tests: do GC in test_pg_regress

## Problem
The Postgres version was updated. The patch has to be updated
accordingly.
## Summary of changes
The patch of the regression test was updated.

.github/actionlint.yml

@@ -20,3 +20,4 @@ config-variables:
   - REMOTE_STORAGE_AZURE_REGION
   - SLACK_UPCOMING_RELEASE_CHANNEL_ID
   - DEV_AWS_OIDC_ROLE_ARN
+  - BENCHMARK_INGEST_TARGET_PROJECTID

.github/actions/allure-report-generate/action.yml

@@ -221,6 +221,8 @@ runs:
         REPORT_URL: ${{ steps.generate-report.outputs.report-url }}
         COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
       with:
+        # Retry script for 5XX server errors: https://github.com/actions/github-script#retries
+        retries: 5
         script: |
           const { REPORT_URL, COMMIT_SHA } = process.env
 

.github/pull_request_template.md

@@ -1,14 +1,3 @@
 ## Problem
 
 ## Summary of changes
-
-## Checklist before requesting a review
-
-- [ ] I have performed a self-review of my code.
-- [ ] If it is a core feature, I have added thorough tests.
-- [ ] Do we need to implement analytics? if so did you add the relevant metrics to the dashboard?
-- [ ] If this PR requires public announcement, mark it with /release-notes label and add several sentences in this section.
-
-## Checklist before merging
-
-- [ ] Do not forget to reformat commit message to not include the above checklist

.github/workflows/build_and_test.yml

@@ -497,6 +497,8 @@ jobs:
           REPORT_URL_NEW: ${{ steps.upload-coverage-report-new.outputs.report-url }}
           COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
         with:
+          # Retry script for 5XX server errors: https://github.com/actions/github-script#retries
+          retries: 5
           script: |
             const { REPORT_URL_NEW, COMMIT_SHA } = process.env
 

.github/workflows/ingest_benchmark.yml

@@ -0,0 +1,372 @@
+name: Benchmarking
+
+on:
+  # uncomment to run on push for debugging your PR
+  # push:
+  #   branches: [ your branch ]
+  schedule:
+    # * is a special character in YAML so you have to quote this string
+    #          ┌───────────── minute (0 - 59)
+    #          │ ┌───────────── hour (0 - 23)
+    #          │ │ ┌───────────── day of the month (1 - 31)
+    #          │ │ │ ┌───────────── month (1 - 12 or JAN-DEC)
+    #          │ │ │ │ ┌───────────── day of the week (0 - 6 or SUN-SAT)
+    - cron:   '0 9 * * *' # run once a day, timezone is utc
+  workflow_dispatch: # adds ability to run this manually
+    
+defaults:
+  run:
+    shell: bash -euxo pipefail {0}
+
+concurrency:
+  # Allow only one workflow globally because we need dedicated resources which only exist once
+  group: ingest-bench-workflow
+  cancel-in-progress: true
+
+jobs:
+  ingest:
+    strategy:
+      matrix:
+        target_project: [new_empty_project, large_existing_project]  
+    permissions:
+      contents: write
+      statuses: write
+      id-token: write # aws-actions/configure-aws-credentials
+    env:
+      PG_CONFIG: /tmp/neon/pg_install/v16/bin/pg_config
+      PSQL: /tmp/neon/pg_install/v16/bin/psql
+      PG_16_LIB_PATH: /tmp/neon/pg_install/v16/lib
+      PGCOPYDB: /pgcopydb/bin/pgcopydb
+      PGCOPYDB_LIB_PATH: /pgcopydb/lib
+    runs-on: [ self-hosted, us-east-2, x64 ]
+    container:
+      image: neondatabase/build-tools:pinned-bookworm
+      credentials:
+        username: ${{ secrets.NEON_DOCKERHUB_USERNAME }}
+        password: ${{ secrets.NEON_DOCKERHUB_PASSWORD }}
+      options: --init
+    timeout-minutes: 1440
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Configure AWS credentials # necessary to download artefacts
+      uses: aws-actions/configure-aws-credentials@v4
+      with:
+        aws-region: eu-central-1
+        role-to-assume: ${{ vars.DEV_AWS_OIDC_ROLE_ARN }}
+        role-duration-seconds: 18000 # 5 hours is currently max associated with IAM role 
+
+    - name: Download Neon artifact
+      uses: ./.github/actions/download
+      with:
+        name: neon-${{ runner.os }}-${{ runner.arch }}-release-artifact
+        path: /tmp/neon/
+        prefix: latest
+
+    - name: Create Neon Project
+      if: ${{ matrix.target_project == 'new_empty_project' }}
+      id: create-neon-project-ingest-target
+      uses: ./.github/actions/neon-project-create
+      with:
+        region_id: aws-us-east-2
+        postgres_version: 16
+        compute_units: '[7, 7]' # we want to test large compute here to avoid compute-side bottleneck
+        api_key: ${{ secrets.NEON_STAGING_API_KEY }}
+
+    - name: Initialize Neon project and retrieve current backpressure seconds
+      if: ${{ matrix.target_project == 'new_empty_project' }}
+      env:
+          NEW_PROJECT_CONNSTR: ${{ steps.create-neon-project-ingest-target.outputs.dsn }}
+          NEW_PROJECT_ID: ${{ steps.create-neon-project-ingest-target.outputs.project_id }}
+      run: |
+        echo "Initializing Neon project with project_id: ${NEW_PROJECT_ID}"
+        export LD_LIBRARY_PATH=${PG_16_LIB_PATH}
+        ${PSQL} "${NEW_PROJECT_CONNSTR}" -c "CREATE EXTENSION IF NOT EXISTS neon; CREATE EXTENSION IF NOT EXISTS neon_utils;"
+        BACKPRESSURE_TIME_BEFORE_INGEST=$(${PSQL} "${NEW_PROJECT_CONNSTR}" -t -c "select backpressure_throttling_time()/1000000;")
+        echo "BACKPRESSURE_TIME_BEFORE_INGEST=${BACKPRESSURE_TIME_BEFORE_INGEST}" >> $GITHUB_ENV
+        echo "NEW_PROJECT_CONNSTR=${NEW_PROJECT_CONNSTR}" >> $GITHUB_ENV
+
+    - name: Create Neon Branch for large tenant
+      if: ${{ matrix.target_project == 'large_existing_project' }}
+      id: create-neon-branch-ingest-target
+      uses: ./.github/actions/neon-branch-create
+      with:
+        project_id: ${{ vars.BENCHMARK_INGEST_TARGET_PROJECTID }}
+        api_key: ${{ secrets.NEON_STAGING_API_KEY }}
+
+    - name: Initialize Neon project and retrieve current backpressure seconds
+      if: ${{ matrix.target_project == 'large_existing_project' }}
+      env:
+          NEW_PROJECT_CONNSTR: ${{ steps.create-neon-branch-ingest-target.outputs.dsn }}
+          NEW_BRANCH_ID: ${{ steps.create-neon-branch-ingest-target.outputs.branch_id }}
+      run: |
+        echo "Initializing Neon branch with branch_id: ${NEW_BRANCH_ID}"
+        export LD_LIBRARY_PATH=${PG_16_LIB_PATH}
+        # Extract the part before the database name
+        base_connstr="${NEW_PROJECT_CONNSTR%/*}"
+        # Extract the query parameters (if any) after the database name
+        query_params="${NEW_PROJECT_CONNSTR#*\?}"
+        # Reconstruct the new connection string
+        if [ "$query_params" != "$NEW_PROJECT_CONNSTR" ]; then
+          new_connstr="${base_connstr}/neondb?${query_params}"
+        else
+          new_connstr="${base_connstr}/neondb"
+        fi
+        ${PSQL} "${new_connstr}" -c "drop database ludicrous;"
+        ${PSQL} "${new_connstr}" -c "CREATE DATABASE ludicrous;"
+        if [ "$query_params" != "$NEW_PROJECT_CONNSTR" ]; then
+          NEW_PROJECT_CONNSTR="${base_connstr}/ludicrous?${query_params}"
+        else
+          NEW_PROJECT_CONNSTR="${base_connstr}/ludicrous"
+        fi
+        ${PSQL} "${NEW_PROJECT_CONNSTR}" -c "CREATE EXTENSION IF NOT EXISTS neon; CREATE EXTENSION IF NOT EXISTS neon_utils;"
+        BACKPRESSURE_TIME_BEFORE_INGEST=$(${PSQL} "${NEW_PROJECT_CONNSTR}" -t -c "select backpressure_throttling_time()/1000000;")
+        echo "BACKPRESSURE_TIME_BEFORE_INGEST=${BACKPRESSURE_TIME_BEFORE_INGEST}" >> $GITHUB_ENV
+        echo "NEW_PROJECT_CONNSTR=${NEW_PROJECT_CONNSTR}" >> $GITHUB_ENV
+      
+        
+    - name: Create pgcopydb filter file
+      run: |
+        cat << EOF > /tmp/pgcopydb_filter.txt
+          [include-only-table]
+          public.events
+          public.emails
+          public.email_transmissions
+          public.payments
+          public.editions
+          public.edition_modules
+          public.sp_content
+          public.email_broadcasts
+          public.user_collections
+          public.devices
+          public.user_accounts
+          public.lessons
+          public.lesson_users
+          public.payment_methods
+          public.orders
+          public.course_emails
+          public.modules
+          public.users
+          public.module_users
+          public.courses
+          public.payment_gateway_keys
+          public.accounts
+          public.roles
+          public.payment_gateways
+          public.management
+          public.event_names
+        EOF
+
+    - name: Invoke pgcopydb
+      env:
+          BENCHMARK_INGEST_SOURCE_CONNSTR: ${{ secrets.BENCHMARK_INGEST_SOURCE_CONNSTR }}
+      run: |
+        export LD_LIBRARY_PATH=${PGCOPYDB_LIB_PATH}:${PG_16_LIB_PATH}
+        export PGCOPYDB_SOURCE_PGURI="${BENCHMARK_INGEST_SOURCE_CONNSTR}"
+        export PGCOPYDB_TARGET_PGURI="${NEW_PROJECT_CONNSTR}"
+        export PGOPTIONS="-c maintenance_work_mem=8388608 -c max_parallel_maintenance_workers=7"
+        ${PG_CONFIG} --bindir
+        ${PGCOPYDB} --version
+        ${PGCOPYDB} clone --skip-vacuum  --no-owner --no-acl --skip-db-properties --table-jobs 4 \
+          --index-jobs 4 --restore-jobs 4 --split-tables-larger-than 10GB --skip-extensions \
+          --use-copy-binary --filters /tmp/pgcopydb_filter.txt 2>&1 | tee /tmp/pgcopydb_${{ matrix.target_project }}.log
+
+    # create dummy pgcopydb log to test parsing
+    # - name: create dummy log for parser test
+    #   run: |
+    #     cat << EOF > /tmp/pgcopydb_${{ matrix.target_project }}.log
+    #     2024-11-04 18:00:53.433 500861 INFO   main.c:136                Running pgcopydb version 0.17.10.g8361a93 from "/usr/lib/postgresql/17/bin/pgcopydb"
+    #     2024-11-04 18:00:53.434 500861 INFO   cli_common.c:1225         [SOURCE] Copying database from "postgres://neondb_owner@ep-bitter-shape-w2c1ir0a.us-east-2.aws.neon.build/neondb?sslmode=require&keepalives=1&keepalives_idle=10&keepalives_interval=10&keepalives_count=60"
+    #     2024-11-04 18:00:53.434 500861 INFO   cli_common.c:1226         [TARGET] Copying database into "postgres://neondb_owner@ep-icy-union-w25qd5pj.us-east-2.aws.neon.build/ludicrous?sslmode=require&keepalives=1&keepalives_idle=10&keepalives_interval=10&keepalives_count=60"
+    #     2024-11-04 18:00:53.442 500861 INFO   copydb.c:105              Using work dir "/tmp/pgcopydb"
+    #     2024-11-04 18:00:53.541 500861 INFO   snapshot.c:107            Exported snapshot "00000008-00000033-1" from the source database
+    #     2024-11-04 18:00:53.556 500865 INFO   cli_clone_follow.c:543    STEP 1: fetch source database tables, indexes, and sequences
+    #     2024-11-04 18:00:54.570 500865 INFO   copydb_schema.c:716       Splitting source candidate tables larger than 10 GB
+    #     2024-11-04 18:00:54.570 500865 INFO   copydb_schema.c:829       Table public.events is 96 GB large which is larger than --split-tables-larger-than 10 GB, and does not have a unique column of type integer: splitting by CTID
+    #     2024-11-04 18:01:05.538 500865 INFO   copydb_schema.c:905       Table public.events is 96 GB large, 10 COPY processes will be used, partitioning on ctid.
+    #     2024-11-04 18:01:05.564 500865 INFO   copydb_schema.c:905       Table public.email_transmissions is 27 GB large, 4 COPY processes will be used, partitioning on id.
+    #     2024-11-04 18:01:05.584 500865 INFO   copydb_schema.c:905       Table public.lessons is 25 GB large, 4 COPY processes will be used, partitioning on id.
+    #     2024-11-04 18:01:05.605 500865 INFO   copydb_schema.c:905       Table public.lesson_users is 16 GB large, 3 COPY processes will be used, partitioning on id.
+    #     2024-11-04 18:01:05.605 500865 INFO   copydb_schema.c:761       Fetched information for 26 tables (including 4 tables split in 21 partitions total), with an estimated total of 907 million tuples and 175 GB on-disk
+    #     2024-11-04 18:01:05.687 500865 INFO   copydb_schema.c:968       Fetched information for 57 indexes (supporting 25 constraints)
+    #     2024-11-04 18:01:05.753 500865 INFO   sequences.c:78            Fetching information for 24 sequences
+    #     2024-11-04 18:01:05.903 500865 INFO   copydb_schema.c:1122      Fetched information for 4 extensions
+    #     2024-11-04 18:01:06.178 500865 INFO   copydb_schema.c:1538      Found 0 indexes (supporting 0 constraints) in the target database
+    #     2024-11-04 18:01:06.184 500865 INFO   cli_clone_follow.c:584    STEP 2: dump the source database schema (pre/post data)
+    #     2024-11-04 18:01:06.186 500865 INFO   pgcmd.c:468                /usr/lib/postgresql/16/bin/pg_dump -Fc --snapshot 00000008-00000033-1 --section=pre-data --section=post-data --file /tmp/pgcopydb/schema/schema.dump 'postgres://neondb_owner@ep-bitter-shape-w2c1ir0a.us-east-2.aws.neon.build/neondb?sslmode=require&keepalives=1&keepalives_idle=10&keepalives_interval=10&keepalives_count=60'
+    #     2024-11-04 18:01:06.952 500865 INFO   cli_clone_follow.c:592    STEP 3: restore the pre-data section to the target database
+    #     2024-11-04 18:01:07.004 500865 INFO   pgcmd.c:1001               /usr/lib/postgresql/16/bin/pg_restore --dbname 'postgres://neondb_owner@ep-icy-union-w25qd5pj.us-east-2.aws.neon.build/ludicrous?sslmode=require&keepalives=1&keepalives_idle=10&keepalives_interval=10&keepalives_count=60' --section pre-data --jobs 4 --no-owner --no-acl --use-list /tmp/pgcopydb/schema/pre-filtered.list /tmp/pgcopydb/schema/schema.dump
+    #     2024-11-04 18:01:07.438 500874 INFO   table-data.c:656          STEP 4: starting 4 table-data COPY processes
+    #     2024-11-04 18:01:07.451 500877 INFO   vacuum.c:139              STEP 8: skipping VACUUM jobs per --skip-vacuum
+    #     2024-11-04 18:01:07.457 500875 INFO   indexes.c:182             STEP 6: starting 4 CREATE INDEX processes
+    #     2024-11-04 18:01:07.457 500875 INFO   indexes.c:183             STEP 7: constraints are built by the CREATE INDEX processes
+    #     2024-11-04 18:01:07.507 500865 INFO   blobs.c:74                Skipping large objects: none found.
+    #     2024-11-04 18:01:07.509 500865 INFO   sequences.c:194           STEP 9: reset sequences values
+    #     2024-11-04 18:01:07.510 500886 INFO   sequences.c:290           Set sequences values on the target database
+    #     2024-11-04 20:49:00.587 500865 INFO   cli_clone_follow.c:608    STEP 10: restore the post-data section to the target database
+    #     2024-11-04 20:49:00.600 500865 INFO   pgcmd.c:1001               /usr/lib/postgresql/16/bin/pg_restore --dbname 'postgres://neondb_owner@ep-icy-union-w25qd5pj.us-east-2.aws.neon.build/ludicrous?sslmode=require&keepalives=1&keepalives_idle=10&keepalives_interval=10&keepalives_count=60' --section post-data --jobs 4 --no-owner --no-acl --use-list /tmp/pgcopydb/schema/post-filtered.list /tmp/pgcopydb/schema/schema.dump
+    #     2024-11-05 10:50:58.508 500865 INFO   cli_clone_follow.c:639    All step are now done, 16h49m elapsed
+    #     2024-11-05 10:50:58.508 500865 INFO   summary.c:3155            Printing summary for 26 tables and 57 indexes
+
+    #       OID | Schema |                 Name | Parts | copy duration | transmitted bytes | indexes | create index duration 
+    #     ------+--------+----------------------+-------+---------------+-------------------+---------+----------------------
+    #     24654 | public |               events |    10 |         1d11h |            878 GB |       1 |                 1h41m
+    #     24623 | public |  email_transmissions |     4 |         4h46m |             99 GB |       3 |                 2h04m
+    #     24665 | public |              lessons |     4 |         4h42m |            161 GB |       4 |                 1m11s
+    #     24661 | public |         lesson_users |     3 |         2h46m |             49 GB |       3 |                39m35s
+    #     24631 | public |               emails |     1 |        34m07s |             10 GB |       2 |                   17s
+    #     24739 | public |             payments |     1 |         5m47s |           1848 MB |       4 |                 4m40s
+    #     24681 | public |         module_users |     1 |         4m57s |           1610 MB |       3 |                 1m50s
+    #     24694 | public |               orders |     1 |         2m50s |            835 MB |       3 |                 1m05s
+    #     24597 | public |              devices |     1 |         1m45s |            498 MB |       2 |                   40s
+    #     24723 | public |      payment_methods |     1 |         1m24s |            548 MB |       2 |                   31s
+    #     24765 | public |     user_collections |     1 |         2m17s |           1005 MB |       2 |                 968ms
+    #     24774 | public |                users |     1 |           52s |            291 MB |       4 |                   27s
+    #     24760 | public |        user_accounts |     1 |           16s |            172 MB |       3 |                   16s
+    #     24606 | public |      edition_modules |     1 |         8s983 |             46 MB |       3 |                 4s749
+    #     24583 | public |        course_emails |     1 |         8s526 |             26 MB |       2 |                 996ms
+    #     24685 | public |              modules |     1 |         1s592 |             21 MB |       3 |                 1s696
+    #     24610 | public |             editions |     1 |         2s199 |           7483 kB |       2 |                 1s032
+    #     24755 | public |           sp_content |     1 |         1s555 |           4177 kB |       0 |                   0ms
+    #     24619 | public |     email_broadcasts |     1 |         744ms |           2645 kB |       2 |                 677ms
+    #     24590 | public |              courses |     1 |         387ms |           1540 kB |       2 |                 367ms
+    #     24704 | public | payment_gateway_keys |     1 |         1s972 |            164 kB |       2 |                  27ms
+    #     24576 | public |             accounts |     1 |          58ms |             24 kB |       1 |                  14ms
+    #     24647 | public |          event_names |     1 |          32ms |             397 B |       1 |                   8ms
+    #     24716 | public |     payment_gateways |     1 |         1s675 |             117 B |       1 |                  11ms
+    #     24748 | public |                roles |     1 |          71ms |             173 B |       1 |                   8ms
+    #     24676 | public |           management |     1 |          33ms |              40 B |       1 |                  19ms
+
+
+    #                                                   Step   Connection    Duration    Transfer   Concurrency
+    #     --------------------------------------------------   ----------  ----------  ----------  ------------
+    #       Catalog Queries (table ordering, filtering, etc)       source         12s                         1
+    #                                             Dump Schema       source       765ms                         1
+    #                                         Prepare Schema       target       466ms                         1
+    #           COPY, INDEX, CONSTRAINTS, VACUUM (wall clock)         both       2h47m                        12
+    #                                       COPY (cumulative)         both       7h46m     1225 GB             4
+    #                               CREATE INDEX (cumulative)       target       4h36m                         4
+    #                               CONSTRAINTS (cumulative)       target       8s493                         4
+    #                                     VACUUM (cumulative)       target         0ms                         4
+    #                                         Reset Sequences         both        60ms                         1
+    #                             Large Objects (cumulative)       (null)         0ms                         0
+    #                                         Finalize Schema         both      14h01m                         4
+    #     --------------------------------------------------   ----------  ----------  ----------  ------------
+    #                               Total Wall Clock Duration         both      16h49m                        20
+
+
+    #     EOF
+
+
+    - name: show tables sizes and retrieve current backpressure seconds
+      run: |
+        export LD_LIBRARY_PATH=${PG_16_LIB_PATH}
+        ${PSQL} "${NEW_PROJECT_CONNSTR}" -c "\dt+"
+        BACKPRESSURE_TIME_AFTER_INGEST=$(${PSQL} "${NEW_PROJECT_CONNSTR}" -t -c "select backpressure_throttling_time()/1000000;")
+        echo "BACKPRESSURE_TIME_AFTER_INGEST=${BACKPRESSURE_TIME_AFTER_INGEST}" >> $GITHUB_ENV
+
+    - name: Parse pgcopydb log and report performance metrics
+      env:
+        PERF_TEST_RESULT_CONNSTR: ${{ secrets.PERF_TEST_RESULT_CONNSTR }}
+      run: |
+        export LD_LIBRARY_PATH=${PG_16_LIB_PATH}
+
+        # Define the log file path
+        LOG_FILE="/tmp/pgcopydb_${{ matrix.target_project }}.log"
+        
+        # Get the current git commit hash
+        git config --global --add safe.directory /__w/neon/neon
+        COMMIT_HASH=$(git rev-parse --short HEAD)
+        
+        # Define the platform and test suite
+        PLATFORM="pg16-${{ matrix.target_project }}-us-east-2-staging"
+        SUIT="pgcopydb_ingest_bench"
+        
+        # Function to convert time (e.g., "2h47m", "4h36m", "118ms", "8s493") to seconds
+        convert_to_seconds() {
+          local duration=$1
+          local total_seconds=0
+    
+          # Check for hours (h)
+          if [[ "$duration" =~ ([0-9]+)h ]]; then
+            total_seconds=$((total_seconds + ${BASH_REMATCH[1]#0} * 3600))
+          fi
+    
+          # Check for seconds (s)
+          if [[ "$duration" =~ ([0-9]+)s ]]; then
+            total_seconds=$((total_seconds + ${BASH_REMATCH[1]#0}))
+          fi
+    
+          # Check for milliseconds (ms) (if applicable)
+          if [[ "$duration" =~ ([0-9]+)ms ]]; then
+            total_seconds=$((total_seconds + ${BASH_REMATCH[1]#0} / 1000))
+            duration=${duration/${BASH_REMATCH[0]}/} # need to remove it to avoid double counting with m 
+          fi
+
+          # Check for minutes (m) - must be checked after ms because m is contained in ms
+          if [[ "$duration" =~ ([0-9]+)m ]]; then
+            total_seconds=$((total_seconds + ${BASH_REMATCH[1]#0} * 60))
+          fi
+    
+          echo $total_seconds
+        }
+
+        # Calculate the backpressure difference in seconds
+        BACKPRESSURE_TIME_DIFF=$(awk "BEGIN {print $BACKPRESSURE_TIME_AFTER_INGEST - $BACKPRESSURE_TIME_BEFORE_INGEST}")
+
+        # Insert the backpressure time difference into the performance database
+        if [ -n "$BACKPRESSURE_TIME_DIFF" ]; then
+          PSQL_CMD="${PSQL} \"${PERF_TEST_RESULT_CONNSTR}\" -c \"
+          INSERT INTO public.perf_test_results (suit, revision, platform, metric_name, metric_value, metric_unit, metric_report_type, recorded_at_timestamp)
+          VALUES ('${SUIT}', '${COMMIT_HASH}', '${PLATFORM}', 'backpressure_time', ${BACKPRESSURE_TIME_DIFF}, 'seconds', 'lower_is_better', now());
+          \""
+          echo "Inserting backpressure time difference: ${BACKPRESSURE_TIME_DIFF} seconds"
+          eval $PSQL_CMD
+        fi
+
+        # Extract and process log lines
+        while IFS= read -r line; do
+          METRIC_NAME=""
+          # Match each desired line and extract the relevant information
+          if [[ "$line" =~ COPY,\ INDEX,\ CONSTRAINTS,\ VACUUM.* ]]; then
+            METRIC_NAME="COPY, INDEX, CONSTRAINTS, VACUUM (wall clock)"
+          elif [[ "$line" =~ COPY\ \(cumulative\).* ]]; then
+            METRIC_NAME="COPY (cumulative)"
+          elif [[ "$line" =~ CREATE\ INDEX\ \(cumulative\).* ]]; then
+            METRIC_NAME="CREATE INDEX (cumulative)"
+          elif [[ "$line" =~ CONSTRAINTS\ \(cumulative\).* ]]; then
+            METRIC_NAME="CONSTRAINTS (cumulative)"
+          elif [[ "$line" =~ Finalize\ Schema.* ]]; then
+            METRIC_NAME="Finalize Schema"
+          elif [[ "$line" =~ Total\ Wall\ Clock\ Duration.* ]]; then
+            METRIC_NAME="Total Wall Clock Duration"
+          fi
+          
+          # If a metric was matched, insert it into the performance database
+          if [ -n "$METRIC_NAME" ]; then
+            DURATION=$(echo "$line" | grep -oP '\d+h\d+m|\d+s|\d+ms|\d{1,2}h\d{1,2}m|\d+\.\d+s' | head -n 1)
+            METRIC_VALUE=$(convert_to_seconds "$DURATION")
+            PSQL_CMD="${PSQL} \"${PERF_TEST_RESULT_CONNSTR}\" -c \"
+            INSERT INTO public.perf_test_results (suit, revision, platform, metric_name, metric_value, metric_unit, metric_report_type, recorded_at_timestamp)
+            VALUES ('${SUIT}', '${COMMIT_HASH}', '${PLATFORM}', '${METRIC_NAME}', ${METRIC_VALUE}, 'seconds', 'lower_is_better', now());
+            \""
+            echo "Inserting ${METRIC_NAME} with value ${METRIC_VALUE} seconds"
+            eval $PSQL_CMD
+          fi
+        done < "$LOG_FILE"
+      
+    - name: Delete Neon Project
+      if: ${{ always() && matrix.target_project == 'new_empty_project' }}
+      uses: ./.github/actions/neon-project-delete
+      with:
+        project_id: ${{ steps.create-neon-project-ingest-target.outputs.project_id }}
+        api_key: ${{ secrets.NEON_STAGING_API_KEY }}
+
+    - name: Delete Neon Branch for large tenant
+      if: ${{ always() && matrix.target_project == 'large_existing_project' }}
+      uses: ./.github/actions/neon-branch-delete
+      with:
+        project_id: ${{ vars.BENCHMARK_INGEST_TARGET_PROJECTID }}
+        branch_id: ${{ steps.create-neon-branch-ingest-target.outputs.branch_id }}
+        api_key: ${{ secrets.NEON_STAGING_API_KEY }}

.github/workflows/neon_extra_builds.yml

@@ -201,6 +201,8 @@ jobs:
           REPORT_URL: ${{ steps.upload-stats.outputs.report-url }}
           SHA: ${{ github.event.pull_request.head.sha || github.sha }}
         with:
+          # Retry script for 5XX server errors: https://github.com/actions/github-script#retries
+          retries: 5
           script: |
             const { REPORT_URL, SHA } = process.env
 

.github/workflows/report-workflow-stats-batch.yml

@@ -0,0 +1,29 @@
+name: Report Workflow Stats Batch
+
+on:
+  schedule:
+    - cron: '*/15 * * * *'
+    - cron: '25 0 * * *'
+
+jobs:
+  gh-workflow-stats-batch:
+    name: GitHub Workflow Stats Batch
+    runs-on: ubuntu-22.04
+    permissions:
+      actions: read
+    steps:
+    - name: Export Workflow Run for the past 2 hours
+      uses: neondatabase/gh-workflow-stats-action@v0.2.1
+      with:
+        db_uri: ${{ secrets.GH_REPORT_STATS_DB_RW_CONNSTR }}
+        db_table: "gh_workflow_stats_batch_neon"
+        gh_token: ${{ secrets.GITHUB_TOKEN }}
+        duration: '2h'
+    - name: Export Workflow Run for the past 24 hours
+      if: github.event.schedule == '25 0 * * *'
+      uses: neondatabase/gh-workflow-stats-action@v0.2.1
+      with:
+        db_uri: ${{ secrets.GH_REPORT_STATS_DB_RW_CONNSTR }}
+        db_table: "gh_workflow_stats_batch_neon"
+        gh_token: ${{ secrets.GITHUB_TOKEN }}
+        duration: '24h'

Cargo.lock

@@ -1229,12 +1229,15 @@ dependencies = [
  "flate2",
  "futures",
  "hyper 0.14.30",
+ "metrics",
  "nix 0.27.1",
  "notify",
  "num_cpus",
+ "once_cell",
  "opentelemetry",
  "opentelemetry_sdk",
  "postgres",
+ "prometheus",
  "regex",
  "remote_storage",
  "reqwest 0.12.4",
@@ -4006,7 +4009,7 @@ dependencies = [
 [[package]]
 name = "postgres"
 version = "0.19.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#a130197713830a0ea0004b539b1f51a66b4c3e18"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -4019,7 +4022,7 @@ dependencies = [
 [[package]]
 name = "postgres-protocol"
 version = "0.6.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#a130197713830a0ea0004b539b1f51a66b4c3e18"
 dependencies = [
  "base64 0.20.0",
  "byteorder",
@@ -4038,7 +4041,7 @@ dependencies = [
 [[package]]
 name = "postgres-types"
 version = "0.2.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#a130197713830a0ea0004b539b1f51a66b4c3e18"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -5660,9 +5663,9 @@ dependencies = [
 
 [[package]]
 name = "smallvec"
-version = "1.13.1"
+version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6ecd384b10a64542d77071bd64bd7b231f4ed5940fba55e98c3de13824cf3d7"
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"
 
 [[package]]
 name = "smol_str"
@@ -6071,9 +6074,9 @@ dependencies = [
 
 [[package]]
 name = "tikv-jemalloc-ctl"
-version = "0.5.4"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "619bfed27d807b54f7f776b9430d4f8060e66ee138a28632ca898584d462c31c"
+checksum = "f21f216790c8df74ce3ab25b534e0718da5a1916719771d3fec23315c99e468b"
 dependencies = [
  "libc",
  "paste",
@@ -6082,9 +6085,9 @@ dependencies = [
 
 [[package]]
 name = "tikv-jemalloc-sys"
-version = "0.5.4+5.3.0-patched"
+version = "0.6.0+5.3.0-1-ge13ca993e8ccb9ba9847cc330696e02839f328f7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "9402443cb8fd499b6f327e40565234ff34dbda27460c5b47db0db77443dd85d1"
+checksum = "cd3c60906412afa9c2b5b5a48ca6a5abe5736aec9eb48ad05037a677e52e4e2d"
 dependencies = [
  "cc",
  "libc",
@@ -6092,9 +6095,9 @@ dependencies = [
 
 [[package]]
 name = "tikv-jemallocator"
-version = "0.5.4"
+version = "0.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "965fe0c26be5c56c94e38ba547249074803efd52adfb66de62107d95aab3eaca"
+checksum = "4cec5ff18518d81584f477e9bfdf957f5bb0979b0bac3af4ca30b5b3ae2d2865"
 dependencies = [
  "libc",
  "tikv-jemalloc-sys",
@@ -6224,7 +6227,7 @@ dependencies = [
 [[package]]
 name = "tokio-postgres"
 version = "0.7.7"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=20031d7a9ee1addeae6e0968e3899ae6bf01cee2#20031d7a9ee1addeae6e0968e3899ae6bf01cee2"
+source = "git+https://github.com/neondatabase/rust-postgres.git?branch=neon#a130197713830a0ea0004b539b1f51a66b4c3e18"
 dependencies = [
  "async-trait",
  "byteorder",

Cargo.toml

@@ -168,8 +168,8 @@ sync_wrapper = "0.1.2"
 tar = "0.4"
 test-context = "0.3"
 thiserror = "1.0"
-tikv-jemallocator = "0.5"
-tikv-jemalloc-ctl = "0.5"
+tikv-jemallocator = { version = "0.6", features = ["stats"] }
+tikv-jemalloc-ctl = { version = "0.6", features = ["stats"] }
 tokio = { version = "1.17", features = ["macros"] }
 tokio-epoll-uring = { git = "https://github.com/neondatabase/tokio-epoll-uring.git" , branch = "main" }
 tokio-io-timeout = "1.2.0"
@@ -203,21 +203,10 @@ env_logger = "0.10"
 log = "0.4"
 
 ## Libraries from neondatabase/ git forks, ideally with changes to be upstreamed
-
-# We want to use the 'neon' branch for these, but there's currently one
-# incompatible change on the branch. See:
-#
-# - 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" }
+postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch = "neon" }
+postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", branch = "neon" }
+postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", branch = "neon" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch = "neon" }
 
 ## Local libraries
 compute_api = { version = "0.1", path = "./libs/compute_api/" }
@@ -255,7 +244,7 @@ tonic-build = "0.12"
 [patch.crates-io]
 
 # Needed to get `tokio-postgres-rustls` to depend on our fork.
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev = "20031d7a9ee1addeae6e0968e3899ae6bf01cee2" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", branch = "neon" }
 
 ################# Binary contents sections
 

compute/compute-node.Dockerfile

@@ -624,16 +624,12 @@ FROM build-deps AS pg-cron-pg-build
 ARG PG_VERSION
 COPY --from=pg-build /usr/local/pgsql/ /usr/local/pgsql/
 
-# 1.6.4 available, supports v17
 # This is an experimental extension that we do not support on prod yet.
 # !Do not remove!
 # We set it in shared_preload_libraries and computes will fail to start if library is not found.
 ENV PATH="/usr/local/pgsql/bin/:$PATH"
-RUN case "${PG_VERSION}" in "v17") \
-    echo "v17 extensions are not supported yet. Quit" && exit 0;; \
-    esac && \
-    wget https://github.com/citusdata/pg_cron/archive/refs/tags/v1.6.0.tar.gz -O pg_cron.tar.gz && \
-    echo "383a627867d730222c272bfd25cd5e151c578d73f696d32910c7db8c665cc7db pg_cron.tar.gz" | sha256sum --check && \
+RUN wget https://github.com/citusdata/pg_cron/archive/refs/tags/v1.6.4.tar.gz -O pg_cron.tar.gz && \
+    echo "52d1850ee7beb85a4cb7185731ef4e5a90d1de216709d8988324b0d02e76af61 pg_cron.tar.gz" | sha256sum --check && \
     mkdir pg_cron-src && cd pg_cron-src && tar xzf ../pg_cron.tar.gz --strip-components=1 -C . && \
     make -j $(getconf _NPROCESSORS_ONLN) && \
     make -j $(getconf _NPROCESSORS_ONLN) install && \
@@ -1475,6 +1471,8 @@ RUN mkdir -p /etc/local_proxy && chown postgres:postgres /etc/local_proxy
 COPY --from=postgres-exporter /bin/postgres_exporter /bin/postgres_exporter
 COPY --from=sql-exporter      /bin/sql_exporter      /bin/sql_exporter
 
+COPY --chown=postgres compute/etc/postgres_exporter.yml /etc/postgres_exporter.yml
+
 COPY --from=sql_exporter_preprocessor --chmod=0644 /home/nonroot/compute/etc/sql_exporter.yml               /etc/sql_exporter.yml
 COPY --from=sql_exporter_preprocessor --chmod=0644 /home/nonroot/compute/etc/neon_collector.yml             /etc/neon_collector.yml
 COPY --from=sql_exporter_preprocessor --chmod=0644 /home/nonroot/compute/etc/sql_exporter_autoscaling.yml   /etc/sql_exporter_autoscaling.yml

compute/etc/neon_collector.jsonnet

@@ -6,6 +6,7 @@
     import 'sql_exporter/compute_backpressure_throttling_seconds.libsonnet',
     import 'sql_exporter/compute_current_lsn.libsonnet',
     import 'sql_exporter/compute_logical_snapshot_files.libsonnet',
+    import 'sql_exporter/compute_max_connections.libsonnet',
     import 'sql_exporter/compute_receive_lsn.libsonnet',
     import 'sql_exporter/compute_subscriptions_count.libsonnet',
     import 'sql_exporter/connection_counts.libsonnet',

compute/etc/sql_exporter/compute_backpressure_throttling_seconds.sql

@@ -1 +1 @@
-SELECT neon.backpressure_throttling_time()::float8 / 1000 AS throttled;
+SELECT (neon.backpressure_throttling_time()::float8 / 1000000) AS throttled;

compute/etc/sql_exporter/compute_max_connections.libsonnet

@@ -0,0 +1,10 @@
+{
+  metric_name: 'compute_max_connections',
+  type: 'gauge',
+  help: 'Max connections allowed for Postgres',
+  key_labels: null,
+  values: [
+    'max_connections',
+  ],
+  query: importstr 'sql_exporter/compute_max_connections.sql',
+}

compute/etc/sql_exporter/compute_max_connections.sql

@@ -0,0 +1 @@
+SELECT current_setting('max_connections') as max_connections;

compute/patches/cloud_regress_pg16.patch

@@ -147,7 +147,7 @@ index 542c2e098c..0062d3024f 100644
  ALTER TABLE ptnowner1 OWNER TO regress_ptnowner;
  ALTER TABLE ptnowner OWNER TO regress_ptnowner;
 diff --git a/src/test/regress/expected/collate.icu.utf8.out b/src/test/regress/expected/collate.icu.utf8.out
-index 97bbe53b64..eac3d42a79 100644
+index 3f9a8f539c..0a51b52940 100644
 --- a/src/test/regress/expected/collate.icu.utf8.out
 +++ b/src/test/regress/expected/collate.icu.utf8.out
 @@ -1016,7 +1016,7 @@ select * from collate_test1 where b ilike 'ABC';
@@ -309,7 +309,7 @@ index b48365ec98..a6ef910055 100644
  -- the wrong partition. This test is *not* guaranteed to trigger that bug, but
  -- does so when shared_buffers is small enough.  To test if we encountered the
 diff --git a/src/test/regress/expected/copy2.out b/src/test/regress/expected/copy2.out
-index faf1a4d1b0..a44c97db52 100644
+index 9a74820ee8..22400a5551 100644
 --- a/src/test/regress/expected/copy2.out
 +++ b/src/test/regress/expected/copy2.out
 @@ -553,8 +553,8 @@ select * from check_con_tbl;
@@ -573,7 +573,7 @@ index 93302a07ef..1a73f083ac 100644
  -- that does not match with what's expected.
  -- This checks all the object types that include schema qualifications.
 diff --git a/src/test/regress/expected/create_view.out b/src/test/regress/expected/create_view.out
-index f3f8c7b5a2..3e3e54ff4c 100644
+index f551624afb..57f1e432d4 100644
 --- a/src/test/regress/expected/create_view.out
 +++ b/src/test/regress/expected/create_view.out
 @@ -18,7 +18,8 @@ CREATE TABLE real_city (
@@ -700,12 +700,12 @@ index 6ed50fdcfa..caa00a345d 100644
  COMMENT ON FOREIGN DATA WRAPPER dummy IS 'useless';
  CREATE FOREIGN DATA WRAPPER postgresql VALIDATOR postgresql_fdw_validator;
 diff --git a/src/test/regress/expected/foreign_key.out b/src/test/regress/expected/foreign_key.out
-index 12e523c737..8872e23935 100644
+index 6b8c2f2414..8e13b7fa46 100644
 --- a/src/test/regress/expected/foreign_key.out
 +++ b/src/test/regress/expected/foreign_key.out
-@@ -1968,7 +1968,7 @@ ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_2
-   FOR VALUES IN (1600);
- -- leave these tables around intentionally
+@@ -1985,7 +1985,7 @@ ALTER TABLE fk_partitioned_fk_6 ATTACH PARTITION fk_partitioned_pk_6 FOR VALUES
+ ERROR:  cannot ALTER TABLE "fk_partitioned_pk_61" because it is being used by active queries in this session
+ DROP TABLE fk_partitioned_pk_6, fk_partitioned_fk_6;
  -- test the case when the referenced table is owned by a different user
 -create role regress_other_partitioned_fk_owner;
 +create role regress_other_partitioned_fk_owner PASSWORD NEON_PASSWORD_PLACEHOLDER;
@@ -713,7 +713,7 @@ index 12e523c737..8872e23935 100644
  set role regress_other_partitioned_fk_owner;
  create table other_partitioned_fk(a int, b int) partition by list (a);
 diff --git a/src/test/regress/expected/generated.out b/src/test/regress/expected/generated.out
-index 0f623f7119..b48588a54e 100644
+index 5881420388..4ae21aa43c 100644
 --- a/src/test/regress/expected/generated.out
 +++ b/src/test/regress/expected/generated.out
 @@ -534,7 +534,7 @@ CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STOR
@@ -762,7 +762,7 @@ index a2036a1597..805d73b9d2 100644
  -- fields, leading to long bucket chains and lots of table expansion.
  -- this is therefore a stress test of the bucket overflow code (unlike
 diff --git a/src/test/regress/expected/identity.out b/src/test/regress/expected/identity.out
-index cc7772349f..98a08eb48d 100644
+index 1b74958de9..078187b542 100644
 --- a/src/test/regress/expected/identity.out
 +++ b/src/test/regress/expected/identity.out
 @@ -520,7 +520,7 @@ ALTER TABLE itest7 ALTER COLUMN a SET GENERATED BY DEFAULT;
@@ -775,10 +775,10 @@ index cc7772349f..98a08eb48d 100644
  GRANT SELECT, INSERT ON itest8 TO regress_identity_user1;
  SET ROLE regress_identity_user1;
 diff --git a/src/test/regress/expected/inherit.out b/src/test/regress/expected/inherit.out
-index 4943429e9b..0257f22b15 100644
+index 8f831c95c3..ec681b52af 100644
 --- a/src/test/regress/expected/inherit.out
 +++ b/src/test/regress/expected/inherit.out
-@@ -2606,7 +2606,7 @@ create index on permtest_parent (left(c, 3));
+@@ -2636,7 +2636,7 @@ create index on permtest_parent (left(c, 3));
  insert into permtest_parent
    select 1, 'a', left(fipshash(i::text), 5) from generate_series(0, 100) i;
  analyze permtest_parent;
@@ -1133,7 +1133,7 @@ index 8475231735..1afae5395f 100644
  SELECT rolname, rolpassword
      FROM pg_authid
 diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out
-index fbb0489a4f..2905194e2c 100644
+index 5b9dba7b32..cc408dad42 100644
 --- a/src/test/regress/expected/privileges.out
 +++ b/src/test/regress/expected/privileges.out
 @@ -20,19 +20,19 @@ SELECT lo_unlink(oid) FROM pg_largeobject_metadata WHERE oid >= 1000 AND oid < 3
@@ -1185,7 +1185,7 @@ index fbb0489a4f..2905194e2c 100644
  GRANT pg_read_all_data TO regress_priv_user6;
  GRANT pg_write_all_data TO regress_priv_user7;
  GRANT pg_read_all_settings TO regress_priv_user8 WITH ADMIN OPTION;
-@@ -145,8 +145,8 @@ REVOKE pg_read_all_settings FROM regress_priv_user8;
+@@ -212,8 +212,8 @@ REVOKE pg_read_all_settings FROM regress_priv_user8;
  DROP USER regress_priv_user10;
  DROP USER regress_priv_user9;
  DROP USER regress_priv_user8;
@@ -1196,7 +1196,7 @@ index fbb0489a4f..2905194e2c 100644
  ALTER GROUP regress_priv_group1 ADD USER regress_priv_user4;
  GRANT regress_priv_group2 TO regress_priv_user2 GRANTED BY regress_priv_user1;
  SET SESSION AUTHORIZATION regress_priv_user1;
-@@ -172,12 +172,16 @@ GRANT regress_priv_role TO regress_priv_user1 WITH ADMIN OPTION GRANTED BY regre
+@@ -239,12 +239,16 @@ GRANT regress_priv_role TO regress_priv_user1 WITH ADMIN OPTION GRANTED BY regre
  ERROR:  permission denied to grant privileges as role "regress_priv_role"
  DETAIL:  The grantor must have the ADMIN option on role "regress_priv_role".
  GRANT regress_priv_role TO regress_priv_user1 WITH ADMIN OPTION GRANTED BY CURRENT_ROLE;
@@ -1213,7 +1213,7 @@ index fbb0489a4f..2905194e2c 100644
  DROP ROLE regress_priv_role;
  SET SESSION AUTHORIZATION regress_priv_user1;
  SELECT session_user, current_user;
-@@ -1709,7 +1713,7 @@ SELECT has_table_privilege('regress_priv_user1', 'atest4', 'SELECT WITH GRANT OP
+@@ -1776,7 +1780,7 @@ SELECT has_table_privilege('regress_priv_user1', 'atest4', 'SELECT WITH GRANT OP
  
  -- security-restricted operations
  \c -
@@ -1222,7 +1222,7 @@ index fbb0489a4f..2905194e2c 100644
  -- Check that index expressions and predicates are run as the table's owner
  -- A dummy index function checking current_user
  CREATE FUNCTION sro_ifun(int) RETURNS int AS $$
-@@ -2601,8 +2605,8 @@ drop cascades to function testns.priv_testagg(integer)
+@@ -2668,8 +2672,8 @@ drop cascades to function testns.priv_testagg(integer)
  drop cascades to function testns.priv_testproc(integer)
  -- Change owner of the schema & and rename of new schema owner
  \c -
@@ -1233,7 +1233,7 @@ index fbb0489a4f..2905194e2c 100644
  SET SESSION ROLE regress_schemauser1;
  CREATE SCHEMA testns;
  SELECT nspname, rolname FROM pg_namespace, pg_roles WHERE pg_namespace.nspname = 'testns' AND pg_namespace.nspowner = pg_roles.oid;
-@@ -2725,7 +2729,7 @@ DROP USER regress_priv_user7;
+@@ -2792,7 +2796,7 @@ DROP USER regress_priv_user7;
  DROP USER regress_priv_user8; -- does not exist
  ERROR:  role "regress_priv_user8" does not exist
  -- permissions with LOCK TABLE
@@ -1242,7 +1242,7 @@ index fbb0489a4f..2905194e2c 100644
  CREATE TABLE lock_table (a int);
  -- LOCK TABLE and SELECT permission
  GRANT SELECT ON lock_table TO regress_locktable_user;
-@@ -2807,7 +2811,7 @@ DROP USER regress_locktable_user;
+@@ -2874,7 +2878,7 @@ DROP USER regress_locktable_user;
  -- pg_backend_memory_contexts.
  -- switch to superuser
  \c -
@@ -1251,7 +1251,7 @@ index fbb0489a4f..2905194e2c 100644
  SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- no
   has_table_privilege 
  ---------------------
-@@ -2851,10 +2855,10 @@ RESET ROLE;
+@@ -2918,10 +2922,10 @@ RESET ROLE;
  -- clean up
  DROP ROLE regress_readallstats;
  -- test role grantor machinery
@@ -1266,7 +1266,7 @@ index fbb0489a4f..2905194e2c 100644
  GRANT regress_group TO regress_group_direct_manager WITH INHERIT FALSE, ADMIN TRUE;
  GRANT regress_group_direct_manager TO regress_group_indirect_manager;
  SET SESSION AUTHORIZATION regress_group_direct_manager;
-@@ -2883,9 +2887,9 @@ DROP ROLE regress_group_direct_manager;
+@@ -2950,9 +2954,9 @@ DROP ROLE regress_group_direct_manager;
  DROP ROLE regress_group_indirect_manager;
  DROP ROLE regress_group_member;
  -- test SET and INHERIT options with object ownership changes
@@ -1813,7 +1813,7 @@ index 5e6969b173..2c4d52237f 100644
  
  -- clean up roles
 diff --git a/src/test/regress/expected/rowsecurity.out b/src/test/regress/expected/rowsecurity.out
-index 97ca9bf72c..b2a7a6f710 100644
+index 218c0c2863..f7af0cfb12 100644
 --- a/src/test/regress/expected/rowsecurity.out
 +++ b/src/test/regress/expected/rowsecurity.out
 @@ -14,13 +14,13 @@ DROP ROLE IF EXISTS regress_rls_group2;
@@ -1917,6 +1917,19 @@ index b79fe9a1c0..e29fab88ab 100644
  ALTER DEFAULT PRIVILEGES FOR ROLE regress_selinto_user
  	  REVOKE INSERT ON TABLES FROM regress_selinto_user;
  GRANT ALL ON SCHEMA selinto_schema TO public;
+diff --git a/src/test/regress/expected/select_parallel.out b/src/test/regress/expected/select_parallel.out
+index afc6ab08c2..dfcd891af3 100644
+--- a/src/test/regress/expected/select_parallel.out
++++ b/src/test/regress/expected/select_parallel.out
+@@ -1220,7 +1220,7 @@ SELECT 1 FROM tenk1_vw_sec
+ 
+ rollback;
+ -- test that function option SET ROLE works in parallel workers.
+-create role regress_parallel_worker;
++create role regress_parallel_worker PASSWORD NEON_PASSWORD_PLACEHOLDER;
+ create function set_and_report_role() returns text as
+   $$ select current_setting('role') $$ language sql parallel safe
+   set role = regress_parallel_worker;
 diff --git a/src/test/regress/expected/select_views.out b/src/test/regress/expected/select_views.out
 index 1aeed8452b..7d9427d070 100644
 --- a/src/test/regress/expected/select_views.out
@@ -2369,7 +2382,7 @@ index 6cb9c926c0..5e689e4062 100644
  ALTER TABLE ptnowner1 OWNER TO regress_ptnowner;
  ALTER TABLE ptnowner OWNER TO regress_ptnowner;
 diff --git a/src/test/regress/sql/collate.icu.utf8.sql b/src/test/regress/sql/collate.icu.utf8.sql
-index 3db9e25913..c66d5aa2c2 100644
+index 8aa902d5ab..24bb823b86 100644
 --- a/src/test/regress/sql/collate.icu.utf8.sql
 +++ b/src/test/regress/sql/collate.icu.utf8.sql
 @@ -353,7 +353,7 @@ reset enable_seqscan;
@@ -2532,7 +2545,7 @@ index 43d2e906dd..6c993d70f0 100644
  -- An earlier bug (see commit b1ecb9b3fcf) could end up using a buffer from
  -- the wrong partition. This test is *not* guaranteed to trigger that bug, but
 diff --git a/src/test/regress/sql/copy2.sql b/src/test/regress/sql/copy2.sql
-index d759635068..d58e50dcc5 100644
+index cf3828c16e..cf3ca38175 100644
 --- a/src/test/regress/sql/copy2.sql
 +++ b/src/test/regress/sql/copy2.sql
 @@ -365,8 +365,8 @@ copy check_con_tbl from stdin;
@@ -2774,7 +2787,7 @@ index 1b7064247a..be5b662ce1 100644
  -- Cases where schema creation fails as objects are qualified with a schema
  -- that does not match with what's expected.
 diff --git a/src/test/regress/sql/create_view.sql b/src/test/regress/sql/create_view.sql
-index 3a78be1b0c..617d2dc8d6 100644
+index ae6841308b..47bc792e30 100644
 --- a/src/test/regress/sql/create_view.sql
 +++ b/src/test/regress/sql/create_view.sql
 @@ -23,7 +23,8 @@ CREATE TABLE real_city (
@@ -2901,11 +2914,11 @@ index aa147b14a9..370e0dd570 100644
  CREATE FOREIGN DATA WRAPPER dummy;
  COMMENT ON FOREIGN DATA WRAPPER dummy IS 'useless';
 diff --git a/src/test/regress/sql/foreign_key.sql b/src/test/regress/sql/foreign_key.sql
-index 22e177f89b..7138d5e1d4 100644
+index 45c7a534cb..32dd26b8cd 100644
 --- a/src/test/regress/sql/foreign_key.sql
 +++ b/src/test/regress/sql/foreign_key.sql
-@@ -1418,7 +1418,7 @@ ALTER TABLE fk_partitioned_fk ATTACH PARTITION fk_partitioned_fk_2
- -- leave these tables around intentionally
+@@ -1435,7 +1435,7 @@ ALTER TABLE fk_partitioned_fk_6 ATTACH PARTITION fk_partitioned_pk_6 FOR VALUES
+ DROP TABLE fk_partitioned_pk_6, fk_partitioned_fk_6;
  
  -- test the case when the referenced table is owned by a different user
 -create role regress_other_partitioned_fk_owner;
@@ -2963,7 +2976,7 @@ index 527024f710..de49c0b85f 100644
  -- the data in this file has a lot of duplicates in the index key
  -- fields, leading to long bucket chains and lots of table expansion.
 diff --git a/src/test/regress/sql/identity.sql b/src/test/regress/sql/identity.sql
-index 91d2e443b4..241c93f373 100644
+index 7537258a75..9041e35e34 100644
 --- a/src/test/regress/sql/identity.sql
 +++ b/src/test/regress/sql/identity.sql
 @@ -287,7 +287,7 @@ ALTER TABLE itest7 ALTER COLUMN a RESTART;
@@ -2976,10 +2989,10 @@ index 91d2e443b4..241c93f373 100644
  GRANT SELECT, INSERT ON itest8 TO regress_identity_user1;
  SET ROLE regress_identity_user1;
 diff --git a/src/test/regress/sql/inherit.sql b/src/test/regress/sql/inherit.sql
-index fe699c54d5..bdd5993f45 100644
+index b5b554a125..109889ad24 100644
 --- a/src/test/regress/sql/inherit.sql
 +++ b/src/test/regress/sql/inherit.sql
-@@ -950,7 +950,7 @@ create index on permtest_parent (left(c, 3));
+@@ -958,7 +958,7 @@ create index on permtest_parent (left(c, 3));
  insert into permtest_parent
    select 1, 'a', left(fipshash(i::text), 5) from generate_series(0, 100) i;
  analyze permtest_parent;
@@ -3218,7 +3231,7 @@ index 53e86b0b6c..f07cf1ec54 100644
  CREATE ROLE regress_passwd5 PASSWORD 'md5e73a4b11df52a6068f8b39f90be36023';
  
 diff --git a/src/test/regress/sql/privileges.sql b/src/test/regress/sql/privileges.sql
-index 3f68cafcd1..004b26831d 100644
+index 249df17a58..b258e7f26a 100644
 --- a/src/test/regress/sql/privileges.sql
 +++ b/src/test/regress/sql/privileges.sql
 @@ -24,18 +24,18 @@ RESET client_min_messages;
@@ -3269,7 +3282,7 @@ index 3f68cafcd1..004b26831d 100644
  
  GRANT pg_read_all_data TO regress_priv_user6;
  GRANT pg_write_all_data TO regress_priv_user7;
-@@ -130,8 +130,8 @@ DROP USER regress_priv_user10;
+@@ -163,8 +163,8 @@ DROP USER regress_priv_user10;
  DROP USER regress_priv_user9;
  DROP USER regress_priv_user8;
  
@@ -3280,7 +3293,7 @@ index 3f68cafcd1..004b26831d 100644
  
  ALTER GROUP regress_priv_group1 ADD USER regress_priv_user4;
  
-@@ -1124,7 +1124,7 @@ SELECT has_table_privilege('regress_priv_user1', 'atest4', 'SELECT WITH GRANT OP
+@@ -1157,7 +1157,7 @@ SELECT has_table_privilege('regress_priv_user1', 'atest4', 'SELECT WITH GRANT OP
  
  -- security-restricted operations
  \c -
@@ -3289,7 +3302,7 @@ index 3f68cafcd1..004b26831d 100644
  
  -- Check that index expressions and predicates are run as the table's owner
  
-@@ -1620,8 +1620,8 @@ DROP SCHEMA testns CASCADE;
+@@ -1653,8 +1653,8 @@ DROP SCHEMA testns CASCADE;
  -- Change owner of the schema & and rename of new schema owner
  \c -
  
@@ -3300,7 +3313,7 @@ index 3f68cafcd1..004b26831d 100644
  
  SET SESSION ROLE regress_schemauser1;
  CREATE SCHEMA testns;
-@@ -1715,7 +1715,7 @@ DROP USER regress_priv_user8; -- does not exist
+@@ -1748,7 +1748,7 @@ DROP USER regress_priv_user8; -- does not exist
  
  
  -- permissions with LOCK TABLE
@@ -3309,7 +3322,7 @@ index 3f68cafcd1..004b26831d 100644
  CREATE TABLE lock_table (a int);
  
  -- LOCK TABLE and SELECT permission
-@@ -1803,7 +1803,7 @@ DROP USER regress_locktable_user;
+@@ -1836,7 +1836,7 @@ DROP USER regress_locktable_user;
  -- switch to superuser
  \c -
  
@@ -3318,7 +3331,7 @@ index 3f68cafcd1..004b26831d 100644
  
  SELECT has_table_privilege('regress_readallstats','pg_backend_memory_contexts','SELECT'); -- no
  SELECT has_table_privilege('regress_readallstats','pg_shmem_allocations','SELECT'); -- no
-@@ -1823,10 +1823,10 @@ RESET ROLE;
+@@ -1856,10 +1856,10 @@ RESET ROLE;
  DROP ROLE regress_readallstats;
  
  -- test role grantor machinery
@@ -3333,7 +3346,7 @@ index 3f68cafcd1..004b26831d 100644
  
  GRANT regress_group TO regress_group_direct_manager WITH INHERIT FALSE, ADMIN TRUE;
  GRANT regress_group_direct_manager TO regress_group_indirect_manager;
-@@ -1848,9 +1848,9 @@ DROP ROLE regress_group_indirect_manager;
+@@ -1881,9 +1881,9 @@ DROP ROLE regress_group_indirect_manager;
  DROP ROLE regress_group_member;
  
  -- test SET and INHERIT options with object ownership changes
@@ -3625,7 +3638,7 @@ index c961b2d730..0859b89c4f 100644
  -- clean up roles
  DROP ROLE regress_test_def_superuser;
 diff --git a/src/test/regress/sql/rowsecurity.sql b/src/test/regress/sql/rowsecurity.sql
-index dec7340538..cdbc03a5cc 100644
+index d3bfd53e23..919ce1d0c6 100644
 --- a/src/test/regress/sql/rowsecurity.sql
 +++ b/src/test/regress/sql/rowsecurity.sql
 @@ -20,13 +20,13 @@ DROP SCHEMA IF EXISTS regress_rls_schema CASCADE;
@@ -3701,6 +3714,19 @@ index 689c448cc2..223ceb1d75 100644
  ALTER DEFAULT PRIVILEGES FOR ROLE regress_selinto_user
  	  REVOKE INSERT ON TABLES FROM regress_selinto_user;
  GRANT ALL ON SCHEMA selinto_schema TO public;
+diff --git a/src/test/regress/sql/select_parallel.sql b/src/test/regress/sql/select_parallel.sql
+index 33d78e16dc..cb193c9b27 100644
+--- a/src/test/regress/sql/select_parallel.sql
++++ b/src/test/regress/sql/select_parallel.sql
+@@ -464,7 +464,7 @@ SELECT 1 FROM tenk1_vw_sec
+ rollback;
+ 
+ -- test that function option SET ROLE works in parallel workers.
+-create role regress_parallel_worker;
++create role regress_parallel_worker PASSWORD NEON_PASSWORD_PLACEHOLDER;
+ 
+ create function set_and_report_role() returns text as
+   $$ select current_setting('role') $$ language sql parallel safe
 diff --git a/src/test/regress/sql/select_views.sql b/src/test/regress/sql/select_views.sql
 index e742f13699..7bd0255df8 100644
 --- a/src/test/regress/sql/select_views.sql

compute/patches/pg_anon.patch

@@ -1,3 +1,45 @@
+commit 00aa659afc9c7336ab81036edec3017168aabf40
+Author: Heikki Linnakangas <heikki@neon.tech>
+Date:   Tue Nov 12 16:59:19 2024 +0200
+
+    Temporarily disable test that depends on timezone
+
+diff --git a/tests/expected/generalization.out b/tests/expected/generalization.out
+index 23ef5fa..9e60deb 100644
+--- a/ext-src/pg_anon-src/tests/expected/generalization.out
++++ b/ext-src/pg_anon-src/tests/expected/generalization.out
+@@ -284,12 +284,9 @@ SELECT anon.generalize_tstzrange('19041107','century');
+  ["Tue Jan 01 00:00:00 1901 PST","Mon Jan 01 00:00:00 2001 PST")
+ (1 row)
+ 
+-SELECT anon.generalize_tstzrange('19041107','millennium');
+-                      generalize_tstzrange                       
+------------------------------------------------------------------
+- ["Thu Jan 01 00:00:00 1001 PST","Mon Jan 01 00:00:00 2001 PST")
+-(1 row)
+-
++-- temporarily disabled, see:
++-- https://gitlab.com/dalibo/postgresql_anonymizer/-/commit/199f0a392b37c59d92ae441fb8f037e094a11a52#note_2148017485
++--SELECT anon.generalize_tstzrange('19041107','millennium');
+ -- generalize_daterange
+ SELECT anon.generalize_daterange('19041107');
+   generalize_daterange   
+diff --git a/tests/sql/generalization.sql b/tests/sql/generalization.sql
+index b868344..b4fc977 100644
+--- a/ext-src/pg_anon-src/tests/sql/generalization.sql
++++ b/ext-src/pg_anon-src/tests/sql/generalization.sql
+@@ -61,7 +61,9 @@ SELECT anon.generalize_tstzrange('19041107','month');
+ SELECT anon.generalize_tstzrange('19041107','year');
+ SELECT anon.generalize_tstzrange('19041107','decade');
+ SELECT anon.generalize_tstzrange('19041107','century');
+-SELECT anon.generalize_tstzrange('19041107','millennium');
++-- temporarily disabled, see:
++-- https://gitlab.com/dalibo/postgresql_anonymizer/-/commit/199f0a392b37c59d92ae441fb8f037e094a11a52#note_2148017485
++--SELECT anon.generalize_tstzrange('19041107','millennium');
+ 
+ -- generalize_daterange
+ SELECT anon.generalize_daterange('19041107');
+
 commit 7dd414ee75f2875cffb1d6ba474df1f135a6fc6f
 Author: Alexey Masterov <alexeymasterov@neon.tech>
 Date:   Fri May 31 06:34:26 2024 +0000

compute/vm-image-spec-bookworm.yaml

@@ -26,7 +26,7 @@ commands:
   - name: postgres-exporter
     user: nobody
     sysvInitAction: respawn
-    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres application_name=postgres-exporter" /bin/postgres_exporter'
+    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres application_name=postgres-exporter" /bin/postgres_exporter --config.file=/etc/postgres_exporter.yml'
   - name: sql-exporter
     user: nobody
     sysvInitAction: respawn

compute/vm-image-spec-bullseye.yaml

@@ -26,7 +26,7 @@ commands:
   - name: postgres-exporter
     user: nobody
     sysvInitAction: respawn
-    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres application_name=postgres-exporter" /bin/postgres_exporter'
+    shell: 'DATA_SOURCE_NAME="user=cloud_admin sslmode=disable dbname=postgres application_name=postgres-exporter" /bin/postgres_exporter --config.file=/etc/postgres_exporter.yml'
   - name: sql-exporter
     user: nobody
     sysvInitAction: respawn

compute_tools/Cargo.toml

@@ -18,9 +18,11 @@ clap.workspace = true
 flate2.workspace = true
 futures.workspace = true
 hyper0 = { workspace = true, features = ["full"] }
+metrics.workspace = true
 nix.workspace = true
 notify.workspace = true
 num_cpus.workspace = true
+once_cell.workspace = true
 opentelemetry.workspace = true
 opentelemetry_sdk.workspace = true
 postgres.workspace = true
@@ -39,6 +41,7 @@ tracing-subscriber.workspace = true
 tracing-utils.workspace = true
 thiserror.workspace = true
 url.workspace = true
+prometheus.workspace = true
 
 compute_api.workspace = true
 utils.workspace = true

compute_tools/src/config.rs

@@ -74,10 +74,17 @@ pub fn write_postgres_conf(
     }
 
     // Locales
-    writeln!(file, "lc_messages='C.UTF-8'")?;
-    writeln!(file, "lc_monetary='C.UTF-8'")?;
-    writeln!(file, "lc_time='C.UTF-8'")?;
-    writeln!(file, "lc_numeric='C.UTF-8'")?;
+    if cfg!(target_os = "macos") {
+        writeln!(file, "lc_messages='C'")?;
+        writeln!(file, "lc_monetary='C'")?;
+        writeln!(file, "lc_time='C'")?;
+        writeln!(file, "lc_numeric='C'")?;
+    } else {
+        writeln!(file, "lc_messages='C.UTF-8'")?;
+        writeln!(file, "lc_monetary='C.UTF-8'")?;
+        writeln!(file, "lc_time='C.UTF-8'")?;
+        writeln!(file, "lc_numeric='C.UTF-8'")?;
+    }
 
     match spec.mode {
         ComputeMode::Primary => {}

compute_tools/src/http/api.rs

@@ -9,6 +9,7 @@ use crate::catalog::SchemaDumpError;
 use crate::catalog::{get_database_schema, get_dbs_and_roles};
 use crate::compute::forward_termination_signal;
 use crate::compute::{ComputeNode, ComputeState, ParsedSpec};
+use crate::installed_extensions;
 use compute_api::requests::{ConfigurationRequest, ExtensionInstallRequest, SetRoleGrantsRequest};
 use compute_api::responses::{
     ComputeStatus, ComputeStatusResponse, ExtensionInstallResult, GenericAPIError,
@@ -19,6 +20,8 @@ use anyhow::Result;
 use hyper::header::CONTENT_TYPE;
 use hyper::service::{make_service_fn, service_fn};
 use hyper::{Body, Method, Request, Response, Server, StatusCode};
+use metrics::Encoder;
+use metrics::TextEncoder;
 use tokio::task;
 use tracing::{debug, error, info, warn};
 use tracing_utils::http::OtelName;
@@ -65,6 +68,28 @@ async fn routes(req: Request<Body>, compute: &Arc<ComputeNode>) -> Response<Body
             Response::new(Body::from(serde_json::to_string(&metrics).unwrap()))
         }
 
+        // Prometheus metrics
+        (&Method::GET, "/metrics") => {
+            debug!("serving /metrics GET request");
+
+            let mut buffer = vec![];
+            let metrics = installed_extensions::collect();
+            let encoder = TextEncoder::new();
+            encoder.encode(&metrics, &mut buffer).unwrap();
+
+            match Response::builder()
+                .status(StatusCode::OK)
+                .header(CONTENT_TYPE, encoder.format_type())
+                .body(Body::from(buffer))
+            {
+                Ok(response) => response,
+                Err(err) => {
+                    let msg = format!("error handling /metrics request: {err}");
+                    error!(msg);
+                    render_json_error(&msg, StatusCode::INTERNAL_SERVER_ERROR)
+                }
+            }
+        }
         // Collect Postgres current usage insights
         (&Method::GET, "/insights") => {
             info!("serving /insights GET request");

compute_tools/src/http/openapi_spec.yaml

@@ -37,6 +37,21 @@ paths:
               schema:
                 $ref: "#/components/schemas/ComputeMetrics"
 
+  /metrics
+    get:
+      tags:
+      - Info
+      summary: Get compute node metrics in text format.
+      description: ""
+      operationId: getComputeMetrics
+      responses:
+        200:
+          description: ComputeMetrics
+          content:
+            text/plain:
+              schema:
+                type: string
+                description: Metrics in text format.
   /insights:
     get:
       tags:

compute_tools/src/installed_extensions.rs

@@ -1,4 +1,5 @@
 use compute_api::responses::{InstalledExtension, InstalledExtensions};
+use metrics::proto::MetricFamily;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use tracing::info;
@@ -8,6 +9,10 @@ use anyhow::Result;
 use postgres::{Client, NoTls};
 use tokio::task;
 
+use metrics::core::Collector;
+use metrics::{register_uint_gauge_vec, UIntGaugeVec};
+use once_cell::sync::Lazy;
+
 /// We don't reuse get_existing_dbs() just for code clarity
 /// and to make database listing query here more explicit.
 ///
@@ -59,6 +64,12 @@ pub async fn get_installed_extensions(connstr: Url) -> Result<InstalledExtension
 
             for (extname, v) in extensions.iter() {
                 let version = v.to_string();
+
+                // increment the number of databases where the version of extension is installed
+                INSTALLED_EXTENSIONS
+                    .with_label_values(&[extname, &version])
+                    .inc();
+
                 extensions_map
                     .entry(extname.to_string())
                     .and_modify(|e| {
@@ -74,9 +85,11 @@ pub async fn get_installed_extensions(connstr: Url) -> Result<InstalledExtension
             }
         }
 
-        Ok(InstalledExtensions {
+        let res = InstalledExtensions {
             extensions: extensions_map.values().cloned().collect(),
-        })
+        };
+
+        Ok(res)
     })
     .await?
 }
@@ -97,6 +110,18 @@ pub fn get_installed_extensions_sync(connstr: Url) -> Result<()> {
         "[NEON_EXT_STAT] {}",
         serde_json::to_string(&result).expect("failed to serialize extensions list")
     );
-
     Ok(())
 }
+
+static INSTALLED_EXTENSIONS: Lazy<UIntGaugeVec> = Lazy::new(|| {
+    register_uint_gauge_vec!(
+        "installed_extensions",
+        "Number of databases where the version of extension is installed",
+        &["extension_name", "version"]
+    )
+    .expect("failed to define a metric")
+});
+
+pub fn collect() -> Vec<MetricFamily> {
+    INSTALLED_EXTENSIONS.collect()
+}

deny.toml

@@ -37,6 +37,7 @@ allow = [
     "BSD-2-Clause",
     "BSD-3-Clause",
     "CC0-1.0",
+    "CDDL-1.0",
     "ISC",
     "MIT",
     "MPL-2.0",

docs/rfcs/038-aux-file-v2.md

@@ -91,7 +91,7 @@ generating the basebackup by scanning the `REPL_ORIGIN_KEY_PREFIX` keyspace.
 There are two places we need to read the aux files from the pageserver:
 
 * On the write path, when the compute node adds an aux file to the pageserver, we will retrieve the key from the storage, append the file to the hashed key, and write it back. The current `get` API already supports that.
-*  We use the vectored get API to retrieve all aux files during generating the basebackup. Because we need to scan a sparse keyspace, we slightly modified the vectored get path. The vectorized API will attempt to retrieve every single key within the requested key range, and therefore, we modified it in a way that keys within `NON_INHERITED_SPARSE_RANGE` will not trigger missing key error.
+*  We use the vectored get API to retrieve all aux files during generating the basebackup. Because we need to scan a sparse keyspace, we slightly modified the vectored get path. The vectorized API used to always attempt to retrieve every single key within the requested key range, and therefore, we modified it in a way that keys within `NON_INHERITED_SPARSE_RANGE` will not trigger missing key error. Furthermore, as aux file reads usually need all layer files intersecting with that key range within the branch and cover a big keyspace, it incurs large overhead for tracking keyspaces that have not been read. Therefore, for sparse keyspaces, we [do not track](https://github.com/neondatabase/neon/pull/9631) `ummapped_keyspace`.
 
 ## Compaction and Image Layer Generation
 

libs/pageserver_api/src/config.rs

@@ -277,7 +277,11 @@ pub mod defaults {
     pub const DEFAULT_WAL_REDO_TIMEOUT: &str = "60 s";
 
     pub const DEFAULT_SUPERUSER: &str = "cloud_admin";
-    pub const DEFAULT_LOCALE: &str = "C.UTF-8";
+    pub const DEFAULT_LOCALE: &str = if cfg!(target_os = "macos") {
+        "C"
+    } else {
+        "C.UTF-8"
+    };
 
     pub const DEFAULT_PAGE_CACHE_SIZE: usize = 8192;
     pub const DEFAULT_MAX_FILE_DESCRIPTORS: usize = 100;

libs/pageserver_api/src/key.rs

@@ -24,7 +24,7 @@ pub struct Key {
 
 /// When working with large numbers of Keys in-memory, it is more efficient to handle them as i128 than as
 /// a struct of fields.
-#[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd)]
+#[derive(Clone, Copy, Hash, PartialEq, Eq, Ord, PartialOrd, Serialize, Deserialize)]
 pub struct CompactKey(i128);
 
 /// The storage key size.

libs/pageserver_api/src/record.rs

@@ -41,6 +41,11 @@ pub enum NeonWalRecord {
         file_path: String,
         content: Option<Bytes>,
     },
+    // Truncate visibility map page
+    TruncateVisibilityMap {
+        trunc_byte: usize,
+        trunc_offs: usize,
+    },
 
     /// A testing record for unit testing purposes. It supports append data to an existing image, or clear it.
     #[cfg(feature = "testing")]
@@ -80,18 +85,18 @@ impl NeonWalRecord {
     }
 
     #[cfg(feature = "testing")]
-    pub fn wal_clear() -> Self {
+    pub fn wal_clear(s: impl AsRef<str>) -> Self {
         Self::Test {
-            append: "".to_string(),
+            append: s.as_ref().to_string(),
             clear: true,
             will_init: false,
         }
     }
 
     #[cfg(feature = "testing")]
-    pub fn wal_init() -> Self {
+    pub fn wal_init(s: impl AsRef<str>) -> Self {
         Self::Test {
-            append: "".to_string(),
+            append: s.as_ref().to_string(),
             clear: true,
             will_init: true,
         }

libs/pageserver_api/src/reltag.rs

@@ -24,7 +24,7 @@ use postgres_ffi::Oid;
 // FIXME: should move 'forknum' as last field to keep this consistent with Postgres.
 // Then we could replace the custom Ord and PartialOrd implementations below with
 // deriving them. This will require changes in walredoproc.c.
-#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy, Serialize)]
+#[derive(Debug, PartialEq, Eq, Hash, Clone, Copy, Serialize, Deserialize)]
 pub struct RelTag {
     pub forknum: u8,
     pub spcnode: Oid,

libs/postgres_ffi/src/pg_constants.rs

@@ -243,8 +243,11 @@ const FSM_LEAF_NODES_PER_PAGE: usize = FSM_NODES_PER_PAGE - FSM_NON_LEAF_NODES_P
 pub const SLOTS_PER_FSM_PAGE: u32 = FSM_LEAF_NODES_PER_PAGE as u32;
 
 /* From visibilitymap.c */
-pub const VM_HEAPBLOCKS_PER_PAGE: u32 =
-    (BLCKSZ as usize - SIZEOF_PAGE_HEADER_DATA) as u32 * (8 / 2); // MAPSIZE * (BITS_PER_BYTE / BITS_PER_HEAPBLOCK)
+
+pub const VM_MAPSIZE: usize = BLCKSZ as usize - MAXALIGN_SIZE_OF_PAGE_HEADER_DATA;
+pub const VM_BITS_PER_HEAPBLOCK: usize = 2;
+pub const VM_HEAPBLOCKS_PER_BYTE: usize = 8 / VM_BITS_PER_HEAPBLOCK;
+pub const VM_HEAPBLOCKS_PER_PAGE: usize = VM_MAPSIZE * VM_HEAPBLOCKS_PER_BYTE;
 
 /* From origin.c */
 pub const REPLICATION_STATE_MAGIC: u32 = 0x1257DADE;

libs/postgres_ffi/src/walrecord.rs

@@ -16,7 +16,7 @@ use utils::bin_ser::DeserializeError;
 use utils::lsn::Lsn;
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlMultiXactCreate {
     pub mid: MultiXactId,
     /* new MultiXact's ID */
@@ -46,7 +46,7 @@ impl XlMultiXactCreate {
 }
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlMultiXactTruncate {
     pub oldest_multi_db: Oid,
     /* to-be-truncated range of multixact offsets */
@@ -72,7 +72,7 @@ impl XlMultiXactTruncate {
 }
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlRelmapUpdate {
     pub dbid: Oid,   /* database ID, or 0 for shared map */
     pub tsid: Oid,   /* database's tablespace, or pg_global */
@@ -90,7 +90,7 @@ impl XlRelmapUpdate {
 }
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlReploriginDrop {
     pub node_id: RepOriginId,
 }
@@ -104,7 +104,7 @@ impl XlReploriginDrop {
 }
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlReploriginSet {
     pub remote_lsn: Lsn,
     pub node_id: RepOriginId,
@@ -120,7 +120,7 @@ impl XlReploriginSet {
 }
 
 #[repr(C)]
-#[derive(Debug, Clone, Copy)]
+#[derive(Debug, Clone, Copy, Serialize, Deserialize)]
 pub struct RelFileNode {
     pub spcnode: Oid, /* tablespace */
     pub dbnode: Oid,  /* database */
@@ -911,7 +911,7 @@ impl XlSmgrCreate {
 }
 
 #[repr(C)]
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlSmgrTruncate {
     pub blkno: BlockNumber,
     pub rnode: RelFileNode,
@@ -984,7 +984,7 @@ impl XlDropDatabase {
 /// xl_xact_parsed_abort structs in PostgreSQL, but we use the same
 /// struct for commits and aborts.
 ///
-#[derive(Debug)]
+#[derive(Debug, Serialize, Deserialize)]
 pub struct XlXactParsedRecord {
     pub xid: TransactionId,
     pub info: u8,

libs/remote_storage/src/error.rs

@@ -15,6 +15,9 @@ pub enum DownloadError {
     ///
     /// Concurrency control is not timed within timeout.
     Timeout,
+    /// Some integrity/consistency check failed during download. This is used during
+    /// timeline loads to cancel the load of a tenant if some timeline detects fatal corruption.
+    Fatal(String),
     /// The file was found in the remote storage, but the download failed.
     Other(anyhow::Error),
 }
@@ -29,6 +32,7 @@ impl std::fmt::Display for DownloadError {
             DownloadError::Unmodified => write!(f, "File was not modified"),
             DownloadError::Cancelled => write!(f, "Cancelled, shutting down"),
             DownloadError::Timeout => write!(f, "timeout"),
+            DownloadError::Fatal(why) => write!(f, "Fatal read error: {why}"),
             DownloadError::Other(e) => write!(f, "Failed to download a remote file: {e:?}"),
         }
     }
@@ -41,7 +45,7 @@ impl DownloadError {
     pub fn is_permanent(&self) -> bool {
         use DownloadError::*;
         match self {
-            BadInput(_) | NotFound | Unmodified | Cancelled => true,
+            BadInput(_) | NotFound | Unmodified | Fatal(_) | Cancelled => true,
             Timeout | Other(_) => false,
         }
     }

libs/utils/src/auth.rs

@@ -40,6 +40,11 @@ pub enum Scope {
     /// Allows access to storage controller APIs used by the scrubber, to interrogate the state
     /// of a tenant & post scrub results.
     Scrubber,
+
+    /// This scope is used for communication with other storage controller instances.
+    /// At the time of writing, this is only used for the step down request.
+    #[serde(rename = "controller_peer")]
+    ControllerPeer,
 }
 
 /// JWT payload. See docs/authentication.md for the format

libs/utils/src/crashsafe.rs

@@ -123,15 +123,27 @@ pub async fn fsync_async_opt(
     Ok(())
 }
 
-/// Like postgres' durable_rename, renames file issuing fsyncs do make it
-/// durable. After return, file and rename are guaranteed to be persisted.
+/// Like postgres' durable_rename, renames a file and issues fsyncs to make it durable. After
+/// returning, both the file and rename are guaranteed to be persisted. Both paths must be on the
+/// same file system.
 ///
-/// Unlike postgres, it only does fsyncs to 1) file to be renamed to make
-/// contents durable; 2) its directory entry to make rename durable 3) again to
-/// already renamed file, which is not required by standards but postgres does
-/// it, let's stick to that. Postgres additionally fsyncs newpath *before*
-/// rename if it exists to ensure that at least one of the files survives, but
-/// current callers don't need that.
+/// Unlike postgres, it only fsyncs 1) the file to make contents durable, and 2) the directory to
+/// make the rename durable. This sequence ensures the target file will never be incomplete.
+///
+/// Postgres also:
+///
+/// * Fsyncs the target file, if it exists, before the rename, to ensure either the new or existing
+///   file survives a crash. Current callers don't need this as it should already be fsynced if
+///   durability is needed.
+///
+/// * Fsyncs the file after the rename. This can be required with certain OSes or file systems (e.g.
+///   NFS), but not on Linux with most common file systems like ext4 (which we currently use).
+///
+/// An audit of 8 other databases found that none fsynced the file after a rename:
+/// <https://github.com/neondatabase/neon/pull/9686#discussion_r1837180535>
+///
+/// eBPF probes confirmed that this is sufficient with ext4, XFS, and ZFS, but possibly not Btrfs:
+/// <https://github.com/neondatabase/neon/pull/9686#discussion_r1837926218>
 ///
 /// virtual_file.rs has similar code, but it doesn't use vfs.
 ///
@@ -149,9 +161,6 @@ pub async fn durable_rename(
     // Time to do the real deal.
     tokio::fs::rename(old_path.as_ref(), new_path.as_ref()).await?;
 
-    // Postgres'ish fsync of renamed file.
-    fsync_async_opt(new_path.as_ref(), do_fsync).await?;
-
     // Now fsync the parent
     let parent = match new_path.as_ref().parent() {
         Some(p) => p,

libs/utils/src/lsn.rs

@@ -138,6 +138,11 @@ impl Lsn {
         self.0.checked_sub(other).map(Lsn)
     }
 
+    /// Subtract a number, saturating at numeric bounds instead of overflowing.
+    pub fn saturating_sub<T: Into<u64>>(self, other: T) -> Lsn {
+        Lsn(self.0.saturating_sub(other.into()))
+    }
+
     /// Subtract a number, returning the difference as i128 to avoid overflow.
     pub fn widening_sub<T: Into<u64>>(self, other: T) -> i128 {
         let other: u64 = other.into();

libs/wal_decoder/src/decoder.rs

@@ -19,7 +19,7 @@ impl InterpretedWalRecord {
     pub fn from_bytes_filtered(
         buf: Bytes,
         shard: &ShardIdentity,
-        record_end_lsn: Lsn,
+        next_record_lsn: Lsn,
         pg_version: u32,
     ) -> anyhow::Result<InterpretedWalRecord> {
         let mut decoded = DecodedWALRecord::default();
@@ -32,18 +32,18 @@ impl InterpretedWalRecord {
             FlushUncommittedRecords::No
         };
 
-        let metadata_record = MetadataRecord::from_decoded(&decoded, record_end_lsn, pg_version)?;
+        let metadata_record = MetadataRecord::from_decoded(&decoded, next_record_lsn, pg_version)?;
         let batch = SerializedValueBatch::from_decoded_filtered(
             decoded,
             shard,
-            record_end_lsn,
+            next_record_lsn,
             pg_version,
         )?;
 
         Ok(InterpretedWalRecord {
             metadata_record,
             batch,
-            end_lsn: record_end_lsn,
+            next_record_lsn,
             flush_uncommitted,
             xid,
         })
@@ -53,7 +53,7 @@ impl InterpretedWalRecord {
 impl MetadataRecord {
     fn from_decoded(
         decoded: &DecodedWALRecord,
-        record_end_lsn: Lsn,
+        next_record_lsn: Lsn,
         pg_version: u32,
     ) -> anyhow::Result<Option<MetadataRecord>> {
         // Note: this doesn't actually copy the bytes since
@@ -74,7 +74,9 @@ impl MetadataRecord {
                 Ok(None)
             }
             pg_constants::RM_CLOG_ID => Self::decode_clog_record(&mut buf, decoded, pg_version),
-            pg_constants::RM_XACT_ID => Self::decode_xact_record(&mut buf, decoded, record_end_lsn),
+            pg_constants::RM_XACT_ID => {
+                Self::decode_xact_record(&mut buf, decoded, next_record_lsn)
+            }
             pg_constants::RM_MULTIXACT_ID => {
                 Self::decode_multixact_record(&mut buf, decoded, pg_version)
             }
@@ -86,7 +88,9 @@ impl MetadataRecord {
             //
             // Alternatively, one can make the checkpoint part of the subscription protocol
             // to the pageserver. This should work fine, but can be done at a later point.
-            pg_constants::RM_XLOG_ID => Self::decode_xlog_record(&mut buf, decoded, record_end_lsn),
+            pg_constants::RM_XLOG_ID => {
+                Self::decode_xlog_record(&mut buf, decoded, next_record_lsn)
+            }
             pg_constants::RM_LOGICALMSG_ID => {
                 Self::decode_logical_message_record(&mut buf, decoded)
             }

libs/wal_decoder/src/models.rs

@@ -32,16 +32,19 @@ use postgres_ffi::walrecord::{
     XlSmgrTruncate, XlXactParsedRecord,
 };
 use postgres_ffi::{Oid, TransactionId};
+use serde::{Deserialize, Serialize};
 use utils::lsn::Lsn;
 
 use crate::serialized_batch::SerializedValueBatch;
 
+#[derive(Serialize, Deserialize)]
 pub enum FlushUncommittedRecords {
     Yes,
     No,
 }
 
 /// An interpreted Postgres WAL record, ready to be handled by the pageserver
+#[derive(Serialize, Deserialize)]
 pub struct InterpretedWalRecord {
     /// Optional metadata record - may cause writes to metadata keys
     /// in the storage engine
@@ -49,8 +52,10 @@ pub struct InterpretedWalRecord {
     /// A pre-serialized batch along with the required metadata for ingestion
     /// by the pageserver
     pub batch: SerializedValueBatch,
-    /// Byte offset within WAL for the end of the original PG WAL record
-    pub end_lsn: Lsn,
+    /// Byte offset within WAL for the start of the next PG WAL record.
+    /// Usually this is the end LSN of the current record, but in case of
+    /// XLOG SWITCH records it will be within the next segment.
+    pub next_record_lsn: Lsn,
     /// Whether to flush all uncommitted modifications to the storage engine
     /// before ingesting this record. This is currently only used for legacy PG
     /// database creations which read pages from a template database. Such WAL
@@ -62,6 +67,7 @@ pub struct InterpretedWalRecord {
 
 /// The interpreted part of the Postgres WAL record which requires metadata
 /// writes to the underlying storage engine.
+#[derive(Serialize, Deserialize)]
 pub enum MetadataRecord {
     Heapam(HeapamRecord),
     Neonrmgr(NeonrmgrRecord),
@@ -77,10 +83,12 @@ pub enum MetadataRecord {
     Replorigin(ReploriginRecord),
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum HeapamRecord {
     ClearVmBits(ClearVmBits),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct ClearVmBits {
     pub new_heap_blkno: Option<u32>,
     pub old_heap_blkno: Option<u32>,
@@ -88,24 +96,29 @@ pub struct ClearVmBits {
     pub flags: u8,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum NeonrmgrRecord {
     ClearVmBits(ClearVmBits),
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum SmgrRecord {
     Create(SmgrCreate),
     Truncate(XlSmgrTruncate),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct SmgrCreate {
     pub rel: RelTag,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum DbaseRecord {
     Create(DbaseCreate),
     Drop(DbaseDrop),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct DbaseCreate {
     pub db_id: Oid,
     pub tablespace_id: Oid,
@@ -113,27 +126,32 @@ pub struct DbaseCreate {
     pub src_tablespace_id: Oid,
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct DbaseDrop {
     pub db_id: Oid,
     pub tablespace_ids: Vec<Oid>,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum ClogRecord {
     ZeroPage(ClogZeroPage),
     Truncate(ClogTruncate),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct ClogZeroPage {
     pub segno: u32,
     pub rpageno: u32,
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct ClogTruncate {
     pub pageno: u32,
     pub oldest_xid: TransactionId,
     pub oldest_xid_db: Oid,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum XactRecord {
     Commit(XactCommon),
     Abort(XactCommon),
@@ -142,6 +160,7 @@ pub enum XactRecord {
     Prepare(XactPrepare),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct XactCommon {
     pub parsed: XlXactParsedRecord,
     pub origin_id: u16,
@@ -150,61 +169,73 @@ pub struct XactCommon {
     pub lsn: Lsn,
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct XactPrepare {
     pub xl_xid: TransactionId,
     pub data: Bytes,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum MultiXactRecord {
     ZeroPage(MultiXactZeroPage),
     Create(XlMultiXactCreate),
     Truncate(XlMultiXactTruncate),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct MultiXactZeroPage {
     pub slru_kind: SlruKind,
     pub segno: u32,
     pub rpageno: u32,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum RelmapRecord {
     Update(RelmapUpdate),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct RelmapUpdate {
     pub update: XlRelmapUpdate,
     pub buf: Bytes,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum XlogRecord {
     Raw(RawXlogRecord),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct RawXlogRecord {
     pub info: u8,
     pub lsn: Lsn,
     pub buf: Bytes,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum LogicalMessageRecord {
     Put(PutLogicalMessage),
     #[cfg(feature = "testing")]
     Failpoint,
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct PutLogicalMessage {
     pub path: String,
     pub buf: Bytes,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum StandbyRecord {
     RunningXacts(StandbyRunningXacts),
 }
 
+#[derive(Serialize, Deserialize)]
 pub struct StandbyRunningXacts {
     pub oldest_running_xid: TransactionId,
 }
 
+#[derive(Serialize, Deserialize)]
 pub enum ReploriginRecord {
     Set(XlReploriginSet),
     Drop(XlReploriginDrop),

libs/wal_decoder/src/serialized_batch.rs

@@ -16,6 +16,7 @@ use pageserver_api::shard::ShardIdentity;
 use pageserver_api::{key::CompactKey, value::Value};
 use postgres_ffi::walrecord::{DecodedBkpBlock, DecodedWALRecord};
 use postgres_ffi::{page_is_new, page_set_lsn, pg_constants, BLCKSZ};
+use serde::{Deserialize, Serialize};
 use utils::bin_ser::BeSer;
 use utils::lsn::Lsn;
 
@@ -29,6 +30,7 @@ static ZERO_PAGE: Bytes = Bytes::from_static(&[0u8; BLCKSZ as usize]);
 /// relation sizes. In the case of "observed" values, we only need to know
 /// the key and LSN, so two types of metadata are supported to save on network
 /// bandwidth.
+#[derive(Serialize, Deserialize)]
 pub enum ValueMeta {
     Serialized(SerializedValueMeta),
     Observed(ObservedValueMeta),
@@ -75,6 +77,7 @@ impl PartialEq for OrderedValueMeta {
 impl Eq for OrderedValueMeta {}
 
 /// Metadata for a [`Value`] serialized into the batch.
+#[derive(Serialize, Deserialize)]
 pub struct SerializedValueMeta {
     pub key: CompactKey,
     pub lsn: Lsn,
@@ -86,12 +89,14 @@ pub struct SerializedValueMeta {
 }
 
 /// Metadata for a [`Value`] observed by the batch
+#[derive(Serialize, Deserialize)]
 pub struct ObservedValueMeta {
     pub key: CompactKey,
     pub lsn: Lsn,
 }
 
 /// Batch of serialized [`Value`]s.
+#[derive(Serialize, Deserialize)]
 pub struct SerializedValueBatch {
     /// [`Value`]s serialized in EphemeralFile's native format,
     /// ready for disk write by the pageserver
@@ -132,7 +137,7 @@ impl SerializedValueBatch {
     pub(crate) fn from_decoded_filtered(
         decoded: DecodedWALRecord,
         shard: &ShardIdentity,
-        record_end_lsn: Lsn,
+        next_record_lsn: Lsn,
         pg_version: u32,
     ) -> anyhow::Result<SerializedValueBatch> {
         // First determine how big the buffer needs to be and allocate it up-front.
@@ -156,13 +161,17 @@ impl SerializedValueBatch {
             let key = rel_block_to_key(rel, blk.blkno);
 
             if !key.is_valid_key_on_write_path() {
-                anyhow::bail!("Unsupported key decoded at LSN {}: {}", record_end_lsn, key);
+                anyhow::bail!(
+                    "Unsupported key decoded at LSN {}: {}",
+                    next_record_lsn,
+                    key
+                );
             }
 
             let key_is_local = shard.is_key_local(&key);
 
             tracing::debug!(
-                lsn=%record_end_lsn,
+                lsn=%next_record_lsn,
                 key=%key,
                 "ingest: shard decision {}",
                 if !key_is_local { "drop" } else { "keep" },
@@ -174,7 +183,7 @@ impl SerializedValueBatch {
                     // its blkno in case it implicitly extends a relation.
                     metadata.push(ValueMeta::Observed(ObservedValueMeta {
                         key: key.to_compact(),
-                        lsn: record_end_lsn,
+                        lsn: next_record_lsn,
                     }))
                 }
 
@@ -205,7 +214,7 @@ impl SerializedValueBatch {
                 // that would corrupt the page.
                 //
                 if !page_is_new(&image) {
-                    page_set_lsn(&mut image, record_end_lsn)
+                    page_set_lsn(&mut image, next_record_lsn)
                 }
                 assert_eq!(image.len(), BLCKSZ as usize);
 
@@ -224,12 +233,12 @@ impl SerializedValueBatch {
 
             metadata.push(ValueMeta::Serialized(SerializedValueMeta {
                 key: key.to_compact(),
-                lsn: record_end_lsn,
+                lsn: next_record_lsn,
                 batch_offset: relative_off,
                 len: val_ser_size,
                 will_init: val.will_init(),
             }));
-            max_lsn = std::cmp::max(max_lsn, record_end_lsn);
+            max_lsn = std::cmp::max(max_lsn, next_record_lsn);
             len += 1;
         }
 

pageserver/benches/bench_ingest.rs

@@ -167,6 +167,7 @@ fn criterion_benchmark(c: &mut Criterion) {
         16384,
         virtual_file::io_engine_for_bench(),
         conf.virtual_file_io_mode,
+        virtual_file::SyncMode::Sync,
     );
     page_cache::init(conf.page_cache_size);
 

pageserver/compaction/src/helpers.rs

@@ -35,6 +35,15 @@ pub fn overlaps_with<T: Ord>(a: &Range<T>, b: &Range<T>) -> bool {
     !(a.end <= b.start || b.end <= a.start)
 }
 
+/// Whether a fully contains b, example as below
+/// ```plain
+/// |      a       |
+///       |  b  |
+/// ```
+pub fn fully_contains<T: Ord>(a: &Range<T>, b: &Range<T>) -> bool {
+    a.start <= b.start && a.end >= b.end
+}
+
 pub fn union_to_keyspace<K: Ord>(a: &mut CompactionKeySpace<K>, b: CompactionKeySpace<K>) {
     let x = std::mem::take(a);
     let mut all_ranges_iter = [x.into_iter(), b.into_iter()]

pageserver/ctl/src/layer_map_analyzer.rs

@@ -138,6 +138,7 @@ pub(crate) async fn main(cmd: &AnalyzeLayerMapCmd) -> Result<()> {
         10,
         virtual_file::api::IoEngineKind::StdFs,
         IoMode::preferred(),
+        virtual_file::SyncMode::Sync,
     );
     pageserver::page_cache::init(100);
 

pageserver/ctl/src/layers.rs

@@ -51,6 +51,7 @@ async fn read_delta_file(path: impl AsRef<Path>, ctx: &RequestContext) -> Result
         10,
         virtual_file::api::IoEngineKind::StdFs,
         IoMode::preferred(),
+        virtual_file::SyncMode::Sync,
     );
     page_cache::init(100);
     let path = Utf8Path::from_path(path.as_ref()).expect("non-Unicode path");
@@ -65,6 +66,7 @@ async fn read_image_file(path: impl AsRef<Path>, ctx: &RequestContext) -> Result
         10,
         virtual_file::api::IoEngineKind::StdFs,
         IoMode::preferred(),
+        virtual_file::SyncMode::Sync,
     );
     page_cache::init(100);
     let path = Utf8Path::from_path(path.as_ref()).expect("non-Unicode path");
@@ -171,6 +173,7 @@ pub(crate) async fn main(cmd: &LayerCmd) -> Result<()> {
                 10,
                 virtual_file::api::IoEngineKind::StdFs,
                 IoMode::preferred(),
+                virtual_file::SyncMode::Sync,
             );
             pageserver::page_cache::init(100);
 

pageserver/ctl/src/main.rs

@@ -209,6 +209,7 @@ async fn print_layerfile(path: &Utf8Path) -> anyhow::Result<()> {
         10,
         virtual_file::api::IoEngineKind::StdFs,
         IoMode::preferred(),
+        virtual_file::SyncMode::Sync,
     );
     page_cache::init(100);
     let ctx = RequestContext::new(TaskKind::DebugTool, DownloadBehavior::Error);

pageserver/src/auth.rs

@@ -19,7 +19,8 @@ pub fn check_permission(claims: &Claims, tenant_id: Option<TenantId>) -> Result<
             | Scope::SafekeeperData
             | Scope::GenerationsApi
             | Scope::Infra
-            | Scope::Scrubber,
+            | Scope::Scrubber
+            | Scope::ControllerPeer,
             _,
         ) => Err(AuthError(
             format!(

pageserver/src/bin/pageserver.rs

@@ -171,11 +171,18 @@ fn main() -> anyhow::Result<()> {
     let scenario = failpoint_support::init();
 
     // Basic initialization of things that don't change after startup
+    tracing::info!("Initializing virtual_file...");
     virtual_file::init(
         conf.max_file_descriptors,
         conf.virtual_file_io_engine,
         conf.virtual_file_io_mode,
+        if conf.no_sync {
+            virtual_file::SyncMode::UnsafeNoSync
+        } else {
+            virtual_file::SyncMode::Sync
+        },
     );
+    tracing::info!("Initializing page_cache...");
     page_cache::init(conf.page_cache_size);
 
     start_pageserver(launch_ts, conf).context("Failed to start pageserver")?;

pageserver/src/http/routes.rs

@@ -324,6 +324,7 @@ impl From<crate::tenant::DeleteTimelineError> for ApiError {
                     .into_boxed_str(),
             ),
             a @ AlreadyInProgress(_) => ApiError::Conflict(a.to_string()),
+            Cancelled => ApiError::ResourceUnavailable("shutting down".into()),
             Other(e) => ApiError::InternalServerError(e),
         }
     }

pageserver/src/tenant.rs

@@ -39,6 +39,7 @@ use remote_timeline_client::UploadQueueNotReadyError;
 use std::collections::BTreeMap;
 use std::fmt;
 use std::future::Future;
+use std::sync::atomic::AtomicBool;
 use std::sync::Weak;
 use std::time::SystemTime;
 use storage_broker::BrokerClientChannel;
@@ -524,6 +525,9 @@ pub struct OffloadedTimeline {
     /// Prevent two tasks from deleting the timeline at the same time. If held, the
     /// timeline is being deleted. If 'true', the timeline has already been deleted.
     pub delete_progress: TimelineDeleteProgress,
+
+    /// Part of the `OffloadedTimeline` object's lifecycle: this needs to be set before we drop it
+    pub deleted_from_ancestor: AtomicBool,
 }
 
 impl OffloadedTimeline {
@@ -533,9 +537,16 @@ impl OffloadedTimeline {
     /// the timeline is not in a stopped state.
     /// Panics if the timeline is not archived.
     fn from_timeline(timeline: &Timeline) -> Result<Self, UploadQueueNotReadyError> {
-        let ancestor_retain_lsn = timeline
-            .get_ancestor_timeline_id()
-            .map(|_timeline_id| timeline.get_ancestor_lsn());
+        let (ancestor_retain_lsn, ancestor_timeline_id) =
+            if let Some(ancestor_timeline) = timeline.ancestor_timeline() {
+                let ancestor_lsn = timeline.get_ancestor_lsn();
+                let ancestor_timeline_id = ancestor_timeline.timeline_id;
+                let mut gc_info = ancestor_timeline.gc_info.write().unwrap();
+                gc_info.insert_child(timeline.timeline_id, ancestor_lsn, MaybeOffloaded::Yes);
+                (Some(ancestor_lsn), Some(ancestor_timeline_id))
+            } else {
+                (None, None)
+            };
         let archived_at = timeline
             .remote_client
             .archived_at_stopped_queue()?
@@ -543,14 +554,17 @@ impl OffloadedTimeline {
         Ok(Self {
             tenant_shard_id: timeline.tenant_shard_id,
             timeline_id: timeline.timeline_id,
-            ancestor_timeline_id: timeline.get_ancestor_timeline_id(),
+            ancestor_timeline_id,
             ancestor_retain_lsn,
             archived_at,
 
             delete_progress: timeline.delete_progress.clone(),
+            deleted_from_ancestor: AtomicBool::new(false),
         })
     }
     fn from_manifest(tenant_shard_id: TenantShardId, manifest: &OffloadedTimelineManifest) -> Self {
+        // We expect to reach this case in tenant loading, where the `retain_lsn` is populated in the parent's `gc_info`
+        // by the `initialize_gc_info` function.
         let OffloadedTimelineManifest {
             timeline_id,
             ancestor_timeline_id,
@@ -564,6 +578,7 @@ impl OffloadedTimeline {
             ancestor_retain_lsn,
             archived_at,
             delete_progress: TimelineDeleteProgress::default(),
+            deleted_from_ancestor: AtomicBool::new(false),
         }
     }
     fn manifest(&self) -> OffloadedTimelineManifest {
@@ -581,6 +596,33 @@ impl OffloadedTimeline {
             archived_at: *archived_at,
         }
     }
+    /// Delete this timeline's retain_lsn from its ancestor, if present in the given tenant
+    fn delete_from_ancestor_with_timelines(
+        &self,
+        timelines: &std::sync::MutexGuard<'_, HashMap<TimelineId, Arc<Timeline>>>,
+    ) {
+        if let (Some(_retain_lsn), Some(ancestor_timeline_id)) =
+            (self.ancestor_retain_lsn, self.ancestor_timeline_id)
+        {
+            if let Some((_, ancestor_timeline)) = timelines
+                .iter()
+                .find(|(tid, _tl)| **tid == ancestor_timeline_id)
+            {
+                ancestor_timeline
+                    .gc_info
+                    .write()
+                    .unwrap()
+                    .remove_child_offloaded(self.timeline_id);
+            }
+        }
+        self.deleted_from_ancestor.store(true, Ordering::Release);
+    }
+    /// Call [`Self::delete_from_ancestor_with_timelines`] instead if possible.
+    ///
+    /// As the entire tenant is being dropped, don't bother deregistering the `retain_lsn` from the ancestor.
+    fn defuse_for_tenant_drop(&self) {
+        self.deleted_from_ancestor.store(true, Ordering::Release);
+    }
 }
 
 impl fmt::Debug for OffloadedTimeline {
@@ -589,6 +631,17 @@ impl fmt::Debug for OffloadedTimeline {
     }
 }
 
+impl Drop for OffloadedTimeline {
+    fn drop(&mut self) {
+        if !self.deleted_from_ancestor.load(Ordering::Acquire) {
+            tracing::warn!(
+                "offloaded timeline {} was dropped without having cleaned it up at the ancestor",
+                self.timeline_id
+            );
+        }
+    }
+}
+
 #[derive(Copy, Clone, PartialEq, Eq, Hash, Debug)]
 pub enum MaybeOffloaded {
     Yes,
@@ -700,6 +753,9 @@ pub enum DeleteTimelineError {
     #[error("Timeline deletion is already in progress")]
     AlreadyInProgress(Arc<tokio::sync::Mutex<DeleteTimelineFlow>>),
 
+    #[error("Cancelled")]
+    Cancelled,
+
     #[error(transparent)]
     Other(#[from] anyhow::Error),
 }
@@ -710,6 +766,7 @@ impl Debug for DeleteTimelineError {
             Self::NotFound => write!(f, "NotFound"),
             Self::HasChildren(c) => f.debug_tuple("HasChildren").field(c).finish(),
             Self::AlreadyInProgress(_) => f.debug_tuple("AlreadyInProgress").finish(),
+            Self::Cancelled => f.debug_tuple("Cancelled").finish(),
             Self::Other(e) => f.debug_tuple("Other").field(e).finish(),
         }
     }
@@ -1433,6 +1490,12 @@ impl Tenant {
                     info!(%timeline_id, "index_part not found on remote");
                     continue;
                 }
+                Err(DownloadError::Fatal(why)) => {
+                    // If, while loading one remote timeline, we saw an indication that our generation
+                    // number is likely invalid, then we should not load the whole tenant.
+                    error!(%timeline_id, "Fatal error loading timeline: {why}");
+                    anyhow::bail!(why.to_string());
+                }
                 Err(e) => {
                     // Some (possibly ephemeral) error happened during index_part download.
                     // Pretend the timeline exists to not delete the timeline directory,
@@ -1521,7 +1584,7 @@ impl Tenant {
         }
         // Complete deletions for offloaded timeline id's.
         offloaded_timelines_list
-            .retain(|(offloaded_id, _offloaded)| {
+            .retain(|(offloaded_id, offloaded)| {
                 // At this point, offloaded_timeline_ids has the list of all offloaded timelines
                 // without a prefix in S3, so they are inexistent.
                 // In the end, existence of a timeline is finally determined by the existence of an index-part.json in remote storage.
@@ -1529,6 +1592,7 @@ impl Tenant {
                 let delete = offloaded_timeline_ids.contains(offloaded_id);
                 if delete {
                     tracing::info!("Removing offloaded timeline {offloaded_id} from manifest as no remote prefix was found");
+                    offloaded.defuse_for_tenant_drop();
                 }
                 !delete
         });
@@ -1917,9 +1981,15 @@ impl Tenant {
                 )));
             };
             let mut offloaded_timelines = self.timelines_offloaded.lock().unwrap();
-            if offloaded_timelines.remove(&timeline_id).is_none() {
-                warn!("timeline already removed from offloaded timelines");
+            match offloaded_timelines.remove(&timeline_id) {
+                Some(offloaded) => {
+                    offloaded.delete_from_ancestor_with_timelines(&timelines);
+                }
+                None => warn!("timeline already removed from offloaded timelines"),
             }
+
+            self.initialize_gc_info(&timelines, &offloaded_timelines, Some(timeline_id));
+
             Arc::clone(timeline)
         };
 
@@ -2657,7 +2727,7 @@ impl Tenant {
                 .filter(|timeline| !(timeline.is_broken() || timeline.is_stopping()));
 
             // Before activation, populate each Timeline's GcInfo with information about its children
-            self.initialize_gc_info(&timelines_accessor, &timelines_offloaded_accessor);
+            self.initialize_gc_info(&timelines_accessor, &timelines_offloaded_accessor, None);
 
             // Spawn gc and compaction loops. The loops will shut themselves
             // down when they notice that the tenant is inactive.
@@ -2772,8 +2842,14 @@ impl Tenant {
                 let timeline_id = timeline.timeline_id;
                 let span = tracing::info_span!("timeline_shutdown", %timeline_id, ?shutdown_mode);
                 js.spawn(async move { timeline.shutdown(shutdown_mode).instrument(span).await });
-            })
-        };
+            });
+        }
+        {
+            let timelines_offloaded = self.timelines_offloaded.lock().unwrap();
+            timelines_offloaded.values().for_each(|timeline| {
+                timeline.defuse_for_tenant_drop();
+            });
+        }
         // test_long_timeline_create_then_tenant_delete is leaning on this message
         tracing::info!("Waiting for timelines...");
         while let Some(res) = js.join_next().await {
@@ -3757,10 +3833,13 @@ impl Tenant {
         &self,
         timelines: &std::sync::MutexGuard<HashMap<TimelineId, Arc<Timeline>>>,
         timelines_offloaded: &std::sync::MutexGuard<HashMap<TimelineId, Arc<OffloadedTimeline>>>,
+        restrict_to_timeline: Option<TimelineId>,
     ) {
-        // This function must be called before activation: after activation timeline create/delete operations
-        // might happen, and this function is not safe to run concurrently with those.
-        assert!(!self.is_active());
+        if restrict_to_timeline.is_none() {
+            // This function must be called before activation: after activation timeline create/delete operations
+            // might happen, and this function is not safe to run concurrently with those.
+            assert!(!self.is_active());
+        }
 
         // Scan all timelines. For each timeline, remember the timeline ID and
         // the branch point where it was created.
@@ -3793,7 +3872,12 @@ impl Tenant {
         let horizon = self.get_gc_horizon();
 
         // Populate each timeline's GcInfo with information about its child branches
-        for timeline in timelines.values() {
+        let timelines_to_write = if let Some(timeline_id) = restrict_to_timeline {
+            itertools::Either::Left(timelines.get(&timeline_id).into_iter())
+        } else {
+            itertools::Either::Right(timelines.values())
+        };
+        for timeline in timelines_to_write {
             let mut branchpoints: Vec<(Lsn, TimelineId, MaybeOffloaded)> = all_branchpoints
                 .remove(&timeline.timeline_id)
                 .unwrap_or_default();
@@ -4786,12 +4870,6 @@ async fn run_initdb(
         .args(["--username", &conf.superuser])
         .args(["--encoding", "utf8"])
         .args(["--locale", &conf.locale])
-        .args(["--lc-collate", &conf.locale])
-        .args(["--lc-ctype", &conf.locale])
-        .args(["--lc-messages", &conf.locale])
-        .args(["--lc-monetary", &conf.locale])
-        .args(["--lc-numeric", &conf.locale])
-        .args(["--lc-time", &conf.locale])
         .arg("--no-instructions")
         .arg("--no-sync")
         .env_clear()
@@ -7763,13 +7841,13 @@ mod tests {
             (
                 get_key(3),
                 Lsn(0x20),
-                Value::WalRecord(NeonWalRecord::wal_clear()),
+                Value::WalRecord(NeonWalRecord::wal_clear("c")),
             ),
             (get_key(4), Lsn(0x10), Value::Image("0x10".into())),
             (
                 get_key(4),
                 Lsn(0x20),
-                Value::WalRecord(NeonWalRecord::wal_init()),
+                Value::WalRecord(NeonWalRecord::wal_init("i")),
             ),
         ];
         let image1 = vec![(get_key(1), "0x10".into())];
@@ -7918,8 +7996,30 @@ mod tests {
 
     #[cfg(feature = "testing")]
     #[tokio::test]
-    async fn test_simple_bottom_most_compaction_deltas() -> anyhow::Result<()> {
-        let harness = TenantHarness::create("test_simple_bottom_most_compaction_deltas").await?;
+    async fn test_simple_bottom_most_compaction_deltas_1() -> anyhow::Result<()> {
+        test_simple_bottom_most_compaction_deltas_helper(
+            "test_simple_bottom_most_compaction_deltas_1",
+            false,
+        )
+        .await
+    }
+
+    #[cfg(feature = "testing")]
+    #[tokio::test]
+    async fn test_simple_bottom_most_compaction_deltas_2() -> anyhow::Result<()> {
+        test_simple_bottom_most_compaction_deltas_helper(
+            "test_simple_bottom_most_compaction_deltas_2",
+            true,
+        )
+        .await
+    }
+
+    #[cfg(feature = "testing")]
+    async fn test_simple_bottom_most_compaction_deltas_helper(
+        test_name: &'static str,
+        use_delta_bottom_layer: bool,
+    ) -> anyhow::Result<()> {
+        let harness = TenantHarness::create(test_name).await?;
         let (tenant, ctx) = harness.load().await;
 
         fn get_key(id: u32) -> Key {
@@ -7950,6 +8050,16 @@ mod tests {
         let img_layer = (0..10)
             .map(|id| (get_key(id), Bytes::from(format!("value {id}@0x10"))))
             .collect_vec();
+        // or, delta layer at 0x10 if `use_delta_bottom_layer` is true
+        let delta4 = (0..10)
+            .map(|id| {
+                (
+                    get_key(id),
+                    Lsn(0x08),
+                    Value::WalRecord(NeonWalRecord::wal_init(format!("value {id}@0x10"))),
+                )
+            })
+            .collect_vec();
 
         let delta1 = vec![
             (
@@ -8003,21 +8113,61 @@ mod tests {
             ),
         ];
 
-        let tline = tenant
-            .create_test_timeline_with_layers(
-                TIMELINE_ID,
-                Lsn(0x10),
-                DEFAULT_PG_VERSION,
-                &ctx,
-                vec![
-                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x10)..Lsn(0x48), delta1),
-                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x10)..Lsn(0x48), delta2),
-                    DeltaLayerTestDesc::new_with_inferred_key_range(Lsn(0x48)..Lsn(0x50), delta3),
-                ], // delta layers
-                vec![(Lsn(0x10), img_layer)], // image layers
-                Lsn(0x50),
-            )
-            .await?;
+        let tline = if use_delta_bottom_layer {
+            tenant
+                .create_test_timeline_with_layers(
+                    TIMELINE_ID,
+                    Lsn(0x08),
+                    DEFAULT_PG_VERSION,
+                    &ctx,
+                    vec![
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x08)..Lsn(0x10),
+                            delta4,
+                        ),
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x20)..Lsn(0x48),
+                            delta1,
+                        ),
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x20)..Lsn(0x48),
+                            delta2,
+                        ),
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x48)..Lsn(0x50),
+                            delta3,
+                        ),
+                    ], // delta layers
+                    vec![], // image layers
+                    Lsn(0x50),
+                )
+                .await?
+        } else {
+            tenant
+                .create_test_timeline_with_layers(
+                    TIMELINE_ID,
+                    Lsn(0x10),
+                    DEFAULT_PG_VERSION,
+                    &ctx,
+                    vec![
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x10)..Lsn(0x48),
+                            delta1,
+                        ),
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x10)..Lsn(0x48),
+                            delta2,
+                        ),
+                        DeltaLayerTestDesc::new_with_inferred_key_range(
+                            Lsn(0x48)..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();
@@ -8127,7 +8277,7 @@ mod tests {
             (
                 key,
                 Lsn(0x10),
-                Value::Image(Bytes::copy_from_slice(b"0x10")),
+                Value::WalRecord(NeonWalRecord::wal_init("0x10")),
             ),
             (
                 key,
@@ -8189,7 +8339,7 @@ mod tests {
                     Lsn(0x20),
                     KeyLogAtLsn(vec![(
                         Lsn(0x20),
-                        Value::Image(Bytes::copy_from_slice(b"0x10;0x20")),
+                        Value::Image(Bytes::from_static(b"0x10;0x20")),
                     )]),
                 ),
                 (
@@ -9171,7 +9321,7 @@ mod tests {
 
             let will_init = will_init_keys.contains(&i);
             if will_init {
-                delta_layer_spec.push((key, lsn, Value::WalRecord(NeonWalRecord::wal_init())));
+                delta_layer_spec.push((key, lsn, Value::WalRecord(NeonWalRecord::wal_init(""))));
 
                 expected_key_values.insert(key, "".to_string());
             } else {
@@ -9229,6 +9379,23 @@ mod tests {
         Ok(())
     }
 
+    fn sort_layer_key(k1: &PersistentLayerKey, k2: &PersistentLayerKey) -> std::cmp::Ordering {
+        (
+            k1.is_delta,
+            k1.key_range.start,
+            k1.key_range.end,
+            k1.lsn_range.start,
+            k1.lsn_range.end,
+        )
+            .cmp(&(
+                k2.is_delta,
+                k2.key_range.start,
+                k2.key_range.end,
+                k2.lsn_range.start,
+                k2.lsn_range.end,
+            ))
+    }
+
     async fn inspect_and_sort(
         tline: &Arc<Timeline>,
         filter: Option<std::ops::Range<Key>>,
@@ -9237,25 +9404,30 @@ mod tests {
         if let Some(filter) = filter {
             all_layers.retain(|layer| overlaps_with(&layer.key_range, &filter));
         }
-        all_layers.sort_by(|k1, k2| {
-            (
-                k1.is_delta,
-                k1.key_range.start,
-                k1.key_range.end,
-                k1.lsn_range.start,
-                k1.lsn_range.end,
-            )
-                .cmp(&(
-                    k2.is_delta,
-                    k2.key_range.start,
-                    k2.key_range.end,
-                    k2.lsn_range.start,
-                    k2.lsn_range.end,
-                ))
-        });
+        all_layers.sort_by(sort_layer_key);
         all_layers
     }
 
+    #[cfg(feature = "testing")]
+    fn check_layer_map_key_eq(
+        mut left: Vec<PersistentLayerKey>,
+        mut right: Vec<PersistentLayerKey>,
+    ) {
+        left.sort_by(sort_layer_key);
+        right.sort_by(sort_layer_key);
+        if left != right {
+            eprintln!("---LEFT---");
+            for left in left.iter() {
+                eprintln!("{}", left);
+            }
+            eprintln!("---RIGHT---");
+            for right in right.iter() {
+                eprintln!("{}", right);
+            }
+            assert_eq!(left, right);
+        }
+    }
+
     #[cfg(feature = "testing")]
     #[tokio::test]
     async fn test_simple_partial_bottom_most_compaction() -> anyhow::Result<()> {
@@ -9348,129 +9520,258 @@ mod tests {
 
         let cancel = CancellationToken::new();
 
-        // Do a partial compaction on key range 0..4, we should generate a image layer; no other layers
-        // can be removed because they might be used for other key ranges.
+        // Do a partial compaction on key range 0..2
         tline
-            .partial_compact_with_gc(Some(get_key(0)..get_key(4)), &cancel, EnumSet::new(), &ctx)
+            .partial_compact_with_gc(get_key(0)..get_key(2), &cancel, EnumSet::new(), &ctx)
             .await
             .unwrap();
         let all_layers = inspect_and_sort(&tline, Some(get_key(0)..get_key(10))).await;
-        assert_eq!(
+        check_layer_map_key_eq(
             all_layers,
             vec![
+                // newly-generated image layer for the partial compaction range 0-2
                 PersistentLayerKey {
-                    key_range: get_key(0)..get_key(4),
+                    key_range: get_key(0)..get_key(2),
                     lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
+                    is_delta: false,
                 },
                 PersistentLayerKey {
                     key_range: get_key(0)..get_key(10),
                     lsn_range: Lsn(0x10)..Lsn(0x11),
-                    is_delta: false
+                    is_delta: false,
                 },
+                // delta1 is split and the second part is rewritten
                 PersistentLayerKey {
-                    key_range: get_key(1)..get_key(4),
+                    key_range: get_key(2)..get_key(4),
                     lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
+                    is_delta: true,
                 },
                 PersistentLayerKey {
                     key_range: get_key(5)..get_key(7),
                     lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
+                    is_delta: true,
                 },
                 PersistentLayerKey {
                     key_range: get_key(8)..get_key(10),
                     lsn_range: Lsn(0x48)..Lsn(0x50),
-                    is_delta: true
-                }
-            ]
+                    is_delta: true,
+                },
+            ],
         );
 
-        // Do a partial compaction on key range 4..10
+        // Do a partial compaction on key range 2..4
         tline
-            .partial_compact_with_gc(Some(get_key(4)..get_key(10)), &cancel, EnumSet::new(), &ctx)
+            .partial_compact_with_gc(get_key(2)..get_key(4), &cancel, EnumSet::new(), &ctx)
             .await
             .unwrap();
         let all_layers = inspect_and_sort(&tline, Some(get_key(0)..get_key(10))).await;
-        assert_eq!(
+        check_layer_map_key_eq(
             all_layers,
             vec![
                 PersistentLayerKey {
-                    key_range: get_key(0)..get_key(4),
+                    key_range: get_key(0)..get_key(2),
                     lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
+                    is_delta: false,
                 },
                 PersistentLayerKey {
-                    // if (in the future) GC kicks in, this layer will be removed
                     key_range: get_key(0)..get_key(10),
                     lsn_range: Lsn(0x10)..Lsn(0x11),
-                    is_delta: false
+                    is_delta: false,
                 },
+                // image layer generated for the compaction range 2-4
                 PersistentLayerKey {
-                    key_range: get_key(4)..get_key(10),
+                    key_range: get_key(2)..get_key(4),
                     lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
+                    is_delta: false,
                 },
+                // we have key2/key3 above the retain_lsn, so we still need this delta layer
                 PersistentLayerKey {
-                    key_range: get_key(1)..get_key(4),
+                    key_range: get_key(2)..get_key(4),
                     lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
+                    is_delta: true,
                 },
                 PersistentLayerKey {
                     key_range: get_key(5)..get_key(7),
                     lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
+                    is_delta: true,
                 },
                 PersistentLayerKey {
                     key_range: get_key(8)..get_key(10),
                     lsn_range: Lsn(0x48)..Lsn(0x50),
-                    is_delta: true
-                }
-            ]
+                    is_delta: true,
+                },
+            ],
+        );
+
+        // Do a partial compaction on key range 4..9
+        tline
+            .partial_compact_with_gc(get_key(4)..get_key(9), &cancel, EnumSet::new(), &ctx)
+            .await
+            .unwrap();
+        let all_layers = inspect_and_sort(&tline, Some(get_key(0)..get_key(10))).await;
+        check_layer_map_key_eq(
+            all_layers,
+            vec![
+                PersistentLayerKey {
+                    key_range: get_key(0)..get_key(2),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(0)..get_key(10),
+                    lsn_range: Lsn(0x10)..Lsn(0x11),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(2)..get_key(4),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(2)..get_key(4),
+                    lsn_range: Lsn(0x20)..Lsn(0x48),
+                    is_delta: true,
+                },
+                // image layer generated for this compaction range
+                PersistentLayerKey {
+                    key_range: get_key(4)..get_key(9),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(8)..get_key(10),
+                    lsn_range: Lsn(0x48)..Lsn(0x50),
+                    is_delta: true,
+                },
+            ],
+        );
+
+        // Do a partial compaction on key range 9..10
+        tline
+            .partial_compact_with_gc(get_key(9)..get_key(10), &cancel, EnumSet::new(), &ctx)
+            .await
+            .unwrap();
+        let all_layers = inspect_and_sort(&tline, Some(get_key(0)..get_key(10))).await;
+        check_layer_map_key_eq(
+            all_layers,
+            vec![
+                PersistentLayerKey {
+                    key_range: get_key(0)..get_key(2),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(0)..get_key(10),
+                    lsn_range: Lsn(0x10)..Lsn(0x11),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(2)..get_key(4),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(2)..get_key(4),
+                    lsn_range: Lsn(0x20)..Lsn(0x48),
+                    is_delta: true,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(4)..get_key(9),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                // image layer generated for the compaction range
+                PersistentLayerKey {
+                    key_range: get_key(9)..get_key(10),
+                    lsn_range: Lsn(0x20)..Lsn(0x21),
+                    is_delta: false,
+                },
+                PersistentLayerKey {
+                    key_range: get_key(8)..get_key(10),
+                    lsn_range: Lsn(0x48)..Lsn(0x50),
+                    is_delta: true,
+                },
+            ],
         );
 
         // Do a partial compaction on key range 0..10, all image layers below LSN 20 can be replaced with new ones.
         tline
-            .partial_compact_with_gc(Some(get_key(0)..get_key(10)), &cancel, EnumSet::new(), &ctx)
+            .partial_compact_with_gc(get_key(0)..get_key(10), &cancel, EnumSet::new(), &ctx)
             .await
             .unwrap();
         let all_layers = inspect_and_sort(&tline, Some(get_key(0)..get_key(10))).await;
-        assert_eq!(
+        check_layer_map_key_eq(
             all_layers,
             vec![
-                PersistentLayerKey {
-                    key_range: get_key(0)..get_key(4),
-                    lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
-                },
+                // aha, we removed all unnecessary image/delta layers and got a very clean layer map!
                 PersistentLayerKey {
                     key_range: get_key(0)..get_key(10),
                     lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
+                    is_delta: false,
                 },
                 PersistentLayerKey {
-                    key_range: get_key(4)..get_key(10),
-                    lsn_range: Lsn(0x20)..Lsn(0x21),
-                    is_delta: false
-                },
-                PersistentLayerKey {
-                    key_range: get_key(1)..get_key(4),
+                    key_range: get_key(2)..get_key(4),
                     lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
-                },
-                PersistentLayerKey {
-                    key_range: get_key(5)..get_key(7),
-                    lsn_range: Lsn(0x20)..Lsn(0x48),
-                    is_delta: true
+                    is_delta: true,
                 },
                 PersistentLayerKey {
                     key_range: get_key(8)..get_key(10),
                     lsn_range: Lsn(0x48)..Lsn(0x50),
-                    is_delta: true
-                }
-            ]
+                    is_delta: true,
+                },
+            ],
         );
 
         Ok(())
     }
+
+    #[cfg(feature = "testing")]
+    #[tokio::test]
+    async fn test_timeline_offload_retain_lsn() -> anyhow::Result<()> {
+        let harness = TenantHarness::create("test_timeline_offload_retain_lsn")
+            .await
+            .unwrap();
+        let (tenant, ctx) = harness.load().await;
+        let tline_parent = tenant
+            .create_test_timeline(TIMELINE_ID, Lsn(0x10), DEFAULT_PG_VERSION, &ctx)
+            .await
+            .unwrap();
+        let tline_child = tenant
+            .branch_timeline_test(&tline_parent, NEW_TIMELINE_ID, Some(Lsn(0x20)), &ctx)
+            .await
+            .unwrap();
+        {
+            let gc_info_parent = tline_parent.gc_info.read().unwrap();
+            assert_eq!(
+                gc_info_parent.retain_lsns,
+                vec![(Lsn(0x20), tline_child.timeline_id, MaybeOffloaded::No)]
+            );
+        }
+        // We have to directly call the remote_client instead of using the archive function to avoid constructing broker client...
+        tline_child
+            .remote_client
+            .schedule_index_upload_for_timeline_archival_state(TimelineArchivalState::Archived)
+            .unwrap();
+        tline_child.remote_client.wait_completion().await.unwrap();
+        offload_timeline(&tenant, &tline_child)
+            .instrument(tracing::info_span!(parent: None, "offload_test", tenant_id=%"test", shard_id=%"test", timeline_id=%"test"))
+            .await.unwrap();
+        let child_timeline_id = tline_child.timeline_id;
+        Arc::try_unwrap(tline_child).unwrap();
+
+        {
+            let gc_info_parent = tline_parent.gc_info.read().unwrap();
+            assert_eq!(
+                gc_info_parent.retain_lsns,
+                vec![(Lsn(0x20), child_timeline_id, MaybeOffloaded::Yes)]
+            );
+        }
+
+        tenant
+            .get_offloaded_timeline(child_timeline_id)
+            .unwrap()
+            .defuse_for_tenant_drop();
+
+        Ok(())
+    }
 }

pageserver/src/tenant/remote_timeline_client.rs

@@ -197,6 +197,7 @@ use utils::backoff::{
     self, exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS,
 };
 use utils::pausable_failpoint;
+use utils::shard::ShardNumber;
 
 use std::collections::{HashMap, VecDeque};
 use std::sync::atomic::{AtomicU32, Ordering};
@@ -243,7 +244,7 @@ use self::index::IndexPart;
 use super::metadata::MetadataUpdate;
 use super::storage_layer::{Layer, LayerName, ResidentLayer};
 use super::upload_queue::{NotInitialized, SetDeletedFlagProgress};
-use super::Generation;
+use super::{DeleteTimelineError, Generation};
 
 pub(crate) use download::{
     download_index_part, download_tenant_manifest, is_temp_download_file,
@@ -574,12 +575,18 @@ impl RemoteTimelineClient {
 
             if latest_index_generation > index_generation {
                 // Unexpected!  Why are we loading such an old index if a more recent one exists?
-                tracing::warn!(
+                // We will refuse to proceed, as there is no reasonable scenario where this should happen, but
+                // there _is_ a clear bug/corruption scenario where it would happen (controller sets the generation
+                // backwards).
+                tracing::error!(
                     ?index_generation,
                     ?latest_index_generation,
                     ?latest_index_mtime,
                     "Found a newer index while loading an old one"
                 );
+                return Err(DownloadError::Fatal(
+                    "Index age exceeds threshold and a newer index exists".into(),
+                ));
             }
         }
 
@@ -1544,15 +1551,17 @@ impl RemoteTimelineClient {
     /// Prerequisites: UploadQueue should be in stopped state and deleted_at should be successfuly set.
     /// The function deletes layer files one by one, then lists the prefix to see if we leaked something
     /// deletes leaked files if any and proceeds with deletion of index file at the end.
-    pub(crate) async fn delete_all(self: &Arc<Self>) -> anyhow::Result<()> {
+    pub(crate) async fn delete_all(self: &Arc<Self>) -> Result<(), DeleteTimelineError> {
         debug_assert_current_span_has_tenant_and_timeline_id();
 
         let layers: Vec<RemotePath> = {
             let mut locked = self.upload_queue.lock().unwrap();
-            let stopped = locked.stopped_mut()?;
+            let stopped = locked.stopped_mut().map_err(DeleteTimelineError::Other)?;
 
             if !matches!(stopped.deleted_at, SetDeletedFlagProgress::Successful(_)) {
-                anyhow::bail!("deleted_at is not set")
+                return Err(DeleteTimelineError::Other(anyhow::anyhow!(
+                    "deleted_at is not set"
+                )));
             }
 
             debug_assert!(stopped.upload_queue_for_deletion.no_pending_work());
@@ -1587,7 +1596,10 @@ impl RemoteTimelineClient {
         };
 
         let layer_deletion_count = layers.len();
-        self.deletion_queue_client.push_immediate(layers).await?;
+        self.deletion_queue_client
+            .push_immediate(layers)
+            .await
+            .map_err(|_| DeleteTimelineError::Cancelled)?;
 
         // Delete the initdb.tar.zst, which is not always present, but deletion attempts of
         // inexistant objects are not considered errors.
@@ -1595,7 +1607,8 @@ impl RemoteTimelineClient {
             remote_initdb_archive_path(&self.tenant_shard_id.tenant_id, &self.timeline_id);
         self.deletion_queue_client
             .push_immediate(vec![initdb_path])
-            .await?;
+            .await
+            .map_err(|_| DeleteTimelineError::Cancelled)?;
 
         // Do not delete index part yet, it is needed for possible retry. If we remove it first
         // and retry will arrive to different pageserver there wont be any traces of it on remote storage
@@ -1603,7 +1616,9 @@ impl RemoteTimelineClient {
 
         // Execute all pending deletions, so that when we proceed to do a listing below, we aren't
         // taking the burden of listing all the layers that we already know we should delete.
-        self.flush_deletion_queue().await?;
+        self.flush_deletion_queue()
+            .await
+            .map_err(|_| DeleteTimelineError::Cancelled)?;
 
         let cancel = shutdown_token();
 
@@ -1666,28 +1681,32 @@ impl RemoteTimelineClient {
         if !remaining_layers.is_empty() {
             self.deletion_queue_client
                 .push_immediate(remaining_layers)
-                .await?;
+                .await
+                .map_err(|_| DeleteTimelineError::Cancelled)?;
         }
 
         fail::fail_point!("timeline-delete-before-index-delete", |_| {
-            Err(anyhow::anyhow!(
+            Err(DeleteTimelineError::Other(anyhow::anyhow!(
                 "failpoint: timeline-delete-before-index-delete"
-            ))?
+            )))?
         });
 
         debug!("enqueuing index part deletion");
         self.deletion_queue_client
             .push_immediate([latest_index].to_vec())
-            .await?;
+            .await
+            .map_err(|_| DeleteTimelineError::Cancelled)?;
 
         // Timeline deletion is rare and we have probably emitted a reasonably number of objects: wait
         // for a flush to a persistent deletion list so that we may be sure deletion will occur.
-        self.flush_deletion_queue().await?;
+        self.flush_deletion_queue()
+            .await
+            .map_err(|_| DeleteTimelineError::Cancelled)?;
 
         fail::fail_point!("timeline-delete-after-index-delete", |_| {
-            Err(anyhow::anyhow!(
+            Err(DeleteTimelineError::Other(anyhow::anyhow!(
                 "failpoint: timeline-delete-after-index-delete"
-            ))?
+            )))?
         });
 
         info!(prefix=%timeline_storage_path, referenced=layer_deletion_count, not_referenced=%not_referenced_count, "done deleting in timeline prefix, including index_part.json");
@@ -2213,6 +2232,28 @@ impl RemoteTimelineClient {
             UploadQueue::Initialized(x) => x.no_pending_work(),
         }
     }
+
+    /// 'foreign' in the sense that it does not belong to this tenant shard.  This method
+    /// is used during GC for other shards to get the index of shard zero.
+    pub(crate) async fn download_foreign_index(
+        &self,
+        shard_number: ShardNumber,
+        cancel: &CancellationToken,
+    ) -> Result<(IndexPart, Generation, std::time::SystemTime), DownloadError> {
+        let foreign_shard_id = TenantShardId {
+            shard_number,
+            shard_count: self.tenant_shard_id.shard_count,
+            tenant_id: self.tenant_shard_id.tenant_id,
+        };
+        download_index_part(
+            &self.storage_impl,
+            &foreign_shard_id,
+            &self.timeline_id,
+            Generation::MAX,
+            cancel,
+        )
+        .await
+    }
 }
 
 pub(crate) struct UploadQueueAccessor<'a> {

pageserver/src/tenant/storage_layer/delta_layer.rs

@@ -653,6 +653,10 @@ impl DeltaLayerWriter {
         })
     }
 
+    pub fn is_empty(&self) -> bool {
+        self.inner.as_ref().unwrap().num_keys == 0
+    }
+
     ///
     /// Append a key-value pair to the file.
     ///

pageserver/src/tenant/storage_layer/filter_iterator.rs

@@ -1,4 +1,4 @@
-use std::ops::Range;
+use std::{ops::Range, sync::Arc};
 
 use anyhow::bail;
 use pageserver_api::{
@@ -9,7 +9,10 @@ use utils::lsn::Lsn;
 
 use pageserver_api::value::Value;
 
-use super::merge_iterator::MergeIterator;
+use super::{
+    merge_iterator::{MergeIterator, MergeIteratorItem},
+    PersistentLayerKey,
+};
 
 /// A filter iterator over merge iterators (and can be easily extended to other types of iterators).
 ///
@@ -48,10 +51,10 @@ impl<'a> FilterIterator<'a> {
         })
     }
 
-    pub async fn next(&mut self) -> anyhow::Result<Option<(Key, Lsn, Value)>> {
-        while let Some(item) = self.inner.next().await? {
+    async fn next_inner<R: MergeIteratorItem>(&mut self) -> anyhow::Result<Option<R>> {
+        while let Some(item) = self.inner.next_inner::<R>().await? {
             while self.current_filter_idx < self.retain_key_filters.len()
-                && item.0 >= self.retain_key_filters[self.current_filter_idx].end
+                && item.key_lsn_value().0 >= self.retain_key_filters[self.current_filter_idx].end
             {
                 // [filter region]    [filter region]     [filter region]
                 //                                     ^ item
@@ -68,7 +71,7 @@ impl<'a> FilterIterator<'a> {
                 //                                                 ^ current filter (nothing)
                 return Ok(None);
             }
-            if self.retain_key_filters[self.current_filter_idx].contains(&item.0) {
+            if self.retain_key_filters[self.current_filter_idx].contains(&item.key_lsn_value().0) {
                 // [filter region]    [filter region]     [filter region]
                 //                                              ^ item
                 //                                        ^ current filter
@@ -81,6 +84,16 @@ impl<'a> FilterIterator<'a> {
         }
         Ok(None)
     }
+
+    pub async fn next(&mut self) -> anyhow::Result<Option<(Key, Lsn, Value)>> {
+        self.next_inner().await
+    }
+
+    pub async fn next_with_trace(
+        &mut self,
+    ) -> anyhow::Result<Option<((Key, Lsn, Value), Arc<PersistentLayerKey>)>> {
+        self.next_inner().await
+    }
 }
 
 #[cfg(test)]

pageserver/src/tenant/storage_layer/merge_iterator.rs

@@ -1,6 +1,7 @@
 use std::{
     cmp::Ordering,
     collections::{binary_heap, BinaryHeap},
+    sync::Arc,
 };
 
 use anyhow::bail;
@@ -13,10 +14,11 @@ use pageserver_api::value::Value;
 use super::{
     delta_layer::{DeltaLayerInner, DeltaLayerIterator},
     image_layer::{ImageLayerInner, ImageLayerIterator},
+    PersistentLayerDesc, PersistentLayerKey,
 };
 
 #[derive(Clone, Copy)]
-enum LayerRef<'a> {
+pub(crate) enum LayerRef<'a> {
     Image(&'a ImageLayerInner),
     Delta(&'a DeltaLayerInner),
 }
@@ -62,18 +64,20 @@ impl LayerIterRef<'_> {
 /// 1. Unified iterator for image and delta layers.
 /// 2. `Ord` for use in [`MergeIterator::heap`] (for the k-merge).
 /// 3. Lazy creation of the real delta/image iterator.
-enum IteratorWrapper<'a> {
+pub(crate) enum IteratorWrapper<'a> {
     NotLoaded {
         ctx: &'a RequestContext,
         first_key_lower_bound: (Key, Lsn),
         layer: LayerRef<'a>,
+        source_desc: Arc<PersistentLayerKey>,
     },
     Loaded {
         iter: PeekableLayerIterRef<'a>,
+        source_desc: Arc<PersistentLayerKey>,
     },
 }
 
-struct PeekableLayerIterRef<'a> {
+pub(crate) struct PeekableLayerIterRef<'a> {
     iter: LayerIterRef<'a>,
     peeked: Option<(Key, Lsn, Value)>, // None == end
 }
@@ -151,6 +155,12 @@ impl<'a> IteratorWrapper<'a> {
             layer: LayerRef::Image(image_layer),
             first_key_lower_bound: (image_layer.key_range().start, image_layer.lsn()),
             ctx,
+            source_desc: PersistentLayerKey {
+                key_range: image_layer.key_range().clone(),
+                lsn_range: PersistentLayerDesc::image_layer_lsn_range(image_layer.lsn()),
+                is_delta: false,
+            }
+            .into(),
         }
     }
 
@@ -162,12 +172,18 @@ impl<'a> IteratorWrapper<'a> {
             layer: LayerRef::Delta(delta_layer),
             first_key_lower_bound: (delta_layer.key_range().start, delta_layer.lsn_range().start),
             ctx,
+            source_desc: PersistentLayerKey {
+                key_range: delta_layer.key_range().clone(),
+                lsn_range: delta_layer.lsn_range().clone(),
+                is_delta: true,
+            }
+            .into(),
         }
     }
 
     fn peek_next_key_lsn_value(&self) -> Option<(&Key, Lsn, Option<&Value>)> {
         match self {
-            Self::Loaded { iter } => iter
+            Self::Loaded { iter, .. } => iter
                 .peek()
                 .as_ref()
                 .map(|(key, lsn, val)| (key, *lsn, Some(val))),
@@ -191,6 +207,7 @@ impl<'a> IteratorWrapper<'a> {
             ctx,
             first_key_lower_bound,
             layer,
+            source_desc,
         } = self
         else {
             unreachable!()
@@ -206,7 +223,10 @@ impl<'a> IteratorWrapper<'a> {
                 );
             }
         }
-        *self = Self::Loaded { iter };
+        *self = Self::Loaded {
+            iter,
+            source_desc: source_desc.clone(),
+        };
         Ok(())
     }
 
@@ -220,11 +240,19 @@ impl<'a> IteratorWrapper<'a> {
     /// The public interfaces to use are [`crate::tenant::storage_layer::delta_layer::DeltaLayerIterator`] and
     /// [`crate::tenant::storage_layer::image_layer::ImageLayerIterator`].
     async fn next(&mut self) -> anyhow::Result<Option<(Key, Lsn, Value)>> {
-        let Self::Loaded { iter } = self else {
+        let Self::Loaded { iter, .. } = self else {
             panic!("must load the iterator before using")
         };
         iter.next().await
     }
+
+    /// Get the persistent layer key corresponding to this iterator
+    fn trace_source(&self) -> Arc<PersistentLayerKey> {
+        match self {
+            Self::Loaded { source_desc, .. } => source_desc.clone(),
+            Self::NotLoaded { source_desc, .. } => source_desc.clone(),
+        }
+    }
 }
 
 /// A merge iterator over delta/image layer iterators.
@@ -242,6 +270,32 @@ pub struct MergeIterator<'a> {
     heap: BinaryHeap<IteratorWrapper<'a>>,
 }
 
+pub(crate) trait MergeIteratorItem {
+    fn new(item: (Key, Lsn, Value), iterator: &IteratorWrapper<'_>) -> Self;
+
+    fn key_lsn_value(&self) -> &(Key, Lsn, Value);
+}
+
+impl MergeIteratorItem for (Key, Lsn, Value) {
+    fn new(item: (Key, Lsn, Value), _: &IteratorWrapper<'_>) -> Self {
+        item
+    }
+
+    fn key_lsn_value(&self) -> &(Key, Lsn, Value) {
+        self
+    }
+}
+
+impl MergeIteratorItem for ((Key, Lsn, Value), Arc<PersistentLayerKey>) {
+    fn new(item: (Key, Lsn, Value), iter: &IteratorWrapper<'_>) -> Self {
+        (item, iter.trace_source().clone())
+    }
+
+    fn key_lsn_value(&self) -> &(Key, Lsn, Value) {
+        &self.0
+    }
+}
+
 impl<'a> MergeIterator<'a> {
     pub fn create(
         deltas: &[&'a DeltaLayerInner],
@@ -260,7 +314,7 @@ impl<'a> MergeIterator<'a> {
         }
     }
 
-    pub async fn next(&mut self) -> anyhow::Result<Option<(Key, Lsn, Value)>> {
+    pub(crate) async fn next_inner<R: MergeIteratorItem>(&mut self) -> anyhow::Result<Option<R>> {
         while let Some(mut iter) = self.heap.peek_mut() {
             if !iter.is_loaded() {
                 // Once we load the iterator, we can know the real first key-value pair in the iterator.
@@ -275,10 +329,22 @@ impl<'a> MergeIterator<'a> {
                 binary_heap::PeekMut::pop(iter);
                 continue;
             };
-            return Ok(Some(item));
+            return Ok(Some(R::new(item, &iter)));
         }
         Ok(None)
     }
+
+    /// Get the next key-value pair from the iterator.
+    pub async fn next(&mut self) -> anyhow::Result<Option<(Key, Lsn, Value)>> {
+        self.next_inner().await
+    }
+
+    /// Get the next key-value pair from the iterator, and trace where the key comes from.
+    pub async fn next_with_trace(
+        &mut self,
+    ) -> anyhow::Result<Option<((Key, Lsn, Value), Arc<PersistentLayerKey>)>> {
+        self.next_inner().await
+    }
 }
 
 #[cfg(test)]
@@ -496,7 +562,7 @@ mod tests {
             (
                 get_key(0),
                 Lsn(0x10),
-                Value::WalRecord(NeonWalRecord::wal_init()),
+                Value::WalRecord(NeonWalRecord::wal_init("")),
             ),
             (
                 get_key(0),
@@ -506,7 +572,7 @@ mod tests {
             (
                 get_key(5),
                 Lsn(0x10),
-                Value::WalRecord(NeonWalRecord::wal_init()),
+                Value::WalRecord(NeonWalRecord::wal_init("")),
             ),
             (
                 get_key(5),

pageserver/src/tenant/timeline.rs

@@ -38,6 +38,7 @@ use pageserver_api::{
     shard::{ShardIdentity, ShardNumber, TenantShardId},
 };
 use rand::Rng;
+use remote_storage::DownloadError;
 use serde_with::serde_as;
 use storage_broker::BrokerClientChannel;
 use tokio::{
@@ -477,8 +478,21 @@ impl GcInfo {
         self.retain_lsns.sort_by_key(|i| i.0);
     }
 
-    pub(super) fn remove_child(&mut self, child_id: TimelineId) {
-        self.retain_lsns.retain(|i| i.1 != child_id);
+    pub(super) fn remove_child_maybe_offloaded(
+        &mut self,
+        child_id: TimelineId,
+        maybe_offloaded: MaybeOffloaded,
+    ) {
+        self.retain_lsns
+            .retain(|i| !(i.1 == child_id && i.2 == maybe_offloaded));
+    }
+
+    pub(super) fn remove_child_not_offloaded(&mut self, child_id: TimelineId) {
+        self.remove_child_maybe_offloaded(child_id, MaybeOffloaded::No);
+    }
+
+    pub(super) fn remove_child_offloaded(&mut self, child_id: TimelineId) {
+        self.remove_child_maybe_offloaded(child_id, MaybeOffloaded::Yes);
     }
 }
 
@@ -3531,7 +3545,7 @@ impl Timeline {
                         self.get_compaction_threshold(),
                         DEFAULT_COMPACTION_THRESHOLD,
                     )
-                    && frozen_layer_total_size >= /* 64 MB */ 64000000
+                    && frozen_layer_total_size >= /* 128 MB */ 128000000
                 {
                     tracing::warn!(
                         "too many frozen layers: {num_frozen_layers} layers with estimated in-mem size of {frozen_layer_total_size} bytes",
@@ -4501,7 +4515,7 @@ impl Drop for Timeline {
             // This lock should never be poisoned, but in case it is we do a .map() instead of
             // an unwrap(), to avoid panicking in a destructor and thereby aborting the process.
             if let Ok(mut gc_info) = ancestor.gc_info.write() {
-                gc_info.remove_child(self.timeline_id)
+                gc_info.remove_child_not_offloaded(self.timeline_id)
             }
         }
     }
@@ -4761,6 +4775,86 @@ impl Timeline {
         Ok(())
     }
 
+    async fn find_gc_time_cutoff(
+        &self,
+        pitr: Duration,
+        cancel: &CancellationToken,
+        ctx: &RequestContext,
+    ) -> Result<Option<Lsn>, PageReconstructError> {
+        debug_assert_current_span_has_tenant_and_timeline_id();
+        if self.shard_identity.is_shard_zero() {
+            // Shard Zero has SLRU data and can calculate the PITR time -> LSN mapping itself
+            let now = SystemTime::now();
+            let time_range = if pitr == Duration::ZERO {
+                humantime::parse_duration(DEFAULT_PITR_INTERVAL).expect("constant is invalid")
+            } else {
+                pitr
+            };
+
+            // If PITR is so large or `now` is so small that this underflows, we will retain no history (highly unexpected case)
+            let time_cutoff = now.checked_sub(time_range).unwrap_or(now);
+            let timestamp = to_pg_timestamp(time_cutoff);
+
+            let time_cutoff = match self.find_lsn_for_timestamp(timestamp, cancel, ctx).await? {
+                LsnForTimestamp::Present(lsn) => Some(lsn),
+                LsnForTimestamp::Future(lsn) => {
+                    // The timestamp is in the future. That sounds impossible,
+                    // but what it really means is that there hasn't been
+                    // any commits since the cutoff timestamp.
+                    //
+                    // In this case we should use the LSN of the most recent commit,
+                    // which is implicitly the last LSN in the log.
+                    debug!("future({})", lsn);
+                    Some(self.get_last_record_lsn())
+                }
+                LsnForTimestamp::Past(lsn) => {
+                    debug!("past({})", lsn);
+                    None
+                }
+                LsnForTimestamp::NoData(lsn) => {
+                    debug!("nodata({})", lsn);
+                    None
+                }
+            };
+            Ok(time_cutoff)
+        } else {
+            // Shards other than shard zero cannot do timestamp->lsn lookups, and must instead learn their GC cutoff
+            // from shard zero's index.  The index doesn't explicitly tell us the time cutoff, but we may assume that
+            // the point up to which shard zero's last_gc_cutoff has advanced will either be the time cutoff, or a
+            // space cutoff that we would also have respected ourselves.
+            match self
+                .remote_client
+                .download_foreign_index(ShardNumber(0), cancel)
+                .await
+            {
+                Ok((index_part, index_generation, _index_mtime)) => {
+                    tracing::info!("GC loaded shard zero metadata (gen {index_generation:?}): latest_gc_cutoff_lsn: {}",
+                        index_part.metadata.latest_gc_cutoff_lsn());
+                    Ok(Some(index_part.metadata.latest_gc_cutoff_lsn()))
+                }
+                Err(DownloadError::NotFound) => {
+                    // This is unexpected, because during timeline creations shard zero persists to remote
+                    // storage before other shards are called, and during timeline deletion non-zeroth shards are
+                    // deleted before the zeroth one.  However, it should be harmless: if we somehow end up in this
+                    // state, then shard zero should _eventually_ write an index when it GCs.
+                    tracing::warn!("GC couldn't find shard zero's index for timeline");
+                    Ok(None)
+                }
+                Err(e) => {
+                    // TODO: this function should return a different error type than page reconstruct error
+                    Err(PageReconstructError::Other(anyhow::anyhow!(e)))
+                }
+            }
+
+            // TODO: after reading shard zero's GC cutoff, we should validate its generation with the storage
+            // controller.  Otherwise, it is possible that we see the GC cutoff go backwards while shard zero
+            // is going through a migration if we read the old location's index and it has GC'd ahead of the
+            // new location.  This is legal in principle, but problematic in practice because it might result
+            // in a timeline creation succeeding on shard zero ('s new location) but then failing on other shards
+            // because they have GC'd past the branch point.
+        }
+    }
+
     /// Find the Lsns above which layer files need to be retained on
     /// garbage collection.
     ///
@@ -4803,40 +4897,7 @@ impl Timeline {
         // - if PITR interval is set, then this is our cutoff.
         // - if PITR interval is not set, then we do a lookup
         //   based on DEFAULT_PITR_INTERVAL, so that size-based retention does not result in keeping history around permanently on idle databases.
-        let time_cutoff = {
-            let now = SystemTime::now();
-            let time_range = if pitr == Duration::ZERO {
-                humantime::parse_duration(DEFAULT_PITR_INTERVAL).expect("constant is invalid")
-            } else {
-                pitr
-            };
-
-            // If PITR is so large or `now` is so small that this underflows, we will retain no history (highly unexpected case)
-            let time_cutoff = now.checked_sub(time_range).unwrap_or(now);
-            let timestamp = to_pg_timestamp(time_cutoff);
-
-            match self.find_lsn_for_timestamp(timestamp, cancel, ctx).await? {
-                LsnForTimestamp::Present(lsn) => Some(lsn),
-                LsnForTimestamp::Future(lsn) => {
-                    // The timestamp is in the future. That sounds impossible,
-                    // but what it really means is that there hasn't been
-                    // any commits since the cutoff timestamp.
-                    //
-                    // In this case we should use the LSN of the most recent commit,
-                    // which is implicitly the last LSN in the log.
-                    debug!("future({})", lsn);
-                    Some(self.get_last_record_lsn())
-                }
-                LsnForTimestamp::Past(lsn) => {
-                    debug!("past({})", lsn);
-                    None
-                }
-                LsnForTimestamp::NoData(lsn) => {
-                    debug!("nodata({})", lsn);
-                    None
-                }
-            }
-        };
+        let time_cutoff = self.find_gc_time_cutoff(pitr, cancel, ctx).await?;
 
         Ok(match (pitr, time_cutoff) {
             (Duration::ZERO, Some(time_cutoff)) => {
@@ -5030,7 +5091,7 @@ impl Timeline {
 
             // 1. Is it newer than GC horizon cutoff point?
             if l.get_lsn_range().end > space_cutoff {
-                debug!(
+                info!(
                     "keeping {} because it's newer than space_cutoff {}",
                     l.layer_name(),
                     space_cutoff,
@@ -5041,7 +5102,7 @@ impl Timeline {
 
             // 2. It is newer than PiTR cutoff point?
             if l.get_lsn_range().end > time_cutoff {
-                debug!(
+                info!(
                     "keeping {} because it's newer than time_cutoff {}",
                     l.layer_name(),
                     time_cutoff,
@@ -5060,7 +5121,7 @@ impl Timeline {
             for retain_lsn in &retain_lsns {
                 // start_lsn is inclusive
                 if &l.get_lsn_range().start <= retain_lsn {
-                    debug!(
+                    info!(
                         "keeping {} because it's still might be referenced by child branch forked at {} is_dropped: xx is_incremental: {}",
                         l.layer_name(),
                         retain_lsn,
@@ -5075,7 +5136,7 @@ impl Timeline {
             if let Some(lsn) = &max_lsn_with_valid_lease {
                 // keep if layer start <= any of the lease
                 if &l.get_lsn_range().start <= lsn {
-                    debug!(
+                    info!(
                         "keeping {} because there is a valid lease preventing GC at {}",
                         l.layer_name(),
                         lsn,
@@ -5107,13 +5168,13 @@ impl Timeline {
             if !layers
                 .image_layer_exists(&l.get_key_range(), &(l.get_lsn_range().end..new_gc_cutoff))
             {
-                debug!("keeping {} because it is the latest layer", l.layer_name());
+                info!("keeping {} because it is the latest layer", l.layer_name());
                 result.layers_not_updated += 1;
                 continue 'outer;
             }
 
             // We didn't find any reason to keep this file, so remove it.
-            debug!(
+            info!(
                 "garbage collecting {} is_dropped: xx is_incremental: {}",
                 l.layer_name(),
                 l.is_incremental(),

pageserver/src/tenant/timeline/compaction.rs

@@ -4,7 +4,7 @@
 //!
 //! The old legacy algorithm is implemented directly in `timeline.rs`.
 
-use std::collections::{BinaryHeap, HashSet};
+use std::collections::{BinaryHeap, HashMap, HashSet};
 use std::ops::{Deref, Range};
 use std::sync::Arc;
 
@@ -56,7 +56,7 @@ use pageserver_api::value::Value;
 
 use utils::lsn::Lsn;
 
-use pageserver_compaction::helpers::overlaps_with;
+use pageserver_compaction::helpers::{fully_contains, overlaps_with};
 use pageserver_compaction::interface::*;
 
 use super::CompactionError;
@@ -64,6 +64,23 @@ use super::CompactionError;
 /// Maximum number of deltas before generating an image layer in bottom-most compaction.
 const COMPACTION_DELTA_THRESHOLD: usize = 5;
 
+pub struct GcCompactionJobDescription {
+    /// All layers to read in the compaction job
+    selected_layers: Vec<Layer>,
+    /// GC cutoff of the job
+    gc_cutoff: Lsn,
+    /// LSNs to retain for the job
+    retain_lsns_below_horizon: Vec<Lsn>,
+    /// Maximum layer LSN processed in this compaction
+    max_layer_lsn: Lsn,
+    /// Only compact layers overlapping with this range
+    compaction_key_range: Range<Key>,
+    /// When partial compaction is enabled, these layers need to be rewritten to ensure no overlap.
+    /// This field is here solely for debugging. The field will not be read once the compaction
+    /// description is generated.
+    rewrite_layers: Vec<Arc<PersistentLayerDesc>>,
+}
+
 /// The result of bottom-most compaction for a single key at each LSN.
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
@@ -1722,7 +1739,8 @@ impl Timeline {
         flags: EnumSet<CompactFlags>,
         ctx: &RequestContext,
     ) -> anyhow::Result<()> {
-        self.partial_compact_with_gc(None, cancel, flags, ctx).await
+        self.partial_compact_with_gc(Key::MIN..Key::MAX, cancel, flags, ctx)
+            .await
     }
 
     /// An experimental compaction building block that combines compaction with garbage collection.
@@ -1732,12 +1750,15 @@ impl Timeline {
     /// layers and image layers, which generates image layers on the gc horizon, drop deltas below gc horizon,
     /// and create delta layers with all deltas >= gc horizon.
     ///
-    /// If `key_range`, it will only compact the keys within the range, aka partial compaction. This functionality
-    /// is not complete yet, and if it is set, only image layers will be generated.
-    ///
+    /// If `key_range` is provided, it will only compact the keys within the range, aka partial compaction.
+    /// Partial compaction will read and process all layers overlapping with the key range, even if it might
+    /// contain extra keys. After the gc-compaction phase completes, delta layers that are not fully contained
+    /// within the key range will be rewritten to ensure they do not overlap with the delta layers. Providing
+    /// Key::MIN..Key..MAX to the function indicates a full compaction, though technically, `Key::MAX` is not
+    /// part of the range.
     pub(crate) async fn partial_compact_with_gc(
         self: &Arc<Self>,
-        compaction_key_range: Option<Range<Key>>,
+        compaction_key_range: Range<Key>,
         cancel: &CancellationToken,
         flags: EnumSet<CompactFlags>,
         ctx: &RequestContext,
@@ -1762,9 +1783,8 @@ impl Timeline {
         .await?;
 
         let dry_run = flags.contains(CompactFlags::DryRun);
-        let partial_compaction = compaction_key_range.is_some();
 
-        if let Some(ref compaction_key_range) = compaction_key_range {
+        if compaction_key_range == (Key::MIN..Key::MAX) {
             info!("running enhanced gc bottom-most compaction, dry_run={dry_run}, compaction_key_range={}..{}", compaction_key_range.start, compaction_key_range.end);
         } else {
             info!("running enhanced gc bottom-most compaction, dry_run={dry_run}");
@@ -1780,7 +1800,7 @@ impl Timeline {
         // The layer selection has the following properties:
         // 1. If a layer is in the selection, all layers below it are in the selection.
         // 2. Inferred from (1), for each key in the layer selection, the value can be reconstructed only with the layers in the layer selection.
-        let (layer_selection, gc_cutoff, retain_lsns_below_horizon) = if !partial_compaction {
+        let job_desc = {
             let guard = self.layers.read().await;
             let layers = guard.layer_map()?;
             let gc_info = self.gc_info.read().unwrap();
@@ -1810,9 +1830,21 @@ impl Timeline {
             };
             // Then, pick all the layers that are below the max_layer_lsn. This is to ensure we can pick all single-key
             // layers to compact.
+            let mut rewrite_layers = Vec::new();
             for desc in layers.iter_historic_layers() {
-                if desc.get_lsn_range().end <= max_layer_lsn {
+                if desc.get_lsn_range().end <= max_layer_lsn
+                    && overlaps_with(&desc.get_key_range(), &compaction_key_range)
+                {
+                    // If the layer overlaps with the compaction key range, we need to read it to obtain all keys within the range,
+                    // even if it might contain extra keys
                     selected_layers.push(guard.get_from_desc(&desc));
+                    // If the layer is not fully contained within the key range, we need to rewrite it if it's a delta layer (it's fine
+                    // to overlap image layers)
+                    if desc.is_delta()
+                        && !fully_contains(&compaction_key_range, &desc.get_key_range())
+                    {
+                        rewrite_layers.push(desc);
+                    }
                 }
             }
             if selected_layers.is_empty() {
@@ -1820,82 +1852,59 @@ impl Timeline {
                 return Ok(());
             }
             retain_lsns_below_horizon.sort();
-            (selected_layers, gc_cutoff, retain_lsns_below_horizon)
-        } else {
-            // In case of partial compaction, we currently only support generating image layers, and therefore,
-            // we pick all layers that are below the lowest retain_lsn and does not intersect with any of the layers.
-            let guard = self.layers.read().await;
-            let layers = guard.layer_map()?;
-            let gc_info = self.gc_info.read().unwrap();
-            let mut min_lsn = gc_info.cutoffs.select_min();
-            for (lsn, _, _) in &gc_info.retain_lsns {
-                if lsn < &min_lsn {
-                    min_lsn = *lsn;
-                }
+            GcCompactionJobDescription {
+                selected_layers,
+                gc_cutoff,
+                retain_lsns_below_horizon,
+                max_layer_lsn,
+                compaction_key_range,
+                rewrite_layers,
             }
-            for lsn in gc_info.leases.keys() {
-                if lsn < &min_lsn {
-                    min_lsn = *lsn;
-                }
-            }
-            let mut selected_layers = Vec::new();
-            drop(gc_info);
-            // |-------| |-------| |-------|
-            // | Delta | | Delta | | Delta | -- min_lsn could be intersecting with the layers
-            // |-------| |-------| |-------| <- we want to pick all the layers below min_lsn, so that
-            // | Delta | | Delta | | Delta |    ...we can remove them after compaction
-            // |-------| |-------| |-------|
-            // Pick all the layers intersect or below the min_lsn, get the largest LSN in the selected layers.
-            let Some(compaction_key_range) = compaction_key_range.as_ref() else {
-                unreachable!()
-            };
-            for desc in layers.iter_historic_layers() {
-                if desc.get_lsn_range().end <= min_lsn
-                    && overlaps_with(&desc.key_range, compaction_key_range)
-                {
-                    selected_layers.push(guard.get_from_desc(&desc));
-                }
-            }
-            if selected_layers.is_empty() {
-                info!("no layers to compact with gc");
-                return Ok(());
-            }
-            (selected_layers, min_lsn, Vec::new())
         };
         let lowest_retain_lsn = if self.ancestor_timeline.is_some() {
-            if partial_compaction {
-                warn!("partial compaction cannot run on child branches (for now)");
-                return Ok(());
-            }
             Lsn(self.ancestor_lsn.0 + 1)
         } else {
-            let res = retain_lsns_below_horizon
+            let res = job_desc
+                .retain_lsns_below_horizon
                 .first()
                 .copied()
-                .unwrap_or(gc_cutoff);
+                .unwrap_or(job_desc.gc_cutoff);
             if cfg!(debug_assertions) {
                 assert_eq!(
                     res,
-                    retain_lsns_below_horizon
+                    job_desc
+                        .retain_lsns_below_horizon
                         .iter()
                         .min()
                         .copied()
-                        .unwrap_or(gc_cutoff)
+                        .unwrap_or(job_desc.gc_cutoff)
                 );
             }
             res
         };
         info!(
-            "picked {} layers for compaction with gc_cutoff={} lowest_retain_lsn={}",
-            layer_selection.len(),
-            gc_cutoff,
-            lowest_retain_lsn
+            "picked {} layers for compaction ({} layers need rewriting) with max_layer_lsn={} gc_cutoff={} lowest_retain_lsn={}, key_range={}..{}",
+            job_desc.selected_layers.len(),
+            job_desc.rewrite_layers.len(),
+            job_desc.max_layer_lsn,
+            job_desc.gc_cutoff,
+            lowest_retain_lsn,
+            job_desc.compaction_key_range.start,
+            job_desc.compaction_key_range.end
         );
 
-        self.check_compaction_space(&layer_selection).await?;
+        for layer in &job_desc.selected_layers {
+            debug!("read layer: {}", layer.layer_desc().key());
+        }
+        for layer in &job_desc.rewrite_layers {
+            debug!("rewrite layer: {}", layer.key());
+        }
+
+        self.check_compaction_space(&job_desc.selected_layers)
+            .await?;
 
         // Generate statistics for the compaction
-        for layer in &layer_selection {
+        for layer in &job_desc.selected_layers {
             let desc = layer.layer_desc();
             if desc.is_delta() {
                 stat.visit_delta_layer(desc.file_size());
@@ -1906,25 +1915,25 @@ impl Timeline {
 
         // Step 1: construct a k-merge iterator over all layers.
         // Also, verify if the layer map can be split by drawing a horizontal line at every LSN start/end split point.
-        let layer_names: Vec<crate::tenant::storage_layer::LayerName> = layer_selection
+        let layer_names = job_desc
+            .selected_layers
             .iter()
             .map(|layer| layer.layer_desc().layer_name())
             .collect_vec();
         if let Some(err) = check_valid_layermap(&layer_names) {
-            bail!("cannot run gc-compaction because {}", err);
+            warn!("gc-compaction layer map check failed because {}, this is normal if partial compaction is not finished yet", err);
         }
         // The maximum LSN we are processing in this compaction loop
-        let end_lsn = layer_selection
+        let end_lsn = job_desc
+            .selected_layers
             .iter()
             .map(|l| l.layer_desc().lsn_range.end)
             .max()
             .unwrap();
-        // We don't want any of the produced layers to cover the full key range (i.e., MIN..MAX) b/c it will then be recognized
-        // as an L0 layer.
         let mut delta_layers = Vec::new();
         let mut image_layers = Vec::new();
         let mut downloaded_layers = Vec::new();
-        for layer in &layer_selection {
+        for layer in &job_desc.selected_layers {
             let resident_layer = layer.download_and_keep_resident().await?;
             downloaded_layers.push(resident_layer);
         }
@@ -1943,8 +1952,8 @@ impl Timeline {
             dense_ks,
             sparse_ks,
         )?;
-        // Step 2: Produce images+deltas. TODO: ensure newly-produced delta does not overlap with other deltas.
-        // Data of the same key.
+
+        // Step 2: Produce images+deltas.
         let mut accumulated_values = Vec::new();
         let mut last_key: Option<Key> = None;
 
@@ -1956,10 +1965,7 @@ impl Timeline {
                     self.conf,
                     self.timeline_id,
                     self.tenant_shard_id,
-                    compaction_key_range
-                        .as_ref()
-                        .map(|x| x.start)
-                        .unwrap_or(Key::MIN),
+                    job_desc.compaction_key_range.start,
                     lowest_retain_lsn,
                     self.get_compaction_target_size(),
                     ctx,
@@ -1979,6 +1985,13 @@ impl Timeline {
         )
         .await?;
 
+        #[derive(Default)]
+        struct RewritingLayers {
+            before: Option<DeltaLayerWriter>,
+            after: Option<DeltaLayerWriter>,
+        }
+        let mut delta_layer_rewriters = HashMap::<Arc<PersistentLayerKey>, RewritingLayers>::new();
+
         /// Returns None if there is no ancestor branch. Throw an error when the key is not found.
         ///
         /// Currently, we always get the ancestor image for each key in the child branch no matter whether the image
@@ -2004,10 +2017,51 @@ impl Timeline {
         // the key and LSN range are determined. However, to keep things simple here, we still
         // create this writer, and discard the writer in the end.
 
-        while let Some((key, lsn, val)) = merge_iter.next().await? {
+        while let Some(((key, lsn, val), desc)) = merge_iter.next_with_trace().await? {
             if cancel.is_cancelled() {
                 return Err(anyhow!("cancelled")); // TODO: refactor to CompactionError and pass cancel error
             }
+            if !job_desc.compaction_key_range.contains(&key) {
+                if !desc.is_delta {
+                    continue;
+                }
+                let rewriter = delta_layer_rewriters.entry(desc.clone()).or_default();
+                let rewriter = if key < job_desc.compaction_key_range.start {
+                    if rewriter.before.is_none() {
+                        rewriter.before = Some(
+                            DeltaLayerWriter::new(
+                                self.conf,
+                                self.timeline_id,
+                                self.tenant_shard_id,
+                                desc.key_range.start,
+                                desc.lsn_range.clone(),
+                                ctx,
+                            )
+                            .await?,
+                        );
+                    }
+                    rewriter.before.as_mut().unwrap()
+                } else if key >= job_desc.compaction_key_range.end {
+                    if rewriter.after.is_none() {
+                        rewriter.after = Some(
+                            DeltaLayerWriter::new(
+                                self.conf,
+                                self.timeline_id,
+                                self.tenant_shard_id,
+                                job_desc.compaction_key_range.end,
+                                desc.lsn_range.clone(),
+                                ctx,
+                            )
+                            .await?,
+                        );
+                    }
+                    rewriter.after.as_mut().unwrap()
+                } else {
+                    unreachable!()
+                };
+                rewriter.put_value(key, lsn, val, ctx).await?;
+                continue;
+            }
             match val {
                 Value::Image(_) => stat.visit_image_key(&val),
                 Value::WalRecord(_) => stat.visit_wal_key(&val),
@@ -2018,35 +2072,27 @@ impl Timeline {
                 }
                 accumulated_values.push((key, lsn, val));
             } else {
-                let last_key = last_key.as_mut().unwrap();
-                stat.on_unique_key_visited();
-                let skip_adding_key = if let Some(ref compaction_key_range) = compaction_key_range {
-                    !compaction_key_range.contains(last_key)
-                } else {
-                    false
-                };
-                if !skip_adding_key {
-                    let retention = self
-                        .generate_key_retention(
-                            *last_key,
-                            &accumulated_values,
-                            gc_cutoff,
-                            &retain_lsns_below_horizon,
-                            COMPACTION_DELTA_THRESHOLD,
-                            get_ancestor_image(self, *last_key, ctx).await?,
-                        )
-                        .await?;
-                    // Put the image into the image layer. Currently we have a single big layer for the compaction.
-                    retention
-                        .pipe_to(
-                            *last_key,
-                            &mut delta_layer_writer,
-                            image_layer_writer.as_mut(),
-                            &mut stat,
-                            ctx,
-                        )
-                        .await?;
-                }
+                let last_key: &mut Key = last_key.as_mut().unwrap();
+                stat.on_unique_key_visited(); // TODO: adjust statistics for partial compaction
+                let retention = self
+                    .generate_key_retention(
+                        *last_key,
+                        &accumulated_values,
+                        job_desc.gc_cutoff,
+                        &job_desc.retain_lsns_below_horizon,
+                        COMPACTION_DELTA_THRESHOLD,
+                        get_ancestor_image(self, *last_key, ctx).await?,
+                    )
+                    .await?;
+                retention
+                    .pipe_to(
+                        *last_key,
+                        &mut delta_layer_writer,
+                        image_layer_writer.as_mut(),
+                        &mut stat,
+                        ctx,
+                    )
+                    .await?;
                 accumulated_values.clear();
                 *last_key = key;
                 accumulated_values.push((key, lsn, val));
@@ -2057,35 +2103,43 @@ impl Timeline {
         let last_key = last_key.expect("no keys produced during compaction");
         stat.on_unique_key_visited();
 
-        let skip_adding_key = if let Some(ref compaction_key_range) = compaction_key_range {
-            !compaction_key_range.contains(&last_key)
-        } else {
-            false
-        };
-        if !skip_adding_key {
-            let retention = self
-                .generate_key_retention(
-                    last_key,
-                    &accumulated_values,
-                    gc_cutoff,
-                    &retain_lsns_below_horizon,
-                    COMPACTION_DELTA_THRESHOLD,
-                    get_ancestor_image(self, last_key, ctx).await?,
-                )
-                .await?;
-            // Put the image into the image layer. Currently we have a single big layer for the compaction.
-            retention
-                .pipe_to(
-                    last_key,
-                    &mut delta_layer_writer,
-                    image_layer_writer.as_mut(),
-                    &mut stat,
-                    ctx,
-                )
-                .await?;
-        }
+        let retention = self
+            .generate_key_retention(
+                last_key,
+                &accumulated_values,
+                job_desc.gc_cutoff,
+                &job_desc.retain_lsns_below_horizon,
+                COMPACTION_DELTA_THRESHOLD,
+                get_ancestor_image(self, last_key, ctx).await?,
+            )
+            .await?;
+        retention
+            .pipe_to(
+                last_key,
+                &mut delta_layer_writer,
+                image_layer_writer.as_mut(),
+                &mut stat,
+                ctx,
+            )
+            .await?;
         // end: move the above part to the loop body
 
+        let mut rewrote_delta_layers = Vec::new();
+        for (key, writers) in delta_layer_rewriters {
+            if let Some(delta_writer_before) = writers.before {
+                let (desc, path) = delta_writer_before
+                    .finish(job_desc.compaction_key_range.start, ctx)
+                    .await?;
+                let layer = Layer::finish_creating(self.conf, self, desc, &path)?;
+                rewrote_delta_layers.push(layer);
+            }
+            if let Some(delta_writer_after) = writers.after {
+                let (desc, path) = delta_writer_after.finish(key.key_range.end, ctx).await?;
+                let layer = Layer::finish_creating(self.conf, self, desc, &path)?;
+                rewrote_delta_layers.push(layer);
+            }
+        }
+
         let discard = |key: &PersistentLayerKey| {
             let key = key.clone();
             async move { KeyHistoryRetention::discard_key(&key, self, dry_run).await }
@@ -2093,10 +2147,7 @@ impl Timeline {
 
         let produced_image_layers = if let Some(writer) = image_layer_writer {
             if !dry_run {
-                let end_key = compaction_key_range
-                    .as_ref()
-                    .map(|x| x.end)
-                    .unwrap_or(Key::MAX);
+                let end_key = job_desc.compaction_key_range.end;
                 writer
                     .finish_with_discard_fn(self, ctx, end_key, discard)
                     .await?
@@ -2117,10 +2168,8 @@ impl Timeline {
             Vec::new()
         };
 
-        if partial_compaction && !produced_delta_layers.is_empty() {
-            bail!("implementation error: partial compaction should not be producing delta layers (for now)");
-        }
-
+        // TODO: make image/delta/rewrote_delta layers generation atomic. At this point, we already generated resident layers, and if
+        // compaction is cancelled at this point, we might have some layers that are not cleaned up.
         let mut compact_to = Vec::new();
         let mut keep_layers = HashSet::new();
         let produced_delta_layers_len = produced_delta_layers.len();
@@ -2128,52 +2177,84 @@ impl Timeline {
         for action in produced_delta_layers {
             match action {
                 BatchWriterResult::Produced(layer) => {
+                    if cfg!(debug_assertions) {
+                        info!("produced delta layer: {}", layer.layer_desc().key());
+                    }
                     stat.produce_delta_layer(layer.layer_desc().file_size());
                     compact_to.push(layer);
                 }
                 BatchWriterResult::Discarded(l) => {
+                    if cfg!(debug_assertions) {
+                        info!("discarded delta layer: {}", l);
+                    }
                     keep_layers.insert(l);
                     stat.discard_delta_layer();
                 }
             }
         }
+        for layer in &rewrote_delta_layers {
+            debug!(
+                "produced rewritten delta layer: {}",
+                layer.layer_desc().key()
+            );
+        }
+        compact_to.extend(rewrote_delta_layers);
         for action in produced_image_layers {
             match action {
                 BatchWriterResult::Produced(layer) => {
+                    debug!("produced image layer: {}", layer.layer_desc().key());
                     stat.produce_image_layer(layer.layer_desc().file_size());
                     compact_to.push(layer);
                 }
                 BatchWriterResult::Discarded(l) => {
+                    debug!("discarded image layer: {}", l);
                     keep_layers.insert(l);
                     stat.discard_image_layer();
                 }
             }
         }
-        let mut layer_selection = layer_selection;
-        layer_selection.retain(|x| !keep_layers.contains(&x.layer_desc().key()));
-        if let Some(ref compaction_key_range) = compaction_key_range {
-            // Partial compaction might select more data than it processes, e.g., if
-            // the compaction_key_range only partially overlaps:
-            //
-            //         [---compaction_key_range---]
-            //   [---A----][----B----][----C----][----D----]
-            //
-            // A,B,C,D are all in the `layer_selection`. The created image layers contain
-            // whatever is needed from B, C, and from `----]` of A, and from  `[--` of D.
-            //
-            // In contrast, `[--A-` and `--D----]` have not been processed, so, we must
-            // keep that data.
-            //
-            // The solution for now is to keep A and D completely.
-            // (layer_selection is what we'll remove from the layer map, so,
-            //  retain what is _not_ fully covered by compaction_key_range).
-            layer_selection.retain(|x| {
-                let key_range = &x.layer_desc().key_range;
-                key_range.start >= compaction_key_range.start
-                    && key_range.end <= compaction_key_range.end
-            });
+
+        let mut layer_selection = job_desc.selected_layers;
+
+        // Partial compaction might select more data than it processes, e.g., if
+        // the compaction_key_range only partially overlaps:
+        //
+        //         [---compaction_key_range---]
+        //   [---A----][----B----][----C----][----D----]
+        //
+        // For delta layers, we will rewrite the layers so that it is cut exactly at
+        // the compaction key range, so we can always discard them. However, for image
+        // layers, as we do not rewrite them for now, we need to handle them differently.
+        // Assume image layers  A, B, C, D are all in the `layer_selection`.
+        //
+        // The created image layers contain whatever is needed from B, C, and from
+        // `----]` of A, and from  `[---` of D.
+        //
+        // In contrast, `[---A` and `D----]` have not been processed, so, we must
+        // keep that data.
+        //
+        // The solution for now is to keep A and D completely if they are image layers.
+        // (layer_selection is what we'll remove from the layer map, so, retain what
+        // is _not_ fully covered by compaction_key_range).
+        for layer in &layer_selection {
+            if !layer.layer_desc().is_delta() {
+                if !overlaps_with(
+                    &layer.layer_desc().key_range,
+                    &job_desc.compaction_key_range,
+                ) {
+                    bail!("violated constraint: image layer outside of compaction key range");
+                }
+                if !fully_contains(
+                    &job_desc.compaction_key_range,
+                    &layer.layer_desc().key_range,
+                ) {
+                    keep_layers.insert(layer.layer_desc().key());
+                }
+            }
         }
 
+        layer_selection.retain(|x| !keep_layers.contains(&x.layer_desc().key()));
+
         info!(
             "gc-compaction statistics: {}",
             serde_json::to_string(&stat)?
@@ -2192,6 +2273,7 @@ impl Timeline {
 
         // Step 3: Place back to the layer map.
         {
+            // TODO: sanity check if the layer map is valid (i.e., should not have overlaps)
             let mut guard = self.layers.write().await;
             guard
                 .open_mut()?

pageserver/src/tenant/timeline/delete.rs

@@ -5,6 +5,7 @@ use std::{
 
 use anyhow::Context;
 use pageserver_api::{models::TimelineState, shard::TenantShardId};
+use remote_storage::DownloadError;
 use tokio::sync::OwnedMutexGuard;
 use tracing::{error, info, info_span, instrument, Instrument};
 use utils::{crashsafe, fs_ext, id::TimelineId, pausable_failpoint};
@@ -16,7 +17,7 @@ use crate::{
         metadata::TimelineMetadata,
         remote_timeline_client::{PersistIndexPartWithDeletedFlagError, RemoteTimelineClient},
         CreateTimelineCause, DeleteTimelineError, MaybeDeletedIndexPart, Tenant,
-        TimelineOrOffloaded,
+        TenantManifestError, TimelineOrOffloaded,
     },
     virtual_file::MaybeFatalIo,
 };
@@ -110,13 +111,6 @@ pub(super) async fn delete_local_timeline_directory(
     info!("finished deleting layer files, releasing locks");
 }
 
-/// Removes remote layers and an index file after them.
-async fn delete_remote_layers_and_index(
-    remote_client: &Arc<RemoteTimelineClient>,
-) -> anyhow::Result<()> {
-    remote_client.delete_all().await.context("delete_all")
-}
-
 /// It is important that this gets called when DeletionGuard is being held.
 /// For more context see comments in [`DeleteTimelineFlow::prepare`]
 async fn remove_maybe_offloaded_timeline_from_tenant(
@@ -147,9 +141,10 @@ async fn remove_maybe_offloaded_timeline_from_tenant(
             );
         }
         TimelineOrOffloaded::Offloaded(timeline) => {
-            timelines_offloaded
+            let offloaded_timeline = timelines_offloaded
                 .remove(&timeline.timeline_id)
                 .expect("timeline that we were deleting was concurrently removed from 'timelines_offloaded' map");
+            offloaded_timeline.delete_from_ancestor_with_timelines(&timelines);
         }
     }
 
@@ -221,11 +216,24 @@ impl DeleteTimelineFlow {
             None => {
                 let remote_client = tenant
                     .build_timeline_client(timeline.timeline_id(), tenant.remote_storage.clone());
-                let result = remote_client
+                let result = match remote_client
                     .download_index_file(&tenant.cancel)
                     .instrument(info_span!("download_index_file"))
                     .await
-                    .map_err(|e| DeleteTimelineError::Other(anyhow::anyhow!("error: {:?}", e)))?;
+                {
+                    Ok(r) => r,
+                    Err(DownloadError::NotFound) => {
+                        // Deletion is already complete
+                        tracing::info!("Timeline already deleted in remote storage");
+                        return Ok(());
+                    }
+                    Err(e) => {
+                        return Err(DeleteTimelineError::Other(anyhow::anyhow!(
+                            "error: {:?}",
+                            e
+                        )));
+                    }
+                };
                 let index_part = match result {
                     MaybeDeletedIndexPart::Deleted(p) => {
                         tracing::info!("Timeline already set as deleted in remote index");
@@ -406,7 +414,12 @@ impl DeleteTimelineFlow {
             "timeline_delete",
             async move {
                 if let Err(err) = Self::background(guard, conf, &tenant, &timeline, remote_client).await {
-                    error!("Error: {err:#}");
+                    // Only log as an error if it's not a cancellation.
+                    if matches!(err, DeleteTimelineError::Cancelled) {
+                        info!("Shutdown during timeline deletion");
+                    }else {
+                        error!("Error: {err:#}");
+                    }
                     if let TimelineOrOffloaded::Timeline(timeline) = timeline {
                         timeline.set_broken(format!("{err:#}"))
                     }
@@ -438,7 +451,7 @@ impl DeleteTimelineFlow {
             Err(anyhow::anyhow!("failpoint: timeline-delete-after-rm"))?
         });
 
-        delete_remote_layers_and_index(&remote_client).await?;
+        remote_client.delete_all().await?;
 
         pausable_failpoint!("in_progress_delete");
 
@@ -449,10 +462,10 @@ impl DeleteTimelineFlow {
         // So indeed, the tenant manifest might refer to an offloaded timeline which has already been deleted.
         // However, we handle this case in tenant loading code so the next time we attach, the issue is
         // resolved.
-        tenant
-            .store_tenant_manifest()
-            .await
-            .map_err(|e| DeleteTimelineError::Other(anyhow::anyhow!(e)))?;
+        tenant.store_tenant_manifest().await.map_err(|e| match e {
+            TenantManifestError::Cancelled => DeleteTimelineError::Cancelled,
+            _ => DeleteTimelineError::Other(e.into()),
+        })?;
 
         *guard = Self::Finished;
 

pageserver/src/tenant/timeline/offload.rs

@@ -66,7 +66,7 @@ pub(crate) async fn offload_timeline(
     let conf = &tenant.conf;
     delete_local_timeline_directory(conf, tenant.tenant_shard_id, &timeline).await;
 
-    remove_timeline_from_tenant(tenant, &timeline, &guard);
+    let remaining_refcount = remove_timeline_from_tenant(tenant, &timeline, &guard);
 
     {
         let mut offloaded_timelines = tenant.timelines_offloaded.lock().unwrap();
@@ -87,16 +87,20 @@ pub(crate) async fn offload_timeline(
     // not our actual state of offloaded timelines.
     tenant.store_tenant_manifest().await?;
 
+    tracing::info!("Timeline offload complete (remaining arc refcount: {remaining_refcount})");
+
     Ok(())
 }
 
 /// It is important that this gets called when DeletionGuard is being held.
 /// For more context see comments in [`DeleteTimelineFlow::prepare`]
+///
+/// Returns the strong count of the timeline `Arc`
 fn remove_timeline_from_tenant(
     tenant: &Tenant,
     timeline: &Timeline,
     _: &DeletionGuard, // using it as a witness
-) {
+) -> usize {
     // Remove the timeline from the map.
     let mut timelines = tenant.timelines.lock().unwrap();
     let children_exist = timelines
@@ -109,7 +113,9 @@ fn remove_timeline_from_tenant(
         panic!("Timeline grew children while we removed layer files");
     }
 
-    timelines
+    let timeline = timelines
         .remove(&timeline.timeline_id)
         .expect("timeline that we were deleting was concurrently removed from 'timelines' map");
+
+    Arc::strong_count(&timeline)
 }

pageserver/src/tenant/timeline/walreceiver/walreceiver_connection.rs

@@ -331,11 +331,11 @@ pub(super) async fn handle_walreceiver_connection(
                         Ok(())
                     }
 
-                    while let Some((record_end_lsn, recdata)) = waldecoder.poll_decode()? {
+                    while let Some((next_record_lsn, recdata)) = waldecoder.poll_decode()? {
                         // It is important to deal with the aligned records as lsn in getPage@LSN is
                         // aligned and can be several bytes bigger. Without this alignment we are
                         // at risk of hitting a deadlock.
-                        if !record_end_lsn.is_aligned() {
+                        if !next_record_lsn.is_aligned() {
                             return Err(WalReceiverError::Other(anyhow!("LSN not aligned")));
                         }
 
@@ -343,7 +343,7 @@ pub(super) async fn handle_walreceiver_connection(
                         let interpreted = InterpretedWalRecord::from_bytes_filtered(
                             recdata,
                             modification.tline.get_shard_identity(),
-                            record_end_lsn,
+                            next_record_lsn,
                             modification.tline.pg_version,
                         )?;
 
@@ -367,10 +367,10 @@ pub(super) async fn handle_walreceiver_connection(
                             .ingest_record(interpreted, &mut modification, &ctx)
                             .await
                             .with_context(|| {
-                                format!("could not ingest record at {record_end_lsn}")
+                                format!("could not ingest record at {next_record_lsn}")
                             })?;
                         if !ingested {
-                            tracing::debug!("ingest: filtered out record @ LSN {record_end_lsn}");
+                            tracing::debug!("ingest: filtered out record @ LSN {next_record_lsn}");
                             WAL_INGEST.records_filtered.inc();
                             filtered_records += 1;
                         }
@@ -380,7 +380,7 @@ pub(super) async fn handle_walreceiver_connection(
                         // to timeout the tests.
                         fail_point!("walreceiver-after-ingest");
 
-                        last_rec_lsn = record_end_lsn;
+                        last_rec_lsn = next_record_lsn;
 
                         // Commit every ingest_batch_size records. Even if we filtered out
                         // all records, we still need to call commit to advance the LSN.

pageserver/src/virtual_file.rs

@@ -175,10 +175,16 @@ impl VirtualFile {
     }
 
     pub async fn sync_all(&self) -> Result<(), Error> {
+        if SYNC_MODE.load(std::sync::atomic::Ordering::Relaxed) == SyncMode::UnsafeNoSync as u8 {
+            return Ok(());
+        }
         self.inner.sync_all().await
     }
 
     pub async fn sync_data(&self) -> Result<(), Error> {
+        if SYNC_MODE.load(std::sync::atomic::Ordering::Relaxed) == SyncMode::UnsafeNoSync as u8 {
+            return Ok(());
+        }
         self.inner.sync_data().await
     }
 
@@ -233,6 +239,27 @@ impl VirtualFile {
     }
 }
 
+/// Indicates whether to enable fsync, fdatasync, or O_SYNC/O_DSYNC when writing
+/// files. Switching this off is unsafe and only used for testing on machines
+/// with slow drives.
+#[repr(u8)]
+pub enum SyncMode {
+    Sync,
+    UnsafeNoSync,
+}
+
+impl TryFrom<u8> for SyncMode {
+    type Error = u8;
+
+    fn try_from(value: u8) -> Result<Self, Self::Error> {
+        Ok(match value {
+            v if v == (SyncMode::Sync as u8) => SyncMode::Sync,
+            v if v == (SyncMode::UnsafeNoSync as u8) => SyncMode::UnsafeNoSync,
+            x => return Err(x),
+        })
+    }
+}
+
 ///
 /// A virtual file descriptor. You can use this just like std::fs::File, but internally
 /// the underlying file is closed if the system is low on file descriptors,
@@ -1332,12 +1359,13 @@ impl OpenFiles {
 /// server startup.
 ///
 #[cfg(not(test))]
-pub fn init(num_slots: usize, engine: IoEngineKind, mode: IoMode) {
+pub fn init(num_slots: usize, engine: IoEngineKind, mode: IoMode, sync_mode: SyncMode) {
     if OPEN_FILES.set(OpenFiles::new(num_slots)).is_err() {
         panic!("virtual_file::init called twice");
     }
     set_io_mode(mode);
     io_engine::init(engine);
+    SYNC_MODE.store(sync_mode as u8, std::sync::atomic::Ordering::Relaxed);
     crate::metrics::virtual_file_descriptor_cache::SIZE_MAX.set(num_slots as u64);
 }
 
@@ -1379,6 +1407,9 @@ pub(crate) fn set_io_mode(mode: IoMode) {
 pub(crate) fn get_io_mode() -> IoMode {
     IoMode::try_from(IO_MODE.load(Ordering::Relaxed)).unwrap()
 }
+
+static SYNC_MODE: AtomicU8 = AtomicU8::new(SyncMode::Sync as u8);
+
 #[cfg(test)]
 mod tests {
     use crate::context::DownloadBehavior;

pageserver/src/walingest.rs

@@ -154,7 +154,7 @@ impl WalIngest {
         WAL_INGEST.records_received.inc();
         let prev_len = modification.len();
 
-        modification.set_lsn(interpreted.end_lsn)?;
+        modification.set_lsn(interpreted.next_record_lsn)?;
 
         if matches!(interpreted.flush_uncommitted, FlushUncommittedRecords::Yes) {
             // Records of this type should always be preceded by a commit(), as they
@@ -587,11 +587,29 @@ impl WalIngest {
                 forknum: VISIBILITYMAP_FORKNUM,
             };
 
-            let mut vm_page_no = blkno / pg_constants::VM_HEAPBLOCKS_PER_PAGE;
-            if blkno % pg_constants::VM_HEAPBLOCKS_PER_PAGE != 0 {
-                // Tail of last remaining vm page has to be zeroed.
-                // We are not precise here and instead of digging in VM bitmap format just clear the whole page.
-                modification.put_rel_page_image_zero(rel, vm_page_no)?;
+            // last remaining block, byte, and bit
+            let mut vm_page_no = blkno / (pg_constants::VM_HEAPBLOCKS_PER_PAGE as u32);
+            let trunc_byte = blkno as usize % pg_constants::VM_HEAPBLOCKS_PER_PAGE
+                / pg_constants::VM_HEAPBLOCKS_PER_BYTE;
+            let trunc_offs = blkno as usize % pg_constants::VM_HEAPBLOCKS_PER_BYTE
+                * pg_constants::VM_BITS_PER_HEAPBLOCK;
+
+            // Unless the new size is exactly at a visibility map page boundary, the
+            // tail bits in the last remaining map page, representing truncated heap
+            // blocks, need to be cleared. This is not only tidy, but also necessary
+            // because we don't get a chance to clear the bits if the heap is extended
+            // again.
+            if (trunc_byte != 0 || trunc_offs != 0)
+                && self.shard.is_key_local(&rel_block_to_key(rel, vm_page_no))
+            {
+                modification.put_rel_wal_record(
+                    rel,
+                    vm_page_no,
+                    NeonWalRecord::TruncateVisibilityMap {
+                        trunc_byte,
+                        trunc_offs,
+                    },
+                )?;
                 vm_page_no += 1;
             }
             let nblocks = get_relsize(modification, rel, ctx).await?;

pageserver/src/walredo/apply_neon.rs

@@ -42,6 +42,34 @@ pub(crate) fn apply_in_neon(
         } => {
             anyhow::bail!("tried to pass postgres wal record to neon WAL redo");
         }
+        //
+        // Code copied from PostgreSQL `visibilitymap_prepare_truncate` function in `visibilitymap.c`
+        //
+        NeonWalRecord::TruncateVisibilityMap {
+            trunc_byte,
+            trunc_offs,
+        } => {
+            // sanity check that this is modifying the correct relation
+            let (rel, _) = key.to_rel_block().context("invalid record")?;
+            assert!(
+                rel.forknum == VISIBILITYMAP_FORKNUM,
+                "TruncateVisibilityMap record on unexpected rel {}",
+                rel
+            );
+            let map = &mut page[pg_constants::MAXALIGN_SIZE_OF_PAGE_HEADER_DATA..];
+            map[*trunc_byte + 1..].fill(0u8);
+            /*----
+             * Mask out the unwanted bits of the last remaining byte.
+             *
+             * ((1 << 0) - 1) = 00000000
+             * ((1 << 1) - 1) = 00000001
+             * ...
+             * ((1 << 6) - 1) = 00111111
+             * ((1 << 7) - 1) = 01111111
+             *----
+             */
+            map[*trunc_byte] &= (1 << *trunc_offs) - 1;
+        }
         NeonWalRecord::ClearVisibilityMapFlags {
             new_heap_blkno,
             old_heap_blkno,
@@ -253,6 +281,10 @@ pub(crate) fn apply_in_neon(
             use bytes::BufMut;
             if *will_init {
                 assert!(*clear, "init record must be clear to ensure correctness");
+                assert!(
+                    page.is_empty(),
+                    "init record must be the first entry to ensure correctness"
+                );
             }
             if *clear {
                 page.clear();

pgxn/neon/logical_replication_monitor.c

@@ -1,7 +1,8 @@
+#include <dirent.h>
 #include <limits.h>
 #include <string.h>
-#include <dirent.h>
 #include <signal.h>
+#include <sys/stat.h>
 
 #include "postgres.h"
 
@@ -21,17 +22,35 @@
 
 static int	logical_replication_max_snap_files = 300;
 
+/*
+ * According to Chi (shyzh), the pageserver _should_ be good with 10 MB worth of
+ * snapshot files. Let's use 8 MB since 8 is a power of 2.
+ */
+static int	logical_replication_max_logicalsnapdir_size = 8000;
+
+/*
+ * A primitive description of a logical snapshot file including the LSN of the
+ * file and its size.
+ */
+typedef struct SnapDesc {
+	XLogRecPtr	lsn;
+	off_t		sz;
+} SnapDesc;
+
 PGDLLEXPORT void LogicalSlotsMonitorMain(Datum main_arg);
 
+/*
+ * Sorts an array of snapshot descriptors by their LSN.
+ */
 static int
-LsnDescComparator(const void *a, const void *b)
+SnapDescComparator(const void *a, const void *b)
 {
-	XLogRecPtr	lsn1 = *((const XLogRecPtr *) a);
-	XLogRecPtr	lsn2 = *((const XLogRecPtr *) b);
+	const SnapDesc	*desc1 = a;
+	const SnapDesc	*desc2 = b;
 
-	if (lsn1 < lsn2)
+	if (desc1->lsn < desc2->lsn)
 		return 1;
-	else if (lsn1 == lsn2)
+	else if (desc1->lsn == desc2->lsn)
 		return 0;
 	else
 		return -1;
@@ -43,28 +62,39 @@ LsnDescComparator(const void *a, const void *b)
  * slots having lower restart_lsn should be dropped.
  */
 static XLogRecPtr
-get_num_snap_files_lsn_threshold(void)
+get_snapshots_cutoff_lsn(void)
 {
-	DIR		   *dirdesc;
-	struct dirent *de;
-	char	   *snap_path = "pg_logical/snapshots/";
-	int			lsns_allocated = 1024;
-	int			lsns_num = 0;
-	XLogRecPtr *lsns;
-	XLogRecPtr	cutoff;
+/* PG 18 has a constant defined for this, PG_LOGICAL_SNAPSHOTS_DIR */
+#define SNAPDIR "pg_logical/snapshots"
 
-	if (logical_replication_max_snap_files < 0)
+	DIR		   *dirdesc;
+	int			dirdesc_fd;
+	struct dirent *de;
+	size_t		snapshot_index = 0;
+	SnapDesc   *snapshot_descriptors;
+	size_t		descriptors_allocated = 1024;
+	XLogRecPtr	cutoff = 0;
+	off_t		logicalsnapdir_size = 0;
+	const int	logical_replication_max_logicalsnapdir_size_bytes = logical_replication_max_logicalsnapdir_size * 1000;
+
+	if (logical_replication_max_snap_files < 0 && logical_replication_max_logicalsnapdir_size < 0)
 		return 0;
 
-	lsns = palloc(sizeof(XLogRecPtr) * lsns_allocated);
+	snapshot_descriptors = palloc(sizeof(*snapshot_descriptors) * descriptors_allocated);
+
+	dirdesc = AllocateDir(SNAPDIR);
+	dirdesc_fd = dirfd(dirdesc);
+	if (dirdesc_fd == -1)
+		ereport(ERROR, errmsg("failed to get a file descriptor for " SNAPDIR ": %m"));
 
 	/* find all .snap files and get their lsns */
-	dirdesc = AllocateDir(snap_path);
-	while ((de = ReadDir(dirdesc, snap_path)) != NULL)
+	while ((de = ReadDir(dirdesc, SNAPDIR)) != NULL)
 	{
-		XLogRecPtr	lsn;
 		uint32		hi;
 		uint32		lo;
+		struct stat	st;
+		XLogRecPtr	lsn;
+		SnapDesc   *desc;
 
 		if (strcmp(de->d_name, ".") == 0 ||
 			strcmp(de->d_name, "..") == 0)
@@ -79,28 +109,69 @@ get_num_snap_files_lsn_threshold(void)
 
 		lsn = ((uint64) hi) << 32 | lo;
 		elog(DEBUG5, "found snap file %X/%X", LSN_FORMAT_ARGS(lsn));
-		if (lsns_allocated == lsns_num)
+
+		if (fstatat(dirdesc_fd, de->d_name, &st, 0) == -1)
+			ereport(ERROR, errmsg("failed to get the size of " SNAPDIR "/%s: %m", de->d_name));
+
+		if (descriptors_allocated == snapshot_index)
 		{
-			lsns_allocated *= 2;
-			lsns = repalloc(lsns, sizeof(XLogRecPtr) * lsns_allocated);
+			descriptors_allocated *= 2;
+			snapshot_descriptors = repalloc(snapshot_descriptors, sizeof(*snapshot_descriptors) * descriptors_allocated);
 		}
-		lsns[lsns_num++] = lsn;
+
+		desc = &snapshot_descriptors[snapshot_index++];
+		desc->lsn = lsn;
+		desc->sz = st.st_size;
 	}
-	/* sort by lsn desc */
-	qsort(lsns, lsns_num, sizeof(XLogRecPtr), LsnDescComparator);
-	/* and take cutoff at logical_replication_max_snap_files */
-	if (logical_replication_max_snap_files > lsns_num)
-		cutoff = 0;
-	/* have less files than cutoff */
-	else
+
+	qsort(snapshot_descriptors, snapshot_index, sizeof(*snapshot_descriptors), SnapDescComparator);
+
+	/* Are there more snapshot files than specified? */
+	if (logical_replication_max_snap_files <= snapshot_index)
 	{
-		cutoff = lsns[logical_replication_max_snap_files - 1];
-		elog(LOG, "ls_monitor: dropping logical slots with restart_lsn lower %X/%X, found %d .snap files, limit is %d",
-			 LSN_FORMAT_ARGS(cutoff), lsns_num, logical_replication_max_snap_files);
+		cutoff = snapshot_descriptors[logical_replication_max_snap_files - 1].lsn;
+		elog(LOG,
+			"ls_monitor: dropping logical slots with restart_lsn lower %X/%X, found %zu snapshot files, limit is %d",
+			LSN_FORMAT_ARGS(cutoff), snapshot_index, logical_replication_max_snap_files);
 	}
-	pfree(lsns);
+
+	/* Is the size of the logical snapshots directory larger than specified?
+	 *
+	 * It's possible we could hit both thresholds, so remove any extra files
+	 * first, and then truncate based on size of the remaining files.
+	 */
+	if (logicalsnapdir_size > logical_replication_max_logicalsnapdir_size_bytes)
+	{
+		/* Unfortunately, iterating the directory does not guarantee any order
+		 * so we can't cache an index in the preceding loop.
+		 */
+
+		off_t		sz;
+		const XLogRecPtr original = cutoff;
+
+		sz = snapshot_descriptors[0].sz;
+		for (size_t i = 1; i < logical_replication_max_snap_files; ++i)
+		{
+			if (sz > logical_replication_max_logicalsnapdir_size_bytes)
+			{
+				cutoff = snapshot_descriptors[i - 1].lsn;
+				break;
+			}
+
+			sz += snapshot_descriptors[i].sz;
+		}
+
+		if (cutoff != original)
+			elog(LOG, "ls_monitor: dropping logical slots with restart_lsn lower than %X/%X, " SNAPDIR " is larger than %d KB",
+					LSN_FORMAT_ARGS(cutoff), logical_replication_max_logicalsnapdir_size);
+	}
+
+	pfree(snapshot_descriptors);
 	FreeDir(dirdesc);
+
 	return cutoff;
+
+#undef SNAPDIR
 }
 
 void
@@ -118,6 +189,16 @@ InitLogicalReplicationMonitor(void)
 							0,
 							NULL, NULL, NULL);
 
+	DefineCustomIntVariable(
+							"neon.logical_replication_max_logicalsnapdir_size",
+							"Maximum allowed size of the pg_logical/snapshots directory (KB). When exceeded, slots are dropped until the limit is met. -1 disables the limit.",
+							NULL,
+							&logical_replication_max_logicalsnapdir_size,
+							8000, -1, INT_MAX,
+							PGC_SIGHUP,
+							GUC_UNIT_KB,
+							NULL, NULL, NULL);
+
 	memset(&bgw, 0, sizeof(bgw));
 	bgw.bgw_flags = BGWORKER_SHMEM_ACCESS;
 	bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
@@ -162,7 +243,7 @@ LogicalSlotsMonitorMain(Datum main_arg)
 		 * If there are too many .snap files, just drop all logical slots to
 		 * prevent aux files bloat.
 		 */
-		cutoff_lsn = get_num_snap_files_lsn_threshold();
+		cutoff_lsn = get_snapshots_cutoff_lsn();
 		if (cutoff_lsn > 0)
 		{
 			for (int i = 0; i < max_replication_slots; i++)

pgxn/neon/neon.c

@@ -512,7 +512,7 @@ neon_shmem_startup_hook(void)
 	if (prev_shmem_startup_hook)
 		prev_shmem_startup_hook();
 
-#if PG_PG_MAJORVERSION_NUM >= 17
+#if PG_MAJORVERSION_NUM >= 17
 	WAIT_EVENT_NEON_LFC_MAINTENANCE = WaitEventExtensionNew("Neon/FileCache_Maintenance");
 	WAIT_EVENT_NEON_LFC_READ = WaitEventExtensionNew("Neon/FileCache_Read");
 	WAIT_EVENT_NEON_LFC_TRUNCATE = WaitEventExtensionNew("Neon/FileCache_Truncate");

safekeeper/src/auth.rs

@@ -20,7 +20,8 @@ pub fn check_permission(claims: &Claims, tenant_id: Option<TenantId>) -> Result<
             | Scope::PageServerApi
             | Scope::GenerationsApi
             | Scope::Infra
-            | Scope::Scrubber,
+            | Scope::Scrubber
+            | Scope::ControllerPeer,
             _,
         ) => Err(AuthError(
             format!(

safekeeper/src/metrics.rs

@@ -55,7 +55,7 @@ pub static WRITE_WAL_SECONDS: Lazy<Histogram> = Lazy::new(|| {
 pub static FLUSH_WAL_SECONDS: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "safekeeper_flush_wal_seconds",
-        "Seconds spent syncing WAL to a disk",
+        "Seconds spent syncing WAL to a disk (excluding segment initialization)",
         DISK_FSYNC_SECONDS_BUCKETS.to_vec()
     )
     .expect("Failed to register safekeeper_flush_wal_seconds histogram")

safekeeper/src/receive_wal.rs

@@ -562,6 +562,9 @@ impl WalAcceptor {
                     // Don't flush the WAL on every append, only periodically via flush_ticker.
                     // This batches multiple appends per fsync. If the channel is empty after
                     // sending the reply, we'll schedule an immediate flush.
+                    //
+                    // Note that a flush can still happen on segment bounds, which will result
+                    // in an AppendResponse.
                     if let ProposerAcceptorMessage::AppendRequest(append_request) = msg {
                         msg = ProposerAcceptorMessage::NoFlushAppendRequest(append_request);
                         dirty = true;

safekeeper/src/safekeeper.rs

@@ -947,6 +947,7 @@ where
         // while first connection still gets some packets later. It might be
         // better to not log this as error! above.
         let write_lsn = self.wal_store.write_lsn();
+        let flush_lsn = self.wal_store.flush_lsn();
         if write_lsn > msg.h.begin_lsn {
             bail!(
                 "append request rewrites WAL written before, write_lsn={}, msg lsn={}",
@@ -979,7 +980,8 @@ where
             self.wal_store.flush_wal().await?;
         }
 
-        // Update commit_lsn.
+        // Update commit_lsn. It will be flushed to the control file regularly by the timeline
+        // manager, off of the WAL ingest hot path.
         if msg.h.commit_lsn != Lsn(0) {
             self.update_commit_lsn(msg.h.commit_lsn).await?;
         }
@@ -992,15 +994,6 @@ where
         self.state.inmem.peer_horizon_lsn =
             max(self.state.inmem.peer_horizon_lsn, msg.h.truncate_lsn);
 
-        // Update truncate and commit LSN in control file.
-        // To avoid negative impact on performance of extra fsync, do it only
-        // when commit_lsn delta exceeds WAL segment size.
-        if self.state.commit_lsn + (self.state.server.wal_seg_size as u64)
-            < self.state.inmem.commit_lsn
-        {
-            self.state.flush().await?;
-        }
-
         trace!(
             "processed AppendRequest of len {}, begin_lsn={}, end_lsn={:?}, commit_lsn={:?}, truncate_lsn={:?}, flushed={:?}",
             msg.wal_data.len(),
@@ -1012,7 +1005,9 @@ where
         );
 
         // If flush_lsn hasn't updated, AppendResponse is not very useful.
-        if !require_flush {
+        // This is the common case for !require_flush, but a flush can still
+        // happen on segment bounds.
+        if !require_flush && flush_lsn == self.flush_lsn() {
             return Ok(None);
         }
 

safekeeper/src/state.rs

@@ -4,6 +4,7 @@
 use std::{cmp::max, ops::Deref};
 
 use anyhow::{bail, Result};
+use postgres_ffi::WAL_SEGMENT_SIZE;
 use safekeeper_api::models::TimelineTermBumpResponse;
 use serde::{Deserialize, Serialize};
 use utils::{
@@ -144,7 +145,7 @@ impl TimelinePersistentState {
             ServerInfo {
                 pg_version: 170000, /* Postgres server version (major * 10000) */
                 system_id: 0,       /* Postgres system identifier */
-                wal_seg_size: 16 * 1024 * 1024,
+                wal_seg_size: WAL_SEGMENT_SIZE as u32,
             },
             vec![],
             Lsn::INVALID,

safekeeper/src/timeline_manager.rs

@@ -515,7 +515,12 @@ impl Manager {
             return;
         }
 
-        if state.cfile_last_persist_at.elapsed() > self.conf.control_file_save_interval {
+        if state.cfile_last_persist_at.elapsed() > self.conf.control_file_save_interval
+            // If the control file's commit_lsn lags more than one segment behind the current
+            // commit_lsn, flush immediately to limit recovery time in case of a crash. We don't do
+            // this on the WAL ingest hot path since it incurs fsync latency.
+            || state.commit_lsn.saturating_sub(state.cfile_commit_lsn).0 >= self.wal_seg_size as u64
+        {
             let mut write_guard = self.tli.write_shared_state().await;
             // it should be done in the background because it blocks manager task, but flush() should
             // be fast enough not to be a problem now

safekeeper/src/wal_storage.rs

@@ -113,6 +113,13 @@ pub struct PhysicalStorage {
     /// non-aligned chunks of data.
     write_record_lsn: Lsn,
 
+    /// The last LSN flushed to disk. May be in the middle of a record.
+    ///
+    /// NB: when the rest of the system refers to `flush_lsn`, it usually
+    /// actually refers to `flush_record_lsn`. This ambiguity can be dangerous
+    /// and should be resolved.
+    flush_lsn: Lsn,
+
     /// The LSN of the last WAL record flushed to disk.
     flush_record_lsn: Lsn,
 
@@ -127,23 +134,29 @@ pub struct PhysicalStorage {
     /// - doesn't point to the end of the segment
     file: Option<File>,
 
-    /// When false, we have just initialized storage using the LSN from find_end_of_wal().
-    /// In this case, [`write_lsn`] can be less than actually written WAL on disk. In particular,
-    /// there can be a case with unexpected .partial file.
+    /// When true, WAL truncation potentially has been interrupted and we need
+    /// to finish it before allowing WAL writes; see truncate_wal for details.
+    /// In this case [`write_lsn`] can be less than actually written WAL on
+    /// disk. In particular, there can be a case with unexpected .partial file.
     ///
     /// Imagine the following:
     /// - 000000010000000000000001
-    ///   - it was fully written, but the last record is split between 2 segments
-    ///   - after restart, `find_end_of_wal()` returned 0/1FFFFF0, which is in the end of this segment
-    ///   - `write_lsn`, `write_record_lsn` and `flush_record_lsn` were initialized to 0/1FFFFF0
+    ///   - it was fully written, but the last record is split between 2
+    ///     segments
+    ///   - after restart, `find_end_of_wal()` returned 0/1FFFFF0, which is in
+    ///     the end of this segment
+    ///   - `write_lsn`, `write_record_lsn` and `flush_record_lsn` were
+    ///     initialized to 0/1FFFFF0
     /// - 000000010000000000000002.partial
-    ///   - it has only 1 byte written, which is not enough to make a full WAL record
+    ///   - it has only 1 byte written, which is not enough to make a full WAL
+    ///     record
     ///
-    /// Partial segment 002 has no WAL records, and it will be removed by the next truncate_wal().
-    /// This flag will be set to true after the first truncate_wal() call.
+    /// Partial segment 002 has no WAL records, and it will be removed by the
+    /// next truncate_wal(). This flag will be set to true after the first
+    /// truncate_wal() call.
     ///
     /// [`write_lsn`]: Self::write_lsn
-    is_truncated_after_restart: bool,
+    pending_wal_truncation: bool,
 }
 
 impl PhysicalStorage {
@@ -205,10 +218,11 @@ impl PhysicalStorage {
             system_id: state.server.system_id,
             write_lsn,
             write_record_lsn: write_lsn,
+            flush_lsn,
             flush_record_lsn: flush_lsn,
             decoder: WalStreamDecoder::new(write_lsn, state.server.pg_version / 10000),
             file: None,
-            is_truncated_after_restart: false,
+            pending_wal_truncation: true,
         })
     }
 
@@ -257,6 +271,9 @@ impl PhysicalStorage {
             // Try to open existing partial file
             Ok((file, true))
         } else {
+            let _timer = WAL_STORAGE_OPERATION_SECONDS
+                .with_label_values(&["initialize_segment"])
+                .start_timer();
             // Create and fill new partial file
             //
             // We're using fdatasync during WAL writing, so file size must not
@@ -274,8 +291,6 @@ impl PhysicalStorage {
             });
             file.set_len(self.wal_seg_size as u64).await?;
 
-            // Note: this doesn't get into observe_flush_seconds metric. But
-            // segment init should be separate metric, if any.
             if let Err(e) = durable_rename(&tmp_path, &wal_file_partial_path, !self.no_sync).await {
                 // Probably rename succeeded, but fsync of it failed. Remove
                 // the file then to avoid using it.
@@ -288,8 +303,9 @@ impl PhysicalStorage {
         }
     }
 
-    /// Write WAL bytes, which are known to be located in a single WAL segment.
-    async fn write_in_segment(&mut self, segno: u64, xlogoff: usize, buf: &[u8]) -> Result<()> {
+    /// Write WAL bytes, which are known to be located in a single WAL segment. Returns true if the
+    /// segment was completed, closed, and flushed to disk.
+    async fn write_in_segment(&mut self, segno: u64, xlogoff: usize, buf: &[u8]) -> Result<bool> {
         let mut file = if let Some(file) = self.file.take() {
             file
         } else {
@@ -313,20 +329,24 @@ impl PhysicalStorage {
             let (wal_file_path, wal_file_partial_path) =
                 wal_file_paths(&self.timeline_dir, segno, self.wal_seg_size);
             fs::rename(wal_file_partial_path, wal_file_path).await?;
+            Ok(true)
         } else {
             // otherwise, file can be reused later
             self.file = Some(file);
+            Ok(false)
         }
-
-        Ok(())
     }
 
     /// Writes WAL to the segment files, until everything is writed. If some segments
     /// are fully written, they are flushed to disk. The last (partial) segment can
     /// be flushed separately later.
     ///
-    /// Updates `write_lsn`.
+    /// Updates `write_lsn` and `flush_lsn`.
     async fn write_exact(&mut self, pos: Lsn, mut buf: &[u8]) -> Result<()> {
+        // TODO: this shouldn't be possible, except possibly with write_lsn == 0.
+        // Rename this method to `append_exact`, and make it append-only, removing
+        // the `pos` parameter and this check. For this reason, we don't update
+        // `flush_lsn` here.
         if self.write_lsn != pos {
             // need to flush the file before discarding it
             if let Some(file) = self.file.take() {
@@ -348,9 +368,13 @@ impl PhysicalStorage {
                 buf.len()
             };
 
-            self.write_in_segment(segno, xlogoff, &buf[..bytes_write])
+            let flushed = self
+                .write_in_segment(segno, xlogoff, &buf[..bytes_write])
                 .await?;
             self.write_lsn += bytes_write as u64;
+            if flushed {
+                self.flush_lsn = self.write_lsn;
+            }
             buf = &buf[bytes_write..];
         }
 
@@ -364,6 +388,9 @@ impl Storage for PhysicalStorage {
         self.write_lsn
     }
     /// flush_lsn returns LSN of last durably stored WAL record.
+    ///
+    /// TODO: flush_lsn() returns flush_record_lsn, but write_lsn() returns write_lsn: confusing.
+    #[allow(clippy::misnamed_getters)]
     fn flush_lsn(&self) -> Lsn {
         self.flush_record_lsn
     }
@@ -404,14 +431,22 @@ impl Storage for PhysicalStorage {
                 startpos
             );
         }
+        if self.pending_wal_truncation {
+            bail!(
+                "write_wal called with pending WAL truncation, write_lsn={}, startpos={}",
+                self.write_lsn,
+                startpos
+            );
+        }
 
         let write_seconds = time_io_closure(self.write_exact(startpos, buf)).await?;
         // WAL is written, updating write metrics
         self.metrics.observe_write_seconds(write_seconds);
         self.metrics.observe_write_bytes(buf.len());
 
-        // figure out last record's end lsn for reporting (if we got the
-        // whole record)
+        // Figure out the last record's end LSN and update `write_record_lsn`
+        // (if we got a whole record). The write may also have closed and
+        // flushed a segment, so update `flush_record_lsn` as well.
         if self.decoder.available() != startpos {
             info!(
                 "restart decoder from {} to {}",
@@ -422,12 +457,15 @@ impl Storage for PhysicalStorage {
             self.decoder = WalStreamDecoder::new(startpos, pg_version);
         }
         self.decoder.feed_bytes(buf);
-        loop {
-            match self.decoder.poll_decode()? {
-                None => break, // no full record yet
-                Some((lsn, _rec)) => {
-                    self.write_record_lsn = lsn;
-                }
+
+        if self.write_record_lsn <= self.flush_lsn {
+            // We may have flushed a previously written record.
+            self.flush_record_lsn = self.write_record_lsn;
+        }
+        while let Some((lsn, _rec)) = self.decoder.poll_decode()? {
+            self.write_record_lsn = lsn;
+            if lsn <= self.flush_lsn {
+                self.flush_record_lsn = lsn;
             }
         }
 
@@ -444,19 +482,17 @@ impl Storage for PhysicalStorage {
             self.fdatasync_file(&unflushed_file).await?;
             self.file = Some(unflushed_file);
         } else {
-            // We have unflushed data (write_lsn != flush_lsn), but no file.
-            // This should only happen if last file was fully written and flushed,
-            // but haven't updated flush_lsn yet.
-            if self.write_lsn.segment_offset(self.wal_seg_size) != 0 {
-                bail!(
-                    "unexpected unflushed data with no open file, write_lsn={}, flush_lsn={}",
-                    self.write_lsn,
-                    self.flush_record_lsn
-                );
-            }
+            // We have unflushed data (write_lsn != flush_lsn), but no file. This
+            // shouldn't happen, since the segment is flushed on close.
+            bail!(
+                "unexpected unflushed data with no open file, write_lsn={}, flush_lsn={}",
+                self.write_lsn,
+                self.flush_record_lsn
+            );
         }
 
         // everything is flushed now, let's update flush_lsn
+        self.flush_lsn = self.write_lsn;
         self.flush_record_lsn = self.write_record_lsn;
         Ok(())
     }
@@ -478,15 +514,35 @@ impl Storage for PhysicalStorage {
             );
         }
 
-        // Quick exit if nothing to do to avoid writing up to 16 MiB of zeros on
-        // disk (this happens on each connect).
-        if self.is_truncated_after_restart
+        // Quick exit if nothing to do and we know that the state is clean to
+        // avoid writing up to 16 MiB of zeros on disk (this happens on each
+        // connect).
+        if !self.pending_wal_truncation
             && end_pos == self.write_lsn
             && end_pos == self.flush_record_lsn
         {
             return Ok(());
         }
 
+        // Atomicity: we start with LSNs reset because once on disk deletion is
+        // started it can't be reversed. However, we might crash/error in the
+        // middle, leaving garbage above the truncation point. In theory,
+        // concatenated with previous records it might form bogus WAL (though
+        // very unlikely in practice because CRC would guard from that). To
+        // protect, set pending_wal_truncation flag before beginning: it means
+        // truncation must be retried and WAL writes are prohibited until it
+        // succeeds. Flag is also set on boot because we don't know if the last
+        // state was clean.
+        //
+        // Protocol (HandleElected before first AppendRequest) ensures we'll
+        // always try to ensure clean truncation before any writes.
+        self.pending_wal_truncation = true;
+
+        self.write_lsn = end_pos;
+        self.flush_lsn = end_pos;
+        self.write_record_lsn = end_pos;
+        self.flush_record_lsn = end_pos;
+
         // Close previously opened file, if any
         if let Some(unflushed_file) = self.file.take() {
             self.fdatasync_file(&unflushed_file).await?;
@@ -512,11 +568,7 @@ impl Storage for PhysicalStorage {
             fs::rename(wal_file_path, wal_file_partial_path).await?;
         }
 
-        // Update LSNs
-        self.write_lsn = end_pos;
-        self.write_record_lsn = end_pos;
-        self.flush_record_lsn = end_pos;
-        self.is_truncated_after_restart = true;
+        self.pending_wal_truncation = false;
         Ok(())
     }
 

storage_controller/src/http.rs

@@ -1033,7 +1033,7 @@ async fn handle_update_preferred_azs(req: Request<Body>) -> Result<Response<Body
 }
 
 async fn handle_step_down(req: Request<Body>) -> Result<Response<Body>, ApiError> {
-    check_permissions(&req, Scope::Admin)?;
+    check_permissions(&req, Scope::ControllerPeer)?;
 
     let req = match maybe_forward(req).await {
         ForwardOutcome::Forwarded(res) => {

storage_controller/src/service.rs

@@ -3642,6 +3642,7 @@ impl Service {
                 match res {
                     Ok(ok) => Ok(ok),
                     Err(mgmt_api::Error::ApiError(StatusCode::CONFLICT, _)) => Ok(StatusCode::CONFLICT),
+                    Err(mgmt_api::Error::ApiError(StatusCode::SERVICE_UNAVAILABLE, msg)) => Err(ApiError::ResourceUnavailable(msg.into())),
                     Err(e) => {
                         Err(
                             ApiError::InternalServerError(anyhow::anyhow!(
@@ -6355,6 +6356,19 @@ impl Service {
 
         // Pick the biggest tenant to split first
         top_n.sort_by_key(|i| i.resident_size);
+
+        // Filter out tenants in a prohibiting scheduling mode
+        {
+            let locked = self.inner.read().unwrap();
+            top_n.retain(|i| {
+                if let Some(shard) = locked.tenants.get(&i.id) {
+                    matches!(shard.get_scheduling_policy(), ShardSchedulingPolicy::Active)
+                } else {
+                    false
+                }
+            });
+        }
+
         let Some(split_candidate) = top_n.into_iter().next() else {
             tracing::debug!("No split-elegible shards found");
             return;

test_runner/fixtures/endpoint/http.py

@@ -46,3 +46,8 @@ class EndpointHttpClient(requests.Session):
         )
         res.raise_for_status()
         return res.json()
+
+    def metrics(self) -> str:
+        res = self.get(f"http://localhost:{self.port}/metrics")
+        res.raise_for_status()
+        return res.text

test_runner/fixtures/neon_api.py

@@ -5,6 +5,8 @@ from typing import TYPE_CHECKING, cast, final
 
 import requests
 
+from fixtures.log_helper import log
+
 if TYPE_CHECKING:
     from typing import Any, Literal, Optional
 
@@ -30,7 +32,11 @@ class NeonAPI:
             kwargs["headers"] = {}
         kwargs["headers"]["Authorization"] = f"Bearer {self.__neon_api_key}"
 
-        return requests.request(method, f"{self.__neon_api_base_url}{endpoint}", **kwargs)
+        resp = requests.request(method, f"{self.__neon_api_base_url}{endpoint}", **kwargs)
+        log.debug("%s %s returned a %d: %s", method, endpoint, resp.status_code, resp.text)
+        resp.raise_for_status()
+
+        return resp
 
     def create_project(
         self,
@@ -66,8 +72,6 @@ class NeonAPI:
             json=data,
         )
 
-        assert resp.status_code == 201
-
         return cast("dict[str, Any]", resp.json())
 
     def get_project_details(self, project_id: str) -> dict[str, Any]:
@@ -79,7 +83,7 @@ class NeonAPI:
                 "Content-Type": "application/json",
             },
         )
-        assert resp.status_code == 200
+
         return cast("dict[str, Any]", resp.json())
 
     def delete_project(
@@ -95,8 +99,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def start_endpoint(
@@ -112,8 +114,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def suspend_endpoint(
@@ -129,8 +129,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def restart_endpoint(
@@ -146,8 +144,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def create_endpoint(
@@ -178,8 +174,6 @@ class NeonAPI:
             json=data,
         )
 
-        assert resp.status_code == 201
-
         return cast("dict[str, Any]", resp.json())
 
     def get_connection_uri(
@@ -206,8 +200,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def get_branches(self, project_id: str) -> dict[str, Any]:
@@ -219,8 +211,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def get_endpoints(self, project_id: str) -> dict[str, Any]:
@@ -232,8 +222,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def get_operations(self, project_id: str) -> dict[str, Any]:
@@ -246,8 +234,6 @@ class NeonAPI:
             },
         )
 
-        assert resp.status_code == 200
-
         return cast("dict[str, Any]", resp.json())
 
     def wait_for_operation_to_finish(self, project_id: str):

test_runner/fixtures/neon_fixtures.py

@@ -286,7 +286,7 @@ class PgProtocol:
         return self.safe_psql_many([query], **kwargs)[0]
 
     def safe_psql_many(
-        self, queries: Iterable[str], log_query=True, **kwargs: Any
+        self, queries: Iterable[str], log_query: bool = True, **kwargs: Any
     ) -> list[list[tuple[Any, ...]]]:
         """
         Execute queries against the node and return all rows.
@@ -306,7 +306,7 @@ class PgProtocol:
                         result.append(cur.fetchall())
         return result
 
-    def safe_psql_scalar(self, query, log_query=True) -> Any:
+    def safe_psql_scalar(self, query: str, log_query: bool = True) -> Any:
         """
         Execute query returning single row with single column.
         """
@@ -1065,6 +1065,9 @@ class NeonEnv:
                 "http_auth_type": http_auth_type,
                 # Default which can be overriden with `NeonEnvBuilder.pageserver_config_override`
                 "availability_zone": "us-east-2a",
+                # Disable pageserver disk syncs in tests: when running tests concurrently, this avoids
+                # the pageserver taking a long time to start up due to syncfs flushing other tests' data
+                "no_sync": True,
             }
             if self.pageserver_virtual_file_io_engine is not None:
                 ps_cfg["virtual_file_io_engine"] = self.pageserver_virtual_file_io_engine
@@ -2376,6 +2379,17 @@ class NeonPageserver(PgProtocol, LogUtils):
         #
         # The entries in the list are regular experessions.
         self.allowed_errors: list[str] = list(DEFAULT_PAGESERVER_ALLOWED_ERRORS)
+        # Store persistent failpoints that should be reapplied on each start
+        self._persistent_failpoints: dict[str, str] = {}
+
+    def add_persistent_failpoint(self, name: str, action: str):
+        """
+        Add a failpoint that will be automatically reapplied each time the pageserver starts.
+        The failpoint will be set immediately if the pageserver is running.
+        """
+        self._persistent_failpoints[name] = action
+        if self.running:
+            self.http_client().configure_failpoints([(name, action)])
 
     def timeline_dir(
         self,
@@ -2443,6 +2457,15 @@ class NeonPageserver(PgProtocol, LogUtils):
         """
         assert self.running is False
 
+        if self._persistent_failpoints:
+            # Tests shouldn't use this mechanism _and_ set FAILPOINTS explicitly
+            assert extra_env_vars is None or "FAILPOINTS" not in extra_env_vars
+            if extra_env_vars is None:
+                extra_env_vars = {}
+            extra_env_vars["FAILPOINTS"] = ",".join(
+                f"{k}={v}" for (k, v) in self._persistent_failpoints.items()
+            )
+
         storage = self.env.pageserver_remote_storage
         if isinstance(storage, S3Storage):
             s3_env_vars = storage.access_env_vars()
@@ -4519,7 +4542,7 @@ def pytest_addoption(parser: Parser):
 
 
 SMALL_DB_FILE_NAME_REGEX: re.Pattern[str] = re.compile(
-    r"config-v1|heatmap-v1|metadata|.+\.(?:toml|pid|json|sql|conf)"
+    r"config-v1|heatmap-v1|tenant-manifest|metadata|.+\.(?:toml|pid|json|sql|conf)"
 )
 
 

test_runner/fixtures/pageserver/allowed_errors.py

@@ -93,6 +93,8 @@ DEFAULT_PAGESERVER_ALLOWED_ERRORS = (
     ".*WARN.*path=/v1/utilization .*request was dropped before completing",
     # Can happen during shutdown
     ".*scheduling deletion on drop failed: queue is in state Stopped.*",
+    # Too many frozen layers error is normal during intensive benchmarks
+    ".*too many frozen layers.*",
 )
 
 

test_runner/fixtures/pg_version.py

@@ -1,10 +1,8 @@
 from __future__ import annotations
 
 import enum
-import os
 from typing import TYPE_CHECKING
 
-import pytest
 from typing_extensions import override
 
 if TYPE_CHECKING:
@@ -18,12 +16,15 @@ This fixture is used to determine which version of Postgres to use for tests.
 
 # Inherit PgVersion from str rather than int to make it easier to pass as a command-line argument
 # TODO: use enum.StrEnum for Python >= 3.11
-@enum.unique
 class PgVersion(str, enum.Enum):
     V14 = "14"
     V15 = "15"
     V16 = "16"
     V17 = "17"
+
+    # Default Postgres Version for tests that don't really depend on Postgres itself
+    DEFAULT = V16
+
     # Instead of making version an optional parameter in methods, we can use this fake entry
     # to explicitly rely on the default server version (could be different from pg_version fixture value)
     NOT_SET = "<-POSTRGRES VERSION IS NOT SET->"
@@ -59,27 +60,3 @@ class PgVersion(str, enum.Enum):
         # Make mypy happy
         # See https://github.com/python/mypy/issues/3974
         return None
-
-
-DEFAULT_VERSION: PgVersion = PgVersion.V16
-
-
-def skip_on_postgres(version: PgVersion, reason: str):
-    return pytest.mark.skipif(
-        PgVersion(os.environ.get("DEFAULT_PG_VERSION", DEFAULT_VERSION)) is version,
-        reason=reason,
-    )
-
-
-def xfail_on_postgres(version: PgVersion, reason: str):
-    return pytest.mark.xfail(
-        PgVersion(os.environ.get("DEFAULT_PG_VERSION", DEFAULT_VERSION)) is version,
-        reason=reason,
-    )
-
-
-def run_only_on_default_postgres(reason: str):
-    return pytest.mark.skipif(
-        PgVersion(os.environ.get("DEFAULT_PG_VERSION", DEFAULT_VERSION)) is not DEFAULT_VERSION,
-        reason=reason,
-    )

test_runner/fixtures/remote_storage.py

@@ -77,14 +77,16 @@ class MockS3Server:
 class LocalFsStorage:
     root: Path
 
-    def tenant_path(self, tenant_id: TenantId) -> Path:
+    def tenant_path(self, tenant_id: Union[TenantId, TenantShardId]) -> Path:
         return self.root / "tenants" / str(tenant_id)
 
-    def timeline_path(self, tenant_id: TenantId, timeline_id: TimelineId) -> Path:
+    def timeline_path(
+        self, tenant_id: Union[TenantId, TenantShardId], timeline_id: TimelineId
+    ) -> Path:
         return self.tenant_path(tenant_id) / "timelines" / str(timeline_id)
 
     def timeline_latest_generation(
-        self, tenant_id: TenantId, timeline_id: TimelineId
+        self, tenant_id: Union[TenantId, TenantShardId], timeline_id: TimelineId
     ) -> Optional[int]:
         timeline_files = os.listdir(self.timeline_path(tenant_id, timeline_id))
         index_parts = [f for f in timeline_files if f.startswith("index_part")]
@@ -102,7 +104,9 @@ class LocalFsStorage:
             raise RuntimeError(f"No index_part found for {tenant_id}/{timeline_id}")
         return generations[-1]
 
-    def index_path(self, tenant_id: TenantId, timeline_id: TimelineId) -> Path:
+    def index_path(
+        self, tenant_id: Union[TenantId, TenantShardId], timeline_id: TimelineId
+    ) -> Path:
         latest_gen = self.timeline_latest_generation(tenant_id, timeline_id)
         if latest_gen is None:
             filename = TIMELINE_INDEX_PART_FILE_NAME
@@ -126,7 +130,9 @@ class LocalFsStorage:
         filename = f"{local_name}-{generation:08x}"
         return self.timeline_path(tenant_id, timeline_id) / filename
 
-    def index_content(self, tenant_id: TenantId, timeline_id: TimelineId) -> Any:
+    def index_content(
+        self, tenant_id: Union[TenantId, TenantShardId], timeline_id: TimelineId
+    ) -> Any:
         with self.index_path(tenant_id, timeline_id).open("r") as f:
             return json.load(f)
 

test_runner/fixtures/utils.py

@@ -25,6 +25,7 @@ from fixtures.pageserver.common_types import (
     parse_delta_layer,
     parse_image_layer,
 )
+from fixtures.pg_version import PgVersion
 
 if TYPE_CHECKING:
     from collections.abc import Iterable
@@ -37,6 +38,7 @@ if TYPE_CHECKING:
 
 
 Fn = TypeVar("Fn", bound=Callable[..., Any])
+
 COMPONENT_BINARIES = {
     "storage_controller": ("storage_controller",),
     "storage_broker": ("storage_broker",),
@@ -519,7 +521,7 @@ def assert_pageserver_backups_equal(left: Path, right: Path, skip_files: set[str
     This is essentially:
 
     lines=$(comm -3 \
-        <(mkdir left && cd left && tar xf "$left" && find . -type f -print0 | xargs sha256sum | sort -k2) \
+        <(mkdir left  && cd left  && tar xf "$left"  && find . -type f -print0 | xargs sha256sum | sort -k2) \
         <(mkdir right && cd right && tar xf "$right" && find . -type f -print0 | xargs sha256sum | sort -k2) \
         | wc -l)
     [ "$lines" = "0" ]
@@ -643,3 +645,40 @@ def allpairs_versions():
         )
         ids.append(f"combination_{''.join(cur_id)}")
     return {"argnames": "combination", "argvalues": tuple(argvalues), "ids": ids}
+
+
+def skip_on_postgres(version: PgVersion, reason: str):
+    return pytest.mark.skipif(
+        PgVersion(os.getenv("DEFAULT_PG_VERSION", PgVersion.DEFAULT)) is version,
+        reason=reason,
+    )
+
+
+def xfail_on_postgres(version: PgVersion, reason: str):
+    return pytest.mark.xfail(
+        PgVersion(os.getenv("DEFAULT_PG_VERSION", PgVersion.DEFAULT)) is version,
+        reason=reason,
+    )
+
+
+def run_only_on_default_postgres(reason: str):
+    return pytest.mark.skipif(
+        PgVersion(os.getenv("DEFAULT_PG_VERSION", PgVersion.DEFAULT)) is not PgVersion.DEFAULT,
+        reason=reason,
+    )
+
+
+def skip_in_debug_build(reason: str):
+    return pytest.mark.skipif(
+        os.getenv("BUILD_TYPE", "debug") == "debug",
+        reason=reason,
+    )
+
+
+def skip_on_ci(reason: str):
+    # `CI` variable is always set to `true` on GitHub
+    # Ref: https://docs.github.com/en/actions/writing-workflows/choosing-what-your-workflow-does/store-information-in-variables#default-environment-variables
+    return pytest.mark.skipif(
+        os.getenv("CI", "false") == "true",
+        reason=reason,
+    )

test_runner/performance/pageserver/pagebench/test_pageserver_max_throughput_getpage_at_latest_lsn.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import json
-import os
 from pathlib import Path
 from typing import TYPE_CHECKING
 
@@ -14,7 +13,7 @@ from fixtures.neon_fixtures import (
     PgBin,
     wait_for_last_flush_lsn,
 )
-from fixtures.utils import get_scale_for_db, humantime_to_ms
+from fixtures.utils import get_scale_for_db, humantime_to_ms, skip_on_ci
 
 from performance.pageserver.util import (
     setup_pageserver_with_tenants,
@@ -38,9 +37,8 @@ if TYPE_CHECKING:
 @pytest.mark.parametrize("pgbench_scale", [get_scale_for_db(200)])
 @pytest.mark.parametrize("n_tenants", [500])
 @pytest.mark.timeout(10000)
-@pytest.mark.skipif(
-    os.getenv("CI", "false") == "true",
-    reason="This test needs lot of resources and should run on dedicated HW, not in github action runners as part of CI",
+@skip_on_ci(
+    "This test needs lot of resources and should run on dedicated HW, not in github action runners as part of CI"
 )
 def test_pageserver_characterize_throughput_with_n_tenants(
     neon_env_builder: NeonEnvBuilder,
@@ -66,9 +64,8 @@ def test_pageserver_characterize_throughput_with_n_tenants(
 @pytest.mark.parametrize("n_clients", [1, 64])
 @pytest.mark.parametrize("n_tenants", [1])
 @pytest.mark.timeout(2400)
-@pytest.mark.skipif(
-    os.getenv("CI", "false") == "true",
-    reason="This test needs lot of resources and should run on dedicated HW, not in github action runners as part of CI",
+@skip_on_ci(
+    "This test needs lot of resources and should run on dedicated HW, not in github action runners as part of CI"
 )
 def test_pageserver_characterize_latencies_with_1_client_and_throughput_with_many_clients_one_tenant(
     neon_env_builder: NeonEnvBuilder,

test_runner/performance/test_logical_replication.py

@@ -1,6 +1,8 @@
 from __future__ import annotations
 
 import time
+from collections.abc import Iterator
+from contextlib import contextmanager
 from typing import TYPE_CHECKING, cast
 
 import psycopg2
@@ -18,7 +20,7 @@ if TYPE_CHECKING:
     from fixtures.benchmark_fixture import NeonBenchmarker
     from fixtures.neon_api import NeonApiEndpoint
     from fixtures.neon_fixtures import NeonEnv, PgBin, VanillaPostgres
-    from psycopg2.extensions import cursor
+    from psycopg2.extensions import connection, cursor
 
 
 @pytest.mark.timeout(1000)
@@ -149,12 +151,16 @@ def test_subscriber_lag(
                 check_pgbench_still_running(pub_workload, "pub")
                 check_pgbench_still_running(sub_workload, "sub")
 
-                with (
-                    psycopg2.connect(pub_connstr) as pub_conn,
-                    psycopg2.connect(sub_connstr) as sub_conn,
-                ):
-                    with pub_conn.cursor() as pub_cur, sub_conn.cursor() as sub_cur:
-                        lag = measure_logical_replication_lag(sub_cur, pub_cur)
+                pub_conn = psycopg2.connect(pub_connstr)
+                sub_conn = psycopg2.connect(sub_connstr)
+                pub_conn.autocommit = True
+                sub_conn.autocommit = True
+
+                with pub_conn.cursor() as pub_cur, sub_conn.cursor() as sub_cur:
+                    lag = measure_logical_replication_lag(sub_cur, pub_cur)
+
+                pub_conn.close()
+                sub_conn.close()
 
                 log.info(f"Replica lagged behind master by {lag} seconds")
                 zenbenchmark.record("replica_lag", lag, "s", MetricReport.LOWER_IS_BETTER)
@@ -206,6 +212,7 @@ def test_publisher_restart(
     sub_conn = psycopg2.connect(sub_connstr)
     pub_conn.autocommit = True
     sub_conn.autocommit = True
+
     with pub_conn.cursor() as pub_cur, sub_conn.cursor() as sub_cur:
         pub_cur.execute("SELECT 1 FROM pg_catalog.pg_publication WHERE pubname = 'pub1'")
         pub_exists = len(pub_cur.fetchall()) != 0
@@ -222,6 +229,7 @@ def test_publisher_restart(
             sub_cur.execute(f"create subscription sub1 connection '{pub_connstr}' publication pub1")
 
         initial_sync_lag = measure_logical_replication_lag(sub_cur, pub_cur)
+
     pub_conn.close()
     sub_conn.close()
 
@@ -248,12 +256,17 @@ def test_publisher_restart(
                     ["pgbench", "-c10", pgbench_duration, "-Mprepared"],
                     env=pub_env,
                 )
-                with (
-                    psycopg2.connect(pub_connstr) as pub_conn,
-                    psycopg2.connect(sub_connstr) as sub_conn,
-                ):
-                    with pub_conn.cursor() as pub_cur, sub_conn.cursor() as sub_cur:
-                        lag = measure_logical_replication_lag(sub_cur, pub_cur)
+
+                pub_conn = psycopg2.connect(pub_connstr)
+                sub_conn = psycopg2.connect(sub_connstr)
+                pub_conn.autocommit = True
+                sub_conn.autocommit = True
+
+                with pub_conn.cursor() as pub_cur, sub_conn.cursor() as sub_cur:
+                    lag = measure_logical_replication_lag(sub_cur, pub_cur)
+
+                pub_conn.close()
+                sub_conn.close()
 
                 log.info(f"Replica lagged behind master by {lag} seconds")
                 zenbenchmark.record("replica_lag", lag, "s", MetricReport.LOWER_IS_BETTER)
@@ -281,6 +294,48 @@ def test_snap_files(
     then runs pgbench inserts while generating large numbers of snapfiles. Then restarts
     the node and tries to peek the replication changes.
     """
+
+    @contextmanager
+    def replication_slot(conn: connection, slot_name: str) -> Iterator[None]:
+        """
+        Make sure that the replication slot doesn't outlive the test. Normally
+        we wouldn't want this behavior, but since the test creates and drops
+        the replication slot, we do.
+
+        We've had problems in the past where this slot sticking around caused
+        issues with the publisher retaining WAL during the execution of the
+        other benchmarks in this suite.
+        """
+
+        def __drop_replication_slot(c: cursor) -> None:
+            c.execute(
+                """
+                DO $$
+                BEGIN
+                    IF EXISTS (
+                        SELECT 1
+                        FROM pg_replication_slots
+                        WHERE slot_name = %(slot_name)s
+                    ) THEN
+                        PERFORM pg_drop_replication_slot(%(slot_name)s);
+                    END IF;
+                END $$;
+                """,
+                {"slot_name": slot_name},
+            )
+
+        with conn.cursor() as c:
+            __drop_replication_slot(c)
+            c.execute(
+                "SELECT pg_create_logical_replication_slot(%(slot_name)s, 'test_decoding')",
+                {"slot_name": slot_name},
+            )
+
+        yield
+
+        with conn.cursor() as c:
+            __drop_replication_slot(c)
+
     test_duration_min = 60
     test_interval_min = 5
     pgbench_duration = f"-T{test_duration_min * 60 * 2}"
@@ -288,50 +343,32 @@ def test_snap_files(
     env = benchmark_project_pub.pgbench_env
     connstr = benchmark_project_pub.connstr
 
-    with psycopg2.connect(connstr) as conn:
-        conn.autocommit = True
-        with conn.cursor() as cur:
-            cur.execute("SELECT rolsuper FROM pg_roles WHERE rolname = 'neondb_owner'")
-            is_super = cast("bool", cur.fetchall()[0][0])
-            assert is_super, "This benchmark won't work if we don't have superuser"
+    conn = psycopg2.connect(connstr)
+    conn.autocommit = True
+
+    with conn.cursor() as cur:
+        cur.execute("SELECT rolsuper FROM pg_roles WHERE rolname = 'neondb_owner'")
+        is_super = cast("bool", cur.fetchall()[0][0])
+        assert is_super, "This benchmark won't work if we don't have superuser"
+
+    conn.close()
 
     pg_bin.run_capture(["pgbench", "-i", "-I", "dtGvp", "-s100"], env=env)
 
     conn = psycopg2.connect(connstr)
     conn.autocommit = True
-    cur = conn.cursor()
-    cur.execute("ALTER SYSTEM SET neon.logical_replication_max_snap_files = -1")
 
-    with psycopg2.connect(connstr) as conn:
-        conn.autocommit = True
-        with conn.cursor() as cur:
-            cur.execute("SELECT pg_reload_conf()")
+    with replication_slot(conn, "slotter"):
+        workload = pg_bin.run_nonblocking(
+            ["pgbench", "-c10", pgbench_duration, "-Mprepared"], env=env
+        )
+        try:
+            start = time.time()
+            prev_measurement = time.time()
+            while time.time() - start < test_duration_min * 60:
+                conn = psycopg2.connect(connstr)
+                conn.autocommit = True
 
-    with psycopg2.connect(connstr) as conn:
-        conn.autocommit = True
-        with conn.cursor() as cur:
-            cur.execute(
-                """
-                DO $$
-                    BEGIN
-                    IF EXISTS (
-                        SELECT 1
-                        FROM pg_replication_slots
-                        WHERE slot_name = 'slotter'
-                    ) THEN
-                        PERFORM pg_drop_replication_slot('slotter');
-                    END IF;
-                END $$;
-            """
-            )
-            cur.execute("SELECT pg_create_logical_replication_slot('slotter', 'test_decoding')")
-
-    workload = pg_bin.run_nonblocking(["pgbench", "-c10", pgbench_duration, "-Mprepared"], env=env)
-    try:
-        start = time.time()
-        prev_measurement = time.time()
-        while time.time() - start < test_duration_min * 60:
-            with psycopg2.connect(connstr) as conn:
                 with conn.cursor() as cur:
                     cur.execute(
                         "SELECT count(*) FROM (SELECT pg_log_standby_snapshot() FROM generate_series(1, 10000) g) s"
@@ -341,12 +378,15 @@ def test_snap_files(
                         "SELECT pg_replication_slot_advance('slotter', pg_current_wal_lsn())"
                     )
 
-            # Measure storage
-            if time.time() - prev_measurement > test_interval_min * 60:
-                storage = benchmark_project_pub.get_synthetic_storage_size()
-                zenbenchmark.record("storage", storage, "B", MetricReport.LOWER_IS_BETTER)
-                prev_measurement = time.time()
-            time.sleep(test_interval_min * 60 / 3)
+                conn.close()
 
-    finally:
-        workload.terminate()
+                # Measure storage
+                if time.time() - prev_measurement > test_interval_min * 60:
+                    storage = benchmark_project_pub.get_synthetic_storage_size()
+                    zenbenchmark.record("storage", storage, "B", MetricReport.LOWER_IS_BETTER)
+                    prev_measurement = time.time()
+                time.sleep(test_interval_min * 60 / 3)
+        finally:
+            workload.terminate()
+
+    conn.close()

test_runner/performance/test_physical_replication.py

@@ -102,15 +102,21 @@ def test_ro_replica_lag(
                     check_pgbench_still_running(master_workload)
                     check_pgbench_still_running(replica_workload)
                     time.sleep(sync_interval_min * 60)
+
+                    conn_master = psycopg2.connect(master_connstr)
+                    conn_replica = psycopg2.connect(replica_connstr)
+                    conn_master.autocommit = True
+                    conn_replica.autocommit = True
+
                     with (
-                        psycopg2.connect(master_connstr) as conn_master,
-                        psycopg2.connect(replica_connstr) as conn_replica,
+                        conn_master.cursor() as cur_master,
+                        conn_replica.cursor() as cur_replica,
                     ):
-                        with (
-                            conn_master.cursor() as cur_master,
-                            conn_replica.cursor() as cur_replica,
-                        ):
-                            lag = measure_replication_lag(cur_master, cur_replica)
+                        lag = measure_replication_lag(cur_master, cur_replica)
+
+                    conn_master.close()
+                    conn_replica.close()
+
                     log.info(f"Replica lagged behind master by {lag} seconds")
                     zenbenchmark.record("replica_lag", lag, "s", MetricReport.LOWER_IS_BETTER)
             finally:
@@ -219,11 +225,15 @@ def test_replication_start_stop(
         pg_bin.run_capture(["pgbench", "-i", "-I", "dtGvp", "-s10"], env=master_env)
 
         # Sync replicas
-        with psycopg2.connect(master_connstr) as conn_master:
-            with conn_master.cursor() as cur_master:
-                for i in range(num_replicas):
-                    conn_replica = psycopg2.connect(replica_connstr[i])
-                    measure_replication_lag(cur_master, conn_replica.cursor())
+        conn_master = psycopg2.connect(master_connstr)
+        conn_master.autocommit = True
+
+        with conn_master.cursor() as cur_master:
+            for i in range(num_replicas):
+                conn_replica = psycopg2.connect(replica_connstr[i])
+                measure_replication_lag(cur_master, conn_replica.cursor())
+
+        conn_master.close()
 
         master_pgbench = pg_bin.run_nonblocking(
             [
@@ -277,17 +287,22 @@ def test_replication_start_stop(
 
             time.sleep(configuration_test_time_sec)
 
-            with psycopg2.connect(master_connstr) as conn_master:
-                with conn_master.cursor() as cur_master:
-                    for ireplica in range(num_replicas):
-                        replica_conn = psycopg2.connect(replica_connstr[ireplica])
-                        lag = measure_replication_lag(cur_master, replica_conn.cursor())
-                        zenbenchmark.record(
-                            f"Replica {ireplica} lag", lag, "s", MetricReport.LOWER_IS_BETTER
-                        )
-                        log.info(
-                            f"Replica {ireplica} lagging behind master by {lag} seconds after configuration {iconfig:>b}"
-                        )
+            conn_master = psycopg2.connect(master_connstr)
+            conn_master.autocommit = True
+
+            with conn_master.cursor() as cur_master:
+                for ireplica in range(num_replicas):
+                    replica_conn = psycopg2.connect(replica_connstr[ireplica])
+                    lag = measure_replication_lag(cur_master, replica_conn.cursor())
+                    zenbenchmark.record(
+                        f"Replica {ireplica} lag", lag, "s", MetricReport.LOWER_IS_BETTER
+                    )
+                    log.info(
+                        f"Replica {ireplica} lagging behind master by {lag} seconds after configuration {iconfig:>b}"
+                    )
+
+            conn_master.close()
+
         master_pgbench.terminate()
     except Exception as e:
         error_occurred = True

test_runner/regress/test_branch_and_gc.py

@@ -8,7 +8,7 @@ from fixtures.common_types import Lsn, TimelineId
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnv
 from fixtures.pageserver.http import TimelineCreate406
-from fixtures.utils import query_scalar
+from fixtures.utils import query_scalar, skip_in_debug_build
 
 
 # Test the GC implementation when running with branching.
@@ -48,10 +48,8 @@ from fixtures.utils import query_scalar
 # Because the delta layer D covering lsn1 is corrupted, creating a branch
 # starting from lsn1 should return an error as follows:
 #     could not find data for key ... at LSN ..., for request at LSN ...
-def test_branch_and_gc(neon_simple_env: NeonEnv, build_type: str):
-    if build_type == "debug":
-        pytest.skip("times out in debug builds")
-
+@skip_in_debug_build("times out in debug builds")
+def test_branch_and_gc(neon_simple_env: NeonEnv):
     env = neon_simple_env
     pageserver_http_client = env.pageserver.http_client()
 

test_runner/regress/test_compaction.py

@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import enum
 import json
-import os
 import time
 from typing import TYPE_CHECKING
 
@@ -13,7 +12,7 @@ from fixtures.neon_fixtures import (
     generate_uploads_and_deletions,
 )
 from fixtures.pageserver.http import PageserverApiException
-from fixtures.utils import wait_until
+from fixtures.utils import skip_in_debug_build, wait_until
 from fixtures.workload import Workload
 
 if TYPE_CHECKING:
@@ -32,7 +31,7 @@ AGGRESIVE_COMPACTION_TENANT_CONF = {
 }
 
 
-@pytest.mark.skipif(os.environ.get("BUILD_TYPE") == "debug", reason="only run with release build")
+@skip_in_debug_build("only run with release build")
 def test_pageserver_compaction_smoke(neon_env_builder: NeonEnvBuilder):
     """
     This is a smoke test that compaction kicks in. The workload repeatedly churns

test_runner/regress/test_download_extensions.py

@@ -12,6 +12,7 @@ from fixtures.neon_fixtures import (
     NeonEnvBuilder,
 )
 from fixtures.pg_version import PgVersion
+from fixtures.utils import skip_on_postgres
 from pytest_httpserver import HTTPServer
 from werkzeug.wrappers.request import Request
 from werkzeug.wrappers.response import Response
@@ -41,17 +42,14 @@ def neon_env_builder_local(
     return neon_env_builder
 
 
+@skip_on_postgres(PgVersion.V16, reason="TODO: PG16 extension building")
+@skip_on_postgres(PgVersion.V17, reason="TODO: PG17 extension building")
 def test_remote_extensions(
     httpserver: HTTPServer,
     neon_env_builder_local: NeonEnvBuilder,
     httpserver_listen_address,
     pg_version,
 ):
-    if pg_version == PgVersion.V16:
-        pytest.skip("TODO: PG16 extension building")
-    if pg_version == PgVersion.V17:
-        pytest.skip("TODO: PG17 extension building")
-
     # setup mock http server
     # that expects request for anon.tar.zst
     # and returns the requested file

test_runner/regress/test_ingestion_layer_size.py

@@ -4,25 +4,22 @@ from collections.abc import Iterable
 from dataclasses import dataclass
 from typing import TYPE_CHECKING
 
-import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder, wait_for_last_flush_lsn
 from fixtures.pageserver.http import HistoricLayerInfo, LayerMapInfo
-from fixtures.utils import human_bytes
+from fixtures.utils import human_bytes, skip_in_debug_build
 
 if TYPE_CHECKING:
     from typing import Union
 
 
-def test_ingesting_large_batches_of_images(neon_env_builder: NeonEnvBuilder, build_type: str):
+@skip_in_debug_build("debug run is unnecessarily slow")
+def test_ingesting_large_batches_of_images(neon_env_builder: NeonEnvBuilder):
     """
     Build a non-small GIN index which includes similarly batched up images in WAL stream as does pgvector
     to show that we no longer create oversized layers.
     """
 
-    if build_type == "debug":
-        pytest.skip("debug run is unnecessarily slow")
-
     minimum_initdb_size = 20 * 1024**2
     checkpoint_distance = 32 * 1024**2
     minimum_good_layer_size = checkpoint_distance * 0.9

test_runner/regress/test_installed_extensions.py

@@ -1,6 +1,14 @@
-from logging import info
+from __future__ import annotations
 
-from fixtures.neon_fixtures import NeonEnv
+import time
+from logging import info
+from typing import TYPE_CHECKING
+
+from fixtures.log_helper import log
+from fixtures.metrics import parse_metrics
+
+if TYPE_CHECKING:
+    from fixtures.neon_fixtures import NeonEnv
 
 
 def test_installed_extensions(neon_simple_env: NeonEnv):
@@ -85,3 +93,52 @@ def test_installed_extensions(neon_simple_env: NeonEnv):
             assert ext["n_databases"] == 2
             ext["versions"].sort()
             assert ext["versions"] == ["1.2", "1.3"]
+
+    # check that /metrics endpoint is available
+    # ensure that we see the metric before and after restart
+    res = client.metrics()
+    info("Metrics: %s", res)
+    m = parse_metrics(res)
+    neon_m = m.query_all("installed_extensions", {"extension_name": "neon", "version": "1.2"})
+    assert len(neon_m) == 1
+    for sample in neon_m:
+        assert sample.value == 2
+    neon_m = m.query_all("installed_extensions", {"extension_name": "neon", "version": "1.3"})
+    assert len(neon_m) == 1
+    for sample in neon_m:
+        assert sample.value == 1
+
+    endpoint.stop()
+    endpoint.start()
+
+    timeout = 10
+    while timeout > 0:
+        try:
+            res = client.metrics()
+            timeout = -1
+            if len(parse_metrics(res).query_all("installed_extensions")) < 4:
+                # Assume that not all metrics that are collected yet
+                time.sleep(1)
+                timeout -= 1
+                continue
+        except Exception:
+            log.exception("failed to get metrics, assume they are not collected yet")
+            time.sleep(1)
+            timeout -= 1
+            continue
+
+        assert (
+            len(parse_metrics(res).query_all("installed_extensions")) >= 4
+        ), "Not all metrics are collected"
+
+        info("After restart metrics: %s", res)
+        m = parse_metrics(res)
+        neon_m = m.query_all("installed_extensions", {"extension_name": "neon", "version": "1.2"})
+        assert len(neon_m) == 1
+        for sample in neon_m:
+            assert sample.value == 1
+
+        neon_m = m.query_all("installed_extensions", {"extension_name": "neon", "version": "1.3"})
+        assert len(neon_m) == 1
+        for sample in neon_m:
+            assert sample.value == 1

test_runner/regress/test_layer_bloating.py

@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import os
 
-import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import (
     NeonEnvBuilder,
@@ -10,12 +9,18 @@ from fixtures.neon_fixtures import (
     wait_for_last_flush_lsn,
 )
 from fixtures.pg_version import PgVersion
+from fixtures.utils import skip_on_postgres
 
 
+@skip_on_postgres(
+    PgVersion.V14,
+    reason="pg_log_standby_snapshot() function is available since Postgres 16",
+)
+@skip_on_postgres(
+    PgVersion.V15,
+    reason="pg_log_standby_snapshot() function is available since Postgres 16",
+)
 def test_layer_bloating(neon_env_builder: NeonEnvBuilder, vanilla_pg):
-    if neon_env_builder.pg_version != PgVersion.V16:
-        pytest.skip("pg_log_standby_snapshot() function is available only in PG16")
-
     env = neon_env_builder.init_start(
         initial_tenant_conf={
             "gc_period": "0s",

test_runner/regress/test_layer_eviction.py

@@ -2,7 +2,6 @@ from __future__ import annotations
 
 import time
 
-import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import (
     NeonEnvBuilder,
@@ -12,17 +11,13 @@ from fixtures.neon_fixtures import (
 from fixtures.pageserver.common_types import parse_layer_file_name
 from fixtures.pageserver.utils import wait_for_upload
 from fixtures.remote_storage import RemoteStorageKind
+from fixtures.utils import skip_in_debug_build
 
 
 # Crates a few layers, ensures that we can evict them (removing locally but keeping track of them anyway)
 # and then download them back.
-def test_basic_eviction(
-    neon_env_builder: NeonEnvBuilder,
-    build_type: str,
-):
-    if build_type == "debug":
-        pytest.skip("times out in debug builds")
-
+@skip_in_debug_build("times out in debug builds")
+def test_basic_eviction(neon_env_builder: NeonEnvBuilder):
     neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.LOCAL_FS)
 
     env = neon_env_builder.init_start(

test_runner/regress/test_logging.py

@@ -5,8 +5,7 @@ import uuid
 import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder
-from fixtures.pg_version import run_only_on_default_postgres
-from fixtures.utils import wait_until
+from fixtures.utils import run_only_on_default_postgres, wait_until
 
 
 @pytest.mark.parametrize("level", ["trace", "debug", "info", "warn", "error"])

test_runner/regress/test_logical_replication.py

@@ -4,24 +4,31 @@ import time
 from functools import partial
 from random import choice
 from string import ascii_lowercase
+from typing import TYPE_CHECKING, cast
 
-from fixtures.common_types import Lsn
+from fixtures.common_types import Lsn, TenantId, TimelineId
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import (
-    NeonEnv,
-    NeonEnvBuilder,
-    PgProtocol,
     logical_replication_sync,
     wait_for_last_flush_lsn,
 )
 from fixtures.utils import wait_until
 
+if TYPE_CHECKING:
+    from fixtures.neon_fixtures import (
+        Endpoint,
+        NeonEnv,
+        NeonEnvBuilder,
+        PgProtocol,
+        VanillaPostgres,
+    )
+
 
 def random_string(n: int):
     return "".join([choice(ascii_lowercase) for _ in range(n)])
 
 
-def test_logical_replication(neon_simple_env: NeonEnv, vanilla_pg):
+def test_logical_replication(neon_simple_env: NeonEnv, vanilla_pg: VanillaPostgres):
     env = neon_simple_env
 
     tenant_id = env.initial_tenant
@@ -160,10 +167,10 @@ COMMIT;
 
 
 # Test that neon.logical_replication_max_snap_files works
-def test_obsolete_slot_drop(neon_simple_env: NeonEnv, vanilla_pg):
-    def slot_removed(ep):
+def test_obsolete_slot_drop(neon_simple_env: NeonEnv, vanilla_pg: VanillaPostgres):
+    def slot_removed(ep: Endpoint):
         assert (
-            endpoint.safe_psql(
+            ep.safe_psql(
                 "select count(*) from pg_replication_slots where slot_name = 'stale_slot'"
             )[0][0]
             == 0
@@ -254,7 +261,7 @@ FROM generate_series(1, 16384) AS seq; -- Inserts enough rows to exceed 16MB of
 
 
 # Tests that walsender correctly blocks until WAL is downloaded from safekeepers
-def test_lr_with_slow_safekeeper(neon_env_builder: NeonEnvBuilder, vanilla_pg):
+def test_lr_with_slow_safekeeper(neon_env_builder: NeonEnvBuilder, vanilla_pg: VanillaPostgres):
     neon_env_builder.num_safekeepers = 3
     env = neon_env_builder.init_start()
 
@@ -336,13 +343,13 @@ FROM generate_series(1, 16384) AS seq; -- Inserts enough rows to exceed 16MB of
 #
 # Most pages start with a contrecord, so we don't do anything special
 # to ensure that.
-def test_restart_endpoint(neon_simple_env: NeonEnv, vanilla_pg):
+def test_restart_endpoint(neon_simple_env: NeonEnv, vanilla_pg: VanillaPostgres):
     env = neon_simple_env
 
     env.create_branch("init")
     endpoint = env.endpoints.create_start("init")
-    tenant_id = endpoint.safe_psql("show neon.tenant_id")[0][0]
-    timeline_id = endpoint.safe_psql("show neon.timeline_id")[0][0]
+    tenant_id = TenantId(cast("str", endpoint.safe_psql("show neon.tenant_id")[0][0]))
+    timeline_id = TimelineId(cast("str", endpoint.safe_psql("show neon.timeline_id")[0][0]))
 
     cur = endpoint.connect().cursor()
     cur.execute("create table t(key int, value text)")
@@ -380,7 +387,7 @@ def test_restart_endpoint(neon_simple_env: NeonEnv, vanilla_pg):
 # logical replication bug as such, but without logical replication,
 # records passed ot the WAL redo process are never large enough to hit
 # the bug.
-def test_large_records(neon_simple_env: NeonEnv, vanilla_pg):
+def test_large_records(neon_simple_env: NeonEnv, vanilla_pg: VanillaPostgres):
     env = neon_simple_env
 
     env.create_branch("init")
@@ -522,15 +529,20 @@ def logical_replication_wait_flush_lsn_sync(publisher: PgProtocol) -> Lsn:
     because for some WAL records like vacuum subscriber won't get any data at
     all.
     """
-    publisher_flush_lsn = Lsn(publisher.safe_psql("SELECT pg_current_wal_flush_lsn()")[0][0])
+    publisher_flush_lsn = Lsn(
+        cast("str", publisher.safe_psql("SELECT pg_current_wal_flush_lsn()")[0][0])
+    )
 
     def check_caughtup():
-        res = publisher.safe_psql(
-            """
+        res = cast(
+            "tuple[str, str, str]",
+            publisher.safe_psql(
+                """
 select sent_lsn, flush_lsn, pg_current_wal_flush_lsn() from pg_stat_replication sr, pg_replication_slots s
    where s.active_pid = sr.pid and s.slot_type = 'logical';
                                   """
-        )[0]
+            )[0],
+        )
         sent_lsn, flush_lsn, curr_publisher_flush_lsn = Lsn(res[0]), Lsn(res[1]), Lsn(res[2])
         log.info(
             f"sent_lsn={sent_lsn}, flush_lsn={flush_lsn}, publisher_flush_lsn={curr_publisher_flush_lsn}, waiting flush_lsn to reach {publisher_flush_lsn}"
@@ -545,7 +557,7 @@ select sent_lsn, flush_lsn, pg_current_wal_flush_lsn() from pg_stat_replication
 # flush_lsn reporting to publisher. Without this, subscriber may ack too far,
 # losing data on restart because publisher implicitly advances positition given
 # in START_REPLICATION to the confirmed_flush_lsn of the slot.
-def test_subscriber_synchronous_commit(neon_simple_env: NeonEnv, vanilla_pg):
+def test_subscriber_synchronous_commit(neon_simple_env: NeonEnv, vanilla_pg: VanillaPostgres):
     env = neon_simple_env
     # use vanilla as publisher to allow writes on it when safekeeper is down
     vanilla_pg.configure(
@@ -593,7 +605,7 @@ def test_subscriber_synchronous_commit(neon_simple_env: NeonEnv, vanilla_pg):
     # logical_replication_wait_flush_lsn_sync is expected to hang while
     # safekeeper is down.
     vanilla_pg.safe_psql("checkpoint;")
-    assert sub.safe_psql_scalar("SELECT count(*) FROM t") == 1000
+    assert cast("int", sub.safe_psql_scalar("SELECT count(*) FROM t")) == 1000
 
     # restart subscriber and ensure it can catch up lost tail again
     sub.stop(mode="immediate")

test_runner/regress/test_neon_cli.py

@@ -1,6 +1,5 @@
 from __future__ import annotations
 
-import os
 import subprocess
 from pathlib import Path
 from typing import cast
@@ -15,7 +14,7 @@ from fixtures.neon_fixtures import (
     parse_project_git_version_output,
 )
 from fixtures.pageserver.http import PageserverHttpClient
-from fixtures.pg_version import PgVersion, skip_on_postgres
+from fixtures.utils import run_only_on_default_postgres, skip_in_debug_build
 
 
 def helper_compare_timeline_list(
@@ -195,10 +194,8 @@ def test_cli_start_stop_multi(neon_env_builder: NeonEnvBuilder):
     res.check_returncode()
 
 
-@skip_on_postgres(PgVersion.V14, reason="does not use postgres")
-@pytest.mark.skipif(
-    os.environ.get("BUILD_TYPE") == "debug", reason="unit test for test support, either build works"
-)
+@run_only_on_default_postgres(reason="does not use postgres")
+@skip_in_debug_build("unit test for test support, either build works")
 def test_parse_project_git_version_output_positive():
     commit = "b6f77b5816cf1dba12a3bc8747941182ce220846"
 
@@ -217,10 +214,8 @@ def test_parse_project_git_version_output_positive():
         assert parse_project_git_version_output(example) == commit
 
 
-@skip_on_postgres(PgVersion.V14, reason="does not use postgres")
-@pytest.mark.skipif(
-    os.environ.get("BUILD_TYPE") == "debug", reason="unit test for test support, either build works"
-)
+@run_only_on_default_postgres(reason="does not use postgres")
+@skip_in_debug_build("unit test for test support, either build works")
 def test_parse_project_git_version_output_local_docker():
     """
     Makes sure the tests don't accept the default version in Dockerfile one gets without providing
@@ -234,10 +229,8 @@ def test_parse_project_git_version_output_local_docker():
     assert input in str(e)
 
 
-@skip_on_postgres(PgVersion.V14, reason="does not use postgres")
-@pytest.mark.skipif(
-    os.environ.get("BUILD_TYPE") == "debug", reason="cli api sanity, either build works"
-)
+@run_only_on_default_postgres(reason="does not use postgres")
+@skip_in_debug_build("unit test for test support, either build works")
 def test_binaries_version_parses(neon_binpath: Path):
     """
     Ensures that we can parse the actual outputs of --version from a set of binaries.

test_runner/regress/test_pageserver_generations.py

@@ -35,9 +35,10 @@ from fixtures.pageserver.utils import (
     wait_for_upload,
 )
 from fixtures.remote_storage import (
+    LocalFsStorage,
     RemoteStorageKind,
 )
-from fixtures.utils import wait_until
+from fixtures.utils import run_only_on_default_postgres, wait_until
 from fixtures.workload import Workload
 
 if TYPE_CHECKING:
@@ -728,3 +729,68 @@ def test_upgrade_generationless_local_file_paths(
     )
     # We should download into the same local path we started with
     assert os.path.exists(victim_path)
+
+
+@run_only_on_default_postgres("Only tests index logic")
+def test_old_index_time_threshold(
+    neon_env_builder: NeonEnvBuilder,
+):
+    """
+    Exercise pageserver's detection of trying to load an ancient non-latest index.
+    (see https://github.com/neondatabase/neon/issues/6951)
+    """
+
+    # Run with local_fs because we will interfere with mtimes by local filesystem access
+    neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.LOCAL_FS)
+    env = neon_env_builder.init_start()
+    tenant_id = env.initial_tenant
+    timeline_id = env.initial_timeline
+
+    workload = Workload(env, tenant_id, timeline_id)
+    workload.init()
+    workload.write_rows(32)
+
+    # Remember generation 1's index path
+    assert isinstance(env.pageserver_remote_storage, LocalFsStorage)
+    index_path = env.pageserver_remote_storage.index_path(tenant_id, timeline_id)
+
+    # Increment generation by detaching+attaching, and write+flush some data to get a new remote index
+    env.storage_controller.tenant_policy_update(tenant_id, {"placement": "Detached"})
+    env.storage_controller.tenant_policy_update(tenant_id, {"placement": {"Attached": 0}})
+    env.storage_controller.reconcile_until_idle()
+    workload.churn_rows(32)
+
+    # A new index should have been written
+    assert env.pageserver_remote_storage.index_path(tenant_id, timeline_id) != index_path
+
+    # Hack the mtime on the generation 1 index
+    log.info(f"Setting old mtime on {index_path}")
+    os.utime(index_path, times=(time.time(), time.time() - 30 * 24 * 3600))
+    env.pageserver.allowed_errors.extend(
+        [
+            ".*Found a newer index while loading an old one.*",
+            ".*Index age exceeds threshold and a newer index exists.*",
+        ]
+    )
+
+    # Detach from storage controller + attach in an old generation directly on the pageserver.
+    workload.stop()
+    env.storage_controller.tenant_policy_update(tenant_id, {"placement": "Detached"})
+    env.storage_controller.reconcile_until_idle()
+    env.storage_controller.tenant_policy_update(tenant_id, {"scheduling": "Stop"})
+    env.storage_controller.allowed_errors.append(".*Scheduling is disabled by policy")
+
+    # The controller would not do this (attach in an old generation): we are doing it to simulate
+    # a hypothetical profound bug in the controller.
+    env.pageserver.http_client().tenant_location_conf(
+        tenant_id, {"generation": 1, "mode": "AttachedSingle", "tenant_conf": {}}
+    )
+
+    # The pageserver should react to this situation by refusing to attach the tenant and putting
+    # it into Broken state
+    env.pageserver.allowed_errors.append(".*tenant is broken.*")
+    with pytest.raises(
+        PageserverApiException,
+        match="tenant is broken: Index age exceeds threshold and a newer index exists",
+    ):
+        env.pageserver.http_client().timeline_detail(tenant_id, timeline_id)

test_runner/regress/test_pageserver_layer_rolling.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import asyncio
-import os
 import time
 from typing import TYPE_CHECKING
 
@@ -16,7 +15,7 @@ from fixtures.neon_fixtures import (
 )
 from fixtures.pageserver.http import PageserverHttpClient
 from fixtures.pageserver.utils import wait_for_last_record_lsn, wait_for_upload
-from fixtures.utils import wait_until
+from fixtures.utils import skip_in_debug_build, wait_until
 
 if TYPE_CHECKING:
     from typing import Optional
@@ -227,12 +226,9 @@ def test_idle_checkpoints(neon_env_builder: NeonEnvBuilder):
         assert get_dirty_bytes(env) >= dirty_after_write
 
 
-@pytest.mark.skipif(
-    # We have to use at least ~100MB of data to hit the lowest limit we can configure, which is
-    # prohibitively slow in debug mode
-    os.getenv("BUILD_TYPE") == "debug",
-    reason="Avoid running bulkier ingest tests in debug mode",
-)
+# We have to use at least ~100MB of data to hit the lowest limit we can configure, which is
+# prohibitively slow in debug mode
+@skip_in_debug_build("Avoid running bulkier ingest tests in debug mode")
 def test_total_size_limit(neon_env_builder: NeonEnvBuilder):
     """
     Test that checkpoints are done based on total ephemeral layer size, even if no one timeline is

test_runner/regress/test_pageserver_restart.py

@@ -8,7 +8,7 @@ import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnvBuilder
 from fixtures.remote_storage import s3_storage
-from fixtures.utils import wait_until
+from fixtures.utils import skip_in_debug_build, wait_until
 
 
 # Test restarting page server, while safekeeper and compute node keep
@@ -155,12 +155,8 @@ def test_pageserver_restart(neon_env_builder: NeonEnvBuilder):
 # safekeeper and compute node keep running.
 @pytest.mark.timeout(540)
 @pytest.mark.parametrize("shard_count", [None, 4])
-def test_pageserver_chaos(
-    neon_env_builder: NeonEnvBuilder, build_type: str, shard_count: Optional[int]
-):
-    if build_type == "debug":
-        pytest.skip("times out in debug builds")
-
+@skip_in_debug_build("times out in debug builds")
+def test_pageserver_chaos(neon_env_builder: NeonEnvBuilder, shard_count: Optional[int]):
     # same rationale as with the immediate stop; we might leave orphan layers behind.
     neon_env_builder.disable_scrub_on_exit()
     neon_env_builder.enable_pageserver_remote_storage(s3_storage())

test_runner/regress/test_pageserver_secondary.py

@@ -17,7 +17,7 @@ from fixtures.pageserver.utils import (
     wait_for_upload_queue_empty,
 )
 from fixtures.remote_storage import LocalFsStorage, RemoteStorageKind, S3Storage, s3_storage
-from fixtures.utils import wait_until
+from fixtures.utils import skip_in_debug_build, wait_until
 from fixtures.workload import Workload
 from werkzeug.wrappers.request import Request
 from werkzeug.wrappers.response import Response
@@ -765,7 +765,7 @@ def test_secondary_background_downloads(neon_env_builder: NeonEnvBuilder):
     assert download_rate < expect_download_rate * 2
 
 
-@pytest.mark.skipif(os.environ.get("BUILD_TYPE") == "debug", reason="only run with release build")
+@skip_in_debug_build("only run with release build")
 @pytest.mark.parametrize("via_controller", [True, False])
 def test_slow_secondary_downloads(neon_env_builder: NeonEnvBuilder, via_controller: bool):
     """

test_runner/regress/test_pg_regress.py

@@ -3,7 +3,6 @@
 #
 from __future__ import annotations
 
-import os
 from concurrent.futures import ThreadPoolExecutor
 from pathlib import Path
 from typing import TYPE_CHECKING, cast
@@ -19,6 +18,7 @@ from fixtures.neon_fixtures import (
 )
 from fixtures.pg_version import PgVersion
 from fixtures.remote_storage import s3_storage
+from fixtures.utils import skip_in_debug_build
 
 if TYPE_CHECKING:
     from typing import Optional
@@ -110,13 +110,15 @@ def post_checks(env: NeonEnv, test_output_dir: Path, db_name: str, endpoint: End
 
     check_restored_datadir_content(test_output_dir, env, endpoint, ignored_files=ignored_files)
 
-    # Ensure that compaction works, on a timeline containing all the diversity that postgres regression tests create.
+    # Ensure that compaction/GC works, on a timeline containing all the diversity that postgres regression tests create.
     # There should have been compactions mid-test as well, this final check is in addition those.
     for shard, pageserver in tenant_get_shards(env, env.initial_tenant):
         pageserver.http_client().timeline_checkpoint(
             shard, env.initial_timeline, force_repartition=True, force_image_layer_creation=True
         )
 
+        pageserver.http_client().timeline_gc(shard, env.initial_timeline, None)
+
 
 # Run the main PostgreSQL regression tests, in src/test/regress.
 #
@@ -329,7 +331,7 @@ def test_sql_regress(
     post_checks(env, test_output_dir, DBNAME, endpoint)
 
 
-@pytest.mark.skipif(os.environ.get("BUILD_TYPE") == "debug", reason="only run with release build")
+@skip_in_debug_build("only run with release build")
 def test_tx_abort_with_many_relations(
     neon_env_builder: NeonEnvBuilder,
 ):

test_runner/regress/test_physical_and_logical_replicaiton.py

@@ -5,7 +5,8 @@ import time
 from fixtures.neon_fixtures import NeonEnv, logical_replication_sync
 
 
-def test_physical_and_logical_replication(neon_simple_env: NeonEnv, vanilla_pg):
+def test_physical_and_logical_replication_slot_not_copied(neon_simple_env: NeonEnv, vanilla_pg):
+    """Test read replica of a primary which has a logical replication publication"""
     env = neon_simple_env
 
     n_records = 100000
@@ -13,7 +14,6 @@ def test_physical_and_logical_replication(neon_simple_env: NeonEnv, vanilla_pg):
     primary = env.endpoints.create_start(
         branch_name="main",
         endpoint_id="primary",
-        config_lines=["min_wal_size=32MB", "max_wal_size=64MB"],
     )
     p_con = primary.connect()
     p_cur = p_con.cursor()
@@ -30,7 +30,6 @@ def test_physical_and_logical_replication(neon_simple_env: NeonEnv, vanilla_pg):
     secondary = env.endpoints.new_replica_start(
         origin=primary,
         endpoint_id="secondary",
-        config_lines=["min_wal_size=32MB", "max_wal_size=64MB"],
     )
 
     s_con = secondary.connect()
@@ -48,3 +47,51 @@ def test_physical_and_logical_replication(neon_simple_env: NeonEnv, vanilla_pg):
     # Check that LR slot is not copied to replica
     s_cur.execute("select count(*) from pg_replication_slots")
     assert s_cur.fetchall()[0][0] == 0
+
+
+def test_aux_not_logged_at_replica(neon_simple_env: NeonEnv, vanilla_pg):
+    """Test that AUX files are not saved at replica"""
+    env = neon_simple_env
+
+    n_records = 20000
+
+    primary = env.endpoints.create_start(
+        branch_name="main",
+        endpoint_id="primary",
+    )
+    p_con = primary.connect()
+    p_cur = p_con.cursor()
+    p_cur.execute("CREATE TABLE t(pk bigint primary key, payload text default repeat('?',200))")
+    p_cur.execute("create publication pub1 for table t")
+
+    # start subscriber
+    vanilla_pg.start()
+    vanilla_pg.safe_psql("CREATE TABLE t(pk bigint primary key, payload text)")
+    connstr = primary.connstr().replace("'", "''")
+    vanilla_pg.safe_psql(f"create subscription sub1 connection '{connstr}' publication pub1")
+
+    for pk in range(n_records):
+        p_cur.execute("insert into t (pk) values (%s)", (pk,))
+
+    # LR snapshot is stored each 15 seconds
+    time.sleep(16)
+
+    # start replica
+    secondary = env.endpoints.new_replica_start(
+        origin=primary,
+        endpoint_id="secondary",
+    )
+
+    s_con = secondary.connect()
+    s_cur = s_con.cursor()
+
+    logical_replication_sync(vanilla_pg, primary)
+
+    assert vanilla_pg.safe_psql("select count(*) from t")[0][0] == n_records
+    s_cur.execute("select count(*) from t")
+    assert s_cur.fetchall()[0][0] == n_records
+
+    vanilla_pg.stop()
+    secondary.stop()
+    primary.stop()
+    assert not secondary.log_contains("cannot make new WAL entries during recovery")

test_runner/regress/test_readonly_node.py

@@ -122,6 +122,7 @@ def test_readonly_node(neon_simple_env: NeonEnv):
         )
 
 
+@pytest.mark.skip("See https://github.com/neondatabase/neon/issues/9754")
 def test_readonly_node_gc(neon_env_builder: NeonEnvBuilder):
     """
     Test static endpoint is protected from GC by acquiring and renewing lsn leases.

test_runner/regress/test_replica_start.py

@@ -30,7 +30,7 @@ import pytest
 from fixtures.log_helper import log
 from fixtures.neon_fixtures import NeonEnv, wait_for_last_flush_lsn, wait_replica_caughtup
 from fixtures.pg_version import PgVersion
-from fixtures.utils import query_scalar, wait_until
+from fixtures.utils import query_scalar, skip_on_postgres, wait_until
 
 CREATE_SUBXACTS_FUNC = """
 create or replace function create_subxacts(n integer) returns void as $$
@@ -137,6 +137,12 @@ def test_replica_start_scan_clog_crashed_xids(neon_simple_env: NeonEnv):
     assert secondary_cur.fetchone() == (1,)
 
 
+@skip_on_postgres(
+    PgVersion.V14, reason="pg_log_standby_snapshot() function is available since Postgres 16"
+)
+@skip_on_postgres(
+    PgVersion.V15, reason="pg_log_standby_snapshot() function is available since Postgres 16"
+)
 def test_replica_start_at_running_xacts(neon_simple_env: NeonEnv, pg_version):
     """
     Test that starting a replica works right after the primary has
@@ -149,9 +155,6 @@ def test_replica_start_at_running_xacts(neon_simple_env: NeonEnv, pg_version):
     """
     env = neon_simple_env
 
-    if env.pg_version == PgVersion.V14 or env.pg_version == PgVersion.V15:
-        pytest.skip("pg_log_standby_snapshot() function is available only in PG16")
-
     primary = env.endpoints.create_start(branch_name="main", endpoint_id="primary")
     primary_conn = primary.connect()
     primary_cur = primary_conn.cursor()

test_runner/regress/test_sharding.py

@@ -19,8 +19,8 @@ from fixtures.neon_fixtures import (
     wait_for_last_flush_lsn,
 )
 from fixtures.pageserver.utils import assert_prefix_empty, assert_prefix_not_empty
-from fixtures.remote_storage import s3_storage
-from fixtures.utils import wait_until
+from fixtures.remote_storage import LocalFsStorage, RemoteStorageKind, s3_storage
+from fixtures.utils import skip_in_debug_build, wait_until
 from fixtures.workload import Workload
 from pytest_httpserver import HTTPServer
 from typing_extensions import override
@@ -853,12 +853,9 @@ def test_sharding_split_stripe_size(
     wait_until(10, 1, assert_restart_notification)
 
 
-@pytest.mark.skipif(
-    # The quantity of data isn't huge, but debug can be _very_ slow, and the things we're
-    # validating in this test don't benefit much from debug assertions.
-    os.getenv("BUILD_TYPE") == "debug",
-    reason="Avoid running bulkier ingest tests in debug mode",
-)
+# The quantity of data isn't huge, but debug can be _very_ slow, and the things we're
+# validating in this test don't benefit much from debug assertions.
+@skip_in_debug_build("Avoid running bulkier ingest tests in debug mode")
 def test_sharding_ingest_layer_sizes(
     neon_env_builder: NeonEnvBuilder,
 ):
@@ -1688,3 +1685,111 @@ def test_top_tenants(neon_env_builder: NeonEnvBuilder):
     )
     assert len(top["shards"]) == n_tenants - 4
     assert set(i["id"] for i in top["shards"]) == set(str(i[0]) for i in tenants[4:])
+
+
+def test_sharding_gc(
+    neon_env_builder: NeonEnvBuilder,
+):
+    """
+    Exercise GC in a sharded tenant: because only shard 0 holds SLRU content, it acts as
+    the "leader" for GC, and other shards read its index to learn what LSN they should
+    GC up to.
+    """
+
+    shard_count = 4
+    neon_env_builder.num_pageservers = shard_count
+    neon_env_builder.enable_pageserver_remote_storage(RemoteStorageKind.LOCAL_FS)
+
+    TENANT_CONF = {
+        # small checkpointing and compaction targets to ensure we generate many upload operations
+        "checkpoint_distance": 128 * 1024,
+        "compaction_threshold": 1,
+        "compaction_target_size": 128 * 1024,
+        # A short PITR horizon, so that we won't have to sleep too long in the test to wait for it to
+        # happen.
+        "pitr_interval": "1s",
+        # disable background compaction and GC. We invoke it manually when we want it to happen.
+        "gc_period": "0s",
+        "compaction_period": "0s",
+        # Disable automatic creation of image layers, as we will create them explicitly when we want them
+        "image_creation_threshold": 9999,
+        "image_layer_creation_check_threshold": 0,
+        "lsn_lease_length": "0s",
+    }
+    env = neon_env_builder.init_start(
+        initial_tenant_shard_count=shard_count, initial_tenant_conf=TENANT_CONF
+    )
+
+    tenant_id = env.initial_tenant
+    timeline_id = env.initial_timeline
+
+    # Create a branch and write some data
+    workload = Workload(env, tenant_id, timeline_id)
+    initial_lsn = Lsn(workload.endpoint().safe_psql("SELECT pg_current_wal_lsn()")[0][0])
+    log.info(f"Started at LSN: {initial_lsn}")
+
+    workload.init()
+
+    # Write enough data to generate multiple layers
+    for _i in range(10):
+        last_lsn = workload.write_rows(32)
+
+    assert last_lsn > initial_lsn
+
+    log.info(f"Wrote up to last LSN: {last_lsn}")
+
+    # Do full image layer generation. When we subsequently wait for PITR, all historic deltas
+    # should be GC-able
+    for shard_number in range(shard_count):
+        shard = TenantShardId(tenant_id, shard_number, shard_count)
+        env.get_tenant_pageserver(shard).http_client().timeline_compact(
+            shard, timeline_id, force_image_layer_creation=True
+        )
+
+    workload.churn_rows(32)
+
+    time.sleep(5)
+
+    # Invoke GC on a non-zero shard and verify its GC cutoff LSN does not advance
+    shard_one = TenantShardId(tenant_id, 1, shard_count)
+    env.get_tenant_pageserver(shard_one).http_client().timeline_gc(
+        shard_one, timeline_id, gc_horizon=None
+    )
+
+    # Check shard 1's index - GC cutoff LSN should not have advanced
+    assert isinstance(env.pageserver_remote_storage, LocalFsStorage)
+    shard_1_index = env.pageserver_remote_storage.index_content(
+        tenant_id=shard_one, timeline_id=timeline_id
+    )
+    shard_1_gc_cutoff_lsn = Lsn(shard_1_index["metadata_bytes"]["latest_gc_cutoff_lsn"])
+    log.info(f"Shard 1 cutoff LSN: {shard_1_gc_cutoff_lsn}")
+    assert shard_1_gc_cutoff_lsn <= last_lsn
+
+    shard_zero = TenantShardId(tenant_id, 0, shard_count)
+    env.get_tenant_pageserver(shard_zero).http_client().timeline_gc(
+        shard_zero, timeline_id, gc_horizon=None
+    )
+
+    # TODO: observe that GC LSN of shard 0 has moved forward in remote storage
+    assert isinstance(env.pageserver_remote_storage, LocalFsStorage)
+    shard_0_index = env.pageserver_remote_storage.index_content(
+        tenant_id=shard_zero, timeline_id=timeline_id
+    )
+    shard_0_gc_cutoff_lsn = Lsn(shard_0_index["metadata_bytes"]["latest_gc_cutoff_lsn"])
+    log.info(f"Shard 0 cutoff LSN: {shard_0_gc_cutoff_lsn}")
+    assert shard_0_gc_cutoff_lsn >= last_lsn
+
+    # Invoke GC on all other shards and verify their GC cutoff LSNs
+    for shard_number in range(1, shard_count):
+        shard = TenantShardId(tenant_id, shard_number, shard_count)
+        env.get_tenant_pageserver(shard).http_client().timeline_gc(
+            shard, timeline_id, gc_horizon=None
+        )
+
+        # Verify GC cutoff LSN advanced to match shard 0
+        shard_index = env.pageserver_remote_storage.index_content(
+            tenant_id=shard, timeline_id=timeline_id
+        )
+        shard_gc_cutoff_lsn = Lsn(shard_index["metadata_bytes"]["latest_gc_cutoff_lsn"])
+        log.info(f"Shard {shard_number} cutoff LSN: {shard_gc_cutoff_lsn}")
+        assert shard_gc_cutoff_lsn == shard_0_gc_cutoff_lsn