notify = "6.0.0"
 num_cpus = "1.15"
 num-traits = "0.2.15"
@@ -122,8 +123,8 @@ opentelemetry = "0.20.0"
 opentelemetry-otlp = { version = "0.13.0", default-features=false, features = ["http-proto", "trace", "http", "reqwest-client"] }
 opentelemetry-semantic-conventions = "0.12.0"
 parking_lot = "0.12"
-parquet = { version = "51.0.0", default-features = false, features = ["zstd"] }
+parquet = { version = "53", default-features = false, features = ["zstd"] }
-parquet_derive = "51.0.0"
+parquet_derive = "53"
 pbkdf2 = { version = "0.12.1", features = ["simple", "std"] }
 pin-project-lite = "0.2"
 procfs = "0.16"
@@ -145,6 +146,7 @@ rustls-split = "0.3"
 scopeguard = "1.1"
 sysinfo = "0.29.2"
 sd-notify = "0.4.1"
+send-future = "0.1.0"
 sentry = { version = "0.32", default-features = false, features = ["backtrace", "contexts", "panic", "rustls", "reqwest" ] }
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1"
@@ -156,11 +158,10 @@ signal-hook = "0.3"
 smallvec = "1.11"
 smol_str = { version = "0.2.0", features = ["serde"] }
 socket2 = "0.5"
-strum = "0.24"
+strum = "0.26"
-strum_macros = "0.24"
+strum_macros = "0.26"
 "subtle"  = "2.5.0"
-# Our PR https://github.com/nical/rust_debug/pull/4 has been merged but no new version released yet
+svg_fmt = "0.4.3"
-svg_fmt = { git = "https://github.com/nical/rust_debug", rev = "28a7d96eecff2f28e75b1ea09f2d499a60d0e3b4" }
 sync_wrapper = "0.1.2"
 tar = "0.4"
 task-local-extensions = "0.1.4"
@@ -176,8 +177,8 @@ tokio-rustls = "0.25"
 tokio-stream = "0.1"
 tokio-tar = "0.3"
 tokio-util = { version = "0.7.10", features = ["io", "rt"] }
-toml = "0.7"
+toml = "0.8"
-toml_edit = "0.19"
+toml_edit = "0.22"
 tonic = {version = "0.9", features = ["tls", "tls-roots"]}
 tower-service = "0.3.2"
 tracing = "0.1"
@@ -200,10 +201,21 @@ env_logger = "0.10"
 log = "0.4"
 
 ## Libraries from neondatabase/ git forks, ideally with changes to be upstreamed
-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
+
-postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
+# We want to use the 'neon' branch for these, but there's currently one
-postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
+# incompatible change on the branch. See:
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
+#
+# - PR #8076 which contained changes that depended on the new changes in
+#   the rust-postgres crate, and
+# - PR #8654 which reverted those changes and made the code in proxy incompatible
+#   with the tip of the 'neon' branch again.
+#
+# When those proxy changes are re-applied (see PR #8747), we can switch using
+# the tip of the 'neon' branch again.
+postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
+postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
+postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
 
 ## Local libraries
 compute_api = { version = "0.1", path = "./libs/compute_api/" }
@@ -240,11 +252,7 @@ tonic-build = "0.9"
 [patch.crates-io]
 
 # Needed to get `tokio-postgres-rustls` to depend on our fork.
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch="neon" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
-
-# bug fixes for UUID
-parquet = { git = "https://github.com/apache/arrow-rs", branch = "master" }
-parquet_derive = { git = "https://github.com/apache/arrow-rs", branch = "master" }
 
 ################# Binary contents sections
 

Dockerfile

@@ -87,6 +87,7 @@ RUN mkdir -p /data/.neon/ && \
        "pg_distrib_dir='/usr/local/'\n" \
        "listen_pg_addr='0.0.0.0:6400'\n" \
        "listen_http_addr='0.0.0.0:9898'\n" \
+       "availability_zone='local'\n" \
   > /data/.neon/pageserver.toml && \
   chown -R neon:neon /data/.neon
 

Dockerfile.build-tools

@@ -192,7 +192,7 @@ WORKDIR /home/nonroot
 
 # Rust
 # Please keep the version of llvm (installed above) in sync with rust llvm (`rustc --version --verbose | grep LLVM`)
-ENV RUSTC_VERSION=1.80.1
+ENV RUSTC_VERSION=1.81.0
 ENV RUSTUP_HOME="/home/nonroot/.rustup"
 ENV PATH="/home/nonroot/.cargo/bin:${PATH}"
 ARG RUSTFILT_VERSION=0.2.1
@@ -207,7 +207,7 @@ RUN curl -sSO https://static.rust-lang.org/rustup/dist/$(uname -m)-unknown-linux
     export PATH="$HOME/.cargo/bin:$PATH" && \
     . "$HOME/.cargo/env" && \
     cargo --version && rustup --version && \
-    rustup component add llvm-tools-preview rustfmt clippy && \
+    rustup component add llvm-tools rustfmt clippy && \
     cargo install rustfilt            --version ${RUSTFILT_VERSION} && \
     cargo install cargo-hakari        --version ${CARGO_HAKARI_VERSION} && \
     cargo install cargo-deny --locked --version ${CARGO_DENY_VERSION} && \

Dockerfile.compute-node

@@ -942,7 +942,7 @@ COPY --from=hll-pg-build /hll.tar.gz /ext-src
 COPY --from=plpgsql-check-pg-build /plpgsql_check.tar.gz /ext-src
 #COPY --from=timescaledb-pg-build /timescaledb.tar.gz /ext-src
 COPY --from=pg-hint-plan-pg-build /pg_hint_plan.tar.gz /ext-src
-COPY patches/pg_hintplan.patch /ext-src
+COPY patches/pg_hint_plan.patch /ext-src
 COPY --from=pg-cron-pg-build /pg_cron.tar.gz /ext-src
 COPY patches/pg_cron.patch /ext-src
 #COPY --from=pg-pgx-ulid-build /home/nonroot/pgx_ulid.tar.gz /ext-src
@@ -964,7 +964,7 @@ RUN cd /ext-src/pgvector-src && patch -p1 <../pgvector.patch
 RUN cd /ext-src/rum-src && patch -p1 <../rum.patch
 # cmake is required for the h3 test
 RUN apt-get update && apt-get install -y cmake
-RUN patch -p1 < /ext-src/pg_hintplan.patch
+RUN cd /ext-src/pg_hint_plan-src && patch -p1 < /ext-src/pg_hint_plan.patch
 COPY --chmod=755 docker-compose/run-tests.sh /run-tests.sh
 RUN patch -p1 </ext-src/pg_anon.patch
 RUN patch -p1 </ext-src/pg_cron.patch

README.md

@@ -64,6 +64,12 @@ brew install protobuf openssl flex bison icu4c pkg-config
 echo 'export PATH="$(brew --prefix openssl)/bin:$PATH"' >> ~/.zshrc
 ```
 
+If you get errors about missing `m4` you may have to install it manually:
+```
+brew install m4
+brew link --force m4
+```
+
 2. [Install Rust](https://www.rust-lang.org/tools/install)
 ```
 # recommended approach from https://www.rust-lang.org/tools/install
@@ -126,7 +132,7 @@ make -j`sysctl -n hw.logicalcpu` -s
 To run the `psql` client, install the `postgresql-client` package or modify `PATH` and `LD_LIBRARY_PATH` to include `pg_install/bin` and `pg_install/lib`, respectively.
 
 To run the integration tests or Python scripts (not required to use the code), install
-Python (3.9 or higher), and install the python3 packages using `./scripts/pysync` (requires [poetry>=1.3](https://python-poetry.org/)) in the project directory.
+Python (3.9 or higher), and install the python3 packages using `./scripts/pysync` (requires [poetry>=1.8](https://python-poetry.org/)) in the project directory.
 
 
 #### Running neon database

compute_tools/src/bin/compute_ctl.rs

@@ -44,6 +44,7 @@ use std::{thread, time::Duration};
 use anyhow::{Context, Result};
 use chrono::Utc;
 use clap::Arg;
+use compute_tools::lsn_lease::launch_lsn_lease_bg_task_for_static;
 use signal_hook::consts::{SIGQUIT, SIGTERM};
 use signal_hook::{consts::SIGINT, iterator::Signals};
 use tracing::{error, info, warn};
@@ -366,6 +367,8 @@ fn wait_spec(
         state.start_time = now;
     }
 
+    launch_lsn_lease_bg_task_for_static(&compute);
+
     Ok(WaitSpecResult {
         compute,
         http_port,

compute_tools/src/lib.rs

@@ -11,6 +11,7 @@ pub mod logger;
 pub mod catalog;
 pub mod compute;
 pub mod extension_server;
+pub mod lsn_lease;
 mod migration;
 pub mod monitor;
 pub mod params;

compute_tools/src/lsn_lease.rs

@@ -0,0 +1,186 @@
+use anyhow::bail;
+use anyhow::Result;
+use postgres::{NoTls, SimpleQueryMessage};
+use std::time::SystemTime;
+use std::{str::FromStr, sync::Arc, thread, time::Duration};
+use utils::id::TenantId;
+use utils::id::TimelineId;
+
+use compute_api::spec::ComputeMode;
+use tracing::{info, warn};
+use utils::{
+    lsn::Lsn,
+    shard::{ShardCount, ShardNumber, TenantShardId},
+};
+
+use crate::compute::ComputeNode;
+
+/// Spawns a background thread to periodically renew LSN leases for static compute.
+/// Do nothing if the compute is not in static mode.
+pub fn launch_lsn_lease_bg_task_for_static(compute: &Arc<ComputeNode>) {
+    let (tenant_id, timeline_id, lsn) = {
+        let state = compute.state.lock().unwrap();
+        let spec = state.pspec.as_ref().expect("Spec must be set");
+        match spec.spec.mode {
+            ComputeMode::Static(lsn) => (spec.tenant_id, spec.timeline_id, lsn),
+            _ => return,
+        }
+    };
+    let compute = compute.clone();
+
+    let span = tracing::info_span!("lsn_lease_bg_task", %tenant_id, %timeline_id, %lsn);
+    thread::spawn(move || {
+        let _entered = span.entered();
+        if let Err(e) = lsn_lease_bg_task(compute, tenant_id, timeline_id, lsn) {
+            // TODO: might need stronger error feedback than logging an warning.
+            warn!("Exited with error: {e}");
+        }
+    });
+}
+
+/// Renews lsn lease periodically so static compute are not affected by GC.
+fn lsn_lease_bg_task(
+    compute: Arc<ComputeNode>,
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+    lsn: Lsn,
+) -> Result<()> {
+    loop {
+        let valid_until = acquire_lsn_lease_with_retry(&compute, tenant_id, timeline_id, lsn)?;
+        let valid_duration = valid_until
+            .duration_since(SystemTime::now())
+            .unwrap_or(Duration::ZERO);
+
+        // Sleep for 60 seconds less than the valid duration but no more than half of the valid duration.
+        let sleep_duration = valid_duration
+            .saturating_sub(Duration::from_secs(60))
+            .max(valid_duration / 2);
+
+        info!(
+            "Succeeded, sleeping for {} seconds",
+            sleep_duration.as_secs()
+        );
+        thread::sleep(sleep_duration);
+    }
+}
+
+/// Acquires lsn lease in a retry loop. Returns the expiration time if a lease is granted.
+/// Returns an error if a lease is explicitly not granted. Otherwise, we keep sending requests.
+fn acquire_lsn_lease_with_retry(
+    compute: &Arc<ComputeNode>,
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+    lsn: Lsn,
+) -> Result<SystemTime> {
+    let mut attempts = 0usize;
+    let mut retry_period_ms: f64 = 500.0;
+    const MAX_RETRY_PERIOD_MS: f64 = 60.0 * 1000.0;
+
+    loop {
+        // Note: List of pageservers is dynamic, need to re-read configs before each attempt.
+        let configs = {
+            let state = compute.state.lock().unwrap();
+
+            let spec = state.pspec.as_ref().expect("spec must be set");
+
+            let conn_strings = spec.pageserver_connstr.split(',');
+
+            conn_strings
+                .map(|connstr| {
+                    let mut config = postgres::Config::from_str(connstr).expect("Invalid connstr");
+                    if let Some(storage_auth_token) = &spec.storage_auth_token {
+                        info!("Got storage auth token from spec file");
+                        config.password(storage_auth_token.clone());
+                    } else {
+                        info!("Storage auth token not set");
+                    }
+                    config
+                })
+                .collect::<Vec<_>>()
+        };
+
+        let result = try_acquire_lsn_lease(tenant_id, timeline_id, lsn, &configs);
+        match result {
+            Ok(Some(res)) => {
+                return Ok(res);
+            }
+            Ok(None) => {
+                bail!("Permanent error: lease could not be obtained, LSN is behind the GC cutoff");
+            }
+            Err(e) => {
+                warn!("Failed to acquire lsn lease: {e} (attempt {attempts}");
+
+                thread::sleep(Duration::from_millis(retry_period_ms as u64));
+                retry_period_ms *= 1.5;
+                retry_period_ms = retry_period_ms.min(MAX_RETRY_PERIOD_MS);
+            }
+        }
+        attempts += 1;
+    }
+}
+
+/// Tries to acquire an LSN lease through PS page_service API.
+fn try_acquire_lsn_lease(
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+    lsn: Lsn,
+    configs: &[postgres::Config],
+) -> Result<Option<SystemTime>> {
+    fn get_valid_until(
+        config: &postgres::Config,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        lsn: Lsn,
+    ) -> Result<Option<SystemTime>> {
+        let mut client = config.connect(NoTls)?;
+        let cmd = format!("lease lsn {} {} {} ", tenant_shard_id, timeline_id, lsn);
+        let res = client.simple_query(&cmd)?;
+        let msg = match res.first() {
+            Some(msg) => msg,
+            None => bail!("empty response"),
+        };
+        let row = match msg {
+            SimpleQueryMessage::Row(row) => row,
+            _ => bail!("error parsing lsn lease response"),
+        };
+
+        // Note: this will be None if a lease is explicitly not granted.
+        let valid_until_str = row.get("valid_until");
+
+        let valid_until = valid_until_str.map(|s| {
+            SystemTime::UNIX_EPOCH
+                .checked_add(Duration::from_millis(u128::from_str(s).unwrap() as u64))
+                .expect("Time larger than max SystemTime could handle")
+        });
+        Ok(valid_until)
+    }
+
+    let shard_count = configs.len();
+
+    let valid_until = if shard_count > 1 {
+        configs
+            .iter()
+            .enumerate()
+            .map(|(shard_number, config)| {
+                let tenant_shard_id = TenantShardId {
+                    tenant_id,
+                    shard_count: ShardCount::new(shard_count as u8),
+                    shard_number: ShardNumber(shard_number as u8),
+                };
+                get_valid_until(config, tenant_shard_id, timeline_id, lsn)
+            })
+            .collect::<Result<Vec<Option<SystemTime>>>>()?
+            .into_iter()
+            .min()
+            .unwrap()
+    } else {
+        get_valid_until(
+            &configs[0],
+            TenantShardId::unsharded(tenant_id),
+            timeline_id,
+            lsn,
+        )?
+    };
+
+    Ok(valid_until)
+}

compute_tools/src/pg_helpers.rs

@@ -22,9 +22,10 @@ use compute_api::spec::{Database, GenericOption, GenericOptions, PgIdent, Role};
 
 const POSTGRES_WAIT_TIMEOUT: Duration = Duration::from_millis(60 * 1000); // milliseconds
 
-/// Escape a string for including it in a SQL literal. Wrapping the result
+/// Escape a string for including it in a SQL literal.
-/// with `E'{}'` or `'{}'` is not required, as it returns a ready-to-use
+///
-/// SQL string literal, e.g. `'db'''` or `E'db\\'`.
+/// Wrapping the result with `E'{}'` or `'{}'` is not required,
+/// as it returns a ready-to-use SQL string literal, e.g. `'db'''` or `E'db\\'`.
 /// See <https://github.com/postgres/postgres/blob/da98d005cdbcd45af563d0c4ac86d0e9772cd15f/src/backend/utils/adt/quote.c#L47>
 /// for the original implementation.
 pub fn escape_literal(s: &str) -> String {

control_plane/Cargo.toml

@@ -6,7 +6,6 @@ license.workspace = true
 
 [dependencies]
 anyhow.workspace = true
-async-trait.workspace = true
 camino.workspace = true
 clap.workspace = true
 comfy-table.workspace = true

control_plane/src/bin/neon_local.rs

@@ -640,6 +640,8 @@ async fn handle_timeline(timeline_match: &ArgMatches, env: &mut local_env::Local
         }
         Some(("branch", branch_match)) => {
             let tenant_id = get_tenant_id(branch_match, env)?;
+            let new_timeline_id =
+                parse_timeline_id(branch_match)?.unwrap_or(TimelineId::generate());
             let new_branch_name = branch_match
                 .get_one::<String>("branch-name")
                 .ok_or_else(|| anyhow!("No branch name provided"))?;
@@ -658,7 +660,6 @@ async fn handle_timeline(timeline_match: &ArgMatches, env: &mut local_env::Local
                 .map(|lsn_str| Lsn::from_str(lsn_str))
                 .transpose()
                 .context("Failed to parse ancestor start Lsn from the request")?;
-            let new_timeline_id = TimelineId::generate();
             let storage_controller = StorageController::from_env(env);
             let create_req = TimelineCreateRequest {
                 new_timeline_id,
@@ -1570,7 +1571,6 @@ fn cli() -> Command {
                         .value_parser(value_parser!(PathBuf))
                         .value_name("config")
                 )
-                .arg(pg_version_arg.clone())
                 .arg(force_arg)
         )
         .subcommand(
@@ -1583,6 +1583,7 @@ fn cli() -> Command {
             .subcommand(Command::new("branch")
                 .about("Create a new timeline, using another timeline as a base, copying its data")
                 .arg(tenant_id_arg.clone())
+                .arg(timeline_id_arg.clone())
                 .arg(branch_name_arg.clone())
                 .arg(Arg::new("ancestor-branch-name").long("ancestor-branch-name")
                     .help("Use last Lsn of another timeline (and its data) as base when creating the new timeline. The timeline gets resolved by its branch name.").required(false))

control_plane/src/local_env.rs

@@ -165,6 +165,9 @@ pub struct NeonStorageControllerConf {
     pub split_threshold: Option<u64>,
 
     pub max_secondary_lag_bytes: Option<u64>,
+
+    #[serde(with = "humantime_serde")]
+    pub heartbeat_interval: Duration,
 }
 
 impl NeonStorageControllerConf {
@@ -172,6 +175,9 @@ impl NeonStorageControllerConf {
     const DEFAULT_MAX_OFFLINE_INTERVAL: std::time::Duration = std::time::Duration::from_secs(10);
 
     const DEFAULT_MAX_WARMING_UP_INTERVAL: std::time::Duration = std::time::Duration::from_secs(30);
+
+    // Very tight heartbeat interval to speed up tests
+    const DEFAULT_HEARTBEAT_INTERVAL: std::time::Duration = std::time::Duration::from_millis(100);
 }
 
 impl Default for NeonStorageControllerConf {
@@ -183,6 +189,7 @@ impl Default for NeonStorageControllerConf {
             database_url: None,
             split_threshold: None,
             max_secondary_lag_bytes: None,
+            heartbeat_interval: Self::DEFAULT_HEARTBEAT_INTERVAL,
         }
     }
 }

control_plane/src/pageserver.rs

@@ -75,14 +75,14 @@ impl PageServerNode {
         }
     }
 
-    fn pageserver_make_identity_toml(&self, node_id: NodeId) -> toml_edit::Document {
+    fn pageserver_make_identity_toml(&self, node_id: NodeId) -> toml_edit::DocumentMut {
-        toml_edit::Document::from_str(&format!("id={node_id}")).unwrap()
+        toml_edit::DocumentMut::from_str(&format!("id={node_id}")).unwrap()
     }
 
     fn pageserver_init_make_toml(
         &self,
         conf: NeonLocalInitPageserverConf,
-    ) -> anyhow::Result<toml_edit::Document> {
+    ) -> anyhow::Result<toml_edit::DocumentMut> {
         assert_eq!(&PageServerConf::from(&conf), &self.conf, "during neon_local init, we derive the runtime state of ps conf (self.conf) from the --config flag fully");
 
         // TODO(christian): instead of what we do here, create a pageserver_api::config::ConfigToml (PR #7656)
@@ -137,9 +137,9 @@ impl PageServerNode {
 
         // Turn `overrides` into a toml document.
         // TODO: above code is legacy code, it should be refactored to use toml_edit directly.
-        let mut config_toml = toml_edit::Document::new();
+        let mut config_toml = toml_edit::DocumentMut::new();
         for fragment_str in overrides {
-            let fragment = toml_edit::Document::from_str(&fragment_str)
+            let fragment = toml_edit::DocumentMut::from_str(&fragment_str)
                 .expect("all fragments in `overrides` are valid toml documents, this function controls that");
             for (key, item) in fragment.iter() {
                 config_toml.insert(key, item.clone());
@@ -181,6 +181,23 @@ impl PageServerNode {
         );
         io::stdout().flush()?;
 
+        // If the config file we got as a CLI argument includes the `availability_zone`
+        // config, then use that to populate the `metadata.json` file for the pageserver.
+        // In production the deployment orchestrator does this for us.
+        let az_id = conf
+            .other
+            .get("availability_zone")
+            .map(|toml| {
+                let az_str = toml.to_string();
+                // Trim the (") chars from the toml representation
+                if az_str.starts_with('"') && az_str.ends_with('"') {
+                    az_str[1..az_str.len() - 1].to_string()
+                } else {
+                    az_str
+                }
+            })
+            .unwrap_or("local".to_string());
+
         let config = self
             .pageserver_init_make_toml(conf)
             .context("make pageserver toml")?;
@@ -216,6 +233,7 @@ impl PageServerNode {
         let (_http_host, http_port) =
             parse_host_port(&self.conf.listen_http_addr).expect("Unable to parse listen_http_addr");
         let http_port = http_port.unwrap_or(9898);
+
         // Intentionally hand-craft JSON: this acts as an implicit format compat test
         // in case the pageserver-side structure is edited, and reflects the real life
         // situation: the metadata is written by some other script.
@@ -226,7 +244,10 @@ impl PageServerNode {
                 postgres_port: self.pg_connection_config.port(),
                 http_host: "localhost".to_string(),
                 http_port,
-                other: HashMap::new(),
+                other: HashMap::from([(
+                    "availability_zone_id".to_string(),
+                    serde_json::json!(az_id),
+                )]),
             })
             .unwrap(),
         )

control_plane/src/safekeeper.rs

@@ -5,6 +5,7 @@
 //! ```text
 //!   .neon/safekeepers/<safekeeper id>
 //! ```
+use std::future::Future;
 use std::io::Write;
 use std::path::PathBuf;
 use std::time::Duration;
@@ -34,12 +35,10 @@ pub enum SafekeeperHttpError {
 
 type Result<T> = result::Result<T, SafekeeperHttpError>;
 
-#[async_trait::async_trait]
+pub(crate) trait ResponseErrorMessageExt: Sized {
-pub trait ResponseErrorMessageExt: Sized {
+    fn error_from_body(self) -> impl Future<Output = Result<Self>> + Send;
-    async fn error_from_body(self) -> Result<Self>;
 }
 
-#[async_trait::async_trait]
 impl ResponseErrorMessageExt for reqwest::Response {
     async fn error_from_body(self) -> Result<Self> {
         let status = self.status();

control_plane/src/storage_controller.rs

@@ -437,6 +437,8 @@ impl StorageController {
             &humantime::Duration::from(self.config.max_offline).to_string(),
             "--max-warming-up-interval",
             &humantime::Duration::from(self.config.max_warming_up).to_string(),
+            "--heartbeat-interval",
+            &humantime::Duration::from(self.config.heartbeat_interval).to_string(),
             "--address-for-peers",
             &address_for_peers.to_string(),
         ]

control_plane/storcon_cli/src/main.rs

@@ -4,8 +4,8 @@ use std::{str::FromStr, time::Duration};
 use clap::{Parser, Subcommand};
 use pageserver_api::{
     controller_api::{
-        NodeAvailabilityWrapper, NodeDescribeResponse, ShardSchedulingPolicy, TenantCreateRequest,
+        NodeAvailabilityWrapper, NodeDescribeResponse, NodeShardResponse, ShardSchedulingPolicy,
-        TenantDescribeResponse, TenantPolicyRequest,
+        TenantCreateRequest, TenantDescribeResponse, TenantPolicyRequest,
     },
     models::{
         EvictionPolicy, EvictionPolicyLayerAccessThreshold, LocationConfigSecondary,
@@ -41,6 +41,8 @@ enum Command {
         listen_http_addr: String,
         #[arg(long)]
         listen_http_port: u16,
+        #[arg(long)]
+        availability_zone_id: String,
     },
 
     /// Modify a node's configuration in the storage controller
@@ -78,7 +80,10 @@ enum Command {
     /// List nodes known to the storage controller
     Nodes {},
     /// List tenants known to the storage controller
-    Tenants {},
+    Tenants {
+        /// If this field is set, it will list the tenants on a specific node
+        node_id: Option<NodeId>,
+    },
     /// Create a new tenant in the storage controller, and by extension on pageservers.
     TenantCreate {
         #[arg(long)]
@@ -147,9 +152,9 @@ enum Command {
         #[arg(long)]
         threshold: humantime::Duration,
     },
-    // Drain a set of specified pageservers by moving the primary attachments to pageservers
+    // Migrate away from a set of specified pageservers by moving the primary attachments to pageservers
     // outside of the specified set.
-    Drain {
+    BulkMigrate {
         // Set of pageserver node ids to drain.
         #[arg(long)]
         nodes: Vec<NodeId>,
@@ -163,6 +168,34 @@ enum Command {
         #[arg(long)]
         dry_run: Option<bool>,
     },
+    /// Start draining the specified pageserver.
+    /// The drain is complete when the schedulling policy returns to active.
+    StartDrain {
+        #[arg(long)]
+        node_id: NodeId,
+    },
+    /// Cancel draining the specified pageserver and wait for `timeout`
+    /// for the operation to be canceled. May be retried.
+    CancelDrain {
+        #[arg(long)]
+        node_id: NodeId,
+        #[arg(long)]
+        timeout: humantime::Duration,
+    },
+    /// Start filling the specified pageserver.
+    /// The drain is complete when the schedulling policy returns to active.
+    StartFill {
+        #[arg(long)]
+        node_id: NodeId,
+    },
+    /// Cancel filling the specified pageserver and wait for `timeout`
+    /// for the operation to be canceled. May be retried.
+    CancelFill {
+        #[arg(long)]
+        node_id: NodeId,
+        #[arg(long)]
+        timeout: humantime::Duration,
+    },
 }
 
 #[derive(Parser)]
@@ -249,6 +282,34 @@ impl FromStr for NodeAvailabilityArg {
     }
 }
 
+async fn wait_for_scheduling_policy<F>(
+    client: Client,
+    node_id: NodeId,
+    timeout: Duration,
+    f: F,
+) -> anyhow::Result<NodeSchedulingPolicy>
+where
+    F: Fn(NodeSchedulingPolicy) -> bool,
+{
+    let waiter = tokio::time::timeout(timeout, async move {
+        loop {
+            let node = client
+                .dispatch::<(), NodeDescribeResponse>(
+                    Method::GET,
+                    format!("control/v1/node/{node_id}"),
+                    None,
+                )
+                .await?;
+
+            if f(node.scheduling) {
+                return Ok::<NodeSchedulingPolicy, mgmt_api::Error>(node.scheduling);
+            }
+        }
+    });
+
+    Ok(waiter.await??)
+}
+
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
     let cli = Cli::parse();
@@ -266,6 +327,7 @@ async fn main() -> anyhow::Result<()> {
             listen_pg_port,
             listen_http_addr,
             listen_http_port,
+            availability_zone_id,
         } => {
             storcon_client
                 .dispatch::<_, ()>(
@@ -277,6 +339,7 @@ async fn main() -> anyhow::Result<()> {
                         listen_pg_port,
                         listen_http_addr,
                         listen_http_port,
+                        availability_zone_id,
                     }),
                 )
                 .await?;
@@ -343,7 +406,41 @@ async fn main() -> anyhow::Result<()> {
                 )
                 .await?;
         }
-        Command::Tenants {} => {
+        Command::Tenants {
+            node_id: Some(node_id),
+        } => {
+            let describe_response = storcon_client
+                .dispatch::<(), NodeShardResponse>(
+                    Method::GET,
+                    format!("control/v1/node/{node_id}/shards"),
+                    None,
+                )
+                .await?;
+            let shards = describe_response.shards;
+            let mut table = comfy_table::Table::new();
+            table.set_header([
+                "Shard",
+                "Intended Primary/Secondary",
+                "Observed Primary/Secondary",
+            ]);
+            for shard in shards {
+                table.add_row([
+                    format!("{}", shard.tenant_shard_id),
+                    match shard.is_intended_secondary {
+                        None => "".to_string(),
+                        Some(true) => "Secondary".to_string(),
+                        Some(false) => "Primary".to_string(),
+                    },
+                    match shard.is_observed_secondary {
+                        None => "".to_string(),
+                        Some(true) => "Secondary".to_string(),
+                        Some(false) => "Primary".to_string(),
+                    },
+                ]);
+            }
+            println!("{table}");
+        }
+        Command::Tenants { node_id: None } => {
             let mut resp = storcon_client
                 .dispatch::<(), Vec<TenantDescribeResponse>>(
                     Method::GET,
@@ -628,7 +725,7 @@ async fn main() -> anyhow::Result<()> {
                 })
                 .await?;
         }
-        Command::Drain {
+        Command::BulkMigrate {
             nodes,
             concurrency,
             max_shards,
@@ -657,7 +754,7 @@ async fn main() -> anyhow::Result<()> {
             }
 
             if nodes.len() != node_to_drain_descs.len() {
-                anyhow::bail!("Drain requested for node which doesn't exist.")
+                anyhow::bail!("Bulk migration requested away from node which doesn't exist.")
             }
 
             node_to_fill_descs.retain(|desc| {
@@ -669,7 +766,7 @@ async fn main() -> anyhow::Result<()> {
             });
 
             if node_to_fill_descs.is_empty() {
-                anyhow::bail!("There are no nodes to drain to")
+                anyhow::bail!("There are no nodes to migrate to")
             }
 
             // Set the node scheduling policy to draining for the nodes which
@@ -690,7 +787,7 @@ async fn main() -> anyhow::Result<()> {
                     .await?;
             }
 
-            // Perform the drain: move each tenant shard scheduled on a node to
+            // Perform the migration: move each tenant shard scheduled on a node to
             // be drained to a node which is being filled. A simple round robin
             // strategy is used to pick the new node.
             let tenants = storcon_client
@@ -703,13 +800,13 @@ async fn main() -> anyhow::Result<()> {
 
             let mut selected_node_idx = 0;
 
-            struct DrainMove {
+            struct MigrationMove {
                 tenant_shard_id: TenantShardId,
                 from: NodeId,
                 to: NodeId,
             }
 
-            let mut moves: Vec<DrainMove> = Vec::new();
+            let mut moves: Vec<MigrationMove> = Vec::new();
 
             let shards = tenants
                 .into_iter()
@@ -739,7 +836,7 @@ async fn main() -> anyhow::Result<()> {
                     continue;
                 }
 
-                moves.push(DrainMove {
+                moves.push(MigrationMove {
                     tenant_shard_id: shard.tenant_shard_id,
                     from: shard
                         .node_attached
@@ -816,6 +913,67 @@ async fn main() -> anyhow::Result<()> {
                 failure
             );
         }
+        Command::StartDrain { node_id } => {
+            storcon_client
+                .dispatch::<(), ()>(
+                    Method::PUT,
+                    format!("control/v1/node/{node_id}/drain"),
+                    None,
+                )
+                .await?;
+            println!("Drain started for {node_id}");
+        }
+        Command::CancelDrain { node_id, timeout } => {
+            storcon_client
+                .dispatch::<(), ()>(
+                    Method::DELETE,
+                    format!("control/v1/node/{node_id}/drain"),
+                    None,
+                )
+                .await?;
+
+            println!("Waiting for node {node_id} to quiesce on scheduling policy ...");
+
+            let final_policy =
+                wait_for_scheduling_policy(storcon_client, node_id, *timeout, |sched| {
+                    use NodeSchedulingPolicy::*;
+                    matches!(sched, Active | PauseForRestart)
+                })
+                .await?;
+
+            println!(
+                "Drain was cancelled for node {node_id}. Schedulling policy is now {final_policy:?}"
+            );
+        }
+        Command::StartFill { node_id } => {
+            storcon_client
+                .dispatch::<(), ()>(Method::PUT, format!("control/v1/node/{node_id}/fill"), None)
+                .await?;
+
+            println!("Fill started for {node_id}");
+        }
+        Command::CancelFill { node_id, timeout } => {
+            storcon_client
+                .dispatch::<(), ()>(
+                    Method::DELETE,
+                    format!("control/v1/node/{node_id}/fill"),
+                    None,
+                )
+                .await?;
+
+            println!("Waiting for node {node_id} to quiesce on scheduling policy ...");
+
+            let final_policy =
+                wait_for_scheduling_policy(storcon_client, node_id, *timeout, |sched| {
+                    use NodeSchedulingPolicy::*;
+                    matches!(sched, Active)
+                })
+                .await?;
+
+            println!(
+                "Fill was cancelled for node {node_id}. Schedulling policy is now {final_policy:?}"
+            );
+        }
     }
 
     Ok(())

docker-compose/run-tests.sh

@@ -3,7 +3,7 @@ set -x
 
 cd /ext-src || exit 2
 FAILED=
-LIST=$( (echo "${SKIP//","/"\n"}"; ls -d -- *-src) | sort | uniq -u)
+LIST=$( (echo -e "${SKIP//","/"\n"}"; ls -d -- *-src) | sort | uniq -u)
 for d in ${LIST}
 do
        [ -d "${d}" ] || continue

docs/rfcs/037-storage-controller-restarts.md

@@ -0,0 +1,259 @@
+# Rolling Storage Controller Restarts
+
+## Summary
+
+This RFC describes the issues around the current storage controller restart procedure
+and describes an implementation which reduces downtime to a few milliseconds on the happy path.
+
+## Motivation
+
+Storage controller upgrades (restarts, more generally) can cause multi-second availability gaps.
+While the storage controller does not sit on the main data path, it's generally not acceptable
+to block management requests for extended periods of time (e.g. https://github.com/neondatabase/neon/issues/8034).
+
+### Current Implementation
+
+The storage controller runs in a Kubernetes Deployment configured for one replica and strategy set to [Recreate](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#recreate-deployment).
+In non Kubernetes terms, during an upgrade, the currently running storage controller is stopped and, only after,
+a new instance is created.
+
+At start-up, the storage controller calls into all the pageservers it manages (retrieved from DB) to learn the
+latest locations of all tenant shards present on them. This is usually fast, but can push into tens of seconds
+under unfavourable circumstances: pageservers are heavily loaded or unavailable.
+
+## Prior Art
+
+There's probably as many ways of handling restarts gracefully as there are distributed systems. Some examples include:
+* Active/Standby architectures: Two or more instance of the same service run, but traffic is only routed to one of them.
+For fail-over, traffic is routed to one of the standbys (which becomes active).
+* Consensus Algorithms (Raft, Paxos and friends): The part of consensus we care about here is leader election: peers communicate to each other
+and use a voting scheme that ensures the existence of a single leader (e.g. Raft epochs).
+
+## Requirements
+
+* Reduce storage controller unavailability during upgrades to milliseconds
+* Minimize the interval in which it's possible for more than one storage controller
+to issue reconciles.
+* Have one uniform implementation for restarts and upgrades
+* Fit in with the current Kubernetes deployment scheme
+
+## Non Goals
+
+* Implement our own consensus algorithm from scratch
+* Completely eliminate downtime storage controller downtime. Instead we aim to reduce it to the point where it looks
+like a transient error to the control plane
+
+## Impacted Components
+
+* storage controller
+* deployment orchestration (i.e. Ansible)
+* helm charts
+
+## Terminology
+
+* Observed State: in-memory mapping between tenant shards and their current pageserver locations - currently built up
+at start-up by quering pageservers
+* Deployment: Kubernetes [primitive](https://kubernetes.io/docs/concepts/workloads/controllers/deployment/) that models
+a set of replicas
+
+## Implementation
+
+### High Level Flow
+
+At a very high level the proposed idea is to start a new storage controller instance while
+the previous one is still running and cut-over to it when it becomes ready. The new instance,
+should coordinate with the existing one and transition responsibility gracefully. While the controller
+has built in safety against split-brain situations (via generation numbers), we'd like to avoid such
+scenarios since they can lead to availability issues for tenants that underwent changes while two controllers
+were operating at the same time and require operator intervention to remedy.
+
+### Kubernetes Deployment Configuration
+
+On the Kubernetes configuration side, the proposal is to update the storage controller `Deployment`
+to use `spec.strategy.type = RollingUpdate`, `spec.strategy.rollingUpdate.maxSurge=1` and `spec.strategy.maxUnavailable=0`.
+Under the hood, Kubernetes creates a new replica set and adds one pod to it (`maxSurge=1`). The old replica set does not
+scale down until the new replica set has one replica in the ready state (`maxUnavailable=0`).
+
+The various possible failure scenarios are investigated in the [Handling Failures](#handling-failures) section.
+
+### Storage Controller Start-Up
+
+This section describes the primitives required on the storage controller side and the flow of the happy path.
+
+#### Database Table For Leader Synchronization
+
+A new table should be added to the storage controller database for leader synchronization during startup.
+This table will always contain at most one row. The proposed name for the table is `leader` and the schema
+contains two elements:
+* `hostname`: represents the hostname for the current storage controller leader - should be addressible
+from other pods in the deployment
+* `start_timestamp`: holds the start timestamp for the current storage controller leader (UTC timezone) - only required
+for failure case handling: see [Previous Leader Crashes Before New Leader Readiness](#previous-leader-crashes-before-new-leader-readiness)
+
+Storage controllers will read the leader row at start-up and then update it to mark themselves as the leader
+at the end of the start-up sequence. We want compare-and-exchange semantics for the update: avoid the
+situation where two concurrent updates succeed and overwrite each other. The default Postgres isolation
+level is `READ COMMITTED`, which isn't strict enough here. This update transaction should use at least `REPEATABLE
+READ` isolation level in order to [prevent lost updates](https://www.interdb.jp/pg/pgsql05/08.html). Currently,
+the storage controller uses the stricter `SERIALIZABLE` isolation level for all transactions. This more than suits
+our needs here.
+
+```
+START TRANSACTION ISOLATION LEVEL REPEATABLE READ
+UPDATE leader SET hostname=<new_hostname>, start_timestamp=<new_start_ts>
+WHERE hostname=<old_hostname>, start_timestampt=<old_start_ts>;
+```
+
+If the transaction fails or if no rows have been updated, then the compare-and-exchange is regarded as a failure.
+
+#### Step Down API
+
+A new HTTP endpoint should be added to the storage controller: `POST /control/v1/step_down`. Upon receiving this
+request the leader cancels any pending reconciles and goes into a mode where it replies with 503 to all other APIs
+and does not issue any location configurations to its pageservers. The successful HTTP response will return a serialized
+snapshot of the observed state.
+
+If other step down requests come in after the initial one, the request is handled and the observed state is returned (required
+for failure scenario handling - see [Handling Failures](#handling-failures)).
+
+#### Graceful Restart Happy Path
+
+At start-up, the first thing the storage controller does is retrieve the sole row from the new
+`leader` table. If such an entry exists, send a `/step_down` PUT API call to the current leader.
+This should be retried a few times with a short backoff (see [1]). The aspiring leader loads the
+observed state into memory and the start-up sequence proceeds as usual, but *without* querying the
+pageservers in order to build up the observed state.
+
+Before doing any reconciliations or persistence change, update the `leader` database table as described in the [Database Table For Leader Synchronization](database-table-for-leader-synchronization)
+section. If this step fails, the storage controller process exits.
+
+Note that no row will exist in the `leaders` table for the first graceful restart. In that case, force update the `leader` table
+(without the WHERE clause) and perform with the pre-existing start-up procedure (i.e. build observed state by querying pageservers).
+
+Summary of proposed new start-up sequence:
+1. Call `/step_down`
+2. Perform any pending database migrations
+3. Load state from database
+4. Load observed state returned in step (1) into memory
+5. Do initial heartbeat round (may be moved after 5)
+7. Mark self as leader by updating the database
+8. Reschedule and reconcile everything
+
+Some things to note from the steps above:
+* The storage controller makes no changes to the cluster state before step (5) (i.e. no location config
+calls to the pageserver and no compute notifications)
+* Ask the current leader to step down before loading state from database so we don't get a lost update
+if the transactions overlap.
+* Before loading the observed state at step (3), cross-validate against the database. If validation fails,
+fall back to asking the pageservers about their current locations.
+* Database migrations should only run **after** the previous instance steps down (or the step down times out).
+
+
+[1] The API call might fail because there's no storage controller running (i.e. [restart](#storage-controller-crash-or-restart)),
+so we don't want to extend the unavailability period by much. We still want to retry since that's not the common case.
+
+### Handling Failures
+
+#### Storage Controller Crash Or Restart
+
+The storage controller may crash or be restarted outside of roll-outs. When a new pod is created, its call to
+`/step_down` will fail since the previous leader is no longer reachable. In this case perform the pre-existing
+start-up procedure and update the leader table (with the WHERE clause). If the update fails, the storage controller
+exists and consistency is maintained.
+
+#### Previous Leader Crashes Before New Leader Readiness
+
+When the previous leader (P1) crashes before the new leader (P2) passses the readiness check, Kubernetes will
+reconcile the old replica set and create a new pod for it (P1'). The `/step_down` API call will fail for P1'
+(see [2]).
+
+Now we have two cases to consider:
+* P2 updates the `leader` table first: The database update from P1' will fail and P1' will exit, or be terminated
+by Kubernetes depending on timings.
+* P1' updates the `leader` table first: The `hostname` field of the `leader` row stays the same, but the `start_timestamp` field changes.
+The database update from P2 will fail (since `start_timestamp` does not match). P2 will exit and Kubernetes will
+create a new replacement pod for it (P2'). Now the entire dance starts again, but with P1' as the leader and P2' as the incumbent.
+
+[2] P1 and P1' may (more likely than not) be the same pod and have the same hostname. The implementation
+should avoid this self reference and fail the API call at the client if the persisted hostname matches
+the current one.
+
+#### Previous Leader Crashes After New Leader Readiness
+
+The deployment's replica sets already satisfy the deployment's replica count requirements and the
+Kubernetes deployment rollout will just clean up the dead pod.
+
+#### New Leader Crashes Before Pasing Readiness Check
+
+The deployment controller scales up the new replica sets by creating a new pod. The entire procedure is repeated
+with the new pod.
+
+#### Network Partition Between New Pod and Previous Leader
+
+This feels very unlikely, but should be considered in any case. P2 (the new aspiring leader) fails the `/step_down`
+API call into P1 (the current leader). P2 proceeds with the pre-existing startup procedure and updates the `leader` table.
+Kubernetes will terminate P1, but there may be a brief period where both storage controller can drive reconciles.
+
+### Dealing With Split Brain Scenarios
+
+As we've seen in the previous section, we can end up with two storage controller running at the same time. The split brain
+duration is not bounded since the Kubernetes controller might become partitioned from the pods (unlikely though). While these
+scenarios are not fatal, they can cause tenant unavailability, so we'd like to reduce the chances of this happening.
+The rest of this section sketches some safety measure. It's likely overkill to implement all of them however.
+
+### Ensure Leadership Before Producing Side Effects
+
+The storage controller has two types of side effects: location config requests into pageservers and compute notifications into the control plane.
+Before issuing either, the storage controller could check that it is indeed still the leader by querying the database. Side effects might still be
+applied if they race with the database updatem, but the situation will eventually be detected. The storage controller process should terminate in these cases.
+
+### Leadership Lease
+
+Up until now, the leadership defined by this RFC is static. In order to bound the length of the split brain scenario, we could require the leadership
+to be renewed periodically. Two new columns would be added to the leaders table:
+1. `last_renewed` - timestamp indicating when the lease was last renewed
+2. `lease_duration` - duration indicating the amount of time after which the lease expires
+
+The leader periodically attempts to renew the lease by checking that it is in fact still the legitimate leader and updating `last_renewed` in the
+same transaction. If the update fails, the process exits. New storage controller instances wishing to become leaders must wait for the current lease
+to expire before acquiring leadership if they have not succesfully received a response to the `/step_down` request.
+
+### Notify Pageserver Of Storage Controller Term
+
+Each time that leadership changes, we can bump a `term` integer column in the `leader` table. This term uniquely identifies a leader.
+Location config requests and re-attach responses can include this term. On the pageserver side, keep the latest term in memory and refuse
+anything which contains a stale term (i.e. smaller than the current one).
+
+### Observability
+
+* The storage controller should expose a metric which describes it's state (`Active | WarmingUp | SteppedDown`).
+Per region alerts should be added on this metric which triggers when:
+  + no storage controller has been in the `Active` state for an extended period of time
+  + more than one storage controllers are in the `Active` state
+
+* An alert that periodically verifies that the `leader` table is in sync with the metric above would be very useful.
+We'd have to expose the storage controller read only database to Grafana (perhaps it is already done).
+
+## Alternatives
+
+### Kubernetes Leases
+
+Kubernetes has a [lease primitive](https://kubernetes.io/docs/concepts/architecture/leases/) which can be used to implement leader election.
+Only one instance may hold a lease at any given time. This lease needs to be periodically renewed and has an expiration period.
+
+In our case, it would work something like this:
+* `/step_down` deletes the lease or stops it from renewing
+* lease acquisition becomes part of the start-up procedure
+
+The kubert crate implements a [lightweight lease API](https://docs.rs/kubert/latest/kubert/lease/struct.LeaseManager.html), but it's still
+not exactly trivial to implement.
+
+This approach has the benefit of baked in observability (`kubectl describe lease`), but:
+* We offload the responsibility to Kubernetes which makes it harder to debug when things go wrong.
+* More code surface than the simple "row in database" approach. Also, most of this code would be in
+a dependency not subject to code review, etc.
+* Hard to test. Our testing infra does not run the storage controller in Kubernetes and changing it do
+so is not simple and complictes and the test set-up.
+
+To my mind, the "row in database" approach is straightforward enough that we don't have to offload this
+to something external.

docs/updating-postgres.md

@@ -21,30 +21,21 @@ _Example: 15.4 is the new minor version to upgrade to from 15.3._
 1. Create a new branch based on the stable branch you are updating.
 
     ```shell
-    git checkout -b my-branch REL_15_STABLE_neon
+    git checkout -b my-branch-15 REL_15_STABLE_neon
     ```
 
-1. Tag the last commit on the stable branch you are updating.
+1. Find the upstream release tags you're looking for. They are of the form `REL_X_Y`.
 
-    ```shell
+1. Merge the upstream tag into the branch you created on the tag and resolve any conflicts.
-    git tag REL_15_3_neon
-    ```
-
-1. Push the new tag to the Neon Postgres repository.
-
-    ```shell
-    git push origin REL_15_3_neon
-    ```
-
-1. Find the release tags you're looking for. They are of the form `REL_X_Y`.
-
-1. Rebase the branch you created on the tag and resolve any conflicts.
 
     ```shell
     git fetch upstream REL_15_4
-    git rebase REL_15_4
+    git merge REL_15_4
     ```
 
+    In the commit message of the merge commit, mention if there were
+    any non-trivial conflicts or other issues.
+
 1. Run the Postgres test suite to make sure our commits have not affected
 Postgres in a negative way.
 
@@ -57,7 +48,7 @@ Postgres in a negative way.
 1. Push your branch to the Neon Postgres repository.
 
     ```shell
-    git push origin my-branch
+    git push origin my-branch-15
     ```
 
 1. Clone the Neon repository if you have not done so already.
@@ -74,7 +65,7 @@ branch.
 1. Update the Git submodule.
 
     ```shell
-    git submodule set-branch --branch my-branch vendor/postgres-v15
+    git submodule set-branch --branch my-branch-15 vendor/postgres-v15
     git submodule update --remote vendor/postgres-v15
     ```
 
@@ -89,14 +80,12 @@ minor Postgres release.
 
 1. Create a pull request, and wait for CI to go green.
 
-1. Force push the rebased Postgres branches into the Neon Postgres repository.
+1. Push the Postgres branches with the merge commits into the Neon Postgres repository.
 
     ```shell
-    git push --force origin my-branch:REL_15_STABLE_neon
+    git push origin my-branch-15:REL_15_STABLE_neon
     ```
 
-    It may require disabling various branch protections.
-
 1. Update your Neon PR to point at the branches.
 
     ```shell

libs/metrics/src/lib.rs

@@ -68,6 +68,7 @@ macro_rules! register_uint_gauge {
 static INTERNAL_REGISTRY: Lazy<Registry> = Lazy::new(Registry::new);
 
 /// Register a collector in the internal registry. MUST be called before the first call to `gather()`.
+///
 /// Otherwise, we can have a deadlock in the `gather()` call, trying to register a new collector
 /// while holding the lock.
 pub fn register_internal(c: Box<dyn Collector>) -> prometheus::Result<()> {

libs/pageserver_api/Cargo.toml

@@ -4,6 +4,10 @@ version = "0.1.0"
 edition.workspace = true
 license.workspace = true
 
+[features]
+# See pageserver/Cargo.toml
+testing = ["dep:nix"]
+
 [dependencies]
 serde.workspace = true
 serde_with.workspace = true
@@ -23,6 +27,12 @@ thiserror.workspace = true
 humantime-serde.workspace = true
 chrono = { workspace = true, features = ["serde"] }
 itertools.workspace = true
+storage_broker.workspace = true
+camino = {workspace = true, features = ["serde1"]}
+remote_storage.workspace = true
+postgres_backend.workspace = true
+nix = {workspace = true, optional = true}
+reqwest.workspace = true
 
 [dev-dependencies]
 bincode.workspace = true

libs/pageserver_api/src/config.rs

@@ -1,15 +1,28 @@
-use std::collections::HashMap;
+use camino::Utf8PathBuf;
-
-use const_format::formatcp;
 
 #[cfg(test)]
 mod tests;
 
+use const_format::formatcp;
 pub const DEFAULT_PG_LISTEN_PORT: u16 = 64000;
 pub const DEFAULT_PG_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_PG_LISTEN_PORT}");
 pub const DEFAULT_HTTP_LISTEN_PORT: u16 = 9898;
 pub const DEFAULT_HTTP_LISTEN_ADDR: &str = formatcp!("127.0.0.1:{DEFAULT_HTTP_LISTEN_PORT}");
 
+use postgres_backend::AuthType;
+use remote_storage::RemoteStorageConfig;
+use serde_with::serde_as;
+use std::{
+    collections::HashMap,
+    num::{NonZeroU64, NonZeroUsize},
+    str::FromStr,
+    time::Duration,
+};
+use utils::logging::LogFormat;
+
+use crate::models::ImageCompressionAlgorithm;
+use crate::models::LsnLease;
+
 // Certain metadata (e.g. externally-addressable name, AZ) is delivered
 // as a separate structure.  This information is not neeed by the pageserver
 // itself, it is only used for registering the pageserver with the control
@@ -29,3 +42,476 @@ pub struct NodeMetadata {
     #[serde(flatten)]
     pub other: HashMap<String, serde_json::Value>,
 }
+
+/// `pageserver.toml`
+///
+/// We use serde derive with `#[serde(default)]` to generate a deserializer
+/// that fills in the default values for each config field.
+///
+/// If there cannot be a static default value because we need to make runtime
+/// checks to determine the default, make it an `Option` (which defaults to None).
+/// The runtime check should be done in the consuming crate, i.e., `pageserver`.
+#[serde_as]
+#[derive(Clone, Debug, serde::Deserialize, serde::Serialize)]
+#[serde(default, deny_unknown_fields)]
+pub struct ConfigToml {
+    // types mapped 1:1 into the runtime PageServerConfig type
+    pub listen_pg_addr: String,
+    pub listen_http_addr: String,
+    pub availability_zone: Option<String>,
+    #[serde(with = "humantime_serde")]
+    pub wait_lsn_timeout: Duration,
+    #[serde(with = "humantime_serde")]
+    pub wal_redo_timeout: Duration,
+    pub superuser: String,
+    pub page_cache_size: usize,
+    pub max_file_descriptors: usize,
+    pub pg_distrib_dir: Option<Utf8PathBuf>,
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub http_auth_type: AuthType,
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub pg_auth_type: AuthType,
+    pub auth_validation_public_key_path: Option<Utf8PathBuf>,
+    pub remote_storage: Option<RemoteStorageConfig>,
+    pub tenant_config: TenantConfigToml,
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub broker_endpoint: storage_broker::Uri,
+    #[serde(with = "humantime_serde")]
+    pub broker_keepalive_interval: Duration,
+    #[serde_as(as = "serde_with::DisplayFromStr")]
+    pub log_format: LogFormat,
+    pub concurrent_tenant_warmup: NonZeroUsize,
+    pub concurrent_tenant_size_logical_size_queries: NonZeroUsize,
+    #[serde(with = "humantime_serde")]
+    pub metric_collection_interval: Duration,
+    pub metric_collection_endpoint: Option<reqwest::Url>,
+    pub metric_collection_bucket: Option<RemoteStorageConfig>,
+    #[serde(with = "humantime_serde")]
+    pub synthetic_size_calculation_interval: Duration,
+    pub disk_usage_based_eviction: Option<DiskUsageEvictionTaskConfig>,
+    pub test_remote_failures: u64,
+    pub ondemand_download_behavior_treat_error_as_warn: bool,
+    #[serde(with = "humantime_serde")]
+    pub background_task_maximum_delay: Duration,
+    pub control_plane_api: Option<reqwest::Url>,
+    pub control_plane_api_token: Option<String>,
+    pub control_plane_emergency_mode: bool,
+    pub heatmap_upload_concurrency: usize,
+    pub secondary_download_concurrency: usize,
+    pub virtual_file_io_engine: Option<crate::models::virtual_file::IoEngineKind>,
+    pub ingest_batch_size: u64,
+    pub max_vectored_read_bytes: MaxVectoredReadBytes,
+    pub image_compression: ImageCompressionAlgorithm,
+    pub ephemeral_bytes_per_memory_kb: usize,
+    pub l0_flush: Option<crate::models::L0FlushConfig>,
+    #[serde(skip_serializing)]
+    // TODO(https://github.com/neondatabase/neon/issues/8184): remove after this field is removed from all pageserver.toml's
+    pub compact_level0_phase1_value_access: serde::de::IgnoredAny,
+    pub virtual_file_direct_io: crate::models::virtual_file::DirectIoMode,
+    pub io_buffer_alignment: usize,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(deny_unknown_fields)]
+pub struct DiskUsageEvictionTaskConfig {
+    pub max_usage_pct: utils::serde_percent::Percent,
+    pub min_avail_bytes: u64,
+    #[serde(with = "humantime_serde")]
+    pub period: Duration,
+    #[cfg(feature = "testing")]
+    pub mock_statvfs: Option<statvfs::mock::Behavior>,
+    /// Select sorting for evicted layers
+    #[serde(default)]
+    pub eviction_order: EvictionOrder,
+}
+
+pub mod statvfs {
+    pub mod mock {
+        #[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+        #[serde(tag = "type")]
+        pub enum Behavior {
+            Success {
+                blocksize: u64,
+                total_blocks: u64,
+                name_filter: Option<utils::serde_regex::Regex>,
+            },
+            #[cfg(feature = "testing")]
+            Failure { mocked_error: MockedError },
+        }
+
+        #[cfg(feature = "testing")]
+        #[derive(Debug, Clone, Copy, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+        #[allow(clippy::upper_case_acronyms)]
+        pub enum MockedError {
+            EIO,
+        }
+
+        #[cfg(feature = "testing")]
+        impl From<MockedError> for nix::Error {
+            fn from(e: MockedError) -> Self {
+                match e {
+                    MockedError::EIO => nix::Error::EIO,
+                }
+            }
+        }
+    }
+}
+
+#[derive(Debug, Clone, Copy, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(tag = "type", content = "args")]
+pub enum EvictionOrder {
+    RelativeAccessed {
+        highest_layer_count_loses_first: bool,
+    },
+}
+
+impl Default for EvictionOrder {
+    fn default() -> Self {
+        Self::RelativeAccessed {
+            highest_layer_count_loses_first: true,
+        }
+    }
+}
+
+#[derive(
+    Eq,
+    PartialEq,
+    Debug,
+    Copy,
+    Clone,
+    strum_macros::EnumString,
+    strum_macros::Display,
+    serde_with::DeserializeFromStr,
+    serde_with::SerializeDisplay,
+)]
+#[strum(serialize_all = "kebab-case")]
+pub enum GetVectoredImpl {
+    Sequential,
+    Vectored,
+}
+
+#[derive(
+    Eq,
+    PartialEq,
+    Debug,
+    Copy,
+    Clone,
+    strum_macros::EnumString,
+    strum_macros::Display,
+    serde_with::DeserializeFromStr,
+    serde_with::SerializeDisplay,
+)]
+#[strum(serialize_all = "kebab-case")]
+pub enum GetImpl {
+    Legacy,
+    Vectored,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(transparent)]
+pub struct MaxVectoredReadBytes(pub NonZeroUsize);
+
+/// A tenant's calcuated configuration, which is the result of merging a
+/// tenant's TenantConfOpt with the global TenantConf from PageServerConf.
+///
+/// For storing and transmitting individual tenant's configuration, see
+/// TenantConfOpt.
+#[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+#[serde(deny_unknown_fields, default)]
+pub struct TenantConfigToml {
+    // Flush out an inmemory layer, if it's holding WAL older than this
+    // This puts a backstop on how much WAL needs to be re-digested if the
+    // page server crashes.
+    // This parameter actually determines L0 layer file size.
+    pub checkpoint_distance: u64,
+    // Inmemory layer is also flushed at least once in checkpoint_timeout to
+    // eventually upload WAL after activity is stopped.
+    #[serde(with = "humantime_serde")]
+    pub checkpoint_timeout: Duration,
+    // Target file size, when creating image and delta layers.
+    // This parameter determines L1 layer file size.
+    pub compaction_target_size: u64,
+    // How often to check if there's compaction work to be done.
+    // Duration::ZERO means automatic compaction is disabled.
+    #[serde(with = "humantime_serde")]
+    pub compaction_period: Duration,
+    // Level0 delta layer threshold for compaction.
+    pub compaction_threshold: usize,
+    pub compaction_algorithm: crate::models::CompactionAlgorithmSettings,
+    // Determines how much history is retained, to allow
+    // branching and read replicas at an older point in time.
+    // The unit is #of bytes of WAL.
+    // Page versions older than this are garbage collected away.
+    pub gc_horizon: u64,
+    // Interval at which garbage collection is triggered.
+    // Duration::ZERO means automatic GC is disabled
+    #[serde(with = "humantime_serde")]
+    pub gc_period: Duration,
+    // Delta layer churn threshold to create L1 image layers.
+    pub image_creation_threshold: usize,
+    // Determines how much history is retained, to allow
+    // branching and read replicas at an older point in time.
+    // The unit is time.
+    // Page versions older than this are garbage collected away.
+    #[serde(with = "humantime_serde")]
+    pub pitr_interval: Duration,
+    /// Maximum amount of time to wait while opening a connection to receive wal, before erroring.
+    #[serde(with = "humantime_serde")]
+    pub walreceiver_connect_timeout: Duration,
+    /// Considers safekeepers stalled after no WAL updates were received longer than this threshold.
+    /// A stalled safekeeper will be changed to a newer one when it appears.
+    #[serde(with = "humantime_serde")]
+    pub lagging_wal_timeout: Duration,
+    /// Considers safekeepers lagging when their WAL is behind another safekeeper for more than this threshold.
+    /// A lagging safekeeper will be changed after `lagging_wal_timeout` time elapses since the last WAL update,
+    /// to avoid eager reconnects.
+    pub max_lsn_wal_lag: NonZeroU64,
+    pub eviction_policy: crate::models::EvictionPolicy,
+    pub min_resident_size_override: Option<u64>,
+    // See the corresponding metric's help string.
+    #[serde(with = "humantime_serde")]
+    pub evictions_low_residence_duration_metric_threshold: Duration,
+
+    /// If non-zero, the period between uploads of a heatmap from attached tenants.  This
+    /// may be disabled if a Tenant will not have secondary locations: only secondary
+    /// locations will use the heatmap uploaded by attached locations.
+    #[serde(with = "humantime_serde")]
+    pub heatmap_period: Duration,
+
+    /// If true then SLRU segments are dowloaded on demand, if false SLRU segments are included in basebackup
+    pub lazy_slru_download: bool,
+
+    pub timeline_get_throttle: crate::models::ThrottleConfig,
+
+    // How much WAL must be ingested before checking again whether a new image layer is required.
+    // Expresed in multiples of checkpoint distance.
+    pub image_layer_creation_check_threshold: u8,
+
+    /// Switch to a new aux file policy. Switching this flag requires the user has not written any aux file into
+    /// the storage before, and this flag cannot be switched back. Otherwise there will be data corruptions.
+    /// There is a `last_aux_file_policy` flag which gets persisted in `index_part.json` once the first aux
+    /// file is written.
+    pub switch_aux_file_policy: crate::models::AuxFilePolicy,
+
+    /// The length for an explicit LSN lease request.
+    /// Layers needed to reconstruct pages at LSN will not be GC-ed during this interval.
+    #[serde(with = "humantime_serde")]
+    pub lsn_lease_length: Duration,
+
+    /// The length for an implicit LSN lease granted as part of `get_lsn_by_timestamp` request.
+    /// Layers needed to reconstruct pages at LSN will not be GC-ed during this interval.
+    #[serde(with = "humantime_serde")]
+    pub lsn_lease_length_for_ts: Duration,
+}
+
+pub mod defaults {
+    use crate::models::ImageCompressionAlgorithm;
+
+    pub use storage_broker::DEFAULT_ENDPOINT as BROKER_DEFAULT_ENDPOINT;
+
+    pub const DEFAULT_WAIT_LSN_TIMEOUT: &str = "300 s";
+    pub const DEFAULT_WAL_REDO_TIMEOUT: &str = "60 s";
+
+    pub const DEFAULT_SUPERUSER: &str = "cloud_admin";
+
+    pub const DEFAULT_PAGE_CACHE_SIZE: usize = 8192;
+    pub const DEFAULT_MAX_FILE_DESCRIPTORS: usize = 100;
+
+    pub const DEFAULT_LOG_FORMAT: &str = "plain";
+
+    pub const DEFAULT_CONCURRENT_TENANT_WARMUP: usize = 8;
+
+    pub const DEFAULT_CONCURRENT_TENANT_SIZE_LOGICAL_SIZE_QUERIES: usize = 1;
+
+    pub const DEFAULT_METRIC_COLLECTION_INTERVAL: &str = "10 min";
+    pub const DEFAULT_METRIC_COLLECTION_ENDPOINT: Option<reqwest::Url> = None;
+    pub const DEFAULT_SYNTHETIC_SIZE_CALCULATION_INTERVAL: &str = "10 min";
+    pub const DEFAULT_BACKGROUND_TASK_MAXIMUM_DELAY: &str = "10s";
+
+    pub const DEFAULT_HEATMAP_UPLOAD_CONCURRENCY: usize = 8;
+    pub const DEFAULT_SECONDARY_DOWNLOAD_CONCURRENCY: usize = 1;
+
+    pub const DEFAULT_INGEST_BATCH_SIZE: u64 = 100;
+
+    pub const DEFAULT_MAX_VECTORED_READ_BYTES: usize = 128 * 1024; // 128 KiB
+
+    pub const DEFAULT_IMAGE_COMPRESSION: ImageCompressionAlgorithm =
+        ImageCompressionAlgorithm::Zstd { level: Some(1) };
+
+    pub const DEFAULT_VALIDATE_VECTORED_GET: bool = false;
+
+    pub const DEFAULT_EPHEMERAL_BYTES_PER_MEMORY_KB: usize = 0;
+
+    pub const DEFAULT_IO_BUFFER_ALIGNMENT: usize = 512;
+}
+
+impl Default for ConfigToml {
+    fn default() -> Self {
+        use defaults::*;
+
+        Self {
+            listen_pg_addr: (DEFAULT_PG_LISTEN_ADDR.to_string()),
+            listen_http_addr: (DEFAULT_HTTP_LISTEN_ADDR.to_string()),
+            availability_zone: (None),
+            wait_lsn_timeout: (humantime::parse_duration(DEFAULT_WAIT_LSN_TIMEOUT)
+                .expect("cannot parse default wait lsn timeout")),
+            wal_redo_timeout: (humantime::parse_duration(DEFAULT_WAL_REDO_TIMEOUT)
+                .expect("cannot parse default wal redo timeout")),
+            superuser: (DEFAULT_SUPERUSER.to_string()),
+            page_cache_size: (DEFAULT_PAGE_CACHE_SIZE),
+            max_file_descriptors: (DEFAULT_MAX_FILE_DESCRIPTORS),
+            pg_distrib_dir: None, // Utf8PathBuf::from("./pg_install"), // TODO: formely, this was std::env::current_dir()
+            http_auth_type: (AuthType::Trust),
+            pg_auth_type: (AuthType::Trust),
+            auth_validation_public_key_path: (None),
+            remote_storage: None,
+            broker_endpoint: (storage_broker::DEFAULT_ENDPOINT
+                .parse()
+                .expect("failed to parse default broker endpoint")),
+            broker_keepalive_interval: (humantime::parse_duration(
+                storage_broker::DEFAULT_KEEPALIVE_INTERVAL,
+            )
+            .expect("cannot parse default keepalive interval")),
+            log_format: (LogFormat::from_str(DEFAULT_LOG_FORMAT).unwrap()),
+
+            concurrent_tenant_warmup: (NonZeroUsize::new(DEFAULT_CONCURRENT_TENANT_WARMUP)
+                .expect("Invalid default constant")),
+            concurrent_tenant_size_logical_size_queries: NonZeroUsize::new(1).unwrap(),
+            metric_collection_interval: (humantime::parse_duration(
+                DEFAULT_METRIC_COLLECTION_INTERVAL,
+            )
+            .expect("cannot parse default metric collection interval")),
+            synthetic_size_calculation_interval: (humantime::parse_duration(
+                DEFAULT_SYNTHETIC_SIZE_CALCULATION_INTERVAL,
+            )
+            .expect("cannot parse default synthetic size calculation interval")),
+            metric_collection_endpoint: (DEFAULT_METRIC_COLLECTION_ENDPOINT),
+
+            metric_collection_bucket: (None),
+
+            disk_usage_based_eviction: (None),
+
+            test_remote_failures: (0),
+
+            ondemand_download_behavior_treat_error_as_warn: (false),
+
+            background_task_maximum_delay: (humantime::parse_duration(
+                DEFAULT_BACKGROUND_TASK_MAXIMUM_DELAY,
+            )
+            .unwrap()),
+
+            control_plane_api: (None),
+            control_plane_api_token: (None),
+            control_plane_emergency_mode: (false),
+
+            heatmap_upload_concurrency: (DEFAULT_HEATMAP_UPLOAD_CONCURRENCY),
+            secondary_download_concurrency: (DEFAULT_SECONDARY_DOWNLOAD_CONCURRENCY),
+
+            ingest_batch_size: (DEFAULT_INGEST_BATCH_SIZE),
+
+            virtual_file_io_engine: None,
+
+            max_vectored_read_bytes: (MaxVectoredReadBytes(
+                NonZeroUsize::new(DEFAULT_MAX_VECTORED_READ_BYTES).unwrap(),
+            )),
+            image_compression: (DEFAULT_IMAGE_COMPRESSION),
+            ephemeral_bytes_per_memory_kb: (DEFAULT_EPHEMERAL_BYTES_PER_MEMORY_KB),
+            l0_flush: None,
+            compact_level0_phase1_value_access: Default::default(),
+            virtual_file_direct_io: crate::models::virtual_file::DirectIoMode::default(),
+
+            io_buffer_alignment: DEFAULT_IO_BUFFER_ALIGNMENT,
+
+            tenant_config: TenantConfigToml::default(),
+        }
+    }
+}
+
+pub mod tenant_conf_defaults {
+
+    // FIXME: This current value is very low. I would imagine something like 1 GB or 10 GB
+    // would be more appropriate. But a low value forces the code to be exercised more,
+    // which is good for now to trigger bugs.
+    // This parameter actually determines L0 layer file size.
+    pub const DEFAULT_CHECKPOINT_DISTANCE: u64 = 256 * 1024 * 1024;
+    pub const DEFAULT_CHECKPOINT_TIMEOUT: &str = "10 m";
+
+    // FIXME the below configs are only used by legacy algorithm. The new algorithm
+    // has different parameters.
+
+    // Target file size, when creating image and delta layers.
+    // This parameter determines L1 layer file size.
+    pub const DEFAULT_COMPACTION_TARGET_SIZE: u64 = 128 * 1024 * 1024;
+
+    pub const DEFAULT_COMPACTION_PERIOD: &str = "20 s";
+    pub const DEFAULT_COMPACTION_THRESHOLD: usize = 10;
+    pub const DEFAULT_COMPACTION_ALGORITHM: crate::models::CompactionAlgorithm =
+        crate::models::CompactionAlgorithm::Legacy;
+
+    pub const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
+
+    // Large DEFAULT_GC_PERIOD is fine as long as PITR_INTERVAL is larger.
+    // If there's a need to decrease this value, first make sure that GC
+    // doesn't hold a layer map write lock for non-trivial operations.
+    // Relevant: https://github.com/neondatabase/neon/issues/3394
+    pub const DEFAULT_GC_PERIOD: &str = "1 hr";
+    pub const DEFAULT_IMAGE_CREATION_THRESHOLD: usize = 3;
+    pub const DEFAULT_PITR_INTERVAL: &str = "7 days";
+    pub const DEFAULT_WALRECEIVER_CONNECT_TIMEOUT: &str = "10 seconds";
+    pub const DEFAULT_WALRECEIVER_LAGGING_WAL_TIMEOUT: &str = "10 seconds";
+    // The default limit on WAL lag should be set to avoid causing disconnects under high throughput
+    // scenarios: since the broker stats are updated ~1/s, a value of 1GiB should be sufficient for
+    // throughputs up to 1GiB/s per timeline.
+    pub const DEFAULT_MAX_WALRECEIVER_LSN_WAL_LAG: u64 = 1024 * 1024 * 1024;
+    pub const DEFAULT_EVICTIONS_LOW_RESIDENCE_DURATION_METRIC_THRESHOLD: &str = "24 hour";
+    // By default ingest enough WAL for two new L0 layers before checking if new image
+    // image layers should be created.
+    pub const DEFAULT_IMAGE_LAYER_CREATION_CHECK_THRESHOLD: u8 = 2;
+
+    pub const DEFAULT_INGEST_BATCH_SIZE: u64 = 100;
+}
+
+impl Default for TenantConfigToml {
+    fn default() -> Self {
+        use tenant_conf_defaults::*;
+        Self {
+            checkpoint_distance: DEFAULT_CHECKPOINT_DISTANCE,
+            checkpoint_timeout: humantime::parse_duration(DEFAULT_CHECKPOINT_TIMEOUT)
+                .expect("cannot parse default checkpoint timeout"),
+            compaction_target_size: DEFAULT_COMPACTION_TARGET_SIZE,
+            compaction_period: humantime::parse_duration(DEFAULT_COMPACTION_PERIOD)
+                .expect("cannot parse default compaction period"),
+            compaction_threshold: DEFAULT_COMPACTION_THRESHOLD,
+            compaction_algorithm: crate::models::CompactionAlgorithmSettings {
+                kind: DEFAULT_COMPACTION_ALGORITHM,
+            },
+            gc_horizon: DEFAULT_GC_HORIZON,
+            gc_period: humantime::parse_duration(DEFAULT_GC_PERIOD)
+                .expect("cannot parse default gc period"),
+            image_creation_threshold: DEFAULT_IMAGE_CREATION_THRESHOLD,
+            pitr_interval: humantime::parse_duration(DEFAULT_PITR_INTERVAL)
+                .expect("cannot parse default PITR interval"),
+            walreceiver_connect_timeout: humantime::parse_duration(
+                DEFAULT_WALRECEIVER_CONNECT_TIMEOUT,
+            )
+            .expect("cannot parse default walreceiver connect timeout"),
+            lagging_wal_timeout: humantime::parse_duration(DEFAULT_WALRECEIVER_LAGGING_WAL_TIMEOUT)
+                .expect("cannot parse default walreceiver lagging wal timeout"),
+            max_lsn_wal_lag: NonZeroU64::new(DEFAULT_MAX_WALRECEIVER_LSN_WAL_LAG)
+                .expect("cannot parse default max walreceiver Lsn wal lag"),
+            eviction_policy: crate::models::EvictionPolicy::NoEviction,
+            min_resident_size_override: None,
+            evictions_low_residence_duration_metric_threshold: humantime::parse_duration(
+                DEFAULT_EVICTIONS_LOW_RESIDENCE_DURATION_METRIC_THRESHOLD,
+            )
+            .expect("cannot parse default evictions_low_residence_duration_metric_threshold"),
+            heatmap_period: Duration::ZERO,
+            lazy_slru_download: false,
+            timeline_get_throttle: crate::models::ThrottleConfig::disabled(),
+            image_layer_creation_check_threshold: DEFAULT_IMAGE_LAYER_CREATION_CHECK_THRESHOLD,
+            switch_aux_file_policy: crate::models::AuxFilePolicy::default_tenant_config(),
+            lsn_lease_length: LsnLease::DEFAULT_LENGTH,
+            lsn_lease_length_for_ts: LsnLease::DEFAULT_LENGTH_FOR_TS,
+        }
+    }
+}

libs/pageserver_api/src/controller_api.rs

@@ -1,4 +1,4 @@
-use std::collections::HashSet;
+use std::collections::{HashMap, HashSet};
 use std::str::FromStr;
 use std::time::{Duration, Instant};
 
@@ -8,6 +8,7 @@ use std::time::{Duration, Instant};
 use serde::{Deserialize, Serialize};
 use utils::id::{NodeId, TenantId};
 
+use crate::models::PageserverUtilization;
 use crate::{
     models::{ShardParameters, TenantConfig},
     shard::{ShardStripeSize, TenantShardId},
@@ -55,6 +56,8 @@ pub struct NodeRegisterRequest {
 
     pub listen_http_addr: String,
     pub listen_http_port: u16,
+
+    pub availability_zone_id: String,
 }
 
 #[derive(Serialize, Deserialize)]
@@ -71,6 +74,17 @@ pub struct TenantPolicyRequest {
     pub scheduling: Option<ShardSchedulingPolicy>,
 }
 
+#[derive(Serialize, Deserialize)]
+pub struct ShardsPreferredAzsRequest {
+    #[serde(flatten)]
+    pub preferred_az_ids: HashMap<TenantShardId, String>,
+}
+
+#[derive(Serialize, Deserialize)]
+pub struct ShardsPreferredAzsResponse {
+    pub updated: Vec<TenantShardId>,
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct TenantLocateResponseShard {
     pub shard_id: TenantShardId,
@@ -98,6 +112,21 @@ pub struct TenantDescribeResponse {
     pub config: TenantConfig,
 }
 
+#[derive(Serialize, Deserialize, Debug)]
+pub struct NodeShardResponse {
+    pub node_id: NodeId,
+    pub shards: Vec<NodeShard>,
+}
+
+#[derive(Serialize, Deserialize, Debug)]
+pub struct NodeShard {
+    pub tenant_shard_id: TenantShardId,
+    /// Whether the shard is observed secondary on a specific node. True = yes, False = no, None = not on this node.
+    pub is_observed_secondary: Option<bool>,
+    /// Whether the shard is intended to be a secondary on a specific node. True = yes, False = no, None = not on this node.
+    pub is_intended_secondary: Option<bool>,
+}
+
 #[derive(Serialize, Deserialize)]
 pub struct NodeDescribeResponse {
     pub id: NodeId,
@@ -129,8 +158,12 @@ pub struct TenantDescribeResponseShard {
     pub is_splitting: bool,
 
     pub scheduling_policy: ShardSchedulingPolicy,
+
+    pub preferred_az_id: Option<String>,
 }
 
+/// Migration request for a given tenant shard to a given node.
+///
 /// Explicitly migrating a particular shard is a low level operation
 /// TODO: higher level "Reschedule tenant" operation where the request
 /// specifies some constraints, e.g. asking it to get off particular node(s)
@@ -140,23 +173,11 @@ pub struct TenantShardMigrateRequest {
     pub node_id: NodeId,
 }
 
-/// Utilisation score indicating how good a candidate a pageserver
+#[derive(Serialize, Clone, Debug)]
-/// is for scheduling the next tenant. See [`crate::models::PageserverUtilization`].
-/// Lower values are better.
-#[derive(Serialize, Deserialize, Clone, Copy, Eq, PartialEq, PartialOrd, Ord, Debug)]
-pub struct UtilizationScore(pub u64);
-
-impl UtilizationScore {
-    pub fn worst() -> Self {
-        UtilizationScore(u64::MAX)
-    }
-}
-
-#[derive(Serialize, Clone, Copy, Debug)]
 #[serde(into = "NodeAvailabilityWrapper")]
 pub enum NodeAvailability {
     // Normal, happy state
-    Active(UtilizationScore),
+    Active(PageserverUtilization),
     // Node is warming up, but we expect it to become available soon. Covers
     // the time span between the re-attach response being composed on the storage controller
     // and the first successful heartbeat after the processing of the re-attach response
@@ -195,7 +216,9 @@ impl From<NodeAvailabilityWrapper> for NodeAvailability {
         match val {
             // Assume the worst utilisation score to begin with. It will later be updated by
             // the heartbeats.
-            NodeAvailabilityWrapper::Active => NodeAvailability::Active(UtilizationScore::worst()),
+            NodeAvailabilityWrapper::Active => {
+                NodeAvailability::Active(PageserverUtilization::full())
+            }
             NodeAvailabilityWrapper::WarmingUp => NodeAvailability::WarmingUp(Instant::now()),
             NodeAvailabilityWrapper::Offline => NodeAvailability::Offline,
         }

libs/pageserver_api/src/key.rs

@@ -108,14 +108,41 @@ impl Key {
         }
     }
 
+    /// This function checks more extensively what keys we can take on the write path.
+    /// If a key beginning with 00 does not have a global/default tablespace OID, it
+    /// will be rejected on the write path.
+    #[allow(dead_code)]
+    pub fn is_valid_key_on_write_path_strong(&self) -> bool {
+        use postgres_ffi::pg_constants::{DEFAULTTABLESPACE_OID, GLOBALTABLESPACE_OID};
+        if !self.is_i128_representable() {
+            return false;
+        }
+        if self.field1 == 0
+            && !(self.field2 == GLOBALTABLESPACE_OID
+                || self.field2 == DEFAULTTABLESPACE_OID
+                || self.field2 == 0)
+        {
+            return false; // User defined tablespaces are not supported
+        }
+        true
+    }
+
+    /// This is a weaker version of `is_valid_key_on_write_path_strong` that simply
+    /// checks if the key is i128 representable. Note that some keys can be successfully
+    /// ingested into the pageserver, but will cause errors on generating basebackup.
+    pub fn is_valid_key_on_write_path(&self) -> bool {
+        self.is_i128_representable()
+    }
+
+    pub fn is_i128_representable(&self) -> bool {
+        self.field2 <= 0xFFFF || self.field2 == 0xFFFFFFFF || self.field2 == 0x22222222
+    }
+
     /// 'field2' is used to store tablespaceid for relations and small enum numbers for other relish.
     /// As long as Neon does not support tablespace (because of lack of access to local file system),
     /// we can assume that only some predefined namespace OIDs are used which can fit in u16
     pub fn to_i128(&self) -> i128 {
-        assert!(
+        assert!(self.is_i128_representable(), "invalid key: {self}");
-            self.field2 <= 0xFFFF || self.field2 == 0xFFFFFFFF || self.field2 == 0x22222222,
-            "invalid key: {self}",
-        );
         (((self.field1 & 0x7F) as i128) << 120)
             | (((self.field2 & 0xFFFF) as i128) << 104)
             | ((self.field3 as i128) << 72)

libs/pageserver_api/src/models.rs

@@ -6,8 +6,9 @@ pub use utilization::PageserverUtilization;
 
 use std::{
     collections::HashMap,
+    fmt::Display,
     io::{BufRead, Read},
-    num::{NonZeroU64, NonZeroUsize},
+    num::{NonZeroU32, NonZeroU64, NonZeroUsize},
     str::FromStr,
     sync::atomic::AtomicUsize,
     time::{Duration, SystemTime},
@@ -61,7 +62,7 @@ use bytes::{Buf, BufMut, Bytes, BytesMut};
     serde::Serialize,
     serde::Deserialize,
     strum_macros::Display,
-    strum_macros::EnumVariantNames,
+    strum_macros::VariantNames,
     strum_macros::AsRefStr,
     strum_macros::IntoStaticStr,
 )]
@@ -304,8 +305,10 @@ pub struct TenantConfig {
     pub lsn_lease_length_for_ts: Option<String>,
 }
 
-/// The policy for the aux file storage. It can be switched through `switch_aux_file_policy`
+/// The policy for the aux file storage.
-/// tenant config. When the first aux file written, the policy will be persisted in the
+///
+/// It can be switched through `switch_aux_file_policy` tenant config.
+/// When the first aux file written, the policy will be persisted in the
 /// `index_part.json` file and has a limited migration path.
 ///
 /// Currently, we only allow the following migration path:
@@ -348,7 +351,7 @@ impl AuxFilePolicy {
 
     /// If a tenant writes aux files without setting `switch_aux_policy`, this value will be used.
     pub fn default_tenant_config() -> Self {
-        Self::V1
+        Self::V2
     }
 }
 
@@ -435,7 +438,9 @@ pub enum CompactionAlgorithm {
     Tiered,
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(
+    Debug, Clone, Copy, PartialEq, Eq, serde_with::DeserializeFromStr, serde_with::SerializeDisplay,
+)]
 pub enum ImageCompressionAlgorithm {
     // Disabled for writes, support decompressing during read path
     Disabled,
@@ -470,11 +475,33 @@ impl FromStr for ImageCompressionAlgorithm {
     }
 }
 
+impl Display for ImageCompressionAlgorithm {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            ImageCompressionAlgorithm::Disabled => write!(f, "disabled"),
+            ImageCompressionAlgorithm::Zstd { level } => {
+                if let Some(level) = level {
+                    write!(f, "zstd({})", level)
+                } else {
+                    write!(f, "zstd")
+                }
+            }
+        }
+    }
+}
+
 #[derive(Eq, PartialEq, Debug, Clone, Serialize, Deserialize)]
 pub struct CompactionAlgorithmSettings {
     pub kind: CompactionAlgorithm,
 }
 
+#[derive(Debug, PartialEq, Eq, Clone, serde::Deserialize, serde::Serialize)]
+#[serde(tag = "mode", rename_all = "kebab-case", deny_unknown_fields)]
+pub enum L0FlushConfig {
+    #[serde(rename_all = "snake_case")]
+    Direct { max_concurrency: NonZeroUsize },
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub struct EvictionPolicyLayerAccessThreshold {
     #[serde(with = "humantime_serde")]
@@ -486,12 +513,11 @@ pub struct EvictionPolicyLayerAccessThreshold {
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
 pub struct ThrottleConfig {
     pub task_kinds: Vec<String>, // TaskKind
-    pub initial: usize,
+    pub initial: u32,
     #[serde(with = "humantime_serde")]
     pub refill_interval: Duration,
-    pub refill_amount: NonZeroUsize,
+    pub refill_amount: NonZeroU32,
-    pub max: usize,
+    pub max: u32,
-    pub fair: bool,
 }
 
 impl ThrottleConfig {
@@ -501,9 +527,8 @@ impl ThrottleConfig {
             // other values don't matter with emtpy `task_kinds`.
             initial: 0,
             refill_interval: Duration::from_millis(1),
-            refill_amount: NonZeroUsize::new(1).unwrap(),
+            refill_amount: NonZeroU32::new(1).unwrap(),
             max: 1,
-            fair: true,
         }
     }
     /// The requests per second allowed  by the given config.
@@ -721,8 +746,14 @@ pub struct TimelineInfo {
 
     pub walreceiver_status: String,
 
+    // ALWAYS add new fields at the end of the struct with `Option` to ensure forward/backward compatibility.
+    // Backward compatibility: you will get a JSON not containing the newly-added field.
+    // Forward compatibility: a previous version of the pageserver will receive a JSON. serde::Deserialize does
+    // not deny unknown fields by default so it's safe to set the field to some value, though it won't be
+    // read.
     /// The last aux file policy being used on this timeline
     pub last_aux_file_policy: Option<AuxFilePolicy>,
+    pub is_archived: Option<bool>,
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize)]
@@ -867,7 +898,9 @@ pub struct WalRedoManagerStatus {
     pub process: Option<WalRedoManagerProcessStatus>,
 }
 
-/// The progress of a secondary tenant is mostly useful when doing a long running download: e.g. initiating
+/// The progress of a secondary tenant.
+///
+/// It is mostly useful when doing a long running download: e.g. initiating
 /// a download job, timing out while waiting for it to run, and then inspecting this status to understand
 /// what's happening.
 #[derive(Default, Debug, Serialize, Deserialize, Clone)]
@@ -1062,7 +1095,7 @@ impl TryFrom<u8> for PagestreamBeMessageTag {
     }
 }
 
-// In the V2 protocol version, a GetPage request contains two LSN values:
+// A GetPage request contains two LSN values:
 //
 // request_lsn: Get the page version at this point in time.  Lsn::Max is a special value that means
 // "get the latest version present". It's used by the primary server, which knows that no one else
@@ -1075,7 +1108,7 @@ impl TryFrom<u8> for PagestreamBeMessageTag {
 // passing an earlier LSN can speed up the request, by allowing the pageserver to process the
 // request without waiting for 'request_lsn' to arrive.
 //
-// The legacy V1 interface contained only one LSN, and a boolean 'latest' flag. The V1 interface was
+// The now-defunct V1 interface contained only one LSN, and a boolean 'latest' flag. The V1 interface was
 // sufficient for the primary; the 'lsn' was equivalent to the 'not_modified_since' value, and
 // 'latest' was set to true. The V2 interface was added because there was no correct way for a
 // standby to request a page at a particular non-latest LSN, and also include the
@@ -1083,15 +1116,11 @@ impl TryFrom<u8> for PagestreamBeMessageTag {
 // request, if the standby knows that the page hasn't been modified since, and risk getting an error
 // if that LSN has fallen behind the GC horizon, or requesting the current replay LSN, which could
 // require the pageserver unnecessarily to wait for the WAL to arrive up to that point. The new V2
-// interface allows sending both LSNs, and let the pageserver do the right thing. There is no
+// interface allows sending both LSNs, and let the pageserver do the right thing. There was no
 // difference in the responses between V1 and V2.
 //
-// The Request structs below reflect the V2 interface. If V1 is used, the parse function
-// maps the old format requests to the new format.
-//
 #[derive(Clone, Copy)]
 pub enum PagestreamProtocolVersion {
-    V1,
     V2,
 }
 
@@ -1230,36 +1259,17 @@ impl PagestreamFeMessage {
         bytes.into()
     }
 
-    pub fn parse<R: std::io::Read>(
+    pub fn parse<R: std::io::Read>(body: &mut R) -> anyhow::Result<PagestreamFeMessage> {
-        body: &mut R,
-        protocol_version: PagestreamProtocolVersion,
-    ) -> anyhow::Result<PagestreamFeMessage> {
         // these correspond to the NeonMessageTag enum in pagestore_client.h
         //
         // TODO: consider using protobuf or serde bincode for less error prone
         // serialization.
         let msg_tag = body.read_u8()?;
 
-        let (request_lsn, not_modified_since) = match protocol_version {
+        // these two fields are the same for every request type
-            PagestreamProtocolVersion::V2 => (
+        let request_lsn = Lsn::from(body.read_u64::<BigEndian>()?);
-                Lsn::from(body.read_u64::<BigEndian>()?),
+        let not_modified_since = Lsn::from(body.read_u64::<BigEndian>()?);
-                Lsn::from(body.read_u64::<BigEndian>()?),
-            ),
-            PagestreamProtocolVersion::V1 => {
-                // In the old protocol, each message starts with a boolean 'latest' flag,
-                // followed by 'lsn'. Convert that to the two LSNs, 'request_lsn' and
-                // 'not_modified_since', used in the new protocol version.
-                let latest = body.read_u8()? != 0;
-                let request_lsn = Lsn::from(body.read_u64::<BigEndian>()?);
-                if latest {
-                    (Lsn::MAX, request_lsn) // get latest version
-                } else {
-                    (request_lsn, request_lsn) // get version at specified LSN
-                }
-            }
-        };
 
-        // The rest of the messages are the same between V1 and V2
         match msg_tag {
             0 => Ok(PagestreamFeMessage::Exists(PagestreamExistsRequest {
                 request_lsn,
@@ -1467,9 +1477,7 @@ mod tests {
         ];
         for msg in messages {
             let bytes = msg.serialize();
-            let reconstructed =
+            let reconstructed = PagestreamFeMessage::parse(&mut bytes.reader()).unwrap();
-                PagestreamFeMessage::parse(&mut bytes.reader(), PagestreamProtocolVersion::V2)
-                    .unwrap();
             assert!(msg == reconstructed);
         }
     }
@@ -1677,21 +1685,33 @@ mod tests {
     #[test]
     fn test_image_compression_algorithm_parsing() {
         use ImageCompressionAlgorithm::*;
-        assert_eq!(
+        let cases = [
-            ImageCompressionAlgorithm::from_str("disabled").unwrap(),
+            ("disabled", Disabled),
-            Disabled
+            ("zstd", Zstd { level: None }),
-        );
+            ("zstd(18)", Zstd { level: Some(18) }),
-        assert_eq!(
+            ("zstd(-3)", Zstd { level: Some(-3) }),
-            ImageCompressionAlgorithm::from_str("zstd").unwrap(),
+        ];
-            Zstd { level: None }
+
-        );
+        for (display, expected) in cases {
-        assert_eq!(
+            assert_eq!(
-            ImageCompressionAlgorithm::from_str("zstd(18)").unwrap(),
+                ImageCompressionAlgorithm::from_str(display).unwrap(),
-            Zstd { level: Some(18) }
+                expected,
-        );
+                "parsing works"
-        assert_eq!(
+            );
-            ImageCompressionAlgorithm::from_str("zstd(-3)").unwrap(),
+            assert_eq!(format!("{expected}"), display, "Display FromStr roundtrip");
-            Zstd { level: Some(-3) }
+
-        );
+            let ser = serde_json::to_string(&expected).expect("serialization");
+            assert_eq!(
+                serde_json::from_str::<ImageCompressionAlgorithm>(&ser).unwrap(),
+                expected,
+                "serde roundtrip"
+            );
+
+            assert_eq!(
+                serde_json::Value::String(display.to_string()),
+                serde_json::to_value(expected).unwrap(),
+                "Display is the serde serialization"
+            );
+        }
     }
 }

libs/pageserver_api/src/models/utilization.rs

@@ -38,7 +38,7 @@ pub struct PageserverUtilization {
     pub max_shard_count: u32,
 
     /// Cached result of [`Self::score`]
-    pub utilization_score: u64,
+    pub utilization_score: Option<u64>,
 
     /// When was this snapshot captured, pageserver local time.
     ///
@@ -50,6 +50,8 @@ fn unity_percent() -> Percent {
     Percent::new(0).unwrap()
 }
 
+pub type RawScore = u64;
+
 impl PageserverUtilization {
     const UTILIZATION_FULL: u64 = 1000000;
 
@@ -62,7 +64,7 @@ impl PageserverUtilization {
     /// - Negative values are forbidden
     /// - Values over UTILIZATION_FULL indicate an overloaded node, which may show degraded performance due to
     ///   layer eviction.
-    pub fn score(&self) -> u64 {
+    pub fn score(&self) -> RawScore {
         let disk_usable_capacity = ((self.disk_usage_bytes + self.free_space_bytes)
             * self.disk_usable_pct.get() as u64)
             / 100;
@@ -74,8 +76,41 @@ impl PageserverUtilization {
         std::cmp::max(disk_utilization_score, shard_utilization_score)
     }
 
-    pub fn refresh_score(&mut self) {
+    pub fn cached_score(&mut self) -> RawScore {
-        self.utilization_score = self.score();
+        match self.utilization_score {
+            None => {
+                let s = self.score();
+                self.utilization_score = Some(s);
+                s
+            }
+            Some(s) => s,
+        }
+    }
+
+    /// If a node is currently hosting more work than it can comfortably handle.  This does not indicate that
+    /// it will fail, but it is a strong signal that more work should not be added unless there is no alternative.
+    ///
+    /// When a node is overloaded, we may override soft affinity preferences and do things like scheduling
+    /// into a node in a less desirable AZ, if all the nodes in the preferred AZ are overloaded.
+    pub fn is_overloaded(score: RawScore) -> bool {
+        // Why the factor of two?  This is unscientific but reflects behavior of real systems:
+        // - In terms of shard counts, a node's preferred max count is a soft limit intended to keep
+        //   startup and housekeeping jobs nice and responsive.  We can go to double this limit if needed
+        //   until some more nodes are deployed.
+        // - In terms of disk space, the node's utilization heuristic assumes every tenant needs to
+        //   hold its biggest timeline fully on disk, which is tends to be an over estimate when
+        //   some tenants are very idle and have dropped layers from disk.  In practice going up to
+        //   double is generally better than giving up and scheduling in a sub-optimal AZ.
+        score >= 2 * Self::UTILIZATION_FULL
+    }
+
+    pub fn adjust_shard_count_max(&mut self, shard_count: u32) {
+        if self.shard_count < shard_count {
+            self.shard_count = shard_count;
+
+            // Dirty cache: this will be calculated next time someone retrives the score
+            self.utilization_score = None;
+        }
     }
 
     /// A utilization structure that has a full utilization score: use this as a placeholder when
@@ -88,7 +123,38 @@ impl PageserverUtilization {
             disk_usable_pct: Percent::new(100).unwrap(),
             shard_count: 1,
             max_shard_count: 1,
-            utilization_score: Self::UTILIZATION_FULL,
+            utilization_score: Some(Self::UTILIZATION_FULL),
+            captured_at: serde_system_time::SystemTime(SystemTime::now()),
+        }
+    }
+}
+
+/// Test helper
+pub mod test_utilization {
+    use super::PageserverUtilization;
+    use std::time::SystemTime;
+    use utils::{
+        serde_percent::Percent,
+        serde_system_time::{self},
+    };
+
+    // Parameters of the imaginary node used for test utilization instances
+    const TEST_DISK_SIZE: u64 = 1024 * 1024 * 1024 * 1024;
+    const TEST_SHARDS_MAX: u32 = 1000;
+
+    /// Unit test helper.  Unconditionally compiled because cfg(test) doesn't carry across crates.  Do
+    /// not abuse this function from non-test code.
+    ///
+    /// Emulates a node with a 1000 shard limit and a 1TB disk.
+    pub fn simple(shard_count: u32, disk_wanted_bytes: u64) -> PageserverUtilization {
+        PageserverUtilization {
+            disk_usage_bytes: disk_wanted_bytes,
+            free_space_bytes: TEST_DISK_SIZE - std::cmp::min(disk_wanted_bytes, TEST_DISK_SIZE),
+            disk_wanted_bytes,
+            disk_usable_pct: Percent::new(100).unwrap(),
+            shard_count,
+            max_shard_count: TEST_SHARDS_MAX,
+            utilization_score: None,
             captured_at: serde_system_time::SystemTime(SystemTime::now()),
         }
     }
@@ -120,7 +186,7 @@ mod tests {
             disk_usage_bytes: u64::MAX,
             free_space_bytes: 0,
             disk_wanted_bytes: u64::MAX,
-            utilization_score: 13,
+            utilization_score: Some(13),
             disk_usable_pct: Percent::new(90).unwrap(),
             shard_count: 100,
             max_shard_count: 200,

libs/postgres_backend/src/lib.rs

@@ -69,8 +69,10 @@ impl QueryError {
 }
 
 /// Returns true if the given error is a normal consequence of a network issue,
-/// or the client closing the connection. These errors can happen during normal
+/// or the client closing the connection.
-/// operations, and don't indicate a bug in our code.
+///
+/// These errors can happen during normal operations,
+/// and don't indicate a bug in our code.
 pub fn is_expected_io_error(e: &io::Error) -> bool {
     use io::ErrorKind::*;
     matches!(
@@ -79,17 +81,16 @@ pub fn is_expected_io_error(e: &io::Error) -> bool {
     )
 }
 
-#[async_trait::async_trait]
 pub trait Handler<IO> {
     /// Handle single query.
     /// postgres_backend will issue ReadyForQuery after calling this (this
     /// might be not what we want after CopyData streaming, but currently we don't
     /// care). It will also flush out the output buffer.
-    async fn process_query(
+    fn process_query(
         &mut self,
         pgb: &mut PostgresBackend<IO>,
         query_string: &str,
-    ) -> Result<(), QueryError>;
+    ) -> impl Future<Output = Result<(), QueryError>>;
 
     /// Called on startup packet receival, allows to process params.
     ///

libs/postgres_backend/tests/simple_select.rs

@@ -23,7 +23,6 @@ async fn make_tcp_pair() -> (TcpStream, TcpStream) {
 
 struct TestHandler {}
 
-#[async_trait::async_trait]
 impl<IO: AsyncRead + AsyncWrite + Unpin + Send> Handler<IO> for TestHandler {
     // return single col 'hey' for any query
     async fn process_query(

libs/postgres_connection/src/lib.rs

@@ -7,6 +7,7 @@ use std::fmt;
 use url::Host;
 
 /// Parses a string of format either `host:port` or `host` into a corresponding pair.
+///
 /// The `host` part should be a correct `url::Host`, while `port` (if present) should be
 /// a valid decimal u16 of digits only.
 pub fn parse_host_port<S: AsRef<str>>(host_port: S) -> Result<(Host, Option<u16>), anyhow::Error> {

libs/postgres_ffi/build.rs

@@ -14,7 +14,7 @@ impl ParseCallbacks for PostgresFfiCallbacks {
     fn include_file(&self, filename: &str) {
         // This does the equivalent of passing bindgen::CargoCallbacks
         // to the builder .parse_callbacks() method.
-        let cargo_callbacks = bindgen::CargoCallbacks;
+        let cargo_callbacks = bindgen::CargoCallbacks::new();
         cargo_callbacks.include_file(filename)
     }
 
@@ -121,6 +121,7 @@ fn main() -> anyhow::Result<()> {
             .allowlist_type("XLogPageHeaderData")
             .allowlist_type("XLogLongPageHeaderData")
             .allowlist_var("XLOG_PAGE_MAGIC")
+            .allowlist_var("PG_MAJORVERSION_NUM")
             .allowlist_var("PG_CONTROL_FILE_SIZE")
             .allowlist_var("PG_CONTROLFILEDATA_OFFSETOF_CRC")
             .allowlist_type("PageHeaderData")

libs/postgres_ffi/src/lib.rs

@@ -44,6 +44,9 @@ macro_rules! postgres_ffi {
             // Re-export some symbols from bindings
             pub use bindings::DBState_DB_SHUTDOWNED;
             pub use bindings::{CheckPoint, ControlFileData, XLogRecord};
+
+            pub const ZERO_CHECKPOINT: bytes::Bytes =
+                bytes::Bytes::from_static(&[0u8; xlog_utils::SIZEOF_CHECKPOINT]);
         }
     };
 }
@@ -106,6 +109,107 @@ macro_rules! dispatch_pgversion {
     };
 }
 
+#[macro_export]
+macro_rules! enum_pgversion_dispatch {
+    ($name:expr, $typ:ident, $bind:ident, $code:block) => {
+        enum_pgversion_dispatch!(
+            name = $name,
+            bind = $bind,
+            typ = $typ,
+            code = $code,
+            pgversions = [
+                V14 : v14,
+                V15 : v15,
+                V16 : v16,
+            ]
+        )
+    };
+    (name = $name:expr,
+     bind = $bind:ident,
+     typ = $typ:ident,
+     code = $code:block,
+     pgversions = [$($variant:ident : $md:ident),+ $(,)?]) => {
+        match $name {
+            $(
+            self::$typ::$variant($bind) => {
+                use $crate::$md as pgv;
+                $code
+            }
+            ),+,
+        }
+    };
+}
+
+#[macro_export]
+macro_rules! enum_pgversion {
+    {$name:ident, pgv :: $t:ident} => {
+        enum_pgversion!{
+            name = $name,
+            typ = $t,
+            pgversions = [
+                V14 : v14,
+                V15 : v15,
+                V16 : v16,
+            ]
+        }
+    };
+    {$name:ident, pgv :: $p:ident :: $t:ident} => {
+        enum_pgversion!{
+            name = $name,
+            path = $p,
+            typ = $t,
+            pgversions = [
+                V14 : v14,
+                V15 : v15,
+                V16 : v16,
+            ]
+        }
+    };
+    {name = $name:ident,
+     typ = $t:ident,
+     pgversions = [$($variant:ident : $md:ident),+ $(,)?]} => {
+        pub enum $name {
+            $($variant ( $crate::$md::$t )),+
+        }
+        impl self::$name {
+            pub fn pg_version(&self) -> u32 {
+                enum_pgversion_dispatch!(self, $name, _ign, {
+                    pgv::bindings::PG_MAJORVERSION_NUM
+                })
+            }
+        }
+        $(
+        impl Into<self::$name> for $crate::$md::$t {
+            fn into(self) -> self::$name {
+                self::$name::$variant (self)
+            }
+        }
+        )+
+    };
+    {name = $name:ident,
+     path = $p:ident,
+     typ = $t:ident,
+     pgversions = [$($variant:ident : $md:ident),+ $(,)?]} => {
+        pub enum $name {
+            $($variant ($crate::$md::$p::$t)),+
+        }
+        impl $name {
+            pub fn pg_version(&self) -> u32 {
+                enum_pgversion_dispatch!(self, $name, _ign, {
+                    pgv::bindings::PG_MAJORVERSION_NUM
+                })
+            }
+        }
+        $(
+        impl Into<$name> for $crate::$md::$p::$t {
+            fn into(self) -> $name {
+                $name::$variant (self)
+            }
+        }
+        )+
+    };
+}
+
 pub mod pg_constants;
 pub mod relfile_utils;
 
@@ -136,9 +240,9 @@ pub const MAX_SEND_SIZE: usize = XLOG_BLCKSZ * 16;
 
 // Export some version independent functions that are used outside of this mod
 pub use v14::xlog_utils::encode_logical_message;
-pub use v14::xlog_utils::from_pg_timestamp;
 pub use v14::xlog_utils::get_current_timestamp;
 pub use v14::xlog_utils::to_pg_timestamp;
+pub use v14::xlog_utils::try_from_pg_timestamp;
 pub use v14::xlog_utils::XLogFileName;
 
 pub use v14::bindings::DBState_DB_SHUTDOWNED;

libs/postgres_ffi/src/xlog_utils.rs

@@ -135,6 +135,8 @@ pub fn get_current_timestamp() -> TimestampTz {
 mod timestamp_conversions {
     use std::time::Duration;
 
+    use anyhow::Context;
+
     use super::*;
 
     const UNIX_EPOCH_JDATE: u64 = 2440588; // == date2j(1970, 1, 1)
@@ -154,18 +156,18 @@ mod timestamp_conversions {
         }
     }
 
-    pub fn from_pg_timestamp(time: TimestampTz) -> SystemTime {
+    pub fn try_from_pg_timestamp(time: TimestampTz) -> anyhow::Result<SystemTime> {
         let time: u64 = time
             .try_into()
-            .expect("timestamp before millenium (postgres epoch)");
+            .context("timestamp before millenium (postgres epoch)")?;
         let since_unix_epoch = time + SECS_DIFF_UNIX_TO_POSTGRES_EPOCH * USECS_PER_SEC;
         SystemTime::UNIX_EPOCH
             .checked_add(Duration::from_micros(since_unix_epoch))
-            .expect("SystemTime overflow")
+            .context("SystemTime overflow")
     }
 }
 
-pub use timestamp_conversions::{from_pg_timestamp, to_pg_timestamp};
+pub use timestamp_conversions::{to_pg_timestamp, try_from_pg_timestamp};
 
 // Returns (aligned) end_lsn of the last record in data_dir with WAL segments.
 // start_lsn must point to some previously known record boundary (beginning of
@@ -545,14 +547,14 @@ mod tests {
     #[test]
     fn test_ts_conversion() {
         let now = SystemTime::now();
-        let round_trip = from_pg_timestamp(to_pg_timestamp(now));
+        let round_trip = try_from_pg_timestamp(to_pg_timestamp(now)).unwrap();
 
         let now_since = now.duration_since(SystemTime::UNIX_EPOCH).unwrap();
         let round_trip_since = round_trip.duration_since(SystemTime::UNIX_EPOCH).unwrap();
         assert_eq!(now_since.as_micros(), round_trip_since.as_micros());
 
         let now_pg = get_current_timestamp();
-        let round_trip_pg = to_pg_timestamp(from_pg_timestamp(now_pg));
+        let round_trip_pg = to_pg_timestamp(try_from_pg_timestamp(now_pg).unwrap());
 
         assert_eq!(now_pg, round_trip_pg);
     }

libs/remote_storage/src/config.rs

@@ -185,7 +185,7 @@ mod tests {
     use super::*;
 
     fn parse(input: &str) -> anyhow::Result<RemoteStorageConfig> {
-        let toml = input.parse::<toml_edit::Document>().unwrap();
+        let toml = input.parse::<toml_edit::DocumentMut>().unwrap();
         RemoteStorageConfig::from_toml(toml.as_item())
     }
 
@@ -235,6 +235,31 @@ timeout = '5s'";
         );
     }
 
+    #[test]
+    fn test_storage_class_serde_roundtrip() {
+        let classes = [
+            None,
+            Some(StorageClass::Standard),
+            Some(StorageClass::IntelligentTiering),
+        ];
+        for class in classes {
+            #[derive(Serialize, Deserialize)]
+            struct Wrapper {
+                #[serde(
+                    deserialize_with = "deserialize_storage_class",
+                    serialize_with = "serialize_storage_class"
+                )]
+                class: Option<StorageClass>,
+            }
+            let wrapped = Wrapper {
+                class: class.clone(),
+            };
+            let serialized = serde_json::to_string(&wrapped).unwrap();
+            let deserialized: Wrapper = serde_json::from_str(&serialized).unwrap();
+            assert_eq!(class, deserialized.class);
+        }
+    }
+
     #[test]
     fn test_azure_parsing() {
         let toml = "\

libs/remote_storage/src/lib.rs

@@ -45,6 +45,8 @@ pub use azure_core::Etag;
 
 pub use error::{DownloadError, TimeTravelError, TimeoutOrCancel};
 
+/// Default concurrency limit for S3 operations
+///
 /// Currently, sync happens with AWS S3, that has two limits on requests per second:
 /// ~200 RPS for IAM services
 /// <https://docs.aws.amazon.com/AmazonRDS/latest/AuroraUserGuide/UsingWithRDS.IAMDBAuth.html>
@@ -300,7 +302,9 @@ pub trait RemoteStorage: Send + Sync + 'static {
     ) -> Result<(), TimeTravelError>;
 }
 
-/// DownloadStream is sensitive to the timeout and cancellation used with the original
+/// Data part of an ongoing [`Download`].
+///
+/// `DownloadStream` is sensitive to the timeout and cancellation used with the original
 /// [`RemoteStorage::download`] request. The type yields `std::io::Result<Bytes>` to be compatible
 /// with `tokio::io::copy_buf`.
 // This has 'static because safekeepers do not use cancellation tokens (yet)

libs/safekeeper_api/src/models.rs

@@ -60,3 +60,16 @@ pub struct TimelineCopyRequest {
     pub target_timeline_id: TimelineId,
     pub until_lsn: Lsn,
 }
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct TimelineTermBumpRequest {
+    /// bump to
+    pub term: Option<u64>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct TimelineTermBumpResponse {
+    // before the request
+    pub previous_term: u64,
+    pub current_term: u64,
+}

libs/tenant_size_model/src/lib.rs

@@ -5,9 +5,10 @@
 mod calculation;
 pub mod svg;
 
-/// StorageModel is the input to the synthetic size calculation. It represents
+/// StorageModel is the input to the synthetic size calculation.
-/// a tree of timelines, with just the information that's needed for the
+///
-/// calculation. This doesn't track timeline names or where each timeline
+/// It represents a tree of timelines, with just the information that's needed
+/// for the calculation. This doesn't track timeline names or where each timeline
 /// begins and ends, for example. Instead, it consists of "points of interest"
 /// on the timelines. A point of interest could be the timeline start or end point,
 /// the oldest point on a timeline that needs to be retained because of PITR

libs/utils/Cargo.toml

@@ -14,7 +14,6 @@ testing = ["fail/failpoints"]
 arc-swap.workspace = true
 sentry.workspace = true
 async-compression.workspace = true
-async-trait.workspace = true
 anyhow.workspace = true
 bincode.workspace = true
 bytes.workspace = true
@@ -26,7 +25,6 @@ hyper = { workspace = true, features = ["full"] }
 fail.workspace = true
 futures = { workspace = true}
 jsonwebtoken.workspace = true
-leaky-bucket.workspace = true
 nix.workspace = true
 once_cell.workspace = true
 pin-project-lite.workspace = true

libs/utils/src/circuit_breaker.rs

@@ -5,8 +5,10 @@ use std::{
 
 use metrics::IntCounter;
 
-/// Circuit breakers are for operations that are expensive and fallible: if they fail repeatedly,
+/// Circuit breakers are for operations that are expensive and fallible.
-/// we will stop attempting them for some period of time, to avoid denial-of-service from retries, and
+///
+/// If a circuit breaker fails repeatedly, we will stop attempting it for some
+/// period of time, to avoid denial-of-service from retries, and
 /// to mitigate the log spam from repeated failures.
 pub struct CircuitBreaker {
     /// An identifier that enables us to log useful errors when a circuit is broken

libs/utils/src/crashsafe.rs

@@ -1,3 +1,4 @@
+use std::os::fd::AsRawFd;
 use std::{
     borrow::Cow,
     fs::{self, File},
@@ -203,6 +204,27 @@ pub fn overwrite(
     Ok(())
 }
 
+/// Syncs the filesystem for the given file descriptor.
+#[cfg_attr(target_os = "macos", allow(unused_variables))]
+pub fn syncfs(fd: impl AsRawFd) -> anyhow::Result<()> {
+    // Linux guarantees durability for syncfs.
+    // POSIX doesn't have syncfs, and further does not actually guarantee durability of sync().
+    #[cfg(target_os = "linux")]
+    {
+        use anyhow::Context;
+        nix::unistd::syncfs(fd.as_raw_fd()).context("syncfs")?;
+    }
+    #[cfg(target_os = "macos")]
+    {
+        // macOS is not a production platform for Neon, don't even bother.
+    }
+    #[cfg(not(any(target_os = "linux", target_os = "macos")))]
+    {
+        compile_error!("Unsupported OS");
+    }
+    Ok(())
+}
+
 #[cfg(test)]
 mod tests {
 

libs/utils/src/id.rs

@@ -249,8 +249,10 @@ macro_rules! id_newtype {
     };
 }
 
-/// Neon timeline IDs are different from PostgreSQL timeline
+/// Neon timeline ID.
-/// IDs. They serve a similar purpose though: they differentiate
+///
+/// They are different from PostgreSQL timeline
+/// IDs, but serve a similar purpose: they differentiate
 /// between different "histories" of the same cluster.  However,
 /// PostgreSQL timeline IDs are a bit cumbersome, because they are only
 /// 32-bits wide, and they must be in ascending order in any given

libs/utils/src/leaky_bucket.rs

@@ -0,0 +1,280 @@
+//! This module implements the Generic Cell Rate Algorithm for a simplified
+//! version of the Leaky Bucket rate limiting system.
+//!
+//! # Leaky Bucket
+//!
+//! If the bucket is full, no new requests are allowed and are throttled/errored.
+//! If the bucket is partially full/empty, new requests are added to the bucket in
+//! terms of "tokens".
+//!
+//! Over time, tokens are removed from the bucket, naturally allowing new requests at a steady rate.
+//!
+//! The bucket size tunes the burst support. The drain rate tunes the steady-rate requests per second.
+//!
+//! # [GCRA](https://en.wikipedia.org/wiki/Generic_cell_rate_algorithm)
+//!
+//! GCRA is a continuous rate leaky-bucket impl that stores minimal state and requires
+//! no background jobs to drain tokens, as the design utilises timestamps to drain automatically over time.
+//!
+//! We store an "empty_at" timestamp as the only state. As time progresses, we will naturally approach
+//! the empty state. The full-bucket state is calculated from `empty_at - config.bucket_width`.
+//!
+//! Another explaination can be found here: <https://brandur.org/rate-limiting>
+
+use std::{sync::Mutex, time::Duration};
+
+use tokio::{sync::Notify, time::Instant};
+
+pub struct LeakyBucketConfig {
+    /// This is the "time cost" of a single request unit.
+    /// Should loosely represent how long it takes to handle a request unit in active resource time.
+    /// Loosely speaking this is the inverse of the steady-rate requests-per-second
+    pub cost: Duration,
+
+    /// total size of the bucket
+    pub bucket_width: Duration,
+}
+
+impl LeakyBucketConfig {
+    pub fn new(rps: f64, bucket_size: f64) -> Self {
+        let cost = Duration::from_secs_f64(rps.recip());
+        let bucket_width = cost.mul_f64(bucket_size);
+        Self { cost, bucket_width }
+    }
+}
+
+pub struct LeakyBucketState {
+    /// Bucket is represented by `allow_at..empty_at` where `allow_at = empty_at - config.bucket_width`.
+    ///
+    /// At any given time, `empty_at - now` represents the number of tokens in the bucket, multiplied by the "time_cost".
+    /// Adding `n` tokens to the bucket is done by moving `empty_at` forward by `n * config.time_cost`.
+    /// If `now < allow_at`, the bucket is considered filled and cannot accept any more tokens.
+    /// Draining the bucket will happen naturally as `now` moves forward.
+    ///
+    /// Let `n` be some "time cost" for the request,
+    /// If now is after empty_at, the bucket is empty and the empty_at is reset to now,
+    /// If now is within the `bucket window + n`, we are within time budget.
+    /// If now is before the `bucket window + n`, we have run out of budget.
+    ///
+    /// This is inspired by the generic cell rate algorithm (GCRA) and works
+    /// exactly the same as a leaky-bucket.
+    pub empty_at: Instant,
+}
+
+impl LeakyBucketState {
+    pub fn with_initial_tokens(config: &LeakyBucketConfig, initial_tokens: f64) -> Self {
+        LeakyBucketState {
+            empty_at: Instant::now() + config.cost.mul_f64(initial_tokens),
+        }
+    }
+
+    pub fn bucket_is_empty(&self, now: Instant) -> bool {
+        // if self.end is after now, the bucket is not empty
+        self.empty_at <= now
+    }
+
+    /// Immediately adds tokens to the bucket, if there is space.
+    ///
+    /// In a scenario where you are waiting for available rate,
+    /// rather than just erroring immediately, `started` corresponds to when this waiting started.
+    ///
+    /// `n` is the number of tokens that will be filled in the bucket.
+    ///
+    /// # Errors
+    ///
+    /// If there is not enough space, no tokens are added. Instead, an error is returned with the time when
+    /// there will be space again.
+    pub fn add_tokens(
+        &mut self,
+        config: &LeakyBucketConfig,
+        started: Instant,
+        n: f64,
+    ) -> Result<(), Instant> {
+        let now = Instant::now();
+
+        // invariant: started <= now
+        debug_assert!(started <= now);
+
+        // If the bucket was empty when we started our search,
+        // we should update the `empty_at` value accordingly.
+        // this prevents us from having negative tokens in the bucket.
+        let mut empty_at = self.empty_at;
+        if empty_at < started {
+            empty_at = started;
+        }
+
+        let n = config.cost.mul_f64(n);
+        let new_empty_at = empty_at + n;
+        let allow_at = new_empty_at.checked_sub(config.bucket_width);
+
+        //                     empty_at
+        //          allow_at    |   new_empty_at
+        //           /          |   /
+        // -------o-[---------o-|--]---------
+        //   now1 ^      now2 ^
+        //
+        // at now1, the bucket would be completely filled if we add n tokens.
+        // at now2, the bucket would be partially filled if we add n tokens.
+
+        match allow_at {
+            Some(allow_at) if now < allow_at => Err(allow_at),
+            _ => {
+                self.empty_at = new_empty_at;
+                Ok(())
+            }
+        }
+    }
+}
+
+pub struct RateLimiter {
+    pub config: LeakyBucketConfig,
+    pub state: Mutex<LeakyBucketState>,
+    /// a queue to provide this fair ordering.
+    pub queue: Notify,
+}
+
+struct Requeue<'a>(&'a Notify);
+
+impl Drop for Requeue<'_> {
+    fn drop(&mut self) {
+        self.0.notify_one();
+    }
+}
+
+impl RateLimiter {
+    pub fn with_initial_tokens(config: LeakyBucketConfig, initial_tokens: f64) -> Self {
+        RateLimiter {
+            state: Mutex::new(LeakyBucketState::with_initial_tokens(
+                &config,
+                initial_tokens,
+            )),
+            config,
+            queue: {
+                let queue = Notify::new();
+                queue.notify_one();
+                queue
+            },
+        }
+    }
+
+    pub fn steady_rps(&self) -> f64 {
+        self.config.cost.as_secs_f64().recip()
+    }
+
+    /// returns true if we did throttle
+    pub async fn acquire(&self, count: usize) -> bool {
+        let mut throttled = false;
+
+        let start = tokio::time::Instant::now();
+
+        // wait until we are the first in the queue
+        let mut notified = std::pin::pin!(self.queue.notified());
+        if !notified.as_mut().enable() {
+            throttled = true;
+            notified.await;
+        }
+
+        // notify the next waiter in the queue when we are done.
+        let _guard = Requeue(&self.queue);
+
+        loop {
+            let res = self
+                .state
+                .lock()
+                .unwrap()
+                .add_tokens(&self.config, start, count as f64);
+            match res {
+                Ok(()) => return throttled,
+                Err(ready_at) => {
+                    throttled = true;
+                    tokio::time::sleep_until(ready_at).await;
+                }
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::time::Duration;
+
+    use tokio::time::Instant;
+
+    use super::{LeakyBucketConfig, LeakyBucketState};
+
+    #[tokio::test(start_paused = true)]
+    async fn check() {
+        let config = LeakyBucketConfig {
+            // average 100rps
+            cost: Duration::from_millis(10),
+            // burst up to 100 requests
+            bucket_width: Duration::from_millis(1000),
+        };
+
+        let mut state = LeakyBucketState {
+            empty_at: Instant::now(),
+        };
+
+        // supports burst
+        {
+            // should work for 100 requests this instant
+            for _ in 0..100 {
+                state.add_tokens(&config, Instant::now(), 1.0).unwrap();
+            }
+            let ready = state.add_tokens(&config, Instant::now(), 1.0).unwrap_err();
+            assert_eq!(ready - Instant::now(), Duration::from_millis(10));
+        }
+
+        // doesn't overfill
+        {
+            // after 1s we should have an empty bucket again.
+            tokio::time::advance(Duration::from_secs(1)).await;
+            assert!(state.bucket_is_empty(Instant::now()));
+
+            // after 1s more, we should not over count the tokens and allow more than 200 requests.
+            tokio::time::advance(Duration::from_secs(1)).await;
+            for _ in 0..100 {
+                state.add_tokens(&config, Instant::now(), 1.0).unwrap();
+            }
+            let ready = state.add_tokens(&config, Instant::now(), 1.0).unwrap_err();
+            assert_eq!(ready - Instant::now(), Duration::from_millis(10));
+        }
+
+        // supports sustained rate over a long period
+        {
+            tokio::time::advance(Duration::from_secs(1)).await;
+
+            // should sustain 100rps
+            for _ in 0..2000 {
+                tokio::time::advance(Duration::from_millis(10)).await;
+                state.add_tokens(&config, Instant::now(), 1.0).unwrap();
+            }
+        }
+
+        // supports requesting more tokens than can be stored in the bucket
+        // we just wait a little bit longer upfront.
+        {
+            // start the bucket completely empty
+            tokio::time::advance(Duration::from_secs(5)).await;
+            assert!(state.bucket_is_empty(Instant::now()));
+
+            // requesting 200 tokens of space should take 200*cost = 2s
+            // but we already have 1s available, so we wait 1s from start.
+            let start = Instant::now();
+
+            let ready = state.add_tokens(&config, start, 200.0).unwrap_err();
+            assert_eq!(ready - Instant::now(), Duration::from_secs(1));
+
+            tokio::time::advance(Duration::from_millis(500)).await;
+            let ready = state.add_tokens(&config, start, 200.0).unwrap_err();
+            assert_eq!(ready - Instant::now(), Duration::from_millis(500));
+
+            tokio::time::advance(Duration::from_millis(500)).await;
+            state.add_tokens(&config, start, 200.0).unwrap();
+
+            // bucket should be completely full now
+            let ready = state.add_tokens(&config, Instant::now(), 1.0).unwrap_err();
+            assert_eq!(ready - Instant::now(), Duration::from_millis(10));
+        }
+    }
+}

libs/utils/src/lib.rs

@@ -71,6 +71,7 @@ pub mod postgres_client;
 
 pub mod tracing_span_assert;
 
+pub mod leaky_bucket;
 pub mod rate_limit;
 
 /// Simple once-barrier and a guard which keeps barrier awaiting.

libs/utils/src/lock_file.rs

@@ -100,7 +100,9 @@ pub enum LockFileRead {
 }
 
 /// Open & try to lock the lock file at the given `path`, returning a [handle][`LockFileRead`] to
-/// inspect its content. It is not an `Err(...)` if the file does not exist or is already locked.
+/// inspect its content.
+///
+/// It is not an `Err(...)` if the file does not exist or is already locked.
 /// Check the [`LockFileRead`] variants for details.
 pub fn read_and_hold_lock_file(path: &Utf8Path) -> anyhow::Result<LockFileRead> {
     let res = fs::OpenOptions::new().read(true).open(path);

libs/utils/src/logging.rs

@@ -3,9 +3,9 @@ use std::str::FromStr;
 use anyhow::Context;
 use metrics::{IntCounter, IntCounterVec};
 use once_cell::sync::Lazy;
-use strum_macros::{EnumString, EnumVariantNames};
+use strum_macros::{EnumString, VariantNames};
 
-#[derive(EnumString, EnumVariantNames, Eq, PartialEq, Debug, Clone, Copy)]
+#[derive(EnumString, strum_macros::Display, VariantNames, Eq, PartialEq, Debug, Clone, Copy)]
 #[strum(serialize_all = "snake_case")]
 pub enum LogFormat {
     Plain,
@@ -188,7 +188,7 @@ impl Drop for TracingPanicHookGuard {
 }
 
 /// Named symbol for our panic hook, which logs the panic.
-fn tracing_panic_hook(info: &std::panic::PanicInfo) {
+fn tracing_panic_hook(info: &std::panic::PanicHookInfo) {
     // following rust 1.66.1 std implementation:
     // https://github.com/rust-lang/rust/blob/90743e7298aca107ddaa0c202a4d3604e29bfeb6/library/std/src/panicking.rs#L235-L288
     let location = info.location();
@@ -274,6 +274,14 @@ impl From<String> for SecretString {
     }
 }
 
+impl FromStr for SecretString {
+    type Err = std::convert::Infallible;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        Ok(Self(s.to_string()))
+    }
+}
+
 impl std::fmt::Debug for SecretString {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         write!(f, "[SECRET]")

libs/utils/src/pageserver_feedback.rs

@@ -8,6 +8,7 @@ use tracing::{trace, warn};
 use crate::lsn::Lsn;
 
 /// Feedback pageserver sends to safekeeper and safekeeper resends to compute.
+///
 /// Serialized in custom flexible key/value format. In replication protocol, it
 /// is marked with NEON_STATUS_UPDATE_TAG_BYTE to differentiate from postgres
 /// Standby status update / Hot standby feedback messages.

libs/utils/src/poison.rs

@@ -65,6 +65,8 @@ impl<T> Poison<T> {
     }
 }
 
+/// Armed pointer to a [`Poison`].
+///
 /// Use [`Self::data`] and [`Self::data_mut`] to access the wrapped state.
 /// Once modifications are done, use [`Self::disarm`].
 /// If [`Guard`] gets dropped instead of calling [`Self::disarm`], the state is poisoned

libs/utils/src/rate_limit.rs

@@ -5,6 +5,15 @@ use std::time::{Duration, Instant};
 pub struct RateLimit {
     last: Option<Instant>,
     interval: Duration,
+    dropped: u64,
+}
+
+pub struct RateLimitStats(u64);
+
+impl std::fmt::Display for RateLimitStats {
+    fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, "{} dropped calls", self.0)
+    }
 }
 
 impl RateLimit {
@@ -12,20 +21,27 @@ impl RateLimit {
         Self {
             last: None,
             interval,
+            dropped: 0,
         }
     }
 
     /// Call `f` if the rate limit allows.
     /// Don't call it otherwise.
     pub fn call<F: FnOnce()>(&mut self, f: F) {
+        self.call2(|_| f())
+    }
+
+    pub fn call2<F: FnOnce(RateLimitStats)>(&mut self, f: F) {
         let now = Instant::now();
         match self.last {
             Some(last) if now - last <= self.interval => {
                 // ratelimit
+                self.dropped += 1;
             }
             _ => {
                 self.last = Some(now);
-                f();
+                f(RateLimitStats(self.dropped));
+                self.dropped = 0;
             }
         }
     }

libs/utils/src/shard.rs

@@ -13,10 +13,11 @@ pub struct ShardNumber(pub u8);
 #[derive(Ord, PartialOrd, Eq, PartialEq, Clone, Copy, Serialize, Deserialize, Debug, Hash)]
 pub struct ShardCount(pub u8);
 
-/// Combination of ShardNumber and ShardCount.  For use within the context of a particular tenant,
+/// Combination of ShardNumber and ShardCount.
-/// when we need to know which shard we're dealing with, but do not need to know the full
+///
-/// ShardIdentity (because we won't be doing any page->shard mapping), and do not need to know
+/// For use within the context of a particular tenant, when we need to know which shard we're
-/// the fully qualified TenantShardId.
+/// dealing with, but do not need to know the full ShardIdentity (because we won't be doing
+/// any page->shard mapping), and do not need to know the fully qualified TenantShardId.
 #[derive(Eq, PartialEq, PartialOrd, Ord, Clone, Copy, Hash)]
 pub struct ShardIndex {
     pub shard_number: ShardNumber,

libs/utils/src/simple_rcu.rs

@@ -49,12 +49,11 @@ use std::sync::{RwLock, RwLockWriteGuard};
 
 use tokio::sync::watch;
 
-///
 /// Rcu allows multiple readers to read and hold onto a value without blocking
-/// (for very long).  Storing to the Rcu updates the value, making new readers
+/// (for very long).
-/// immediately see the new value, but it also waits for all current readers to
-/// finish.
 ///
+/// Storing to the Rcu updates the value, making new readers immediately see
+/// the new value, but it also waits for all current readers to finish.
 pub struct Rcu<V> {
     inner: RwLock<RcuInner<V>>,
 }

libs/utils/src/sync/heavier_once_cell.rs

@@ -5,7 +5,9 @@ use std::sync::{
 use tokio::sync::Semaphore;
 
 /// Custom design like [`tokio::sync::OnceCell`] but using [`OwnedSemaphorePermit`] instead of
-/// `SemaphorePermit`, allowing use of `take` which does not require holding an outer mutex guard
+/// `SemaphorePermit`.
+///
+/// Allows use of `take` which does not require holding an outer mutex guard
 /// for the duration of initialization.
 ///
 /// Has no unsafe, builds upon [`tokio::sync::Semaphore`] and [`std::sync::Mutex`].

libs/utils/src/toml_edit_ext.rs

@@ -10,7 +10,7 @@ pub fn deserialize_item<T>(item: &toml_edit::Item) -> Result<T, Error>
 where
     T: serde::de::DeserializeOwned,
 {
-    let document: toml_edit::Document = match item {
+    let document: toml_edit::DocumentMut = match item {
         toml_edit::Item::Table(toml) => toml.clone().into(),
         toml_edit::Item::Value(toml_edit::Value::InlineTable(toml)) => {
             toml.clone().into_table().into()

libs/utils/src/vec_map.rs

@@ -7,6 +7,7 @@ pub enum VecMapOrdering {
 }
 
 /// Ordered map datastructure implemented in a Vec.
+///
 /// Append only - can only add keys that are larger than the
 /// current max key.
 /// Ordering can be adjusted using [`VecMapOrdering`]

libs/utils/src/yielding_loop.rs

@@ -6,9 +6,10 @@ pub enum YieldingLoopError {
     Cancelled,
 }
 
-/// Helper for long synchronous loops, e.g. over all tenants in the system.  Periodically
+/// Helper for long synchronous loops, e.g. over all tenants in the system.
-/// yields to avoid blocking the executor, and after resuming checks the provided
+///
-/// cancellation token to drop out promptly on shutdown.
+/// Periodically yields to avoid blocking the executor, and after resuming
+/// checks the provided cancellation token to drop out promptly on shutdown.
 #[inline(always)]
 pub async fn yielding_loop<I, T, F>(
     interval: usize,
@@ -23,7 +24,7 @@ where
     for (i, item) in iter.enumerate() {
         visitor(item);
 
-        if i + 1 % interval == 0 {
+        if (i + 1) % interval == 0 {
             tokio::task::yield_now().await;
             if cancel.is_cancelled() {
                 return Err(YieldingLoopError::Cancelled);

libs/walproposer/build.rs

@@ -4,7 +4,6 @@
 use std::{env, path::PathBuf, process::Command};
 
 use anyhow::{anyhow, Context};
-use bindgen::CargoCallbacks;
 
 fn main() -> anyhow::Result<()> {
     // Tell cargo to invalidate the built crate whenever the wrapper changes
@@ -64,16 +63,25 @@ fn main() -> anyhow::Result<()> {
             .map_err(|s| anyhow!("Bad postgres server path {s:?}"))?
     };
 
+    let unwind_abi_functions = [
+        "log_internal",
+        "recovery_download",
+        "start_streaming",
+        "finish_sync_safekeepers",
+        "wait_event_set",
+        "WalProposerStart",
+    ];
+
     // The bindgen::Builder is the main entry point
     // to bindgen, and lets you build up options for
     // the resulting bindings.
-    let bindings = bindgen::Builder::default()
+    let mut builder = bindgen::Builder::default()
         // The input header we would like to generate
         // bindings for.
         .header("bindgen_deps.h")
         // Tell cargo to invalidate the built crate whenever any of the
         // included header files changed.
-        .parse_callbacks(Box::new(CargoCallbacks))
+        .parse_callbacks(Box::new(bindgen::CargoCallbacks::new()))
         .allowlist_type("WalProposer")
         .allowlist_type("WalProposerConfig")
         .allowlist_type("walproposer_api")
@@ -95,6 +103,7 @@ fn main() -> anyhow::Result<()> {
         .allowlist_var("ERROR")
         .allowlist_var("FATAL")
         .allowlist_var("PANIC")
+        .allowlist_var("PG_VERSION_NUM")
         .allowlist_var("WPEVENT")
         .allowlist_var("WL_LATCH_SET")
         .allowlist_var("WL_SOCKET_READABLE")
@@ -104,7 +113,12 @@ fn main() -> anyhow::Result<()> {
         .allowlist_var("WL_SOCKET_MASK")
         .clang_arg("-DWALPROPOSER_LIB")
         .clang_arg(format!("-I{pgxn_neon}"))
-        .clang_arg(format!("-I{inc_server_path}"))
+        .clang_arg(format!("-I{inc_server_path}"));
+
+    for name in unwind_abi_functions {
+        builder = builder.override_abi(bindgen::Abi::CUnwind, name);
+    }
+    let bindings = builder
         // Finish the builder and generate the bindings.
         .generate()
         // Unwrap the Result and panic on failure.

libs/walproposer/src/api_bindings.rs

@@ -33,7 +33,7 @@ extern "C" fn get_shmem_state(wp: *mut WalProposer) -> *mut WalproposerShmemStat
     }
 }
 
-extern "C" fn start_streaming(wp: *mut WalProposer, startpos: XLogRecPtr) {
+extern "C-unwind" fn start_streaming(wp: *mut WalProposer, startpos: XLogRecPtr) {
     unsafe {
         let callback_data = (*(*wp).config).callback_data;
         let api = callback_data as *mut Box<dyn ApiImpl>;
@@ -187,7 +187,7 @@ extern "C" fn conn_blocking_write(
     }
 }
 
-extern "C" fn recovery_download(wp: *mut WalProposer, sk: *mut Safekeeper) -> bool {
+extern "C-unwind" fn recovery_download(wp: *mut WalProposer, sk: *mut Safekeeper) -> bool {
     unsafe {
         let callback_data = (*(*(*sk).wp).config).callback_data;
         let api = callback_data as *mut Box<dyn ApiImpl>;
@@ -272,7 +272,7 @@ extern "C" fn rm_safekeeper_event_set(sk: *mut Safekeeper) {
     }
 }
 
-extern "C" fn wait_event_set(
+extern "C-unwind" fn wait_event_set(
     wp: *mut WalProposer,
     timeout: ::std::os::raw::c_long,
     event_sk: *mut *mut Safekeeper,
@@ -324,7 +324,7 @@ extern "C" fn get_redo_start_lsn(wp: *mut WalProposer) -> XLogRecPtr {
     }
 }
 
-extern "C" fn finish_sync_safekeepers(wp: *mut WalProposer, lsn: XLogRecPtr) {
+extern "C-unwind" fn finish_sync_safekeepers(wp: *mut WalProposer, lsn: XLogRecPtr) {
     unsafe {
         let callback_data = (*(*wp).config).callback_data;
         let api = callback_data as *mut Box<dyn ApiImpl>;
@@ -340,7 +340,7 @@ extern "C" fn process_safekeeper_feedback(wp: *mut WalProposer, sk: *mut Safekee
     }
 }
 
-extern "C" fn log_internal(
+extern "C-unwind" fn log_internal(
     wp: *mut WalProposer,
     level: ::std::os::raw::c_int,
     line: *const ::std::os::raw::c_char,

libs/walproposer/src/walproposer.rs

@@ -282,7 +282,11 @@ mod tests {
     use std::cell::UnsafeCell;
     use utils::id::TenantTimelineId;
 
-    use crate::{api_bindings::Level, bindings::NeonWALReadResult, walproposer::Wrapper};
+    use crate::{
+        api_bindings::Level,
+        bindings::{NeonWALReadResult, PG_VERSION_NUM},
+        walproposer::Wrapper,
+    };
 
     use super::ApiImpl;
 
@@ -489,41 +493,79 @@ mod tests {
 
         let (sender, receiver) = sync_channel(1);
 
+        // Messages definitions are at walproposer.h
+        // xxx: it would be better to extract them from safekeeper crate and
+        // use serialization/deserialization here.
+        let greeting_tag = (b'g' as u64).to_ne_bytes();
+        let proto_version = 2_u32.to_ne_bytes();
+        let pg_version: [u8; 4] = PG_VERSION_NUM.to_ne_bytes();
+        let proposer_id = [0; 16];
+        let system_id = 0_u64.to_ne_bytes();
+        let tenant_id = ttid.tenant_id.as_arr();
+        let timeline_id = ttid.timeline_id.as_arr();
+        let pg_tli = 1_u32.to_ne_bytes();
+        let wal_seg_size = 16777216_u32.to_ne_bytes();
+        let proposer_greeting = [
+            greeting_tag.as_slice(),
+            proto_version.as_slice(),
+            pg_version.as_slice(),
+            proposer_id.as_slice(),
+            system_id.as_slice(),
+            tenant_id.as_slice(),
+            timeline_id.as_slice(),
+            pg_tli.as_slice(),
+            wal_seg_size.as_slice(),
+        ]
+        .concat();
+
+        let voting_tag = (b'v' as u64).to_ne_bytes();
+        let vote_request_term = 3_u64.to_ne_bytes();
+        let proposer_id = [0; 16];
+        let vote_request = [
+            voting_tag.as_slice(),
+            vote_request_term.as_slice(),
+            proposer_id.as_slice(),
+        ]
+        .concat();
+
+        let acceptor_greeting_term = 2_u64.to_ne_bytes();
+        let acceptor_greeting_node_id = 1_u64.to_ne_bytes();
+        let acceptor_greeting = [
+            greeting_tag.as_slice(),
+            acceptor_greeting_term.as_slice(),
+            acceptor_greeting_node_id.as_slice(),
+        ]
+        .concat();
+
+        let vote_response_term = 3_u64.to_ne_bytes();
+        let vote_given = 1_u64.to_ne_bytes();
+        let flush_lsn = 0x539_u64.to_ne_bytes();
+        let truncate_lsn = 0x539_u64.to_ne_bytes();
+        let th_len = 1_u32.to_ne_bytes();
+        let th_term = 2_u64.to_ne_bytes();
+        let th_lsn = 0x539_u64.to_ne_bytes();
+        let timeline_start_lsn = 0x539_u64.to_ne_bytes();
+        let vote_response = [
+            voting_tag.as_slice(),
+            vote_response_term.as_slice(),
+            vote_given.as_slice(),
+            flush_lsn.as_slice(),
+            truncate_lsn.as_slice(),
+            th_len.as_slice(),
+            th_term.as_slice(),
+            th_lsn.as_slice(),
+            timeline_start_lsn.as_slice(),
+        ]
+        .concat();
+
         let my_impl: Box<dyn ApiImpl> = Box::new(MockImpl {
             wait_events: Cell::new(WaitEventsData {
                 sk: std::ptr::null_mut(),
                 event_mask: 0,
             }),
-            expected_messages: vec![
+            expected_messages: vec![proposer_greeting, vote_request],
-                // TODO: When updating Postgres versions, this test will cause
-                // problems. Postgres version in message needs updating.
-                //
-                // Greeting(ProposerGreeting { protocol_version: 2, pg_version: 160003, proposer_id: [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0], system_id: 0, timeline_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tenant_id: 9e4c8f36063c6c6e93bc20d65a820f3d, tli: 1, wal_seg_size: 16777216 })
-                vec![
-                    103, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 3, 113, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-                    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 158, 76, 143, 54, 6, 60, 108, 110,
-                    147, 188, 32, 214, 90, 130, 15, 61, 158, 76, 143, 54, 6, 60, 108, 110, 147,
-                    188, 32, 214, 90, 130, 15, 61, 1, 0, 0, 0, 0, 0, 0, 1,
-                ],
-                // VoteRequest(VoteRequest { term: 3 })
-                vec![
-                    118, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-                    0, 0, 0, 0, 0, 0,
-                ],
-            ],
             expected_ptr: AtomicUsize::new(0),
-            safekeeper_replies: vec![
+            safekeeper_replies: vec![acceptor_greeting, vote_response],
-                // Greeting(AcceptorGreeting { term: 2, node_id: NodeId(1) })
-                vec![
-                    103, 0, 0, 0, 0, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0,
-                ],
-                // VoteResponse(VoteResponse { term: 3, vote_given: 1, flush_lsn: 0/539, truncate_lsn: 0/539, term_history: [(2, 0/539)], timeline_start_lsn: 0/539 })
-                vec![
-                    118, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 57,
-                    5, 0, 0, 0, 0, 0, 0, 57, 5, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 0, 0, 0,
-                    0, 57, 5, 0, 0, 0, 0, 0, 0, 57, 5, 0, 0, 0, 0, 0, 0,
-                ],
-            ],
             replies_ptr: AtomicUsize::new(0),
             sync_channel: sender,
             shmem: UnsafeCell::new(crate::api_bindings::empty_shmem()),

pageserver/Cargo.toml

@@ -8,7 +8,7 @@ license.workspace = true
 default = []
 # Enables test-only APIs, incuding failpoints. In particular, enables the `fail_point!` macro,
 # which adds some runtime cost to run tests on outage conditions
-testing = ["fail/failpoints"]
+testing = ["fail/failpoints", "pageserver_api/testing" ]
 
 [dependencies]
 anyhow.workspace = true
@@ -16,6 +16,7 @@ arc-swap.workspace = true
 async-compression.workspace = true
 async-stream.workspace = true
 async-trait.workspace = true
+bit_field.workspace = true
 byteorder.workspace = true
 bytes.workspace = true
 camino.workspace = true
@@ -36,7 +37,6 @@ humantime.workspace = true
 humantime-serde.workspace = true
 hyper.workspace = true
 itertools.workspace = true
-leaky-bucket.workspace = true
 md5.workspace = true
 nix.workspace = true
 # hack to get the number of worker threads tokio uses
@@ -52,6 +52,7 @@ rand.workspace = true
 range-set-blaze = { version = "0.1.16", features = ["alloc"] }
 regex.workspace = true
 scopeguard.workspace = true
+send-future.workspace = true
 serde.workspace = true
 serde_json = { workspace = true, features = ["raw_value"] }
 serde_path_to_error.workspace = true
@@ -100,6 +101,7 @@ procfs.workspace = true
 criterion.workspace = true
 hex-literal.workspace = true
 tokio = { workspace = true, features = ["process", "sync", "fs", "rt", "io-util", "time", "test-util"] }
+indoc.workspace = true
 
 [[bench]]
 name = "bench_layer_map"

pageserver/benches/bench_ingest.rs

@@ -10,6 +10,7 @@ use pageserver::{
     page_cache,
     repository::Value,
     task_mgr::TaskKind,
+    tenant::storage_layer::inmemory_layer::SerializedBatch,
     tenant::storage_layer::InMemoryLayer,
     virtual_file,
 };
@@ -67,12 +68,16 @@ async fn ingest(
     let layer =
         InMemoryLayer::create(conf, timeline_id, tenant_shard_id, lsn, entered, &ctx).await?;
 
-    let data = Value::Image(Bytes::from(vec![0u8; put_size])).ser()?;
+    let data = Value::Image(Bytes::from(vec![0u8; put_size]));
+    let data_ser_size = data.serialized_size().unwrap() as usize;
     let ctx = RequestContext::new(
         pageserver::task_mgr::TaskKind::WalReceiverConnectionHandler,
         pageserver::context::DownloadBehavior::Download,
     );
 
+    const BATCH_SIZE: usize = 16;
+    let mut batch = Vec::new();
+
     for i in 0..put_count {
         lsn += put_size as u64;
 
@@ -95,7 +100,17 @@ async fn ingest(
             }
         }
 
-        layer.put_value(key.to_compact(), lsn, &data, &ctx).await?;
+        batch.push((key.to_compact(), lsn, data_ser_size, data.clone()));
+        if batch.len() >= BATCH_SIZE {
+            let this_batch = std::mem::take(&mut batch);
+            let serialized = SerializedBatch::from_values(this_batch).unwrap();
+            layer.put_batch(serialized, &ctx).await?;
+        }
+    }
+    if !batch.is_empty() {
+        let this_batch = std::mem::take(&mut batch);
+        let serialized = SerializedBatch::from_values(this_batch).unwrap();
+        layer.put_batch(serialized, &ctx).await?;
     }
     layer.freeze(lsn + 1).await;
 
@@ -149,7 +164,11 @@ fn criterion_benchmark(c: &mut Criterion) {
     let conf: &'static PageServerConf = Box::leak(Box::new(
         pageserver::config::PageServerConf::dummy_conf(temp_dir.path().to_path_buf()),
     ));
-    virtual_file::init(16384, virtual_file::io_engine_for_bench());
+    virtual_file::init(
+        16384,
+        virtual_file::io_engine_for_bench(),
+        pageserver_api::config::defaults::DEFAULT_IO_BUFFER_ALIGNMENT,
+    );
     page_cache::init(conf.page_cache_size);
 
     {

pageserver/client/Cargo.toml

@@ -7,7 +7,6 @@ license.workspace = true
 [dependencies]
 pageserver_api.workspace = true
 thiserror.workspace = true
-async-trait.workspace = true
 reqwest = { workspace = true, features = [ "stream" ] }
 utils.workspace = true
 serde.workspace = true

pageserver/client/src/lib.rs

@@ -1,2 +1,20 @@
 pub mod mgmt_api;
 pub mod page_service;
+
+/// For timeline_block_unblock_gc, distinguish the two different operations. This could be a bool.
+// If file structure is per-kind not per-feature then where to put this?
+#[derive(Clone, Copy)]
+pub enum BlockUnblock {
+    Block,
+    Unblock,
+}
+
+impl std::fmt::Display for BlockUnblock {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        let s = match self {
+            BlockUnblock::Block => "block",
+            BlockUnblock::Unblock => "unblock",
+        };
+        f.write_str(s)
+    }
+}

pageserver/client/src/mgmt_api.rs

@@ -12,6 +12,8 @@ use utils::{
 
 pub use reqwest::Body as ReqwestBody;
 
+use crate::BlockUnblock;
+
 pub mod util;
 
 #[derive(Debug, Clone)]
@@ -419,6 +421,24 @@ impl Client {
         }
     }
 
+    pub async fn timeline_archival_config(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        req: &TimelineArchivalConfigRequest,
+    ) -> Result<()> {
+        let uri = format!(
+            "{}/v1/tenant/{tenant_shard_id}/timeline/{timeline_id}/archival_config",
+            self.mgmt_api_endpoint
+        );
+
+        self.request(Method::POST, &uri, req)
+            .await?
+            .json()
+            .await
+            .map_err(Error::ReceiveBody)
+    }
+
     pub async fn timeline_detach_ancestor(
         &self,
         tenant_shard_id: TenantShardId,
@@ -436,6 +456,20 @@ impl Client {
             .map_err(Error::ReceiveBody)
     }
 
+    pub async fn timeline_block_unblock_gc(
+        &self,
+        tenant_shard_id: TenantShardId,
+        timeline_id: TimelineId,
+        dir: BlockUnblock,
+    ) -> Result<()> {
+        let uri = format!(
+            "{}/v1/tenant/{tenant_shard_id}/timeline/{timeline_id}/{dir}_gc",
+            self.mgmt_api_endpoint,
+        );
+
+        self.request(Method::POST, &uri, ()).await.map(|_| ())
+    }
+
     pub async fn tenant_reset(&self, tenant_shard_id: TenantShardId) -> Result<()> {
         let uri = format!(
             "{}/v1/tenant/{}/reset",
@@ -506,6 +540,16 @@ impl Client {
             .map_err(Error::ReceiveBody)
     }
 
+    /// Configs io buffer alignment at runtime.
+    pub async fn put_io_alignment(&self, align: usize) -> Result<()> {
+        let uri = format!("{}/v1/io_alignment", self.mgmt_api_endpoint);
+        self.request(Method::PUT, uri, align)
+            .await?
+            .json()
+            .await
+            .map_err(Error::ReceiveBody)
+    }
+
     pub async fn get_utilization(&self) -> Result<PageserverUtilization> {
         let uri = format!("{}/v1/utilization", self.mgmt_api_endpoint);
         self.get(uri)

pageserver/ctl/src/layer_map_analyzer.rs

@@ -144,7 +144,11 @@ pub(crate) async fn main(cmd: &AnalyzeLayerMapCmd) -> Result<()> {
     let ctx = RequestContext::new(TaskKind::DebugTool, DownloadBehavior::Error);
 
     // Initialize virtual_file (file desriptor cache) and page cache which are needed to access layer persistent B-Tree.
-    pageserver::virtual_file::init(10, virtual_file::api::IoEngineKind::StdFs);
+    pageserver::virtual_file::init(
+        10,
+        virtual_file::api::IoEngineKind::StdFs,
+        pageserver_api::config::defaults::DEFAULT_IO_BUFFER_ALIGNMENT,
+    );
     pageserver::page_cache::init(100);
 
     let mut total_delta_layers = 0usize;

pageserver/ctl/src/layers.rs

@@ -59,7 +59,7 @@ pub(crate) enum LayerCmd {
 
 async fn read_delta_file(path: impl AsRef<Path>, ctx: &RequestContext) -> Result<()> {
     let path = Utf8Path::from_path(path.as_ref()).expect("non-Unicode path");
-    virtual_file::init(10, virtual_file::api::IoEngineKind::StdFs);
+    virtual_file::init(10, virtual_file::api::IoEngineKind::StdFs, 1);
     page_cache::init(100);
     let file = VirtualFile::open(path, ctx).await?;
     let file_id = page_cache::next_file_id();
@@ -89,6 +89,7 @@ async fn read_delta_file(path: impl AsRef<Path>, ctx: &RequestContext) -> Result
     for (k, v) in all {
         let value = cursor.read_blob(v.pos(), ctx).await?;
         println!("key:{} value_len:{}", k, value.len());
+        assert!(k.is_i128_representable(), "invalid key: ");
     }
     // TODO(chi): special handling for last key?
     Ok(())
@@ -189,7 +190,11 @@ pub(crate) async fn main(cmd: &LayerCmd) -> Result<()> {
             new_tenant_id,
             new_timeline_id,
         } => {
-            pageserver::virtual_file::init(10, virtual_file::api::IoEngineKind::StdFs);
+            pageserver::virtual_file::init(
+                10,
+                virtual_file::api::IoEngineKind::StdFs,
+                pageserver_api::config::defaults::DEFAULT_IO_BUFFER_ALIGNMENT,
+            );
             pageserver::page_cache::init(100);
 
             let ctx = RequestContext::new(TaskKind::DebugTool, DownloadBehavior::Error);

pageserver/ctl/src/main.rs

@@ -26,7 +26,7 @@ use pageserver::{
     tenant::{dump_layerfile_from_path, metadata::TimelineMetadata},
     virtual_file,
 };
-use pageserver_api::shard::TenantShardId;
+use pageserver_api::{config::defaults::DEFAULT_IO_BUFFER_ALIGNMENT, shard::TenantShardId};
 use postgres_ffi::ControlFileData;
 use remote_storage::{RemotePath, RemoteStorageConfig};
 use tokio_util::sync::CancellationToken;
@@ -174,7 +174,7 @@ async fn main() -> anyhow::Result<()> {
                 println!("specified prefix '{}' failed validation", cmd.prefix);
                 return Ok(());
             };
-            let toml_document = toml_edit::Document::from_str(&cmd.config_toml_str)?;
+            let toml_document = toml_edit::DocumentMut::from_str(&cmd.config_toml_str)?;
             let toml_item = toml_document
                 .get("remote_storage")
                 .expect("need remote_storage");
@@ -205,7 +205,11 @@ fn read_pg_control_file(control_file_path: &Utf8Path) -> anyhow::Result<()> {
 
 async fn print_layerfile(path: &Utf8Path) -> anyhow::Result<()> {
     // Basic initialization of things that don't change after startup
-    virtual_file::init(10, virtual_file::api::IoEngineKind::StdFs);
+    virtual_file::init(
+        10,
+        virtual_file::api::IoEngineKind::StdFs,
+        DEFAULT_IO_BUFFER_ALIGNMENT,
+    );
     page_cache::init(100);
     let ctx = RequestContext::new(TaskKind::DebugTool, DownloadBehavior::Error);
     dump_layerfile_from_path(path, true, &ctx).await

pageserver/pagebench/src/cmd/getpage_latest_lsn.rs

@@ -58,6 +58,11 @@ pub(crate) struct Args {
     /// [`pageserver_api::models::virtual_file::IoEngineKind`].
     #[clap(long)]
     set_io_engine: Option<pageserver_api::models::virtual_file::IoEngineKind>,
+
+    /// Before starting the benchmark, live-reconfigure the pageserver to use specified alignment for io buffers.
+    #[clap(long)]
+    set_io_alignment: Option<usize>,
+
     targets: Option<Vec<TenantTimelineId>>,
 }
 
@@ -124,6 +129,10 @@ async fn main_impl(
         mgmt_api_client.put_io_engine(engine_str).await?;
     }
 
+    if let Some(align) = args.set_io_alignment {
+        mgmt_api_client.put_io_alignment(align).await?;
+    }
+
     // discover targets
     let timelines: Vec<TenantTimelineId> = crate::util::cli::targets::discover(
         &mgmt_api_client,

pageserver/src/assert_u64_eq_usize.rs

@@ -0,0 +1,39 @@
+//! `u64`` and `usize`` aren't guaranteed to be identical in Rust, but life is much simpler if that's the case.
+
+pub(crate) const _ASSERT_U64_EQ_USIZE: () = {
+    if std::mem::size_of::<usize>() != std::mem::size_of::<u64>() {
+        panic!("the traits defined in this module assume that usize and u64 can be converted to each other without loss of information");
+    }
+};
+
+pub(crate) trait U64IsUsize {
+    fn into_usize(self) -> usize;
+}
+
+impl U64IsUsize for u64 {
+    #[inline(always)]
+    fn into_usize(self) -> usize {
+        #[allow(clippy::let_unit_value)]
+        let _ = _ASSERT_U64_EQ_USIZE;
+        self as usize
+    }
+}
+
+pub(crate) trait UsizeIsU64 {
+    fn into_u64(self) -> u64;
+}
+
+impl UsizeIsU64 for usize {
+    #[inline(always)]
+    fn into_u64(self) -> u64 {
+        #[allow(clippy::let_unit_value)]
+        let _ = _ASSERT_U64_EQ_USIZE;
+        self as u64
+    }
+}
+
+pub const fn u64_to_usize(x: u64) -> usize {
+    #[allow(clippy::let_unit_value)]
+    let _ = _ASSERT_U64_EQ_USIZE;
+    x as usize
+}

pageserver/src/bin/pageserver.rs

@@ -5,6 +5,7 @@
 use std::env;
 use std::env::{var, VarError};
 use std::io::Read;
+use std::str::FromStr;
 use std::sync::Arc;
 use std::time::Duration;
 
@@ -36,6 +37,7 @@ use pageserver::{
     virtual_file,
 };
 use postgres_backend::AuthType;
+use utils::crashsafe::syncfs;
 use utils::failpoint_support;
 use utils::logging::TracingErrorLayerEnablement;
 use utils::{
@@ -124,19 +126,53 @@ fn main() -> anyhow::Result<()> {
     // after setting up logging, log the effective IO engine choice and read path implementations
     info!(?conf.virtual_file_io_engine, "starting with virtual_file IO engine");
     info!(?conf.virtual_file_direct_io, "starting with virtual_file Direct IO settings");
-    info!(?conf.compact_level0_phase1_value_access, "starting with setting for compact_level0_phase1_value_access");
+    info!(?conf.io_buffer_alignment, "starting with setting for IO buffer alignment");
 
+    // The tenants directory contains all the pageserver local disk state.
+    // Create if not exists and make sure all the contents are durable before proceeding.
+    // Ensuring durability eliminates a whole bug class where we come up after an unclean shutdown.
+    // After unclea shutdown, we don't know if all the filesystem content we can read via syscalls is actually durable or not.
+    // Examples for that: OOM kill, systemd killing us during shutdown, self abort due to unrecoverable IO error.
     let tenants_path = conf.tenants_path();
-    if !tenants_path.exists() {
+    {
-        utils::crashsafe::create_dir_all(conf.tenants_path())
+        let open = || {
-            .with_context(|| format!("Failed to create tenants root dir at '{tenants_path}'"))?;
+            nix::dir::Dir::open(
+                tenants_path.as_std_path(),
+                nix::fcntl::OFlag::O_DIRECTORY | nix::fcntl::OFlag::O_RDONLY,
+                nix::sys::stat::Mode::empty(),
+            )
+        };
+        let dirfd = match open() {
+            Ok(dirfd) => dirfd,
+            Err(e) => match e {
+                nix::errno::Errno::ENOENT => {
+                    utils::crashsafe::create_dir_all(&tenants_path).with_context(|| {
+                        format!("Failed to create tenants root dir at '{tenants_path}'")
+                    })?;
+                    open().context("open tenants dir after creating it")?
+                }
+                e => anyhow::bail!(e),
+            },
+        };
+
+        let started = Instant::now();
+        syncfs(dirfd)?;
+        let elapsed = started.elapsed();
+        info!(
+            elapsed_ms = elapsed.as_millis(),
+            "made tenant directory contents durable"
+        );
     }
 
     // Initialize up failpoints support
     let scenario = failpoint_support::init();
 
     // Basic initialization of things that don't change after startup
-    virtual_file::init(conf.max_file_descriptors, conf.virtual_file_io_engine);
+    virtual_file::init(
+        conf.max_file_descriptors,
+        conf.virtual_file_io_engine,
+        conf.io_buffer_alignment,
+    );
     page_cache::init(conf.page_cache_size);
 
     start_pageserver(launch_ts, conf).context("Failed to start pageserver")?;
@@ -172,27 +208,15 @@ fn initialize_config(
         }
     };
 
-    let config: toml_edit::Document = match std::fs::File::open(cfg_file_path) {
+    let config_file_contents =
-        Ok(mut f) => {
+        std::fs::read_to_string(cfg_file_path).context("read config file from filesystem")?;
-            let md = f.metadata().context("stat config file")?;
+    let config_toml = serde_path_to_error::deserialize(
-            if md.is_file() {
+        toml_edit::de::Deserializer::from_str(&config_file_contents)
-                let mut s = String::new();
+            .context("build toml deserializer")?,
-                f.read_to_string(&mut s).context("read config file")?;
+    )
-                s.parse().context("parse config file toml")?
+    .context("deserialize config toml")?;
-            } else {
+    let conf = PageServerConf::parse_and_validate(identity.id, config_toml, workdir)
-                anyhow::bail!("directory entry exists but is not a file: {cfg_file_path}");
+        .context("runtime-validation of config toml")?;
-            }
-        }
-        Err(e) => {
-            anyhow::bail!("open pageserver config: {e}: {cfg_file_path}");
-        }
-    };
-
-    debug!("Using pageserver toml: {config}");
-
-    // Construct the runtime representation
-    let conf = PageServerConf::parse_and_validate(identity.id, &config, workdir)
-        .context("Failed to parse pageserver configuration")?;
 
     Ok(Box::leak(Box::new(conf)))
 }

pageserver/src/consumption_metrics.rs

@@ -1,6 +1,8 @@
 //! Periodically collect consumption metrics for all active tenants
 //! and push them to a HTTP endpoint.
 use crate::config::PageServerConf;
+use crate::consumption_metrics::metrics::MetricsKey;
+use crate::consumption_metrics::upload::KeyGen as _;
 use crate::context::{DownloadBehavior, RequestContext};
 use crate::task_mgr::{self, TaskKind, BACKGROUND_RUNTIME};
 use crate::tenant::size::CalculateSyntheticSizeError;
@@ -8,6 +10,7 @@ use crate::tenant::tasks::BackgroundLoopKind;
 use crate::tenant::{mgr::TenantManager, LogicalSizeCalculationCause, Tenant};
 use camino::Utf8PathBuf;
 use consumption_metrics::EventType;
+use itertools::Itertools as _;
 use pageserver_api::models::TenantState;
 use remote_storage::{GenericRemoteStorage, RemoteStorageConfig};
 use reqwest::Url;
@@ -19,9 +22,8 @@ use tokio_util::sync::CancellationToken;
 use tracing::*;
 use utils::id::NodeId;
 
-mod metrics;
-use crate::consumption_metrics::metrics::MetricsKey;
 mod disk_cache;
+mod metrics;
 mod upload;
 
 const DEFAULT_HTTP_REPORTING_TIMEOUT: Duration = Duration::from_secs(60);
@@ -143,6 +145,12 @@ async fn collect_metrics(
         // these are point in time, with variable "now"
         let metrics = metrics::collect_all_metrics(&tenant_manager, &cached_metrics, &ctx).await;
 
+        // Pre-generate event idempotency keys, to reuse them across the bucket
+        // and HTTP sinks.
+        let idempotency_keys = std::iter::repeat_with(|| node_id.as_str().generate())
+            .take(metrics.len())
+            .collect_vec();
+
         let metrics = Arc::new(metrics);
 
         // why not race cancellation here? because we are one of the last tasks, and if we are
@@ -161,8 +169,14 @@ async fn collect_metrics(
             }
 
             if let Some(bucket_client) = &bucket_client {
-                let res =
+                let res = upload::upload_metrics_bucket(
-                    upload::upload_metrics_bucket(bucket_client, &cancel, &node_id, &metrics).await;
+                    bucket_client,
+                    &cancel,
+                    &node_id,
+                    &metrics,
+                    &idempotency_keys,
+                )
+                .await;
                 if let Err(e) = res {
                     tracing::error!("failed to upload to S3: {e:#}");
                 }
@@ -174,9 +188,9 @@ async fn collect_metrics(
                 &client,
                 metric_collection_endpoint,
                 &cancel,
-                &node_id,
                 &metrics,
                 &mut cached_metrics,
+                &idempotency_keys,
             )
             .await;
             if let Err(e) = res {

pageserver/src/consumption_metrics/upload.rs

@@ -24,16 +24,16 @@ pub(super) async fn upload_metrics_http(
     client: &reqwest::Client,
     metric_collection_endpoint: &reqwest::Url,
     cancel: &CancellationToken,
-    node_id: &str,
     metrics: &[RawMetric],
     cached_metrics: &mut Cache,
+    idempotency_keys: &[IdempotencyKey<'_>],
 ) -> anyhow::Result<()> {
     let mut uploaded = 0;
     let mut failed = 0;
 
     let started_at = std::time::Instant::now();
 
-    let mut iter = serialize_in_chunks(CHUNK_SIZE, metrics, node_id);
+    let mut iter = serialize_in_chunks(CHUNK_SIZE, metrics, idempotency_keys);
 
     while let Some(res) = iter.next() {
         let (chunk, body) = res?;
@@ -87,6 +87,7 @@ pub(super) async fn upload_metrics_bucket(
     cancel: &CancellationToken,
     node_id: &str,
     metrics: &[RawMetric],
+    idempotency_keys: &[IdempotencyKey<'_>],
 ) -> anyhow::Result<()> {
     if metrics.is_empty() {
         // Skip uploads if we have no metrics, so that readers don't have to handle the edge case
@@ -106,7 +107,7 @@ pub(super) async fn upload_metrics_bucket(
 
     // Serialize and write into compressed buffer
     let started_at = std::time::Instant::now();
-    for res in serialize_in_chunks(CHUNK_SIZE, metrics, node_id) {
+    for res in serialize_in_chunks(CHUNK_SIZE, metrics, idempotency_keys) {
         let (_chunk, body) = res?;
         gzip_writer.write_all(&body).await?;
     }
@@ -134,29 +135,31 @@ pub(super) async fn upload_metrics_bucket(
     Ok(())
 }
 
-// The return type is quite ugly, but we gain testability in isolation
+/// Serializes the input metrics as JSON in chunks of chunk_size. The provided
-fn serialize_in_chunks<'a, F>(
+/// idempotency keys are injected into the corresponding metric events (reused
+/// across different metrics sinks), and must have the same length as input.
+fn serialize_in_chunks<'a>(
     chunk_size: usize,
     input: &'a [RawMetric],
-    factory: F,
+    idempotency_keys: &'a [IdempotencyKey<'a>],
 ) -> impl ExactSizeIterator<Item = Result<(&'a [RawMetric], bytes::Bytes), serde_json::Error>> + 'a
-where
-    F: KeyGen<'a> + 'a,
 {
     use bytes::BufMut;
 
-    struct Iter<'a, F> {
+    assert_eq!(input.len(), idempotency_keys.len());
+
+    struct Iter<'a> {
         inner: std::slice::Chunks<'a, RawMetric>,
+        idempotency_keys: std::slice::Iter<'a, IdempotencyKey<'a>>,
         chunk_size: usize,
 
         // write to a BytesMut so that we can cheaply clone the frozen Bytes for retries
         buffer: bytes::BytesMut,
         // chunk amount of events are reused to produce the serialized document
         scratch: Vec<Event<Ids, Name>>,
-        factory: F,
     }
 
-    impl<'a, F: KeyGen<'a>> Iterator for Iter<'a, F> {
+    impl<'a> Iterator for Iter<'a> {
         type Item = Result<(&'a [RawMetric], bytes::Bytes), serde_json::Error>;
 
         fn next(&mut self) -> Option<Self::Item> {
@@ -167,17 +170,14 @@ where
                 self.scratch.extend(
                     chunk
                         .iter()
-                        .map(|raw_metric| raw_metric.as_event(&self.factory.generate())),
+                        .zip(&mut self.idempotency_keys)
+                        .map(|(raw_metric, key)| raw_metric.as_event(key)),
                 );
             } else {
                 // next rounds: update_in_place to reuse allocations
                 assert_eq!(self.scratch.len(), self.chunk_size);
-                self.scratch
+                itertools::izip!(self.scratch.iter_mut(), chunk, &mut self.idempotency_keys)
-                    .iter_mut()
+                    .for_each(|(slot, raw_metric, key)| raw_metric.update_in_place(slot, key));
-                    .zip(chunk.iter())
-                    .for_each(|(slot, raw_metric)| {
-                        raw_metric.update_in_place(slot, &self.factory.generate())
-                    });
             }
 
             let res = serde_json::to_writer(
@@ -198,18 +198,19 @@ where
         }
     }
 
-    impl<'a, F: KeyGen<'a>> ExactSizeIterator for Iter<'a, F> {}
+    impl<'a> ExactSizeIterator for Iter<'a> {}
 
     let buffer = bytes::BytesMut::new();
     let inner = input.chunks(chunk_size);
+    let idempotency_keys = idempotency_keys.iter();
     let scratch = Vec::new();
 
     Iter {
         inner,
+        idempotency_keys,
         chunk_size,
         buffer,
         scratch,
-        factory,
     }
 }
 
@@ -268,7 +269,7 @@ impl RawMetricExt for RawMetric {
     }
 }
 
-trait KeyGen<'a>: Copy {
+pub(crate) trait KeyGen<'a> {
     fn generate(&self) -> IdempotencyKey<'a>;
 }
 
@@ -389,7 +390,10 @@ mod tests {
         let examples = metric_samples();
         assert!(examples.len() > 1);
 
-        let factory = FixedGen::new(Utc::now(), "1", 42);
+        let now = Utc::now();
+        let idempotency_keys = (0..examples.len())
+            .map(|i| FixedGen::new(now, "1", i as u16).generate())
+            .collect::<Vec<_>>();
 
         // need to use Event here because serde_json::Value uses default hashmap, not linked
         // hashmap
@@ -398,13 +402,13 @@ mod tests {
             events: Vec<Event<Ids, Name>>,
         }
 
-        let correct = serialize_in_chunks(examples.len(), &examples, factory)
+        let correct = serialize_in_chunks(examples.len(), &examples, &idempotency_keys)
             .map(|res| res.unwrap().1)
             .flat_map(|body| serde_json::from_slice::<EventChunk>(&body).unwrap().events)
             .collect::<Vec<_>>();
 
         for chunk_size in 1..examples.len() {
-            let actual = serialize_in_chunks(chunk_size, &examples, factory)
+            let actual = serialize_in_chunks(chunk_size, &examples, &idempotency_keys)
                 .map(|res| res.unwrap().1)
                 .flat_map(|body| serde_json::from_slice::<EventChunk>(&body).unwrap().events)
                 .collect::<Vec<_>>();

pageserver/src/context.rs

@@ -1,7 +1,9 @@
-//! This module defines `RequestContext`, a structure that we use throughout
+//! Defines [`RequestContext`].
-//! the pageserver to propagate high-level context from places
+//!
-//! that _originate_ activity down to the shared code paths at the
+//! It is a structure that we use throughout the pageserver to propagate
-//! heart of the pageserver. It's inspired by Golang's `context.Context`.
+//! high-level context from places that _originate_ activity down to the
+//! shared code paths at the heart of the pageserver. It's inspired by
+//! Golang's `context.Context`.
 //!
 //! For example, in `Timeline::get(page_nr, lsn)` we need to answer the following questions:
 //! 1. What high-level activity ([`TaskKind`]) needs this page?
@@ -105,8 +107,10 @@ pub struct RequestContext {
 #[derive(Clone, Copy, PartialEq, Eq, Debug, enum_map::Enum, strum_macros::IntoStaticStr)]
 pub enum PageContentKind {
     Unknown,
+    DeltaLayerSummary,
     DeltaLayerBtreeNode,
     DeltaLayerValue,
+    ImageLayerSummary,
     ImageLayerBtreeNode,
     ImageLayerValue,
     InMemoryLayer,

pageserver/src/control_plane_client.rs

@@ -141,12 +141,32 @@ impl ControlPlaneGenerationsApi for ControlPlaneClient {
                         m.other
                     );
 
+                    let az_id = {
+                        let az_id_from_metadata = m
+                            .other
+                            .get("availability_zone_id")
+                            .and_then(|jv| jv.as_str().map(|str| str.to_owned()));
+
+                        match az_id_from_metadata {
+                            Some(az_id) => Some(az_id),
+                            None => {
+                                tracing::warn!("metadata.json does not contain an 'availability_zone_id' field");
+                                conf.availability_zone.clone()
+                            }
+                        }
+                    };
+
+                    if az_id.is_none() {
+                        panic!("Availablity zone id could not be inferred from metadata.json or pageserver config");
+                    }
+
                     Some(NodeRegisterRequest {
                         node_id: conf.id,
                         listen_pg_addr: m.postgres_host,
                         listen_pg_port: m.postgres_port,
                         listen_http_addr: m.http_host,
                         listen_http_port: m.http_port,
+                        availability_zone_id: az_id.expect("Checked above"),
                     })
                 }
                 Err(e) => {

pageserver/src/disk_usage_eviction_task.rs

@@ -41,19 +41,15 @@
 // - The `#[allow(dead_code)]` above various structs are to suppress warnings about only the Debug impl
 //   reading these fields. We use the Debug impl for semi-structured logging, though.
 
-use std::{
+use std::{sync::Arc, time::SystemTime};
-    sync::Arc,
-    time::{Duration, SystemTime},
-};
 
 use anyhow::Context;
-use pageserver_api::shard::TenantShardId;
+use pageserver_api::{config::DiskUsageEvictionTaskConfig, shard::TenantShardId};
 use remote_storage::GenericRemoteStorage;
-use serde::{Deserialize, Serialize};
+use serde::Serialize;
 use tokio::time::Instant;
 use tokio_util::sync::CancellationToken;
 use tracing::{debug, error, info, instrument, warn, Instrument};
-use utils::serde_percent::Percent;
 use utils::{completion, id::TimelineId};
 
 use crate::{
@@ -69,23 +65,9 @@ use crate::{
     CancellableTask, DiskUsageEvictionTask,
 };
 
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
-pub struct DiskUsageEvictionTaskConfig {
-    pub max_usage_pct: Percent,
-    pub min_avail_bytes: u64,
-    #[serde(with = "humantime_serde")]
-    pub period: Duration,
-    #[cfg(feature = "testing")]
-    pub mock_statvfs: Option<crate::statvfs::mock::Behavior>,
-    /// Select sorting for evicted layers
-    #[serde(default)]
-    pub eviction_order: EvictionOrder,
-}
-
 /// Selects the sort order for eviction candidates *after* per tenant `min_resident_size`
 /// partitioning.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
-#[serde(tag = "type", content = "args")]
 pub enum EvictionOrder {
     /// Order the layers to be evicted by how recently they have been accessed relatively within
     /// the set of resident layers of a tenant.
@@ -96,23 +78,22 @@ pub enum EvictionOrder {
         /// we read tenants is deterministic. If we find the need to use this as `false`, we need
         /// to ensure nondeterminism by adding in a random number to break the
         /// `relative_last_activity==0.0` ties.
-        #[serde(default = "default_highest_layer_count_loses_first")]
         highest_layer_count_loses_first: bool,
     },
 }
 
-impl Default for EvictionOrder {
+impl From<pageserver_api::config::EvictionOrder> for EvictionOrder {
-    fn default() -> Self {
+    fn from(value: pageserver_api::config::EvictionOrder) -> Self {
-        Self::RelativeAccessed {
+        match value {
-            highest_layer_count_loses_first: true,
+            pageserver_api::config::EvictionOrder::RelativeAccessed {
+                highest_layer_count_loses_first,
+            } => Self::RelativeAccessed {
+                highest_layer_count_loses_first,
+            },
         }
     }
 }
 
-fn default_highest_layer_count_loses_first() -> bool {
-    true
-}
-
 impl EvictionOrder {
     fn sort(&self, candidates: &mut [(EvictionPartition, EvictionCandidate)]) {
         use EvictionOrder::*;
@@ -295,7 +276,7 @@ async fn disk_usage_eviction_task_iteration(
         storage,
         usage_pre,
         tenant_manager,
-        task_config.eviction_order,
+        task_config.eviction_order.into(),
         cancel,
     )
     .await;
@@ -1257,7 +1238,6 @@ mod filesystem_level_usage {
 
     #[test]
     fn max_usage_pct_pressure() {
-        use super::EvictionOrder;
         use super::Usage as _;
         use std::time::Duration;
         use utils::serde_percent::Percent;
@@ -1269,7 +1249,7 @@ mod filesystem_level_usage {
                 period: Duration::MAX,
                 #[cfg(feature = "testing")]
                 mock_statvfs: None,
-                eviction_order: EvictionOrder::default(),
+                eviction_order: pageserver_api::config::EvictionOrder::default(),
             },
             total_bytes: 100_000,
             avail_bytes: 0,

pageserver/src/http/routes.rs

@@ -318,6 +318,27 @@ impl From<crate::tenant::DeleteTimelineError> for ApiError {
     }
 }
 
+impl From<crate::tenant::TimelineArchivalError> for ApiError {
+    fn from(value: crate::tenant::TimelineArchivalError) -> Self {
+        use crate::tenant::TimelineArchivalError::*;
+        match value {
+            NotFound => ApiError::NotFound(anyhow::anyhow!("timeline not found").into()),
+            Timeout => ApiError::Timeout("hit pageserver internal timeout".into()),
+            e @ HasArchivedParent(_) => {
+                ApiError::PreconditionFailed(e.to_string().into_boxed_str())
+            }
+            HasUnarchivedChildren(children) => ApiError::PreconditionFailed(
+                format!(
+                    "Cannot archive timeline which has non-archived child timelines: {children:?}"
+                )
+                .into_boxed_str(),
+            ),
+            a @ AlreadyInProgress => ApiError::Conflict(a.to_string()),
+            Other(e) => ApiError::InternalServerError(e),
+        }
+    }
+}
+
 impl From<crate::tenant::mgr::DeleteTimelineError> for ApiError {
     fn from(value: crate::tenant::mgr::DeleteTimelineError) -> Self {
         use crate::tenant::mgr::DeleteTimelineError::*;
@@ -405,6 +426,8 @@ async fn build_timeline_info_common(
     let current_logical_size = timeline.get_current_logical_size(logical_size_task_priority, ctx);
     let current_physical_size = Some(timeline.layer_size_sum().await);
     let state = timeline.current_state();
+    // Report is_archived = false if the timeline is still loading
+    let is_archived = timeline.is_archived().unwrap_or(false);
     let remote_consistent_lsn_projected = timeline
         .get_remote_consistent_lsn_projected()
         .unwrap_or(Lsn(0));
@@ -445,6 +468,7 @@ async fn build_timeline_info_common(
         pg_version: timeline.pg_version,
 
         state,
+        is_archived: Some(is_archived),
 
         walreceiver_status,
 
@@ -686,9 +710,7 @@ async fn timeline_archival_config_handler(
 
         tenant
             .apply_timeline_archival_config(timeline_id, request_data.state)
-            .await
+            .await?;
-            .context("applying archival config")
-            .map_err(ApiError::InternalServerError)?;
         Ok::<_, ApiError>(())
     }
     .instrument(info_span!("timeline_archival_config",
@@ -852,7 +874,10 @@ async fn get_timestamp_of_lsn_handler(
 
     match result {
         Some(time) => {
-            let time = format_rfc3339(postgres_ffi::from_pg_timestamp(time)).to_string();
+            let time = format_rfc3339(
+                postgres_ffi::try_from_pg_timestamp(time).map_err(ApiError::InternalServerError)?,
+            )
+            .to_string();
             json_response(StatusCode::OK, time)
         }
         None => Err(ApiError::NotFound(
@@ -1706,13 +1731,12 @@ async fn timeline_compact_handler(
         flags |= CompactFlags::ForceImageLayerCreation;
     }
     if Some(true) == parse_query_param::<_, bool>(&request, "enhanced_gc_bottom_most_compaction")? {
-        if !cfg!(feature = "testing") {
-            return Err(ApiError::InternalServerError(anyhow!(
-                "enhanced_gc_bottom_most_compaction is only available in testing mode"
-            )));
-        }
         flags |= CompactFlags::EnhancedGcBottomMostCompaction;
     }
+    if Some(true) == parse_query_param::<_, bool>(&request, "dry_run")? {
+        flags |= CompactFlags::DryRun;
+    }
+
     let wait_until_uploaded =
         parse_query_param::<_, bool>(&request, "wait_until_uploaded")?.unwrap_or(false);
 
@@ -2052,7 +2076,7 @@ async fn disk_usage_eviction_run(
         evict_bytes: u64,
 
         #[serde(default)]
-        eviction_order: crate::disk_usage_eviction_task::EvictionOrder,
+        eviction_order: pageserver_api::config::EvictionOrder,
     }
 
     #[derive(Debug, Clone, Copy, serde::Serialize)]
@@ -2088,7 +2112,7 @@ async fn disk_usage_eviction_run(
         &state.remote_storage,
         usage,
         &state.tenant_manager,
-        config.eviction_order,
+        config.eviction_order.into(),
         &cancel,
     )
     .await;
@@ -2330,6 +2354,20 @@ async fn put_io_engine_handler(
     json_response(StatusCode::OK, ())
 }
 
+async fn put_io_alignment_handler(
+    mut r: Request<Body>,
+    _cancel: CancellationToken,
+) -> Result<Response<Body>, ApiError> {
+    check_permission(&r, None)?;
+    let align: usize = json_request(&mut r).await?;
+    crate::virtual_file::set_io_buffer_alignment(align).map_err(|align| {
+        ApiError::PreconditionFailed(
+            format!("Requested io alignment ({align}) is not a power of two").into(),
+        )
+    })?;
+    json_response(StatusCode::OK, ())
+}
+
 /// Polled by control plane.
 ///
 /// See [`crate::utilization`].
@@ -2942,7 +2980,7 @@ pub fn make_router(
         )
         .put(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/compact",
-            |r| testing_api_handler("run timeline compaction", r, timeline_compact_handler),
+            |r| api_handler(r, timeline_compact_handler),
         )
         .put(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/checkpoint",
@@ -3017,6 +3055,9 @@ pub fn make_router(
             |r| api_handler(r, timeline_collect_keyspace),
         )
         .put("/v1/io_engine", |r| api_handler(r, put_io_engine_handler))
+        .put("/v1/io_alignment", |r| {
+            api_handler(r, put_io_alignment_handler)
+        })
         .put(
             "/v1/tenant/:tenant_shard_id/timeline/:timeline_id/force_aux_policy_switch",
             |r| api_handler(r, force_aux_policy_switch_handler),

pageserver/src/import_datadir.rs

@@ -19,6 +19,7 @@ use crate::metrics::WAL_INGEST;
 use crate::pgdatadir_mapping::*;
 use crate::tenant::Timeline;
 use crate::walingest::WalIngest;
+use crate::walrecord::decode_wal_record;
 use crate::walrecord::DecodedWALRecord;
 use pageserver_api::reltag::{RelTag, SlruKind};
 use postgres_ffi::pg_constants;
@@ -310,11 +311,13 @@ async fn import_wal(
 
         let mut nrecords = 0;
         let mut modification = tline.begin_modification(last_lsn);
-        let mut decoded = DecodedWALRecord::default();
         while last_lsn <= endpoint {
             if let Some((lsn, recdata)) = waldecoder.poll_decode()? {
+                let mut decoded = DecodedWALRecord::default();
+                decode_wal_record(recdata, &mut decoded, tline.pg_version)?;
+
                 walingest
-                    .ingest_record(recdata, lsn, &mut modification, &mut decoded, ctx)
+                    .ingest_record(decoded, lsn, &mut modification, ctx)
                     .await?;
                 WAL_INGEST.records_committed.inc();
 
@@ -449,11 +452,12 @@ pub async fn import_wal_from_tar(
         waldecoder.feed_bytes(&bytes[offset..]);
 
         let mut modification = tline.begin_modification(last_lsn);
-        let mut decoded = DecodedWALRecord::default();
         while last_lsn <= end_lsn {
             if let Some((lsn, recdata)) = waldecoder.poll_decode()? {
+                let mut decoded = DecodedWALRecord::default();
+                decode_wal_record(recdata, &mut decoded, tline.pg_version)?;
                 walingest
-                    .ingest_record(recdata, lsn, &mut modification, &mut decoded, ctx)
+                    .ingest_record(decoded, lsn, &mut modification, ctx)
                     .await?;
                 modification.commit(ctx).await?;
                 last_lsn = lsn;

pageserver/src/l0_flush.rs

@@ -1,9 +1,7 @@
 use std::{num::NonZeroUsize, sync::Arc};
 
-#[derive(Debug, PartialEq, Eq, Clone, serde::Deserialize)]
+#[derive(Debug, PartialEq, Eq, Clone)]
-#[serde(tag = "mode", rename_all = "kebab-case", deny_unknown_fields)]
 pub enum L0FlushConfig {
-    #[serde(rename_all = "snake_case")]
     Direct { max_concurrency: NonZeroUsize },
 }
 
@@ -16,6 +14,16 @@ impl Default for L0FlushConfig {
     }
 }
 
+impl From<pageserver_api::models::L0FlushConfig> for L0FlushConfig {
+    fn from(config: pageserver_api::models::L0FlushConfig) -> Self {
+        match config {
+            pageserver_api::models::L0FlushConfig::Direct { max_concurrency } => {
+                Self::Direct { max_concurrency }
+            }
+        }
+    }
+}
+
 #[derive(Clone)]
 pub struct L0FlushGlobalState(Arc<Inner>);
 

pageserver/src/lib.rs

@@ -16,6 +16,7 @@ pub mod l0_flush;
 use futures::{stream::FuturesUnordered, StreamExt};
 pub use pageserver_api::keyspace;
 use tokio_util::sync::CancellationToken;
+mod assert_u64_eq_usize;
 pub mod aux_file;
 pub mod metrics;
 pub mod page_cache;

pageserver/src/metrics.rs

@@ -9,7 +9,7 @@ use metrics::{
 use once_cell::sync::Lazy;
 use pageserver_api::shard::TenantShardId;
 use strum::{EnumCount, VariantNames};
-use strum_macros::{EnumVariantNames, IntoStaticStr};
+use strum_macros::{IntoStaticStr, VariantNames};
 use tracing::warn;
 use utils::id::TimelineId;
 
@@ -27,7 +27,7 @@ const CRITICAL_OP_BUCKETS: &[f64] = &[
 ];
 
 // Metrics collected on operations on the storage repository.
-#[derive(Debug, EnumVariantNames, IntoStaticStr)]
+#[derive(Debug, VariantNames, IntoStaticStr)]
 #[strum(serialize_all = "kebab_case")]
 pub(crate) enum StorageTimeOperation {
     #[strum(serialize = "layer flush")]
@@ -1552,7 +1552,6 @@ pub(crate) static LIVE_CONNECTIONS: Lazy<IntCounterPairVec> = Lazy::new(|| {
 #[derive(Clone, Copy, enum_map::Enum, IntoStaticStr)]
 pub(crate) enum ComputeCommandKind {
     PageStreamV2,
-    PageStream,
     Basebackup,
     Fullbackup,
     LeaseLsn,
@@ -1803,6 +1802,14 @@ pub(crate) static SECONDARY_RESIDENT_PHYSICAL_SIZE: Lazy<UIntGaugeVec> = Lazy::n
     .expect("failed to define a metric")
 });
 
+pub(crate) static NODE_UTILIZATION_SCORE: Lazy<UIntGauge> = Lazy::new(|| {
+    register_uint_gauge!(
+        "pageserver_utilization_score",
+        "The utilization score we report to the storage controller for scheduling, where 0 is empty, 1000000 is full, and anything above is considered overloaded",
+    )
+    .expect("failed to define a metric")
+});
+
 pub(crate) static SECONDARY_HEATMAP_TOTAL_SIZE: Lazy<UIntGaugeVec> = Lazy::new(|| {
     register_uint_gauge_vec!(
         "pageserver_secondary_heatmap_total_size",

pageserver/src/page_service.rs

@@ -557,7 +557,7 @@ impl PageServerHandler {
         pgb: &mut PostgresBackend<IO>,
         tenant_id: TenantId,
         timeline_id: TimelineId,
-        protocol_version: PagestreamProtocolVersion,
+        _protocol_version: PagestreamProtocolVersion,
         ctx: RequestContext,
     ) -> Result<(), QueryError>
     where
@@ -601,8 +601,7 @@ impl PageServerHandler {
             fail::fail_point!("ps::handle-pagerequest-message");
 
             // parse request
-            let neon_fe_msg =
+            let neon_fe_msg = PagestreamFeMessage::parse(&mut copy_data_bytes.reader())?;
-                PagestreamFeMessage::parse(&mut copy_data_bytes.reader(), protocol_version)?;
 
             // invoke handler function
             let (handler_result, span) = match neon_fe_msg {
@@ -754,16 +753,21 @@ impl PageServerHandler {
         }
 
         if request_lsn < **latest_gc_cutoff_lsn {
-            // Check explicitly for INVALID just to get a less scary error message if the
+            let gc_info = &timeline.gc_info.read().unwrap();
-            // request is obviously bogus
+            if !gc_info.leases.contains_key(&request_lsn) {
-            return Err(if request_lsn == Lsn::INVALID {
+                // The requested LSN is below gc cutoff and is not guarded by a lease.
-                PageStreamError::BadRequest("invalid LSN(0) in request".into())
+
-            } else {
+                // Check explicitly for INVALID just to get a less scary error message if the
-                PageStreamError::BadRequest(format!(
+                // request is obviously bogus
+                return Err(if request_lsn == Lsn::INVALID {
+                    PageStreamError::BadRequest("invalid LSN(0) in request".into())
+                } else {
+                    PageStreamError::BadRequest(format!(
                         "tried to request a page version that was garbage collected. requested at {} gc cutoff {}",
                         request_lsn, **latest_gc_cutoff_lsn
                     ).into())
-            });
+                });
+            }
         }
 
         // Wait for WAL up to 'not_modified_since' to arrive, if necessary
@@ -790,6 +794,8 @@ impl PageServerHandler {
         }
     }
 
+    /// Handles the lsn lease request.
+    /// If a lease cannot be obtained, the client will receive NULL.
     #[instrument(skip_all, fields(shard_id, %lsn))]
     async fn handle_make_lsn_lease<IO>(
         &mut self,
@@ -812,19 +818,25 @@ impl PageServerHandler {
             .await?;
         set_tracing_field_shard_id(&timeline);
 
-        let lease = timeline.make_lsn_lease(lsn, timeline.get_lsn_lease_length(), ctx)?;
+        let lease = timeline
-        let valid_until = lease
+            .make_lsn_lease(lsn, timeline.get_lsn_lease_length(), ctx)
-            .valid_until
+            .inspect_err(|e| {
-            .duration_since(SystemTime::UNIX_EPOCH)
+                warn!("{e}");
-            .map_err(|e| QueryError::Other(e.into()))?;
+            })
+            .ok();
+        let valid_until_str = lease.map(|l| {
+            l.valid_until
+                .duration_since(SystemTime::UNIX_EPOCH)
+                .expect("valid_until is earlier than UNIX_EPOCH")
+                .as_millis()
+                .to_string()
+        });
+        let bytes = valid_until_str.as_ref().map(|x| x.as_bytes());
 
         pgb.write_message_noflush(&BeMessage::RowDescription(&[RowDescriptor::text_col(
             b"valid_until",
         )]))?
-        .write_message_noflush(&BeMessage::DataRow(&[Some(
+        .write_message_noflush(&BeMessage::DataRow(&[bytes]))?;
-            &valid_until.as_millis().to_be_bytes(),
-        )]))?
-        .write_message_noflush(&BeMessage::CommandComplete(b"SELECT 1"))?;
 
         Ok(())
     }
@@ -1187,7 +1199,6 @@ impl PageServerHandler {
     }
 }
 
-#[async_trait::async_trait]
 impl<IO> postgres_backend::Handler<IO> for PageServerHandler
 where
     IO: AsyncRead + AsyncWrite + Send + Sync + Unpin,
@@ -1275,35 +1286,6 @@ where
                 ctx,
             )
             .await?;
-        } else if let Some(params) = parts.strip_prefix(&["pagestream"]) {
-            if params.len() != 2 {
-                return Err(QueryError::Other(anyhow::anyhow!(
-                    "invalid param number for pagestream command"
-                )));
-            }
-            let tenant_id = TenantId::from_str(params[0])
-                .with_context(|| format!("Failed to parse tenant id from {}", params[0]))?;
-            let timeline_id = TimelineId::from_str(params[1])
-                .with_context(|| format!("Failed to parse timeline id from {}", params[1]))?;
-
-            tracing::Span::current()
-                .record("tenant_id", field::display(tenant_id))
-                .record("timeline_id", field::display(timeline_id));
-
-            self.check_permission(Some(tenant_id))?;
-
-            COMPUTE_COMMANDS_COUNTERS
-                .for_command(ComputeCommandKind::PageStream)
-                .inc();
-
-            self.handle_pagerequests(
-                pgb,
-                tenant_id,
-                timeline_id,
-                PagestreamProtocolVersion::V1,
-                ctx,
-            )
-            .await?;
         } else if let Some(params) = parts.strip_prefix(&["basebackup"]) {
             if params.len() < 2 {
                 return Err(QueryError::Other(anyhow::anyhow!(

pageserver/src/pgdatadir_mapping.rs

@@ -15,12 +15,11 @@ use crate::{aux_file, repository::*};
 use anyhow::{ensure, Context};
 use bytes::{Buf, Bytes, BytesMut};
 use enum_map::Enum;
-use itertools::Itertools;
 use pageserver_api::key::{
     dbdir_key_range, rel_block_to_key, rel_dir_to_key, rel_key_range, rel_size_to_key,
     relmap_file_key, repl_origin_key, repl_origin_key_range, slru_block_to_key, slru_dir_to_key,
     slru_segment_key_range, slru_segment_size_to_key, twophase_file_key, twophase_key_range,
-    AUX_FILES_KEY, CHECKPOINT_KEY, CONTROLFILE_KEY, DBDIR_KEY, TWOPHASEDIR_KEY,
+    CompactKey, AUX_FILES_KEY, CHECKPOINT_KEY, CONTROLFILE_KEY, DBDIR_KEY, TWOPHASEDIR_KEY,
 };
 use pageserver_api::keyspace::SparseKeySpace;
 use pageserver_api::models::AuxFilePolicy;
@@ -37,7 +36,6 @@ use tokio_util::sync::CancellationToken;
 use tracing::{debug, info, trace, warn};
 use utils::bin_ser::DeserializeError;
 use utils::pausable_failpoint;
-use utils::vec_map::{VecMap, VecMapOrdering};
 use utils::{bin_ser::BeSer, lsn::Lsn};
 
 /// Max delta records appended to the AUX_FILES_KEY (for aux v1). The write path will write a full image once this threshold is reached.
@@ -170,10 +168,13 @@ impl Timeline {
         DatadirModification {
             tline: self,
             pending_lsns: Vec::new(),
-            pending_updates: HashMap::new(),
+            pending_metadata_pages: HashMap::new(),
+            pending_data_pages: Vec::new(),
+            pending_zero_data_pages: Default::default(),
             pending_deletions: Vec::new(),
             pending_nblocks: 0,
             pending_directory_entries: Vec::new(),
+            pending_bytes: 0,
             lsn,
         }
     }
@@ -727,7 +728,21 @@ impl Timeline {
     ) -> Result<HashMap<String, Bytes>, PageReconstructError> {
         let current_policy = self.last_aux_file_policy.load();
         match current_policy {
-            Some(AuxFilePolicy::V1) | None => self.list_aux_files_v1(lsn, ctx).await,
+            Some(AuxFilePolicy::V1) => {
+                let res = self.list_aux_files_v1(lsn, ctx).await?;
+                let empty_str = if res.is_empty() { ", empty" } else { "" };
+                warn!(
+                    "this timeline is using deprecated aux file policy V1 (policy=v1{empty_str})"
+                );
+                Ok(res)
+            }
+            None => {
+                let res = self.list_aux_files_v1(lsn, ctx).await?;
+                if !res.is_empty() {
+                    warn!("this timeline is using deprecated aux file policy V1 (policy=None)");
+                }
+                Ok(res)
+            }
             Some(AuxFilePolicy::V2) => self.list_aux_files_v2(lsn, ctx).await,
             Some(AuxFilePolicy::CrossValidation) => {
                 let v1_result = self.list_aux_files_v1(lsn, ctx).await;
@@ -1006,9 +1021,10 @@ impl Timeline {
 }
 
 /// DatadirModification represents an operation to ingest an atomic set of
-/// updates to the repository. It is created by the 'begin_record'
+/// updates to the repository.
-/// function. It is called for each WAL record, so that all the modifications
+///
-/// by a one WAL record appear atomic.
+/// It is created by the 'begin_record' function. It is called for each WAL
+/// record, so that all the modifications by a one WAL record appear atomic.
 pub struct DatadirModification<'a> {
     /// The timeline this modification applies to. You can access this to
     /// read the state, but note that any pending updates are *not* reflected
@@ -1022,21 +1038,51 @@ pub struct DatadirModification<'a> {
     // The put-functions add the modifications here, and they are flushed to the
     // underlying key-value store by the 'finish' function.
     pending_lsns: Vec<Lsn>,
-    pending_updates: HashMap<Key, Vec<(Lsn, Value)>>,
     pending_deletions: Vec<(Range<Key>, Lsn)>,
     pending_nblocks: i64,
 
+    /// Metadata writes, indexed by key so that they can be read from not-yet-committed modifications
+    /// while ingesting subsequent records. See [`Self::is_data_key`] for the definition of 'metadata'.
+    pending_metadata_pages: HashMap<CompactKey, Vec<(Lsn, usize, Value)>>,
+
+    /// Data writes, ready to be flushed into an ephemeral layer. See [`Self::is_data_key`] for
+    /// which keys are stored here.
+    pending_data_pages: Vec<(CompactKey, Lsn, usize, Value)>,
+
+    // Sometimes during ingest, for example when extending a relation, we would like to write a zero page.  However,
+    // if we encounter a write from postgres in the same wal record, we will drop this entry.
+    //
+    // Unlike other 'pending' fields, this does not last until the next call to commit(): it is flushed
+    // at the end of each wal record, and all these writes implicitly are at lsn Self::lsn
+    pending_zero_data_pages: HashSet<CompactKey>,
+
     /// For special "directory" keys that store key-value maps, track the size of the map
     /// if it was updated in this modification.
     pending_directory_entries: Vec<(DirectoryKind, usize)>,
+
+    /// An **approximation** of how large our EphemeralFile write will be when committed.
+    pending_bytes: usize,
 }
 
 impl<'a> DatadirModification<'a> {
+    // When a DatadirModification is committed, we do a monolithic serialization of all its contents.  WAL records can
+    // contain multiple pages, so the pageserver's record-based batch size isn't sufficient to bound this allocation: we
+    // additionally specify a limit on how much payload a DatadirModification may contain before it should be committed.
+    pub(crate) const MAX_PENDING_BYTES: usize = 8 * 1024 * 1024;
+
     /// Get the current lsn
     pub(crate) fn get_lsn(&self) -> Lsn {
         self.lsn
     }
 
+    pub(crate) fn approx_pending_bytes(&self) -> usize {
+        self.pending_bytes
+    }
+
+    pub(crate) fn has_dirty_data_pages(&self) -> bool {
+        (!self.pending_data_pages.is_empty()) || (!self.pending_zero_data_pages.is_empty())
+    }
+
     /// Set the current lsn
     pub(crate) fn set_lsn(&mut self, lsn: Lsn) -> anyhow::Result<()> {
         ensure!(
@@ -1045,6 +1091,10 @@ impl<'a> DatadirModification<'a> {
             lsn,
             self.lsn
         );
+
+        // If we are advancing LSN, then state from previous wal record should have been flushed.
+        assert!(self.pending_zero_data_pages.is_empty());
+
         if lsn > self.lsn {
             self.pending_lsns.push(self.lsn);
             self.lsn = lsn;
@@ -1052,6 +1102,17 @@ impl<'a> DatadirModification<'a> {
         Ok(())
     }
 
+    /// In this context, 'metadata' means keys that are only read by the pageserver internally, and 'data' means
+    /// keys that represent literal blocks that postgres can read.  So data includes relation blocks and
+    /// SLRU blocks, which are read directly by postgres, and everything else is considered metadata.
+    ///
+    /// The distinction is important because data keys are handled on a fast path where dirty writes are
+    /// not readable until this modification is committed, whereas metadata keys are visible for read
+    /// via [`Self::get`] as soon as their record has been ingested.
+    fn is_data_key(key: &Key) -> bool {
+        key.is_rel_block_key() || key.is_slru_block_key()
+    }
+
     /// Initialize a completely new repository.
     ///
     /// This inserts the directory metadata entries that are assumed to
@@ -1144,6 +1205,13 @@ impl<'a> DatadirModification<'a> {
         img: Bytes,
     ) -> anyhow::Result<()> {
         anyhow::ensure!(rel.relnode != 0, RelationError::InvalidRelnode);
+        let key = rel_block_to_key(rel, blknum);
+        if !key.is_valid_key_on_write_path() {
+            anyhow::bail!(
+                "the request contains data not supported by pageserver at {}",
+                key
+            );
+        }
         self.put(rel_block_to_key(rel, blknum), Value::Image(img));
         Ok(())
     }
@@ -1155,10 +1223,63 @@ impl<'a> DatadirModification<'a> {
         blknum: BlockNumber,
         img: Bytes,
     ) -> anyhow::Result<()> {
-        self.put(slru_block_to_key(kind, segno, blknum), Value::Image(img));
+        let key = slru_block_to_key(kind, segno, blknum);
+        if !key.is_valid_key_on_write_path() {
+            anyhow::bail!(
+                "the request contains data not supported by pageserver at {}",
+                key
+            );
+        }
+        self.put(key, Value::Image(img));
         Ok(())
     }
 
+    pub(crate) fn put_rel_page_image_zero(
+        &mut self,
+        rel: RelTag,
+        blknum: BlockNumber,
+    ) -> anyhow::Result<()> {
+        anyhow::ensure!(rel.relnode != 0, RelationError::InvalidRelnode);
+        let key = rel_block_to_key(rel, blknum);
+        if !key.is_valid_key_on_write_path() {
+            anyhow::bail!(
+                "the request contains data not supported by pageserver: {} @ {}",
+                key,
+                self.lsn
+            );
+        }
+        self.pending_zero_data_pages.insert(key.to_compact());
+        self.pending_bytes += ZERO_PAGE.len();
+        Ok(())
+    }
+
+    pub(crate) fn put_slru_page_image_zero(
+        &mut self,
+        kind: SlruKind,
+        segno: u32,
+        blknum: BlockNumber,
+    ) -> anyhow::Result<()> {
+        let key = slru_block_to_key(kind, segno, blknum);
+        if !key.is_valid_key_on_write_path() {
+            anyhow::bail!(
+                "the request contains data not supported by pageserver: {} @ {}",
+                key,
+                self.lsn
+            );
+        }
+        self.pending_zero_data_pages.insert(key.to_compact());
+        self.pending_bytes += ZERO_PAGE.len();
+        Ok(())
+    }
+
+    /// Call this at the end of each WAL record.
+    pub(crate) fn on_record_end(&mut self) {
+        let pending_zero_data_pages = std::mem::take(&mut self.pending_zero_data_pages);
+        for key in pending_zero_data_pages {
+            self.put_data(key, Value::Image(ZERO_PAGE.clone()));
+        }
+    }
+
     /// Store a relmapper file (pg_filenode.map) in the repository
     pub async fn put_relmap_file(
         &mut self,
@@ -1576,6 +1697,7 @@ impl<'a> DatadirModification<'a> {
                 if aux_files_key_v1.is_empty() {
                     None
                 } else {
+                    warn!("this timeline is using deprecated aux file policy V1 (detected existing v1 files)");
                     self.tline.do_switch_aux_policy(AuxFilePolicy::V1)?;
                     Some(AuxFilePolicy::V1)
                 }
@@ -1756,7 +1878,7 @@ impl<'a> DatadirModification<'a> {
     /// retains all the metadata, but data pages are flushed. That's again OK
     /// for bulk import, where you are just loading data pages and won't try to
     /// modify the same pages twice.
-    pub async fn flush(&mut self, ctx: &RequestContext) -> anyhow::Result<()> {
+    pub(crate) async fn flush(&mut self, ctx: &RequestContext) -> anyhow::Result<()> {
         // Unless we have accumulated a decent amount of changes, it's not worth it
         // to scan through the pending_updates list.
         let pending_nblocks = self.pending_nblocks;
@@ -1767,23 +1889,12 @@ impl<'a> DatadirModification<'a> {
         let mut writer = self.tline.writer().await;
 
         // Flush relation and  SLRU data blocks, keep metadata.
-        let mut retained_pending_updates = HashMap::<_, Vec<_>>::new();
+        let pending_data_pages = std::mem::take(&mut self.pending_data_pages);
-        for (key, values) in self.pending_updates.drain() {
-            for (lsn, value) in values {
-                if key.is_rel_block_key() || key.is_slru_block_key() {
-                    // This bails out on first error without modifying pending_updates.
-                    // That's Ok, cf this function's doc comment.
-                    writer.put(key, lsn, &value, ctx).await?;
-                } else {
-                    retained_pending_updates
-                        .entry(key)
-                        .or_default()
-                        .push((lsn, value));
-                }
-            }
-        }
 
-        self.pending_updates = retained_pending_updates;
+        // This bails out on first error without modifying pending_updates.
+        // That's Ok, cf this function's doc comment.
+        writer.put_batch(pending_data_pages, ctx).await?;
+        self.pending_bytes = 0;
 
         if pending_nblocks != 0 {
             writer.update_current_logical_size(pending_nblocks * i64::from(BLCKSZ));
@@ -1803,23 +1914,31 @@ impl<'a> DatadirModification<'a> {
     /// All the modifications in this atomic update are stamped by the specified LSN.
     ///
     pub async fn commit(&mut self, ctx: &RequestContext) -> anyhow::Result<()> {
+        // Commit should never be called mid-wal-record
+        assert!(self.pending_zero_data_pages.is_empty());
+
         let mut writer = self.tline.writer().await;
 
         let pending_nblocks = self.pending_nblocks;
         self.pending_nblocks = 0;
 
-        if !self.pending_updates.is_empty() {
+        // Ordering: the items in this batch do not need to be in any global order, but values for
-            // The put_batch call below expects expects the inputs to be sorted by Lsn,
+        // a particular Key must be in Lsn order relative to one another.  InMemoryLayer relies on
-            // so we do that first.
+        // this to do efficient updates to its index.
-            let lsn_ordered_batch: VecMap<Lsn, (Key, Value)> = VecMap::from_iter(
+        let mut write_batch = std::mem::take(&mut self.pending_data_pages);
-                self.pending_updates
-                    .drain()
-                    .map(|(key, vals)| vals.into_iter().map(move |(lsn, val)| (lsn, (key, val))))
-                    .kmerge_by(|lhs, rhs| lhs.0 < rhs.0),
-                VecMapOrdering::GreaterOrEqual,
-            );
 
-            writer.put_batch(lsn_ordered_batch, ctx).await?;
+        write_batch.extend(
+            self.pending_metadata_pages
+                .drain()
+                .flat_map(|(key, values)| {
+                    values
+                        .into_iter()
+                        .map(move |(lsn, value_size, value)| (key, lsn, value_size, value))
+                }),
+        );
+
+        if !write_batch.is_empty() {
+            writer.put_batch(write_batch, ctx).await?;
         }
 
         if !self.pending_deletions.is_empty() {
@@ -1844,37 +1963,64 @@ impl<'a> DatadirModification<'a> {
             writer.update_directory_entries_count(kind, count as u64);
         }
 
+        self.pending_bytes = 0;
+
         Ok(())
     }
 
     pub(crate) fn len(&self) -> usize {
-        self.pending_updates.len() + self.pending_deletions.len()
+        self.pending_metadata_pages.len()
+            + self.pending_data_pages.len()
+            + self.pending_deletions.len()
     }
 
-    // Internal helper functions to batch the modifications
+    /// Read a page from the Timeline we are writing to.  For metadata pages, this passes through
-
+    /// a cache in Self, which makes writes earlier in this modification visible to WAL records later
+    /// in the modification.
+    ///
+    /// For data pages, reads pass directly to the owning Timeline: any ingest code which reads a data
+    /// page must ensure that the pages they read are already committed in Timeline, for example
+    /// DB create operations are always preceded by a call to commit().  This is special cased because
+    /// it's rare: all the 'normal' WAL operations will only read metadata pages such as relation sizes,
+    /// and not data pages.
     async fn get(&self, key: Key, ctx: &RequestContext) -> Result<Bytes, PageReconstructError> {
-        // Have we already updated the same key? Read the latest pending updated
+        if !Self::is_data_key(&key) {
-        // version in that case.
+            // Have we already updated the same key? Read the latest pending updated
-        //
+            // version in that case.
-        // Note: we don't check pending_deletions. It is an error to request a
+            //
-        // value that has been removed, deletion only avoids leaking storage.
+            // Note: we don't check pending_deletions. It is an error to request a
-        if let Some(values) = self.pending_updates.get(&key) {
+            // value that has been removed, deletion only avoids leaking storage.
-            if let Some((_, value)) = values.last() {
+            if let Some(values) = self.pending_metadata_pages.get(&key.to_compact()) {
-                return if let Value::Image(img) = value {
+                if let Some((_, _, value)) = values.last() {
-                    Ok(img.clone())
+                    return if let Value::Image(img) = value {
-                } else {
+                        Ok(img.clone())
-                    // Currently, we never need to read back a WAL record that we
+                    } else {
-                    // inserted in the same "transaction". All the metadata updates
+                        // Currently, we never need to read back a WAL record that we
-                    // work directly with Images, and we never need to read actual
+                        // inserted in the same "transaction". All the metadata updates
-                    // data pages. We could handle this if we had to, by calling
+                        // work directly with Images, and we never need to read actual
-                    // the walredo manager, but let's keep it simple for now.
+                        // data pages. We could handle this if we had to, by calling
-                    Err(PageReconstructError::Other(anyhow::anyhow!(
+                        // the walredo manager, but let's keep it simple for now.
-                        "unexpected pending WAL record"
+                        Err(PageReconstructError::Other(anyhow::anyhow!(
-                    )))
+                            "unexpected pending WAL record"
-                };
+                        )))
+                    };
+                }
+            }
+        } else {
+            // This is an expensive check, so we only do it in debug mode. If reading a data key,
+            // this key should never be present in pending_data_pages. We ensure this by committing
+            // modifications before ingesting DB create operations, which are the only kind that reads
+            // data pages during ingest.
+            if cfg!(debug_assertions) {
+                for (dirty_key, _, _, _) in &self.pending_data_pages {
+                    debug_assert!(&key.to_compact() != dirty_key);
+                }
+
+                debug_assert!(!self.pending_zero_data_pages.contains(&key.to_compact()))
             }
         }
+
+        // Metadata page cache miss, or we're reading a data page.
         let lsn = Lsn::max(self.tline.get_last_record_lsn(), self.lsn);
         self.tline.get(key, lsn, ctx).await
     }
@@ -1886,15 +2032,48 @@ impl<'a> DatadirModification<'a> {
     }
 
     fn put(&mut self, key: Key, val: Value) {
-        let values = self.pending_updates.entry(key).or_default();
+        if Self::is_data_key(&key) {
+            self.put_data(key.to_compact(), val)
+        } else {
+            self.put_metadata(key.to_compact(), val)
+        }
+    }
+
+    fn put_data(&mut self, key: CompactKey, val: Value) {
+        let val_serialized_size = val.serialized_size().unwrap() as usize;
+
+        // If this page was previously zero'd in the same WalRecord, then drop the previous zero page write.  This
+        // is an optimization that avoids persisting both the zero page generated by us (e.g. during a relation extend),
+        // and the subsequent postgres-originating write
+        if self.pending_zero_data_pages.remove(&key) {
+            self.pending_bytes -= ZERO_PAGE.len();
+        }
+
+        self.pending_bytes += val_serialized_size;
+        self.pending_data_pages
+            .push((key, self.lsn, val_serialized_size, val))
+    }
+
+    fn put_metadata(&mut self, key: CompactKey, val: Value) {
+        let values = self.pending_metadata_pages.entry(key).or_default();
         // Replace the previous value if it exists at the same lsn
-        if let Some((last_lsn, last_value)) = values.last_mut() {
+        if let Some((last_lsn, last_value_ser_size, last_value)) = values.last_mut() {
             if *last_lsn == self.lsn {
+                // Update the pending_bytes contribution from this entry, and update the serialized size in place
+                self.pending_bytes -= *last_value_ser_size;
+                *last_value_ser_size = val.serialized_size().unwrap() as usize;
+                self.pending_bytes += *last_value_ser_size;
+
+                // Use the latest value, this replaces any earlier write to the same (key,lsn), such as much
+                // have been generated by synthesized zero page writes prior to the first real write to a page.
                 *last_value = val;
                 return;
             }
         }
-        values.push((self.lsn, val));
+
+        let val_serialized_size = val.serialized_size().unwrap() as usize;
+        self.pending_bytes += val_serialized_size;
+        values.push((self.lsn, val_serialized_size, val));
     }
 
     fn delete(&mut self, key_range: Range<Key>) {
@@ -1905,6 +2084,7 @@ impl<'a> DatadirModification<'a> {
 
 /// This struct facilitates accessing either a committed key from the timeline at a
 /// specific LSN, or the latest uncommitted key from a pending modification.
+///
 /// During WAL ingestion, the records from multiple LSNs may be batched in the same
 /// modification before being flushed to the timeline. Hence, the routines in WalIngest
 /// need to look up the keys in the modification first before looking them up in the
@@ -2024,7 +2204,7 @@ mod tests {
 
         let (tenant, ctx) = harness.load().await;
         let tline = tenant
-            .create_empty_timeline(TIMELINE_ID, Lsn(0), DEFAULT_PG_VERSION, &ctx)
+            .create_empty_timeline(TIMELINE_ID, Lsn(0x10), DEFAULT_PG_VERSION, &ctx)
             .await?;
         let tline = tline.raw_timeline().unwrap();
 

pageserver/src/statvfs.rs

@@ -60,32 +60,7 @@ pub mod mock {
     use regex::Regex;
     use tracing::log::info;
 
-    #[derive(Debug, Clone, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
+    pub use pageserver_api::config::statvfs::mock::Behavior;
-    #[serde(tag = "type")]
-    pub enum Behavior {
-        Success {
-            blocksize: u64,
-            total_blocks: u64,
-            name_filter: Option<utils::serde_regex::Regex>,
-        },
-        Failure {
-            mocked_error: MockedError,
-        },
-    }
-
-    #[derive(Debug, Clone, Copy, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
-    #[allow(clippy::upper_case_acronyms)]
-    pub enum MockedError {
-        EIO,
-    }
-
-    impl From<MockedError> for nix::Error {
-        fn from(e: MockedError) -> Self {
-            match e {
-                MockedError::EIO => nix::Error::EIO,
-            }
-        }
-    }
 
     pub fn get(tenants_dir: &Utf8Path, behavior: &Behavior) -> nix::Result<Statvfs> {
         info!("running mocked statvfs");
@@ -116,6 +91,7 @@ pub mod mock {
                     block_size: *blocksize,
                 })
             }
+            #[cfg(feature = "testing")]
             Behavior::Failure { mocked_error } => Err((*mocked_error).into()),
         }
     }

pageserver/src/task_mgr.rs

@@ -146,6 +146,12 @@ impl FromStr for TokioRuntimeMode {
     }
 }
 
+static TOKIO_THREAD_STACK_SIZE: Lazy<NonZeroUsize> = Lazy::new(|| {
+    env::var("NEON_PAGESERVER_TOKIO_THREAD_STACK_SIZE")
+        // the default 2MiB are insufficent, especially in debug mode
+        .unwrap_or_else(|| NonZeroUsize::new(4 * 1024 * 1024).unwrap())
+});
+
 static ONE_RUNTIME: Lazy<Option<tokio::runtime::Runtime>> = Lazy::new(|| {
     let thread_name = "pageserver-tokio";
     let Some(mode) = env::var("NEON_PAGESERVER_USE_ONE_RUNTIME") else {
@@ -164,6 +170,7 @@ static ONE_RUNTIME: Lazy<Option<tokio::runtime::Runtime>> = Lazy::new(|| {
             tokio::runtime::Builder::new_current_thread()
                 .thread_name(thread_name)
                 .enable_all()
+                .thread_stack_size(TOKIO_THREAD_STACK_SIZE.get())
                 .build()
                 .expect("failed to create one single runtime")
         }
@@ -173,6 +180,7 @@ static ONE_RUNTIME: Lazy<Option<tokio::runtime::Runtime>> = Lazy::new(|| {
                 .thread_name(thread_name)
                 .enable_all()
                 .worker_threads(num_workers.get())
+                .thread_stack_size(TOKIO_THREAD_STACK_SIZE.get())
                 .build()
                 .expect("failed to create one multi-threaded runtime")
         }
@@ -199,6 +207,7 @@ macro_rules! pageserver_runtime {
                     .thread_name($name)
                     .worker_threads(TOKIO_WORKER_THREADS.get())
                     .enable_all()
+                    .thread_stack_size(TOKIO_THREAD_STACK_SIZE.get())
                     .build()
                     .expect(std::concat!("Failed to create runtime ", $name))
             });

pageserver/src/tenant.rs

@@ -1,8 +1,9 @@
+//! Timeline repository implementation that keeps old data in layer files, and
+//! the recent changes in ephemeral files.
 //!
-//! Timeline repository implementation that keeps old data in files on disk, and
+//! See tenant/*_layer.rs files. The functions here are responsible for locating
-//! the recent changes in memory. See tenant/*_layer.rs files.
+//! the correct layer for the get/put call, walking back the timeline branching
-//! The functions here are responsible for locating the correct layer for the
+//! history as needed.
-//! get/put call, walking back the timeline branching history as needed.
 //!
 //! The files are stored in the .neon/tenants/<tenant_id>/timelines/<timeline_id>
 //! directory. See docs/pageserver-storage.md for how the files are managed.
@@ -501,6 +502,42 @@ impl Debug for DeleteTimelineError {
     }
 }
 
+#[derive(thiserror::Error)]
+pub enum TimelineArchivalError {
+    #[error("NotFound")]
+    NotFound,
+
+    #[error("Timeout")]
+    Timeout,
+
+    #[error("ancestor is archived: {}", .0)]
+    HasArchivedParent(TimelineId),
+
+    #[error("HasUnarchivedChildren")]
+    HasUnarchivedChildren(Vec<TimelineId>),
+
+    #[error("Timeline archival is already in progress")]
+    AlreadyInProgress,
+
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
+
+impl Debug for TimelineArchivalError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::NotFound => write!(f, "NotFound"),
+            Self::Timeout => write!(f, "Timeout"),
+            Self::HasArchivedParent(p) => f.debug_tuple("HasArchivedParent").field(p).finish(),
+            Self::HasUnarchivedChildren(c) => {
+                f.debug_tuple("HasUnarchivedChildren").field(c).finish()
+            }
+            Self::AlreadyInProgress => f.debug_tuple("AlreadyInProgress").finish(),
+            Self::Other(e) => f.debug_tuple("Other").field(e).finish(),
+        }
+    }
+}
+
 pub enum SetStoppingError {
     AlreadyStopping(completion::Barrier),
     Broken,
@@ -845,6 +882,12 @@ impl Tenant {
                         });
                     };
 
+                // TODO: should also be rejecting tenant conf changes that violate this check.
+                if let Err(e) = crate::tenant::storage_layer::inmemory_layer::IndexEntry::validate_checkpoint_distance(tenant_clone.get_checkpoint_distance()) {
+                    make_broken(&tenant_clone, anyhow::anyhow!(e), BrokenVerbosity::Error);
+                    return Ok(());
+                }
+
                 let mut init_order = init_order;
                 // take the completion because initial tenant loading will complete when all of
                 // these tasks complete.
@@ -1326,24 +1369,59 @@ impl Tenant {
         &self,
         timeline_id: TimelineId,
         state: TimelineArchivalState,
-    ) -> anyhow::Result<()> {
+    ) -> Result<(), TimelineArchivalError> {
-        let timeline = self
+        info!("setting timeline archival config");
-            .get_timeline(timeline_id, false)
+        let timeline = {
-            .context("Cannot apply timeline archival config to inexistent timeline")?;
+            let timelines = self.timelines.lock().unwrap();
+
+            let Some(timeline) = timelines.get(&timeline_id) else {
+                return Err(TimelineArchivalError::NotFound);
+            };
+
+            if state == TimelineArchivalState::Unarchived {
+                if let Some(ancestor_timeline) = timeline.ancestor_timeline() {
+                    if ancestor_timeline.is_archived() == Some(true) {
+                        return Err(TimelineArchivalError::HasArchivedParent(
+                            ancestor_timeline.timeline_id,
+                        ));
+                    }
+                }
+            }
+
+            // Ensure that there are no non-archived child timelines
+            let children: Vec<TimelineId> = timelines
+                .iter()
+                .filter_map(|(id, entry)| {
+                    if entry.get_ancestor_timeline_id() != Some(timeline_id) {
+                        return None;
+                    }
+                    if entry.is_archived() == Some(true) {
+                        return None;
+                    }
+                    Some(*id)
+                })
+                .collect();
+
+            if !children.is_empty() && state == TimelineArchivalState::Archived {
+                return Err(TimelineArchivalError::HasUnarchivedChildren(children));
+            }
+            Arc::clone(timeline)
+        };
 
         let upload_needed = timeline
             .remote_client
             .schedule_index_upload_for_timeline_archival_state(state)?;
 
         if upload_needed {
+            info!("Uploading new state");
             const MAX_WAIT: Duration = Duration::from_secs(10);
             let Ok(v) =
                 tokio::time::timeout(MAX_WAIT, timeline.remote_client.wait_completion()).await
             else {
                 tracing::warn!("reached timeout for waiting on upload queue");
-                bail!("reached timeout for upload queue flush");
+                return Err(TimelineArchivalError::Timeout);
             };
-            v?;
+            v.map_err(|e| TimelineArchivalError::Other(anyhow::anyhow!(e)))?;
         }
         Ok(())
     }
@@ -3741,13 +3819,21 @@ impl Tenant {
     /// less than this (via eviction and on-demand downloads), but this function enables
     /// the Tenant to advertise how much storage it would prefer to have to provide fast I/O
     /// by keeping important things on local disk.
+    ///
+    /// This is a heuristic, not a guarantee: tenants that are long-idle will actually use less
+    /// than they report here, due to layer eviction.  Tenants with many active branches may
+    /// actually use more than they report here.
     pub(crate) fn local_storage_wanted(&self) -> u64 {
-        let mut wanted = 0;
         let timelines = self.timelines.lock().unwrap();
-        for timeline in timelines.values() {
+
-            wanted += timeline.metrics.visible_physical_size_gauge.get();
+        // Heuristic: we use the max() of the timelines' visible sizes, rather than the sum.  This
-        }
+        // reflects the observation that on tenants with multiple large branches, typically only one
-        wanted
+        // of them is used actively enough to occupy space on disk.
+        timelines
+            .values()
+            .map(|t| t.metrics.visible_physical_size_gauge.get())
+            .max()
+            .unwrap_or(0)
     }
 }
 
@@ -5932,10 +6018,10 @@ mod tests {
             .await
             .unwrap();
 
-        // the default aux file policy to switch is v1 if not set by the admins
+        // the default aux file policy to switch is v2 if not set by the admins
         assert_eq!(
             harness.tenant_conf.switch_aux_file_policy,
-            AuxFilePolicy::V1
+            AuxFilePolicy::default_tenant_config()
         );
         let (tenant, ctx) = harness.load().await;
 
@@ -5979,8 +6065,8 @@ mod tests {
         );
         assert_eq!(
             tline.last_aux_file_policy.load(),
-            Some(AuxFilePolicy::V1),
+            Some(AuxFilePolicy::V2),
-            "aux file is written with switch_aux_file_policy unset (which is v1), so we should keep v1"
+            "aux file is written with switch_aux_file_policy unset (which is v2), so we should use v2 there"
         );
 
         // we can read everything from the storage
@@ -6002,8 +6088,8 @@ mod tests {
 
         assert_eq!(
             tline.last_aux_file_policy.load(),
-            Some(AuxFilePolicy::V1),
+            Some(AuxFilePolicy::V2),
-            "keep v1 storage format when new files are written"
+            "keep v2 storage format when new files are written"
         );
 
         let files = tline.list_aux_files(lsn, &ctx).await.unwrap();
@@ -6019,7 +6105,7 @@ mod tests {
 
         // child copies the last flag even if that is not on remote storage yet
         assert_eq!(child.get_switch_aux_file_policy(), AuxFilePolicy::V2);
-        assert_eq!(child.last_aux_file_policy.load(), Some(AuxFilePolicy::V1));
+        assert_eq!(child.last_aux_file_policy.load(), Some(AuxFilePolicy::V2));
 
         let files = child.list_aux_files(lsn, &ctx).await.unwrap();
         assert_eq!(files.get("pg_logical/mappings/test1"), None);
@@ -7005,18 +7091,14 @@ mod tests {
             vec![
                 // Image layer at GC horizon
                 PersistentLayerKey {
-                    key_range: {
+                    key_range: Key::MIN..Key::MAX,
-                        let mut key = Key::MAX;
-                        key.field6 -= 1;
-                        Key::MIN..key
-                    },
                     lsn_range: Lsn(0x30)..Lsn(0x31),
                     is_delta: false
                 },
-                // The delta layer that is cut in the middle
+                // The delta layer below the horizon
                 PersistentLayerKey {
                     key_range: get_key(3)..get_key(4),
-                    lsn_range: Lsn(0x30)..Lsn(0x41),
+                    lsn_range: Lsn(0x30)..Lsn(0x48),
                     is_delta: true
                 },
                 // The delta3 layer that should not be picked for the compaction
@@ -7996,6 +8078,214 @@ mod tests {
         Ok(())
     }
 
+    #[tokio::test]
+    async fn test_simple_bottom_most_compaction_with_retain_lsns_single_key() -> anyhow::Result<()>
+    {
+        let harness =
+            TenantHarness::create("test_simple_bottom_most_compaction_with_retain_lsns_single_key")
+                .await?;
+        let (tenant, ctx) = harness.load().await;
+
+        fn get_key(id: u32) -> Key {
+            // using aux key here b/c they are guaranteed to be inside `collect_keyspace`.
+            let mut key = Key::from_hex("620000000033333333444444445500000000").unwrap();
+            key.field6 = id;
+            key
+        }
+
+        let img_layer = (0..10)
+            .map(|id| (get_key(id), Bytes::from(format!("value {id}@0x10"))))
+            .collect_vec();
+
+        let delta1 = vec![
+            (
+                get_key(1),
+                Lsn(0x20),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x20")),
+            ),
+            (
+                get_key(1),
+                Lsn(0x28),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x28")),
+            ),
+        ];
+        let delta2 = vec![
+            (
+                get_key(1),
+                Lsn(0x30),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x30")),
+            ),
+            (
+                get_key(1),
+                Lsn(0x38),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x38")),
+            ),
+        ];
+        let delta3 = vec![
+            (
+                get_key(8),
+                Lsn(0x48),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x48")),
+            ),
+            (
+                get_key(9),
+                Lsn(0x48),
+                Value::WalRecord(NeonWalRecord::wal_append("@0x48")),
+            ),
+        ];
+
+        let tline = tenant
+            .create_test_timeline_with_layers(
+                TIMELINE_ID,
+                Lsn(0x10),
+                DEFAULT_PG_VERSION,
+                &ctx,
+                vec![
+                    // delta1 and delta 2 only contain a single key but multiple updates
+                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x10)..Lsn(0x30), delta1),
+                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x30)..Lsn(0x50), delta2),
+                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x10)..Lsn(0x50), delta3),
+                ], // delta layers
+                vec![(Lsn(0x10), img_layer)], // image layers
+                Lsn(0x50),
+            )
+            .await?;
+        {
+            // Update GC info
+            let mut guard = tline.gc_info.write().unwrap();
+            *guard = GcInfo {
+                retain_lsns: vec![
+                    (Lsn(0x10), tline.timeline_id),
+                    (Lsn(0x20), tline.timeline_id),
+                ],
+                cutoffs: GcCutoffs {
+                    time: Lsn(0x30),
+                    space: Lsn(0x30),
+                },
+                leases: Default::default(),
+                within_ancestor_pitr: false,
+            };
+        }
+
+        let expected_result = [
+            Bytes::from_static(b"value 0@0x10"),
+            Bytes::from_static(b"value 1@0x10@0x20@0x28@0x30@0x38"),
+            Bytes::from_static(b"value 2@0x10"),
+            Bytes::from_static(b"value 3@0x10"),
+            Bytes::from_static(b"value 4@0x10"),
+            Bytes::from_static(b"value 5@0x10"),
+            Bytes::from_static(b"value 6@0x10"),
+            Bytes::from_static(b"value 7@0x10"),
+            Bytes::from_static(b"value 8@0x10@0x48"),
+            Bytes::from_static(b"value 9@0x10@0x48"),
+        ];
+
+        let expected_result_at_gc_horizon = [
+            Bytes::from_static(b"value 0@0x10"),
+            Bytes::from_static(b"value 1@0x10@0x20@0x28@0x30"),
+            Bytes::from_static(b"value 2@0x10"),
+            Bytes::from_static(b"value 3@0x10"),
+            Bytes::from_static(b"value 4@0x10"),
+            Bytes::from_static(b"value 5@0x10"),
+            Bytes::from_static(b"value 6@0x10"),
+            Bytes::from_static(b"value 7@0x10"),
+            Bytes::from_static(b"value 8@0x10"),
+            Bytes::from_static(b"value 9@0x10"),
+        ];
+
+        let expected_result_at_lsn_20 = [
+            Bytes::from_static(b"value 0@0x10"),
+            Bytes::from_static(b"value 1@0x10@0x20"),
+            Bytes::from_static(b"value 2@0x10"),
+            Bytes::from_static(b"value 3@0x10"),
+            Bytes::from_static(b"value 4@0x10"),
+            Bytes::from_static(b"value 5@0x10"),
+            Bytes::from_static(b"value 6@0x10"),
+            Bytes::from_static(b"value 7@0x10"),
+            Bytes::from_static(b"value 8@0x10"),
+            Bytes::from_static(b"value 9@0x10"),
+        ];
+
+        let expected_result_at_lsn_10 = [
+            Bytes::from_static(b"value 0@0x10"),
+            Bytes::from_static(b"value 1@0x10"),
+            Bytes::from_static(b"value 2@0x10"),
+            Bytes::from_static(b"value 3@0x10"),
+            Bytes::from_static(b"value 4@0x10"),
+            Bytes::from_static(b"value 5@0x10"),
+            Bytes::from_static(b"value 6@0x10"),
+            Bytes::from_static(b"value 7@0x10"),
+            Bytes::from_static(b"value 8@0x10"),
+            Bytes::from_static(b"value 9@0x10"),
+        ];
+
+        let verify_result = || async {
+            let gc_horizon = {
+                let gc_info = tline.gc_info.read().unwrap();
+                gc_info.cutoffs.time
+            };
+            for idx in 0..10 {
+                assert_eq!(
+                    tline
+                        .get(get_key(idx as u32), Lsn(0x50), &ctx)
+                        .await
+                        .unwrap(),
+                    &expected_result[idx]
+                );
+                assert_eq!(
+                    tline
+                        .get(get_key(idx as u32), gc_horizon, &ctx)
+                        .await
+                        .unwrap(),
+                    &expected_result_at_gc_horizon[idx]
+                );
+                assert_eq!(
+                    tline
+                        .get(get_key(idx as u32), Lsn(0x20), &ctx)
+                        .await
+                        .unwrap(),
+                    &expected_result_at_lsn_20[idx]
+                );
+                assert_eq!(
+                    tline
+                        .get(get_key(idx as u32), Lsn(0x10), &ctx)
+                        .await
+                        .unwrap(),
+                    &expected_result_at_lsn_10[idx]
+                );
+            }
+        };
+
+        verify_result().await;
+
+        let cancel = CancellationToken::new();
+        let mut dryrun_flags = EnumSet::new();
+        dryrun_flags.insert(CompactFlags::DryRun);
+
+        tline
+            .compact_with_gc(&cancel, dryrun_flags, &ctx)
+            .await
+            .unwrap();
+        // We expect layer map to be the same b/c the dry run flag, but we don't know whether there will be other background jobs
+        // cleaning things up, and therefore, we don't do sanity checks on the layer map during unit tests.
+        verify_result().await;
+
+        tline
+            .compact_with_gc(&cancel, EnumSet::new(), &ctx)
+            .await
+            .unwrap();
+        verify_result().await;
+
+        // compact again
+        tline
+            .compact_with_gc(&cancel, EnumSet::new(), &ctx)
+            .await
+            .unwrap();
+        verify_result().await;
+
+        Ok(())
+    }
+
     #[tokio::test]
     async fn test_simple_bottom_most_compaction_on_branch() -> anyhow::Result<()> {
         let harness = TenantHarness::create("test_simple_bottom_most_compaction_on_branch").await?;

pageserver/src/tenant/blob_io.rs

@@ -148,7 +148,7 @@ pub(super) const LEN_COMPRESSION_BIT_MASK: u8 = 0xf0;
 
 /// The maximum size of blobs we support. The highest few bits
 /// are reserved for compression and other further uses.
-const MAX_SUPPORTED_LEN: usize = 0x0fff_ffff;
+pub(crate) const MAX_SUPPORTED_BLOB_LEN: usize = 0x0fff_ffff;
 
 pub(super) const BYTE_UNCOMPRESSED: u8 = 0x80;
 pub(super) const BYTE_ZSTD: u8 = BYTE_UNCOMPRESSED | 0x10;
@@ -326,7 +326,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
                 (self.write_all(io_buf.slice_len(), ctx).await, srcbuf)
             } else {
                 // Write a 4-byte length header
-                if len > MAX_SUPPORTED_LEN {
+                if len > MAX_SUPPORTED_BLOB_LEN {
                     return (
                         (
                             io_buf.slice_len(),

pageserver/src/tenant/block_io.rs

@@ -2,7 +2,6 @@
 //! Low-level Block-oriented I/O functions
 //!
 
-use super::ephemeral_file::EphemeralFile;
 use super::storage_layer::delta_layer::{Adapter, DeltaLayerInner};
 use crate::context::RequestContext;
 use crate::page_cache::{self, FileId, PageReadGuard, PageWriteGuard, ReadBufResult, PAGE_SZ};
@@ -81,9 +80,7 @@ impl<'a> Deref for BlockLease<'a> {
 /// Unlike traits, we also support the read function to be async though.
 pub(crate) enum BlockReaderRef<'a> {
     FileBlockReader(&'a FileBlockReader<'a>),
-    EphemeralFile(&'a EphemeralFile),
     Adapter(Adapter<&'a DeltaLayerInner>),
-    Slice(&'a [u8]),
     #[cfg(test)]
     TestDisk(&'a super::disk_btree::tests::TestDisk),
     #[cfg(test)]
@@ -100,9 +97,7 @@ impl<'a> BlockReaderRef<'a> {
         use BlockReaderRef::*;
         match self {
             FileBlockReader(r) => r.read_blk(blknum, ctx).await,
-            EphemeralFile(r) => r.read_blk(blknum, ctx).await,
             Adapter(r) => r.read_blk(blknum, ctx).await,
-            Slice(s) => Self::read_blk_slice(s, blknum),
             #[cfg(test)]
             TestDisk(r) => r.read_blk(blknum),
             #[cfg(test)]
@@ -111,24 +106,6 @@ impl<'a> BlockReaderRef<'a> {
     }
 }
 
-impl<'a> BlockReaderRef<'a> {
-    fn read_blk_slice(slice: &[u8], blknum: u32) -> std::io::Result<BlockLease> {
-        let start = (blknum as usize).checked_mul(PAGE_SZ).unwrap();
-        let end = start.checked_add(PAGE_SZ).unwrap();
-        if end > slice.len() {
-            return Err(std::io::Error::new(
-                std::io::ErrorKind::UnexpectedEof,
-                format!("slice too short, len={} end={}", slice.len(), end),
-            ));
-        }
-        let slice = &slice[start..end];
-        let page_sized: &[u8; PAGE_SZ] = slice
-            .try_into()
-            .expect("we add PAGE_SZ to start, so the slice must have PAGE_SZ");
-        Ok(BlockLease::Slice(page_sized))
-    }
-}
-
 ///
 /// A "cursor" for efficiently reading multiple pages from a BlockReader
 ///

pageserver/src/tenant/config.rs

@@ -9,11 +9,10 @@
 //! may lead to a data loss.
 //!
 use anyhow::bail;
+pub(crate) use pageserver_api::config::TenantConfigToml as TenantConf;
 use pageserver_api::models::AuxFilePolicy;
-use pageserver_api::models::CompactionAlgorithm;
 use pageserver_api::models::CompactionAlgorithmSettings;
 use pageserver_api::models::EvictionPolicy;
-use pageserver_api::models::LsnLease;
 use pageserver_api::models::{self, ThrottleConfig};
 use pageserver_api::shard::{ShardCount, ShardIdentity, ShardNumber, ShardStripeSize};
 use serde::de::IntoDeserializer;
@@ -23,50 +22,6 @@ use std::num::NonZeroU64;
 use std::time::Duration;
 use utils::generation::Generation;
 
-pub mod defaults {
-
-    // FIXME: This current value is very low. I would imagine something like 1 GB or 10 GB
-    // would be more appropriate. But a low value forces the code to be exercised more,
-    // which is good for now to trigger bugs.
-    // This parameter actually determines L0 layer file size.
-    pub const DEFAULT_CHECKPOINT_DISTANCE: u64 = 256 * 1024 * 1024;
-    pub const DEFAULT_CHECKPOINT_TIMEOUT: &str = "10 m";
-
-    // FIXME the below configs are only used by legacy algorithm. The new algorithm
-    // has different parameters.
-
-    // Target file size, when creating image and delta layers.
-    // This parameter determines L1 layer file size.
-    pub const DEFAULT_COMPACTION_TARGET_SIZE: u64 = 128 * 1024 * 1024;
-
-    pub const DEFAULT_COMPACTION_PERIOD: &str = "20 s";
-    pub const DEFAULT_COMPACTION_THRESHOLD: usize = 10;
-    pub const DEFAULT_COMPACTION_ALGORITHM: super::CompactionAlgorithm =
-        super::CompactionAlgorithm::Legacy;
-
-    pub const DEFAULT_GC_HORIZON: u64 = 64 * 1024 * 1024;
-
-    // Large DEFAULT_GC_PERIOD is fine as long as PITR_INTERVAL is larger.
-    // If there's a need to decrease this value, first make sure that GC
-    // doesn't hold a layer map write lock for non-trivial operations.
-    // Relevant: https://github.com/neondatabase/neon/issues/3394
-    pub const DEFAULT_GC_PERIOD: &str = "1 hr";
-    pub const DEFAULT_IMAGE_CREATION_THRESHOLD: usize = 3;
-    pub const DEFAULT_PITR_INTERVAL: &str = "7 days";
-    pub const DEFAULT_WALRECEIVER_CONNECT_TIMEOUT: &str = "10 seconds";
-    pub const DEFAULT_WALRECEIVER_LAGGING_WAL_TIMEOUT: &str = "10 seconds";
-    // The default limit on WAL lag should be set to avoid causing disconnects under high throughput
-    // scenarios: since the broker stats are updated ~1/s, a value of 1GiB should be sufficient for
-    // throughputs up to 1GiB/s per timeline.
-    pub const DEFAULT_MAX_WALRECEIVER_LSN_WAL_LAG: u64 = 1024 * 1024 * 1024;
-    pub const DEFAULT_EVICTIONS_LOW_RESIDENCE_DURATION_METRIC_THRESHOLD: &str = "24 hour";
-    // By default ingest enough WAL for two new L0 layers before checking if new image
-    // image layers should be created.
-    pub const DEFAULT_IMAGE_LAYER_CREATION_CHECK_THRESHOLD: u8 = 2;
-
-    pub const DEFAULT_INGEST_BATCH_SIZE: u64 = 100;
-}
-
 #[derive(Debug, Copy, Clone, Serialize, Deserialize, PartialEq, Eq)]
 pub(crate) enum AttachmentMode {
     /// Our generation is current as far as we know, and as far as we know we are the only attached
@@ -281,96 +236,20 @@ impl LocationConf {
     }
 }
 
-/// A tenant's calcuated configuration, which is the result of merging a
+impl Default for LocationConf {
-/// tenant's TenantConfOpt with the global TenantConf from PageServerConf.
+    // TODO: this should be removed once tenant loading can guarantee that we are never
-///
+    // loading from a directory without a configuration.
-/// For storing and transmitting individual tenant's configuration, see
+    // => tech debt since https://github.com/neondatabase/neon/issues/1555
-/// TenantConfOpt.
+    fn default() -> Self {
-#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
+        Self {
-pub struct TenantConf {
+            mode: LocationMode::Attached(AttachedLocationConfig {
-    // Flush out an inmemory layer, if it's holding WAL older than this
+                generation: Generation::none(),
-    // This puts a backstop on how much WAL needs to be re-digested if the
+                attach_mode: AttachmentMode::Single,
-    // page server crashes.
+            }),
-    // This parameter actually determines L0 layer file size.
+            tenant_conf: TenantConfOpt::default(),
-    pub checkpoint_distance: u64,
+            shard: ShardIdentity::unsharded(),
-    // Inmemory layer is also flushed at least once in checkpoint_timeout to
+        }
-    // eventually upload WAL after activity is stopped.
+    }
-    #[serde(with = "humantime_serde")]
-    pub checkpoint_timeout: Duration,
-    // Target file size, when creating image and delta layers.
-    // This parameter determines L1 layer file size.
-    pub compaction_target_size: u64,
-    // How often to check if there's compaction work to be done.
-    // Duration::ZERO means automatic compaction is disabled.
-    #[serde(with = "humantime_serde")]
-    pub compaction_period: Duration,
-    // Level0 delta layer threshold for compaction.
-    pub compaction_threshold: usize,
-    pub compaction_algorithm: CompactionAlgorithmSettings,
-    // Determines how much history is retained, to allow
-    // branching and read replicas at an older point in time.
-    // The unit is #of bytes of WAL.
-    // Page versions older than this are garbage collected away.
-    pub gc_horizon: u64,
-    // Interval at which garbage collection is triggered.
-    // Duration::ZERO means automatic GC is disabled
-    #[serde(with = "humantime_serde")]
-    pub gc_period: Duration,
-    // Delta layer churn threshold to create L1 image layers.
-    pub image_creation_threshold: usize,
-    // Determines how much history is retained, to allow
-    // branching and read replicas at an older point in time.
-    // The unit is time.
-    // Page versions older than this are garbage collected away.
-    #[serde(with = "humantime_serde")]
-    pub pitr_interval: Duration,
-    /// Maximum amount of time to wait while opening a connection to receive wal, before erroring.
-    #[serde(with = "humantime_serde")]
-    pub walreceiver_connect_timeout: Duration,
-    /// Considers safekeepers stalled after no WAL updates were received longer than this threshold.
-    /// A stalled safekeeper will be changed to a newer one when it appears.
-    #[serde(with = "humantime_serde")]
-    pub lagging_wal_timeout: Duration,
-    /// Considers safekeepers lagging when their WAL is behind another safekeeper for more than this threshold.
-    /// A lagging safekeeper will be changed after `lagging_wal_timeout` time elapses since the last WAL update,
-    /// to avoid eager reconnects.
-    pub max_lsn_wal_lag: NonZeroU64,
-    pub eviction_policy: EvictionPolicy,
-    pub min_resident_size_override: Option<u64>,
-    // See the corresponding metric's help string.
-    #[serde(with = "humantime_serde")]
-    pub evictions_low_residence_duration_metric_threshold: Duration,
-
-    /// If non-zero, the period between uploads of a heatmap from attached tenants.  This
-    /// may be disabled if a Tenant will not have secondary locations: only secondary
-    /// locations will use the heatmap uploaded by attached locations.
-    #[serde(with = "humantime_serde")]
-    pub heatmap_period: Duration,
-
-    /// If true then SLRU segments are dowloaded on demand, if false SLRU segments are included in basebackup
-    pub lazy_slru_download: bool,
-
-    pub timeline_get_throttle: pageserver_api::models::ThrottleConfig,
-
-    // How much WAL must be ingested before checking again whether a new image layer is required.
-    // Expresed in multiples of checkpoint distance.
-    pub image_layer_creation_check_threshold: u8,
-
-    /// Switch to a new aux file policy. Switching this flag requires the user has not written any aux file into
-    /// the storage before, and this flag cannot be switched back. Otherwise there will be data corruptions.
-    /// There is a `last_aux_file_policy` flag which gets persisted in `index_part.json` once the first aux
-    /// file is written.
-    pub switch_aux_file_policy: AuxFilePolicy,
-
-    /// The length for an explicit LSN lease request.
-    /// Layers needed to reconstruct pages at LSN will not be GC-ed during this interval.
-    #[serde(with = "humantime_serde")]
-    pub lsn_lease_length: Duration,
-
-    /// The length for an implicit LSN lease granted as part of `get_lsn_by_timestamp` request.
-    /// Layers needed to reconstruct pages at LSN will not be GC-ed during this interval.
-    #[serde(with = "humantime_serde")]
-    pub lsn_lease_length_for_ts: Duration,
 }
 
 /// Same as TenantConf, but this struct preserves the information about
@@ -545,51 +424,6 @@ impl TenantConfOpt {
     }
 }
 
-impl Default for TenantConf {
-    fn default() -> Self {
-        use defaults::*;
-        Self {
-            checkpoint_distance: DEFAULT_CHECKPOINT_DISTANCE,
-            checkpoint_timeout: humantime::parse_duration(DEFAULT_CHECKPOINT_TIMEOUT)
-                .expect("cannot parse default checkpoint timeout"),
-            compaction_target_size: DEFAULT_COMPACTION_TARGET_SIZE,
-            compaction_period: humantime::parse_duration(DEFAULT_COMPACTION_PERIOD)
-                .expect("cannot parse default compaction period"),
-            compaction_threshold: DEFAULT_COMPACTION_THRESHOLD,
-            compaction_algorithm: CompactionAlgorithmSettings {
-                kind: DEFAULT_COMPACTION_ALGORITHM,
-            },
-            gc_horizon: DEFAULT_GC_HORIZON,
-            gc_period: humantime::parse_duration(DEFAULT_GC_PERIOD)
-                .expect("cannot parse default gc period"),
-            image_creation_threshold: DEFAULT_IMAGE_CREATION_THRESHOLD,
-            pitr_interval: humantime::parse_duration(DEFAULT_PITR_INTERVAL)
-                .expect("cannot parse default PITR interval"),
-            walreceiver_connect_timeout: humantime::parse_duration(
-                DEFAULT_WALRECEIVER_CONNECT_TIMEOUT,
-            )
-            .expect("cannot parse default walreceiver connect timeout"),
-            lagging_wal_timeout: humantime::parse_duration(DEFAULT_WALRECEIVER_LAGGING_WAL_TIMEOUT)
-                .expect("cannot parse default walreceiver lagging wal timeout"),
-            max_lsn_wal_lag: NonZeroU64::new(DEFAULT_MAX_WALRECEIVER_LSN_WAL_LAG)
-                .expect("cannot parse default max walreceiver Lsn wal lag"),
-            eviction_policy: EvictionPolicy::NoEviction,
-            min_resident_size_override: None,
-            evictions_low_residence_duration_metric_threshold: humantime::parse_duration(
-                DEFAULT_EVICTIONS_LOW_RESIDENCE_DURATION_METRIC_THRESHOLD,
-            )
-            .expect("cannot parse default evictions_low_residence_duration_metric_threshold"),
-            heatmap_period: Duration::ZERO,
-            lazy_slru_download: false,
-            timeline_get_throttle: crate::tenant::throttle::Config::disabled(),
-            image_layer_creation_check_threshold: DEFAULT_IMAGE_LAYER_CREATION_CHECK_THRESHOLD,
-            switch_aux_file_policy: AuxFilePolicy::default_tenant_config(),
-            lsn_lease_length: LsnLease::DEFAULT_LENGTH,
-            lsn_lease_length_for_ts: LsnLease::DEFAULT_LENGTH_FOR_TS,
-        }
-    }
-}
-
 impl TryFrom<&'_ models::TenantConfig> for TenantConfOpt {
     type Error = anyhow::Error;
 
@@ -618,7 +452,8 @@ impl TryFrom<toml_edit::Item> for TenantConfOpt {
                     .map_err(|e| anyhow::anyhow!("{}: {}", e.path(), e.inner().message()));
             }
             toml_edit::Item::Table(table) => {
-                let deserializer = toml_edit::de::Deserializer::new(table.into());
+                let deserializer =
+                    toml_edit::de::Deserializer::from(toml_edit::DocumentMut::from(table));
                 return serde_path_to_error::deserialize(deserializer)
                     .map_err(|e| anyhow::anyhow!("{}: {}", e.path(), e.inner().message()));
             }

pageserver/src/tenant/ephemeral_file.rs

@@ -1,13 +1,21 @@
 //! Implementation of append-only file data structure
 //! used to keep in-memory layers spilled on disk.
 
+use crate::assert_u64_eq_usize::{U64IsUsize, UsizeIsU64};
 use crate::config::PageServerConf;
 use crate::context::RequestContext;
 use crate::page_cache;
-use crate::tenant::block_io::{BlockCursor, BlockLease, BlockReader};
+use crate::tenant::storage_layer::inmemory_layer::vectored_dio_read::File;
-use crate::virtual_file::{self, VirtualFile};
+use crate::virtual_file::owned_buffers_io::slice::SliceMutExt;
+use crate::virtual_file::owned_buffers_io::util::size_tracking_writer;
+use crate::virtual_file::owned_buffers_io::write::Buffer;
+use crate::virtual_file::{self, owned_buffers_io, VirtualFile};
+use bytes::BytesMut;
 use camino::Utf8PathBuf;
+use num_traits::Num;
 use pageserver_api::shard::TenantShardId;
+use tokio_epoll_uring::{BoundedBuf, Slice};
+use tracing::error;
 
 use std::io;
 use std::sync::atomic::AtomicU64;
@@ -16,12 +24,17 @@ use utils::id::TimelineId;
 pub struct EphemeralFile {
     _tenant_shard_id: TenantShardId,
     _timeline_id: TimelineId,
-
+    page_cache_file_id: page_cache::FileId,
-    rw: page_caching::RW,
+    bytes_written: u64,
+    buffered_writer: owned_buffers_io::write::BufferedWriter<
+        BytesMut,
+        size_tracking_writer::Writer<VirtualFile>,
+    >,
+    /// Gate guard is held on as long as we need to do operations in the path (delete on drop)
+    _gate_guard: utils::sync::gate::GateGuard,
 }
 
-mod page_caching;
+const TAIL_SZ: usize = 64 * 1024;
-mod zero_padded_read_write;
 
 impl EphemeralFile {
     pub async fn create(
@@ -51,60 +64,178 @@ impl EphemeralFile {
         )
         .await?;
 
+        let page_cache_file_id = page_cache::next_file_id(); // XXX get rid, we're not page-caching anymore
+
         Ok(EphemeralFile {
             _tenant_shard_id: tenant_shard_id,
             _timeline_id: timeline_id,
-            rw: page_caching::RW::new(file, gate_guard),
+            page_cache_file_id,
+            bytes_written: 0,
+            buffered_writer: owned_buffers_io::write::BufferedWriter::new(
+                size_tracking_writer::Writer::new(file),
+                BytesMut::with_capacity(TAIL_SZ),
+            ),
+            _gate_guard: gate_guard,
         })
     }
+}
 
+impl Drop for EphemeralFile {
+    fn drop(&mut self) {
+        // unlink the file
+        // we are clear to do this, because we have entered a gate
+        let path = &self.buffered_writer.as_inner().as_inner().path;
+        let res = std::fs::remove_file(path);
+        if let Err(e) = res {
+            if e.kind() != std::io::ErrorKind::NotFound {
+                // just never log the not found errors, we cannot do anything for them; on detach
+                // the tenant directory is already gone.
+                //
+                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
+                error!("could not remove ephemeral file '{path}': {e}");
+            }
+        }
+    }
+}
+
+impl EphemeralFile {
     pub(crate) fn len(&self) -> u64 {
-        self.rw.bytes_written()
+        self.bytes_written
     }
 
     pub(crate) fn page_cache_file_id(&self) -> page_cache::FileId {
-        self.rw.page_cache_file_id()
+        self.page_cache_file_id
     }
 
-    /// See [`self::page_caching::RW::load_to_vec`].
     pub(crate) async fn load_to_vec(&self, ctx: &RequestContext) -> Result<Vec<u8>, io::Error> {
-        self.rw.load_to_vec(ctx).await
+        let size = self.len().into_usize();
+        let vec = Vec::with_capacity(size);
+        let (slice, nread) = self.read_exact_at_eof_ok(0, vec.slice_full(), ctx).await?;
+        assert_eq!(nread, size);
+        let vec = slice.into_inner();
+        assert_eq!(vec.len(), nread);
+        assert_eq!(vec.capacity(), size, "we shouldn't be reallocating");
+        Ok(vec)
     }
 
-    pub(crate) async fn read_blk(
+    /// Returns the offset at which the first byte of the input was written, for use
-        &self,
+    /// in constructing indices over the written value.
-        blknum: u32,
+    ///
-        ctx: &RequestContext,
+    /// Panics if the write is short because there's no way we can recover from that.
-    ) -> Result<BlockLease, io::Error> {
+    /// TODO: make upstack handle this as an error.
-        self.rw.read_blk(blknum, ctx).await
+    pub(crate) async fn write_raw(
-    }
-
-    pub(crate) async fn write_blob(
         &mut self,
         srcbuf: &[u8],
         ctx: &RequestContext,
-    ) -> Result<u64, io::Error> {
+    ) -> std::io::Result<u64> {
-        let pos = self.rw.bytes_written();
+        let pos = self.bytes_written;
 
-        // Write the length field
+        let new_bytes_written = pos.checked_add(srcbuf.len().into_u64()).ok_or_else(|| {
-        if srcbuf.len() < 0x80 {
+            std::io::Error::new(
-            // short one-byte length header
+                std::io::ErrorKind::Other,
-            let len_buf = [srcbuf.len() as u8];
+                format!(
-
+                    "write would grow EphemeralFile beyond u64::MAX: len={pos} writen={srcbuf_len}",
-            self.rw.write_all_borrowed(&len_buf, ctx).await?;
+                    srcbuf_len = srcbuf.len(),
-        } else {
+                ),
-            let mut len_buf = u32::to_be_bytes(srcbuf.len() as u32);
+            )
-            len_buf[0] |= 0x80;
+        })?;
-            self.rw.write_all_borrowed(&len_buf, ctx).await?;
-        }
 
         // Write the payload
-        self.rw.write_all_borrowed(srcbuf, ctx).await?;
+        let nwritten = self
+            .buffered_writer
+            .write_buffered_borrowed(srcbuf, ctx)
+            .await?;
+        assert_eq!(
+            nwritten,
+            srcbuf.len(),
+            "buffered writer has no short writes"
+        );
+
+        self.bytes_written = new_bytes_written;
 
         Ok(pos)
     }
 }
 
+impl super::storage_layer::inmemory_layer::vectored_dio_read::File for EphemeralFile {
+    async fn read_exact_at_eof_ok<'a, 'b, B: tokio_epoll_uring::IoBufMut + Send>(
+        &'b self,
+        start: u64,
+        dst: tokio_epoll_uring::Slice<B>,
+        ctx: &'a RequestContext,
+    ) -> std::io::Result<(tokio_epoll_uring::Slice<B>, usize)> {
+        let file_size_tracking_writer = self.buffered_writer.as_inner();
+        let flushed_offset = file_size_tracking_writer.bytes_written();
+
+        let buffer = self.buffered_writer.inspect_buffer();
+        let buffered = &buffer[0..buffer.pending()];
+
+        let dst_cap = dst.bytes_total().into_u64();
+        let end = {
+            // saturating_add is correct here because the max file size is u64::MAX, so,
+            // if start + dst.len() > u64::MAX, then we know it will be a short read
+            let mut end: u64 = start.saturating_add(dst_cap);
+            if end > self.bytes_written {
+                end = self.bytes_written;
+            }
+            end
+        };
+
+        // inclusive, exclusive
+        #[derive(Debug)]
+        struct Range<N>(N, N);
+        impl<N: Num + Clone + Copy + PartialOrd + Ord> Range<N> {
+            fn len(&self) -> N {
+                if self.0 > self.1 {
+                    N::zero()
+                } else {
+                    self.1 - self.0
+                }
+            }
+        }
+        let written_range = Range(start, std::cmp::min(end, flushed_offset));
+        let buffered_range = Range(std::cmp::max(start, flushed_offset), end);
+
+        let dst = if written_range.len() > 0 {
+            let file: &VirtualFile = file_size_tracking_writer.as_inner();
+            let bounds = dst.bounds();
+            let slice = file
+                .read_exact_at(dst.slice(0..written_range.len().into_usize()), start, ctx)
+                .await?;
+            Slice::from_buf_bounds(Slice::into_inner(slice), bounds)
+        } else {
+            dst
+        };
+
+        let dst = if buffered_range.len() > 0 {
+            let offset_in_buffer = buffered_range
+                .0
+                .checked_sub(flushed_offset)
+                .unwrap()
+                .into_usize();
+            let to_copy =
+                &buffered[offset_in_buffer..(offset_in_buffer + buffered_range.len().into_usize())];
+            let bounds = dst.bounds();
+            let mut view = dst.slice({
+                let start = written_range.len().into_usize();
+                let end = start
+                    .checked_add(buffered_range.len().into_usize())
+                    .unwrap();
+                start..end
+            });
+            view.as_mut_rust_slice_full_zeroed()
+                .copy_from_slice(to_copy);
+            Slice::from_buf_bounds(Slice::into_inner(view), bounds)
+        } else {
+            dst
+        };
+
+        // TODO: in debug mode, randomize the remaining bytes in `dst` to catch bugs
+
+        Ok((dst, (end - start).into_usize()))
+    }
+}
+
 /// Does the given filename look like an ephemeral file?
 pub fn is_ephemeral_file(filename: &str) -> bool {
     if let Some(rest) = filename.strip_prefix("ephemeral-") {
@@ -114,19 +245,13 @@ pub fn is_ephemeral_file(filename: &str) -> bool {
     }
 }
 
-impl BlockReader for EphemeralFile {
-    fn block_cursor(&self) -> super::block_io::BlockCursor<'_> {
-        BlockCursor::new(super::block_io::BlockReaderRef::EphemeralFile(self))
-    }
-}
-
 #[cfg(test)]
 mod tests {
+    use rand::Rng;
+
     use super::*;
     use crate::context::DownloadBehavior;
     use crate::task_mgr::TaskKind;
-    use crate::tenant::block_io::BlockReaderRef;
-    use rand::{thread_rng, RngCore};
     use std::fs;
     use std::str::FromStr;
 
@@ -157,69 +282,6 @@ mod tests {
         Ok((conf, tenant_shard_id, timeline_id, ctx))
     }
 
-    #[tokio::test]
-    async fn test_ephemeral_blobs() -> Result<(), io::Error> {
-        let (conf, tenant_id, timeline_id, ctx) = harness("ephemeral_blobs")?;
-
-        let gate = utils::sync::gate::Gate::default();
-
-        let entered = gate.enter().unwrap();
-
-        let mut file = EphemeralFile::create(conf, tenant_id, timeline_id, entered, &ctx).await?;
-
-        let pos_foo = file.write_blob(b"foo", &ctx).await?;
-        assert_eq!(
-            b"foo",
-            file.block_cursor()
-                .read_blob(pos_foo, &ctx)
-                .await?
-                .as_slice()
-        );
-        let pos_bar = file.write_blob(b"bar", &ctx).await?;
-        assert_eq!(
-            b"foo",
-            file.block_cursor()
-                .read_blob(pos_foo, &ctx)
-                .await?
-                .as_slice()
-        );
-        assert_eq!(
-            b"bar",
-            file.block_cursor()
-                .read_blob(pos_bar, &ctx)
-                .await?
-                .as_slice()
-        );
-
-        let mut blobs = Vec::new();
-        for i in 0..10000 {
-            let data = Vec::from(format!("blob{}", i).as_bytes());
-            let pos = file.write_blob(&data, &ctx).await?;
-            blobs.push((pos, data));
-        }
-        // also test with a large blobs
-        for i in 0..100 {
-            let data = format!("blob{}", i).as_bytes().repeat(100);
-            let pos = file.write_blob(&data, &ctx).await?;
-            blobs.push((pos, data));
-        }
-
-        let cursor = BlockCursor::new(BlockReaderRef::EphemeralFile(&file));
-        for (pos, expected) in blobs {
-            let actual = cursor.read_blob(pos, &ctx).await?;
-            assert_eq!(actual, expected);
-        }
-
-        // Test a large blob that spans multiple pages
-        let mut large_data = vec![0; 20000];
-        thread_rng().fill_bytes(&mut large_data);
-        let pos_large = file.write_blob(&large_data, &ctx).await?;
-        let result = file.block_cursor().read_blob(pos_large, &ctx).await?;
-        assert_eq!(result, large_data);
-
-        Ok(())
-    }
-
     #[tokio::test]
     async fn ephemeral_file_holds_gate_open() {
         const FOREVER: std::time::Duration = std::time::Duration::from_secs(5);
@@ -253,4 +315,151 @@ mod tests {
             .expect("closing completes right away")
             .expect("closing does not panic");
     }
+
+    #[tokio::test]
+    async fn test_ephemeral_file_basics() {
+        let (conf, tenant_id, timeline_id, ctx) = harness("test_ephemeral_file_basics").unwrap();
+
+        let gate = utils::sync::gate::Gate::default();
+
+        let mut file =
+            EphemeralFile::create(conf, tenant_id, timeline_id, gate.enter().unwrap(), &ctx)
+                .await
+                .unwrap();
+
+        let cap = file.buffered_writer.inspect_buffer().capacity();
+
+        let write_nbytes = cap + cap / 2;
+
+        let content: Vec<u8> = rand::thread_rng()
+            .sample_iter(rand::distributions::Standard)
+            .take(write_nbytes)
+            .collect();
+
+        let mut value_offsets = Vec::new();
+        for i in 0..write_nbytes {
+            let off = file.write_raw(&content[i..i + 1], &ctx).await.unwrap();
+            value_offsets.push(off);
+        }
+
+        assert!(file.len() as usize == write_nbytes);
+        for i in 0..write_nbytes {
+            assert_eq!(value_offsets[i], i.into_u64());
+            let buf = Vec::with_capacity(1);
+            let (buf_slice, nread) = file
+                .read_exact_at_eof_ok(i.into_u64(), buf.slice_full(), &ctx)
+                .await
+                .unwrap();
+            let buf = buf_slice.into_inner();
+            assert_eq!(nread, 1);
+            assert_eq!(&buf, &content[i..i + 1]);
+        }
+
+        let file_contents =
+            std::fs::read(&file.buffered_writer.as_inner().as_inner().path).unwrap();
+        assert_eq!(file_contents, &content[0..cap]);
+
+        let buffer_contents = file.buffered_writer.inspect_buffer();
+        assert_eq!(buffer_contents, &content[cap..write_nbytes]);
+    }
+
+    #[tokio::test]
+    async fn test_flushes_do_happen() {
+        let (conf, tenant_id, timeline_id, ctx) = harness("test_flushes_do_happen").unwrap();
+
+        let gate = utils::sync::gate::Gate::default();
+
+        let mut file =
+            EphemeralFile::create(conf, tenant_id, timeline_id, gate.enter().unwrap(), &ctx)
+                .await
+                .unwrap();
+
+        let cap = file.buffered_writer.inspect_buffer().capacity();
+
+        let content: Vec<u8> = rand::thread_rng()
+            .sample_iter(rand::distributions::Standard)
+            .take(cap + cap / 2)
+            .collect();
+
+        file.write_raw(&content, &ctx).await.unwrap();
+
+        // assert the state is as this test expects it to be
+        assert_eq!(
+            &file.load_to_vec(&ctx).await.unwrap(),
+            &content[0..cap + cap / 2]
+        );
+        let md = file
+            .buffered_writer
+            .as_inner()
+            .as_inner()
+            .path
+            .metadata()
+            .unwrap();
+        assert_eq!(
+            md.len(),
+            cap.into_u64(),
+            "buffered writer does one write if we write 1.5x buffer capacity"
+        );
+        assert_eq!(
+            &file.buffered_writer.inspect_buffer()[0..cap / 2],
+            &content[cap..cap + cap / 2]
+        );
+    }
+
+    #[tokio::test]
+    async fn test_read_split_across_file_and_buffer() {
+        // This test exercises the logic on the read path that splits the logical read
+        // into a read from the flushed part (= the file) and a copy from the buffered writer's buffer.
+        //
+        // This test build on the assertions in test_flushes_do_happen
+
+        let (conf, tenant_id, timeline_id, ctx) =
+            harness("test_read_split_across_file_and_buffer").unwrap();
+
+        let gate = utils::sync::gate::Gate::default();
+
+        let mut file =
+            EphemeralFile::create(conf, tenant_id, timeline_id, gate.enter().unwrap(), &ctx)
+                .await
+                .unwrap();
+
+        let cap = file.buffered_writer.inspect_buffer().capacity();
+
+        let content: Vec<u8> = rand::thread_rng()
+            .sample_iter(rand::distributions::Standard)
+            .take(cap + cap / 2)
+            .collect();
+
+        file.write_raw(&content, &ctx).await.unwrap();
+
+        let test_read = |start: usize, len: usize| {
+            let file = &file;
+            let ctx = &ctx;
+            let content = &content;
+            async move {
+                let (buf, nread) = file
+                    .read_exact_at_eof_ok(
+                        start.into_u64(),
+                        Vec::with_capacity(len).slice_full(),
+                        ctx,
+                    )
+                    .await
+                    .unwrap();
+                assert_eq!(nread, len);
+                assert_eq!(&buf.into_inner(), &content[start..(start + len)]);
+            }
+        };
+
+        // completely within the file range
+        assert!(20 < cap, "test assumption");
+        test_read(10, 10).await;
+        // border onto edge of file
+        test_read(cap - 10, 10).await;
+        // read across file and buffer
+        test_read(cap - 10, 20).await;
+        // stay from start of buffer
+        test_read(cap, 10).await;
+        // completely within buffer
+        test_read(cap + 10, 10).await;
+    }
 }

pageserver/src/tenant/ephemeral_file/page_caching.rs

@@ -1,153 +0,0 @@
-//! Wrapper around [`super::zero_padded_read_write::RW`] that uses the
-//! [`crate::page_cache`] to serve reads that need to go to the underlying [`VirtualFile`].
-//!
-//! Subject to removal in <https://github.com/neondatabase/neon/pull/8537>
-
-use crate::context::RequestContext;
-use crate::page_cache::{self, PAGE_SZ};
-use crate::tenant::block_io::BlockLease;
-use crate::virtual_file::owned_buffers_io::util::size_tracking_writer;
-use crate::virtual_file::VirtualFile;
-
-use std::io::{self};
-use tokio_epoll_uring::BoundedBuf;
-use tracing::*;
-
-use super::zero_padded_read_write;
-
-/// See module-level comment.
-pub struct RW {
-    page_cache_file_id: page_cache::FileId,
-    rw: super::zero_padded_read_write::RW<size_tracking_writer::Writer<VirtualFile>>,
-    /// Gate guard is held on as long as we need to do operations in the path (delete on drop).
-    _gate_guard: utils::sync::gate::GateGuard,
-}
-
-impl RW {
-    pub fn new(file: VirtualFile, _gate_guard: utils::sync::gate::GateGuard) -> Self {
-        let page_cache_file_id = page_cache::next_file_id();
-        Self {
-            page_cache_file_id,
-            rw: super::zero_padded_read_write::RW::new(size_tracking_writer::Writer::new(file)),
-            _gate_guard,
-        }
-    }
-
-    pub fn page_cache_file_id(&self) -> page_cache::FileId {
-        self.page_cache_file_id
-    }
-
-    pub(crate) async fn write_all_borrowed(
-        &mut self,
-        srcbuf: &[u8],
-        ctx: &RequestContext,
-    ) -> Result<usize, io::Error> {
-        // It doesn't make sense to proactively fill the page cache on the Pageserver write path
-        // because Compute is unlikely to access recently written data.
-        self.rw.write_all_borrowed(srcbuf, ctx).await
-    }
-
-    pub(crate) fn bytes_written(&self) -> u64 {
-        self.rw.bytes_written()
-    }
-
-    /// Load all blocks that can be read via [`Self::read_blk`] into a contiguous memory buffer.
-    ///
-    /// This includes the blocks that aren't yet flushed to disk by the internal buffered writer.
-    /// The last block is zero-padded to [`PAGE_SZ`], so, the returned buffer is always a multiple of [`PAGE_SZ`].
-    pub(super) async fn load_to_vec(&self, ctx: &RequestContext) -> Result<Vec<u8>, io::Error> {
-        // round up to the next PAGE_SZ multiple, required by blob_io
-        let size = {
-            let s = usize::try_from(self.bytes_written()).unwrap();
-            if s % PAGE_SZ == 0 {
-                s
-            } else {
-                s.checked_add(PAGE_SZ - (s % PAGE_SZ)).unwrap()
-            }
-        };
-        let vec = Vec::with_capacity(size);
-
-        // read from disk what we've already flushed
-        let file_size_tracking_writer = self.rw.as_writer();
-        let flushed_range = 0..usize::try_from(file_size_tracking_writer.bytes_written()).unwrap();
-        let mut vec = file_size_tracking_writer
-            .as_inner()
-            .read_exact_at(
-                vec.slice(0..(flushed_range.end - flushed_range.start)),
-                u64::try_from(flushed_range.start).unwrap(),
-                ctx,
-            )
-            .await?
-            .into_inner();
-
-        // copy from in-memory buffer what we haven't flushed yet but would return when accessed via read_blk
-        let buffered = self.rw.get_tail_zero_padded();
-        vec.extend_from_slice(buffered);
-        assert_eq!(vec.len(), size);
-        assert_eq!(vec.len() % PAGE_SZ, 0);
-        Ok(vec)
-    }
-
-    pub(crate) async fn read_blk(
-        &self,
-        blknum: u32,
-        ctx: &RequestContext,
-    ) -> Result<BlockLease, io::Error> {
-        match self.rw.read_blk(blknum).await? {
-            zero_padded_read_write::ReadResult::NeedsReadFromWriter { writer } => {
-                let cache = page_cache::get();
-                match cache
-                    .read_immutable_buf(self.page_cache_file_id, blknum, ctx)
-                    .await
-                    .map_err(|e| {
-                        std::io::Error::new(
-                            std::io::ErrorKind::Other,
-                            // order path before error because error is anyhow::Error => might have many contexts
-                            format!(
-                                "ephemeral file: read immutable page #{}: {}: {:#}",
-                                blknum,
-                                self.rw.as_writer().as_inner().path,
-                                e,
-                            ),
-                        )
-                    })? {
-                    page_cache::ReadBufResult::Found(guard) => {
-                        return Ok(BlockLease::PageReadGuard(guard))
-                    }
-                    page_cache::ReadBufResult::NotFound(write_guard) => {
-                        let write_guard = writer
-                            .as_inner()
-                            .read_exact_at_page(write_guard, blknum as u64 * PAGE_SZ as u64, ctx)
-                            .await?;
-                        let read_guard = write_guard.mark_valid();
-                        return Ok(BlockLease::PageReadGuard(read_guard));
-                    }
-                }
-            }
-            zero_padded_read_write::ReadResult::ServedFromZeroPaddedMutableTail { buffer } => {
-                Ok(BlockLease::EphemeralFileMutableTail(buffer))
-            }
-        }
-    }
-}
-
-impl Drop for RW {
-    fn drop(&mut self) {
-        // There might still be pages in the [`crate::page_cache`] for this file.
-        // We leave them there, [`crate::page_cache::PageCache::find_victim`] will evict them when needed.
-
-        // unlink the file
-        // we are clear to do this, because we have entered a gate
-        let path = &self.rw.as_writer().as_inner().path;
-        let res = std::fs::remove_file(path);
-        if let Err(e) = res {
-            if e.kind() != std::io::ErrorKind::NotFound {
-                // just never log the not found errors, we cannot do anything for them; on detach
-                // the tenant directory is already gone.
-                //
-                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
-                error!("could not remove ephemeral file '{path}': {e}");
-            }
-        }
-    }
-}

pageserver/src/tenant/ephemeral_file/zero_padded_read_write.rs

@@ -1,145 +0,0 @@
-//! The heart of how [`super::EphemeralFile`] does its reads and writes.
-//!
-//! # Writes
-//!
-//! [`super::EphemeralFile`] writes small, borrowed buffers using [`RW::write_all_borrowed`].
-//! The [`RW`] batches these into [`TAIL_SZ`] bigger writes, using [`owned_buffers_io::write::BufferedWriter`].
-//!
-//! # Reads
-//!
-//! [`super::EphemeralFile`] always reads full [`PAGE_SZ`]ed blocks using [`RW::read_blk`].
-//!
-//! The [`RW`] serves these reads either from the buffered writer's in-memory buffer
-//! or redirects the caller to read from the underlying [`OwnedAsyncWriter`]
-//! if the read is for the prefix that has already been flushed.
-//!
-//! # Current Usage
-//!
-//! The current user of this module is [`super::page_caching::RW`].
-
-mod zero_padded;
-
-use crate::{
-    context::RequestContext,
-    page_cache::PAGE_SZ,
-    virtual_file::owned_buffers_io::{
-        self,
-        write::{Buffer, OwnedAsyncWriter},
-    },
-};
-
-const TAIL_SZ: usize = 64 * 1024;
-
-/// See module-level comment.
-pub struct RW<W: OwnedAsyncWriter> {
-    buffered_writer: owned_buffers_io::write::BufferedWriter<
-        zero_padded::Buffer<TAIL_SZ>,
-        owned_buffers_io::util::size_tracking_writer::Writer<W>,
-    >,
-}
-
-pub enum ReadResult<'a, W> {
-    NeedsReadFromWriter { writer: &'a W },
-    ServedFromZeroPaddedMutableTail { buffer: &'a [u8; PAGE_SZ] },
-}
-
-impl<W> RW<W>
-where
-    W: OwnedAsyncWriter,
-{
-    pub fn new(writer: W) -> Self {
-        let bytes_flushed_tracker =
-            owned_buffers_io::util::size_tracking_writer::Writer::new(writer);
-        let buffered_writer = owned_buffers_io::write::BufferedWriter::new(
-            bytes_flushed_tracker,
-            zero_padded::Buffer::default(),
-        );
-        Self { buffered_writer }
-    }
-
-    pub(crate) fn as_writer(&self) -> &W {
-        self.buffered_writer.as_inner().as_inner()
-    }
-
-    pub async fn write_all_borrowed(
-        &mut self,
-        buf: &[u8],
-        ctx: &RequestContext,
-    ) -> std::io::Result<usize> {
-        self.buffered_writer.write_buffered_borrowed(buf, ctx).await
-    }
-
-    pub fn bytes_written(&self) -> u64 {
-        let flushed_offset = self.buffered_writer.as_inner().bytes_written();
-        let buffer: &zero_padded::Buffer<TAIL_SZ> = self.buffered_writer.inspect_buffer();
-        flushed_offset + u64::try_from(buffer.pending()).unwrap()
-    }
-
-    /// Get a slice of all blocks that [`Self::read_blk`] would return as [`ReadResult::ServedFromZeroPaddedMutableTail`].
-    pub fn get_tail_zero_padded(&self) -> &[u8] {
-        let buffer: &zero_padded::Buffer<TAIL_SZ> = self.buffered_writer.inspect_buffer();
-        let buffer_written_up_to = buffer.pending();
-        // pad to next page boundary
-        let read_up_to = if buffer_written_up_to % PAGE_SZ == 0 {
-            buffer_written_up_to
-        } else {
-            buffer_written_up_to
-                .checked_add(PAGE_SZ - (buffer_written_up_to % PAGE_SZ))
-                .unwrap()
-        };
-        &buffer.as_zero_padded_slice()[0..read_up_to]
-    }
-
-    pub(crate) async fn read_blk(&self, blknum: u32) -> Result<ReadResult<'_, W>, std::io::Error> {
-        let flushed_offset = self.buffered_writer.as_inner().bytes_written();
-        let buffer: &zero_padded::Buffer<TAIL_SZ> = self.buffered_writer.inspect_buffer();
-        let buffered_offset = flushed_offset + u64::try_from(buffer.pending()).unwrap();
-        let read_offset = (blknum as u64) * (PAGE_SZ as u64);
-
-        // The trailing page ("block") might only be partially filled,
-        // yet the blob_io code relies on us to return a full PAGE_SZed slice anyway.
-        // Moreover, it has to be zero-padded, because when we still had
-        // a write-back page cache, it provided pre-zeroed pages, and blob_io came to rely on it.
-        // DeltaLayer probably has the same issue, not sure why it needs no special treatment.
-        // => check here that the read doesn't go beyond this potentially trailing
-        // => the zero-padding is done in the `else` branch below
-        let blocks_written = if buffered_offset % (PAGE_SZ as u64) == 0 {
-            buffered_offset / (PAGE_SZ as u64)
-        } else {
-            (buffered_offset / (PAGE_SZ as u64)) + 1
-        };
-        if (blknum as u64) >= blocks_written {
-            return Err(std::io::Error::new(std::io::ErrorKind::Other, anyhow::anyhow!("read past end of ephemeral_file: read=0x{read_offset:x} buffered=0x{buffered_offset:x} flushed=0x{flushed_offset}")));
-        }
-
-        // assertions for the `if-else` below
-        assert_eq!(
-            flushed_offset % (TAIL_SZ as u64), 0,
-            "we only use write_buffered_borrowed to write to the buffered writer, so it's guaranteed that flushes happen buffer.cap()-sized chunks"
-        );
-        assert_eq!(
-            flushed_offset % (PAGE_SZ as u64),
-            0,
-            "the logic below can't handle if the page is spread across the flushed part and the buffer"
-        );
-
-        if read_offset < flushed_offset {
-            assert!(read_offset + (PAGE_SZ as u64) <= flushed_offset);
-            Ok(ReadResult::NeedsReadFromWriter {
-                writer: self.as_writer(),
-            })
-        } else {
-            let read_offset_in_buffer = read_offset
-                .checked_sub(flushed_offset)
-                .expect("would have taken `if` branch instead of this one");
-            let read_offset_in_buffer = usize::try_from(read_offset_in_buffer).unwrap();
-            let zero_padded_slice = buffer.as_zero_padded_slice();
-            let page = &zero_padded_slice[read_offset_in_buffer..(read_offset_in_buffer + PAGE_SZ)];
-            Ok(ReadResult::ServedFromZeroPaddedMutableTail {
-                buffer: page
-                    .try_into()
-                    .expect("the slice above got it as page-size slice"),
-            })
-        }
-    }
-}

pageserver/src/tenant/ephemeral_file/zero_padded_read_write/zero_padded.rs

@@ -1,110 +0,0 @@
-//! A [`crate::virtual_file::owned_buffers_io::write::Buffer`] whose
-//! unwritten range is guaranteed to be zero-initialized.
-//! This is used by [`crate::tenant::ephemeral_file::zero_padded_read_write::RW::read_blk`]
-//! to serve page-sized reads of the trailing page when the trailing page has only been partially filled.
-
-use std::mem::MaybeUninit;
-
-use crate::virtual_file::owned_buffers_io::io_buf_ext::FullSlice;
-
-/// See module-level comment.
-pub struct Buffer<const N: usize> {
-    allocation: Box<[u8; N]>,
-    written: usize,
-}
-
-impl<const N: usize> Default for Buffer<N> {
-    fn default() -> Self {
-        Self {
-            allocation: Box::new(
-                // SAFETY: zeroed memory is a valid [u8; N]
-                unsafe { MaybeUninit::zeroed().assume_init() },
-            ),
-            written: 0,
-        }
-    }
-}
-
-impl<const N: usize> Buffer<N> {
-    #[inline(always)]
-    fn invariants(&self) {
-        // don't check by default, unoptimized is too expensive even for debug mode
-        if false {
-            debug_assert!(self.written <= N, "{}", self.written);
-            debug_assert!(self.allocation[self.written..N].iter().all(|v| *v == 0));
-        }
-    }
-
-    pub fn as_zero_padded_slice(&self) -> &[u8; N] {
-        &self.allocation
-    }
-}
-
-impl<const N: usize> crate::virtual_file::owned_buffers_io::write::Buffer for Buffer<N> {
-    type IoBuf = Self;
-
-    fn cap(&self) -> usize {
-        self.allocation.len()
-    }
-
-    fn extend_from_slice(&mut self, other: &[u8]) {
-        self.invariants();
-        let remaining = self.allocation.len() - self.written;
-        if other.len() > remaining {
-            panic!("calling extend_from_slice() with insufficient remaining capacity");
-        }
-        self.allocation[self.written..(self.written + other.len())].copy_from_slice(other);
-        self.written += other.len();
-        self.invariants();
-    }
-
-    fn pending(&self) -> usize {
-        self.written
-    }
-
-    fn flush(self) -> FullSlice<Self> {
-        self.invariants();
-        let written = self.written;
-        FullSlice::must_new(tokio_epoll_uring::BoundedBuf::slice(self, 0..written))
-    }
-
-    fn reuse_after_flush(iobuf: Self::IoBuf) -> Self {
-        let Self {
-            mut allocation,
-            written,
-        } = iobuf;
-        allocation[0..written].fill(0);
-        let new = Self {
-            allocation,
-            written: 0,
-        };
-        new.invariants();
-        new
-    }
-}
-
-/// We have this trait impl so that the `flush` method in the `Buffer` impl above can produce a
-/// [`tokio_epoll_uring::BoundedBuf::slice`] of the [`Self::written`] range of the data.
-///
-/// Remember that bytes_init is generally _not_ a tracker of the amount
-/// of valid data in the io buffer; we use `Slice` for that.
-/// The `IoBuf` is _only_ for keeping track of uninitialized memory, a bit like MaybeUninit.
-///
-/// SAFETY:
-///
-/// The [`Self::allocation`] is stable becauses boxes are stable.
-/// The memory is zero-initialized, so, bytes_init is always N.
-unsafe impl<const N: usize> tokio_epoll_uring::IoBuf for Buffer<N> {
-    fn stable_ptr(&self) -> *const u8 {
-        self.allocation.as_ptr()
-    }
-
-    fn bytes_init(&self) -> usize {
-        // Yes, N, not self.written; Read the full comment of this impl block!
-        N
-    }
-
-    fn bytes_total(&self) -> usize {
-        N
-    }
-}