Merge pull request #4997 from neondatabase/sk/proxy-release-23-07-15

Fix lint

.dockerignore

@@ -21,4 +21,5 @@
 !workspace_hack/
 !neon_local/
 !scripts/ninstall.sh
+!scripts/combine_control_files.py
 !vm-cgconfig.conf

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

@@ -2,6 +2,12 @@ name: 'Create Allure report'
 description: 'Generate Allure report from uploaded by actions/allure-report-store tests results'
 
 outputs:
+  base-url:
+    description: 'Base URL for Allure report'
+    value: ${{ steps.generate-report.outputs.base-url }}
+  base-s3-url:
+    description: 'Base S3 URL for Allure report'
+    value: ${{ steps.generate-report.outputs.base-s3-url }}
   report-url:
     description: 'Allure report URL'
     value: ${{ steps.generate-report.outputs.report-url }}
@@ -63,8 +69,8 @@ runs:
           rm -f ${ALLURE_ZIP}
         fi
       env:
-        ALLURE_VERSION: 2.22.1
-        ALLURE_ZIP_SHA256: fdc7a62d94b14c5e0bf25198ae1feded6b005fdbed864b4d3cb4e5e901720b0b
+        ALLURE_VERSION: 2.23.1
+        ALLURE_ZIP_SHA256: 11141bfe727504b3fd80c0f9801eb317407fd0ac983ebb57e671f14bac4bcd86
 
     # Potentially we could have several running build for the same key (for example, for the main branch), so we use improvised lock for this
     - name: Acquire lock
@@ -102,6 +108,11 @@ runs:
         REPORT_PREFIX=reports/${BRANCH_OR_PR}
         RAW_PREFIX=reports-raw/${BRANCH_OR_PR}/${GITHUB_RUN_ID}
 
+        BASE_URL=https://${BUCKET}.s3.amazonaws.com/${REPORT_PREFIX}/${GITHUB_RUN_ID}
+        BASE_S3_URL=s3://${BUCKET}/${REPORT_PREFIX}/${GITHUB_RUN_ID}
+        REPORT_URL=${BASE_URL}/index.html
+        REPORT_JSON_URL=${BASE_URL}/data/suites.json
+
         # Get previously uploaded data for this run
         ZSTD_NBTHREADS=0
 
@@ -110,10 +121,9 @@ runs:
           # There's no previously uploaded data for this $GITHUB_RUN_ID
           exit 0
         fi
-        for S3_FILEPATH in ${S3_FILEPATHS}; do
-          time aws s3 cp --only-show-errors "s3://${BUCKET}/${S3_FILEPATH}" "${WORKDIR}"
 
-          archive=${WORKDIR}/$(basename $S3_FILEPATH)
+        time aws s3 cp --recursive --only-show-errors "s3://${BUCKET}/${RAW_PREFIX}/" "${WORKDIR}/"
+        for archive in $(find ${WORKDIR} -name "*.tar.zst"); do
           mkdir -p ${archive%.tar.zst}
           time tar -xf ${archive} -C ${archive%.tar.zst}
           rm -f ${archive}
@@ -129,10 +139,9 @@ runs:
         sed -i 's|<a href="." class=|<a href="https://'${BUCKET}'.s3.amazonaws.com/'${REPORT_PREFIX}'/latest/index.html?nocache='"'+Date.now()+'"'" class=|g' ${WORKDIR}/report/app.js
 
         # Upload a history and the final report (in this particular order to not to have duplicated history in 2 places)
+        # Use sync for the final report to delete files from previous runs
         time aws s3 mv --recursive --only-show-errors "${WORKDIR}/report/history" "s3://${BUCKET}/${REPORT_PREFIX}/latest/history"
-        time aws s3 mv --recursive --only-show-errors "${WORKDIR}/report" "s3://${BUCKET}/${REPORT_PREFIX}/${GITHUB_RUN_ID}"
-
-        REPORT_URL=https://${BUCKET}.s3.amazonaws.com/${REPORT_PREFIX}/${GITHUB_RUN_ID}/index.html
+        time aws s3 sync --delete --only-show-errors "${WORKDIR}/report" "s3://${BUCKET}/${REPORT_PREFIX}/${GITHUB_RUN_ID}"
 
         # Generate redirect
         cat <<EOF > ${WORKDIR}/index.html
@@ -144,8 +153,10 @@ runs:
         EOF
         time aws s3 cp --only-show-errors ${WORKDIR}/index.html "s3://${BUCKET}/${REPORT_PREFIX}/latest/index.html"
 
-        echo "report-url=${REPORT_URL}"                                   >> $GITHUB_OUTPUT
-        echo "report-json-url=${REPORT_URL%/index.html}/data/suites.json" >> $GITHUB_OUTPUT
+        echo "base-url=${BASE_URL}"               >> $GITHUB_OUTPUT
+        echo "base-s3-url=${BASE_S3_URL}"         >> $GITHUB_OUTPUT
+        echo "report-url=${REPORT_URL}"           >> $GITHUB_OUTPUT
+        echo "report-json-url=${REPORT_JSON_URL}" >> $GITHUB_OUTPUT
 
         echo "[Allure Report](${REPORT_URL})" >> ${GITHUB_STEP_SUMMARY}
 

.github/actions/download/action.yml

@@ -31,7 +31,7 @@ runs:
         BUCKET=neon-github-public-dev
         FILENAME=$(basename $ARCHIVE)
 
-        S3_KEY=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${PREFIX%$GITHUB_RUN_ATTEMPT} | jq -r '.Contents[].Key' | grep ${FILENAME} | sort --version-sort | tail -1 || true)
+        S3_KEY=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${PREFIX%$GITHUB_RUN_ATTEMPT} | jq -r '.Contents[]?.Key' | grep ${FILENAME} | sort --version-sort | tail -1 || true)
         if [ -z "${S3_KEY}" ]; then
           if [ "${SKIP_IF_DOES_NOT_EXIST}" = "true" ]; then
             echo 'SKIPPED=true' >> $GITHUB_OUTPUT

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

@@ -209,4 +209,4 @@ runs:
       uses: ./.github/actions/allure-report-store
       with:
         report-dir: /tmp/test_output/allure/results
-        unique-key: ${{ inputs.build_type }}
+        unique-key: ${{ inputs.build_type }}-${{ inputs.pg_version }}

.github/workflows/build_and_test.yml

@@ -471,6 +471,26 @@ jobs:
             --build-type ${BUILD_TYPE} \
             --ingest suites.json
 
+      - name: Store Allure test stat in the DB (new)
+        if: ${{ !cancelled() && steps.create-allure-report.outputs.report-json-url }}
+        env:
+          COMMIT_SHA: ${{ github.event.pull_request.head.sha || github.sha }}
+          REPORT_JSON_URL: ${{ steps.create-allure-report.outputs.report-json-url }}
+          TEST_RESULT_CONNSTR: ${{ secrets.REGRESS_TEST_RESULT_CONNSTR_NEW }}
+          BASE_S3_URL: ${{ steps.create-allure-report.outputs.base-s3-url }}
+        run: |
+          aws s3 cp --only-show-errors --recursive ${BASE_S3_URL}/data/test-cases ./test-cases
+
+          ./scripts/pysync
+
+          export DATABASE_URL="$TEST_RESULT_CONNSTR"
+          poetry run python3 scripts/ingest_regress_test_result-new-format.py \
+            --reference ${GITHUB_REF} \
+            --revision ${COMMIT_SHA} \
+            --run-id ${GITHUB_RUN_ID} \
+            --run-attempt ${GITHUB_RUN_ATTEMPT} \
+            --test-cases-dir ./test-cases
+
   coverage-report:
     runs-on: [ self-hosted, gen3, small ]
     container:
@@ -794,7 +814,7 @@ jobs:
       run:
         shell: sh -eu {0}
     env:
-      VM_BUILDER_VERSION: v0.13.1
+      VM_BUILDER_VERSION: v0.15.4
 
     steps:
       - name: Checkout
@@ -955,22 +975,15 @@ jobs:
         version: [ v14, v15 ]
 
     env:
-      # While on transition period we extract public extensions from compute-node image and custom extensions from extensions image.
-      # Later all the extensions will be moved to extensions image.
       EXTENSIONS_IMAGE: ${{ github.ref_name == 'release' && '093970136003' || '369495373322'}}.dkr.ecr.eu-central-1.amazonaws.com/extensions-${{ matrix.version }}:latest
-      COMPUTE_NODE_IMAGE: ${{ github.ref_name == 'release' && '093970136003' || '369495373322'}}.dkr.ecr.eu-central-1.amazonaws.com/compute-node-${{ matrix.version }}:latest
       AWS_ACCESS_KEY_ID: ${{ github.ref_name == 'release' && secrets.AWS_ACCESS_KEY_PROD || secrets.AWS_ACCESS_KEY_DEV }}
       AWS_SECRET_ACCESS_KEY: ${{ github.ref_name == 'release' && secrets.AWS_SECRET_KEY_PROD || secrets.AWS_SECRET_KEY_DEV }}
-      S3_BUCKETS: |
-        ${{ github.ref_name == 'release' &&
-          'neon-prod-extensions-ap-southeast-1 neon-prod-extensions-eu-central-1 neon-prod-extensions-us-east-1 neon-prod-extensions-us-east-2 neon-prod-extensions-us-west-2' ||
-          'neon-dev-extensions-eu-central-1 neon-dev-extensions-eu-west-1 neon-dev-extensions-us-east-2' }}
+      S3_BUCKETS: ${{ github.ref_name == 'release' && vars.S3_EXTENSIONS_BUCKETS_PROD || vars.S3_EXTENSIONS_BUCKETS_DEV }}
 
     steps:
       - name: Pull postgres-extensions image
         run: |
           docker pull ${EXTENSIONS_IMAGE}
-          docker pull ${COMPUTE_NODE_IMAGE}
 
       - name: Create postgres-extensions container
         id: create-container
@@ -978,46 +991,23 @@ jobs:
           EID=$(docker create ${EXTENSIONS_IMAGE} true)
           echo "EID=${EID}" >> $GITHUB_OUTPUT
 
-          CID=$(docker create ${COMPUTE_NODE_IMAGE} true)
-          echo "CID=${CID}" >> $GITHUB_OUTPUT
-
       - name: Extract postgres-extensions from container
         run: |
-          rm -rf ./extensions-to-upload ./custom-extensions # Just in case
+          rm -rf ./extensions-to-upload # Just in case
+          mkdir -p extensions-to-upload
 
-          # In compute image we have a bit different directory layout
-          mkdir -p extensions-to-upload/share
-          docker cp ${{ steps.create-container.outputs.CID }}:/usr/local/share/extension ./extensions-to-upload/share/extension
-          docker cp ${{ steps.create-container.outputs.CID }}:/usr/local/lib             ./extensions-to-upload/lib
-
-          # Delete Neon extensitons (they always present on compute-node image)
-          rm -rf ./extensions-to-upload/share/extension/neon*
-          rm -rf ./extensions-to-upload/lib/neon*
-
-          # Delete leftovers from the extension build step
-          rm -rf ./extensions-to-upload/lib/pgxs
-          rm -rf ./extensions-to-upload/lib/pkgconfig
-
-          docker cp ${{ steps.create-container.outputs.EID }}:/extensions ./custom-extensions
-          for EXT_NAME in $(ls ./custom-extensions); do
-            mkdir -p ./extensions-to-upload/${EXT_NAME}/share
-
-            mv ./custom-extensions/${EXT_NAME}/share/extension ./extensions-to-upload/${EXT_NAME}/share/extension
-            mv ./custom-extensions/${EXT_NAME}/lib             ./extensions-to-upload/${EXT_NAME}/lib
-          done
+          docker cp ${{ steps.create-container.outputs.EID }}:/extensions/ ./extensions-to-upload/
+          docker cp ${{ steps.create-container.outputs.EID }}:/ext_index.json ./extensions-to-upload/
 
       - name: Upload postgres-extensions to S3
-        # TODO: Reenable step after switching to the new extensions format (tar-gzipped + index.json)
-        if: false
         run: |
-          for BUCKET in $(echo ${S3_BUCKETS}); do
+          for BUCKET in $(echo ${S3_BUCKETS:-[]} | jq --raw-output '.[]'); do
             aws s3 cp --recursive --only-show-errors ./extensions-to-upload s3://${BUCKET}/${{ needs.tag.outputs.build-tag }}/${{ matrix.version }}
           done
 
       - name: Cleanup
-        if: ${{ always() && (steps.create-container.outputs.CID || steps.create-container.outputs.EID) }}
+        if: ${{ always() && steps.create-container.outputs.EID }}
         run: |
-          docker rm ${{ steps.create-container.outputs.CID }} || true
           docker rm ${{ steps.create-container.outputs.EID }} || true
 
   deploy:
@@ -1097,7 +1087,7 @@ jobs:
             OLD_PREFIX=artifacts/${GITHUB_RUN_ID}
             FILENAME=neon-${{ runner.os }}-${build_type}-artifact.tar.zst
 
-            S3_KEY=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${OLD_PREFIX} | jq -r '.Contents[].Key' | grep ${FILENAME} | sort --version-sort | tail -1 || true)
+            S3_KEY=$(aws s3api list-objects-v2 --bucket ${BUCKET} --prefix ${OLD_PREFIX} | jq -r '.Contents[]?.Key' | grep ${FILENAME} | sort --version-sort | tail -1 || true)
             if [ -z "${S3_KEY}" ]; then
               echo >&2 "Neither s3://${BUCKET}/${OLD_PREFIX}/${FILENAME} nor its version from previous attempts exist"
               exit 1

Cargo.lock

@@ -740,6 +740,9 @@ name = "cc"
 version = "1.0.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "50d30906286121d95be3d479533b458f87493b30a4b5f79a607db8f5d11aa91f"
+dependencies = [
+ "jobserver",
+]
 
 [[package]]
 name = "cexpr"
@@ -907,12 +910,14 @@ dependencies = [
  "opentelemetry",
  "postgres",
  "regex",
+ "remote_storage",
  "reqwest",
  "serde",
  "serde_json",
  "tar",
  "tokio",
  "tokio-postgres",
+ "toml_edit",
  "tracing",
  "tracing-opentelemetry",
  "tracing-subscriber",
@@ -920,6 +925,7 @@ dependencies = [
  "url",
  "utils",
  "workspace_hack",
+ "zstd",
 ]
 
 [[package]]
@@ -980,6 +986,7 @@ dependencies = [
  "tar",
  "thiserror",
  "toml",
+ "tracing",
  "url",
  "utils",
  "workspace_hack",
@@ -1972,6 +1979,15 @@ version = "1.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "453ad9f582a441959e5f0d088b02ce04cfe8d51a8eaf077f12ac6d3e94164ca6"
 
+[[package]]
+name = "jobserver"
+version = "0.1.26"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "936cfd212a0155903bcbc060e316fb6cc7cbf2e1907329391ebadc1fe0ce77c2"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "js-sys"
 version = "0.3.63"
@@ -2506,6 +2522,7 @@ dependencies = [
  "pageserver",
  "postgres_ffi",
  "svg_fmt",
+ "tokio",
  "utils",
  "workspace_hack",
 ]
@@ -2544,6 +2561,7 @@ dependencies = [
  "metrics",
  "nix",
  "num-traits",
+ "num_cpus",
  "once_cell",
  "pageserver_api",
  "pin-project-lite",
@@ -2780,7 +2798,7 @@ dependencies = [
 [[package]]
 name = "postgres"
 version = "0.19.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=1aaedab101b23f7612042850d8f2036810fa7c7f#1aaedab101b23f7612042850d8f2036810fa7c7f"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=9011f7110db12b5e15afaf98f8ac834501d50ddc#9011f7110db12b5e15afaf98f8ac834501d50ddc"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -2793,7 +2811,7 @@ dependencies = [
 [[package]]
 name = "postgres-native-tls"
 version = "0.5.0"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=1aaedab101b23f7612042850d8f2036810fa7c7f#1aaedab101b23f7612042850d8f2036810fa7c7f"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=9011f7110db12b5e15afaf98f8ac834501d50ddc#9011f7110db12b5e15afaf98f8ac834501d50ddc"
 dependencies = [
  "native-tls",
  "tokio",
@@ -2804,7 +2822,7 @@ dependencies = [
 [[package]]
 name = "postgres-protocol"
 version = "0.6.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=1aaedab101b23f7612042850d8f2036810fa7c7f#1aaedab101b23f7612042850d8f2036810fa7c7f"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=9011f7110db12b5e15afaf98f8ac834501d50ddc#9011f7110db12b5e15afaf98f8ac834501d50ddc"
 dependencies = [
  "base64 0.20.0",
  "byteorder",
@@ -2822,7 +2840,7 @@ dependencies = [
 [[package]]
 name = "postgres-types"
 version = "0.2.4"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=1aaedab101b23f7612042850d8f2036810fa7c7f#1aaedab101b23f7612042850d8f2036810fa7c7f"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=9011f7110db12b5e15afaf98f8ac834501d50ddc#9011f7110db12b5e15afaf98f8ac834501d50ddc"
 dependencies = [
  "bytes",
  "fallible-iterator",
@@ -3235,6 +3253,7 @@ dependencies = [
  "metrics",
  "once_cell",
  "pin-project-lite",
+ "scopeguard",
  "serde",
  "serde_json",
  "tempfile",
@@ -4312,7 +4331,7 @@ dependencies = [
 [[package]]
 name = "tokio-postgres"
 version = "0.7.7"
-source = "git+https://github.com/neondatabase/rust-postgres.git?rev=1aaedab101b23f7612042850d8f2036810fa7c7f#1aaedab101b23f7612042850d8f2036810fa7c7f"
+source = "git+https://github.com/neondatabase/rust-postgres.git?rev=9011f7110db12b5e15afaf98f8ac834501d50ddc#9011f7110db12b5e15afaf98f8ac834501d50ddc"
 dependencies = [
  "async-trait",
  "byteorder",
@@ -5294,6 +5313,7 @@ version = "0.1.0"
 dependencies = [
  "anyhow",
  "bytes",
+ "cc",
  "chrono",
  "clap",
  "clap_builder",
@@ -5394,3 +5414,33 @@ name = "zeroize"
 version = "1.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2a0956f1ba7c7909bfb66c2e9e4124ab6f6482560f6628b5aaeba39207c9aad9"
+
+[[package]]
+name = "zstd"
+version = "0.12.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1a27595e173641171fc74a1232b7b1c7a7cb6e18222c11e9dfb9888fa424c53c"
+dependencies = [
+ "zstd-safe",
+]
+
+[[package]]
+name = "zstd-safe"
+version = "6.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ee98ffd0b48ee95e6c5168188e44a54550b1564d9d530ee21d5f0eaed1069581"
+dependencies = [
+ "libc",
+ "zstd-sys",
+]
+
+[[package]]
+name = "zstd-sys"
+version = "2.0.8+zstd.1.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5556e6ee25d32df2586c098bbfa278803692a20d0ab9565e049480d52707ec8c"
+dependencies = [
+ "cc",
+ "libc",
+ "pkg-config",
+]

Cargo.toml

@@ -144,11 +144,11 @@ env_logger = "0.10"
 log = "0.4"
 
 ## Libraries from neondatabase/ git forks, ideally with changes to be upstreamed
-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
-postgres-native-tls = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
-postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
-postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
+postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
+postgres-native-tls = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
+postgres-protocol = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
+postgres-types = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
 
 ## Other git libraries
 heapless = { default-features=false, features=[], git = "https://github.com/japaric/heapless.git", rev = "644653bf3b831c6bb4963be2de24804acf5e5001" } # upstream release pending
@@ -183,7 +183,7 @@ tonic-build = "0.9"
 
 # This is only needed for proxy's tests.
 # TODO: we should probably fork `tokio-postgres-rustls` instead.
-tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="1aaedab101b23f7612042850d8f2036810fa7c7f" }
+tokio-postgres = { git = "https://github.com/neondatabase/rust-postgres.git", rev="9011f7110db12b5e15afaf98f8ac834501d50ddc" }
 
 ################# Binary contents sections
 

Dockerfile

@@ -51,6 +51,7 @@ RUN set -e \
       --bin safekeeper  \
       --bin storage_broker  \
       --bin proxy  \
+      --bin neon_local \
       --locked --release \
     && cachepot -s
 
@@ -76,6 +77,7 @@ COPY --from=build --chown=neon:neon /home/nonroot/target/release/pagectl
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/safekeeper          /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/storage_broker         /usr/local/bin
 COPY --from=build --chown=neon:neon /home/nonroot/target/release/proxy               /usr/local/bin
+COPY --from=build --chown=neon:neon /home/nonroot/target/release/neon_local               /usr/local/bin
 
 COPY --from=pg-build /home/nonroot/pg_install/v14 /usr/local/v14/
 COPY --from=pg-build /home/nonroot/pg_install/v15 /usr/local/v15/

Dockerfile.compute-node

@@ -13,7 +13,7 @@ FROM debian:bullseye-slim AS build-deps
 RUN apt update &&  \
     apt install -y git autoconf automake libtool build-essential bison flex libreadline-dev \
     zlib1g-dev libxml2-dev libcurl4-openssl-dev libossp-uuid-dev wget pkg-config libssl-dev \
-    libicu-dev libxslt1-dev liblz4-dev libzstd-dev
+    libicu-dev libxslt1-dev liblz4-dev libzstd-dev zstd
 
 #########################################################################################
 #
@@ -77,6 +77,7 @@ ENV PATH "/usr/local/pgsql/bin:$PATH"
 RUN wget https://download.osgeo.org/postgis/source/postgis-3.3.2.tar.gz -O postgis.tar.gz && \
     echo "9a2a219da005a1730a39d1959a1c7cec619b1efb009b65be80ffc25bad299068 postgis.tar.gz" | sha256sum --check && \
     mkdir postgis-src && cd postgis-src && tar xvzf ../postgis.tar.gz --strip-components=1 -C . && \
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /before.txt &&\
     ./autogen.sh && \
     ./configure --with-sfcgal=/usr/local/bin/sfcgal-config && \
     make -j $(getconf _NPROCESSORS_ONLN) install && \
@@ -89,17 +90,28 @@ RUN wget https://download.osgeo.org/postgis/source/postgis-3.3.2.tar.gz -O postg
     echo 'trusted = true' >> /usr/local/pgsql/share/extension/postgis_tiger_geocoder.control && \
     echo 'trusted = true' >> /usr/local/pgsql/share/extension/postgis_topology.control && \
     echo 'trusted = true' >> /usr/local/pgsql/share/extension/address_standardizer.control && \
-    echo 'trusted = true' >> /usr/local/pgsql/share/extension/address_standardizer_data_us.control
+    echo 'trusted = true' >> /usr/local/pgsql/share/extension/address_standardizer_data_us.control && \
+    mkdir -p /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/postgis.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/postgis_raster.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/postgis_sfcgal.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/postgis_tiger_geocoder.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/postgis_topology.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/address_standardizer.control /extensions/postgis && \
+    cp /usr/local/pgsql/share/extension/address_standardizer_data_us.control /extensions/postgis
 
 RUN wget https://github.com/pgRouting/pgrouting/archive/v3.4.2.tar.gz -O pgrouting.tar.gz && \
     echo "cac297c07d34460887c4f3b522b35c470138760fe358e351ad1db4edb6ee306e pgrouting.tar.gz" | sha256sum --check && \
     mkdir pgrouting-src && cd pgrouting-src && tar xvzf ../pgrouting.tar.gz --strip-components=1 -C . && \
-    mkdir build && \
-    cd build && \
+    mkdir build && cd build && \
     cmake -DCMAKE_BUILD_TYPE=Release .. && \
     make -j $(getconf _NPROCESSORS_ONLN) && \
     make -j $(getconf _NPROCESSORS_ONLN) install && \
-    echo 'trusted = true' >> /usr/local/pgsql/share/extension/pgrouting.control
+    echo 'trusted = true' >> /usr/local/pgsql/share/extension/pgrouting.control && \
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /after.txt &&\
+    cp /usr/local/pgsql/share/extension/pgrouting.control /extensions/postgis && \
+    sort -o /before.txt /before.txt && sort -o /after.txt /after.txt && \
+    comm -13 /before.txt /after.txt | tar --directory=/usr/local/pgsql --zstd -cf /extensions/postgis.tar.zst -T -
 
 #########################################################################################
 #
@@ -419,12 +431,16 @@ RUN apt-get update && \
     wget https://github.com/ketteq-neon/postgres-exts/archive/e0bd1a9d9313d7120c1b9c7bb15c48c0dede4c4e.tar.gz -O kq_imcx.tar.gz && \
     echo "dc93a97ff32d152d32737ba7e196d9687041cda15e58ab31344c2f2de8855336 kq_imcx.tar.gz" | sha256sum --check && \
     mkdir kq_imcx-src && cd kq_imcx-src && tar xvzf ../kq_imcx.tar.gz --strip-components=1 -C . && \
-    mkdir build && \
-    cd build && \
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /before.txt &&\
+    mkdir build && cd build && \
     cmake -DCMAKE_BUILD_TYPE=Release .. && \
     make -j $(getconf _NPROCESSORS_ONLN) && \
     make -j $(getconf _NPROCESSORS_ONLN) install && \
-    echo 'trusted = true' >> /usr/local/pgsql/share/extension/kq_imcx.control
+    echo 'trusted = true' >> /usr/local/pgsql/share/extension/kq_imcx.control && \
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /after.txt &&\
+    mkdir -p /extensions/kq_imcx && cp /usr/local/pgsql/share/extension/kq_imcx.control /extensions/kq_imcx && \
+    sort -o /before.txt /before.txt && sort -o /after.txt /after.txt && \
+    comm -13 /before.txt /after.txt | tar --directory=/usr/local/pgsql --zstd -cf /extensions/kq_imcx.tar.zst -T -
 
 #########################################################################################
 #
@@ -535,10 +551,8 @@ FROM build-deps AS pg-embedding-pg-build
 COPY --from=pg-build /usr/local/pgsql/ /usr/local/pgsql/
 
 ENV PATH "/usr/local/pgsql/bin/:$PATH"
-# eeb3ba7c3a60c95b2604dd543c64b2f1bb4a3703 made on 15/07/2023
-# There is no release tag yet
-RUN wget https://github.com/neondatabase/pg_embedding/archive/eeb3ba7c3a60c95b2604dd543c64b2f1bb4a3703.tar.gz -O pg_embedding.tar.gz && \
-    echo "030846df723652f99a8689ce63b66fa0c23477a7fd723533ab8a6b28ab70730f pg_embedding.tar.gz" | sha256sum --check && \
+RUN wget https://github.com/neondatabase/pg_embedding/archive/refs/tags/0.3.5.tar.gz -O pg_embedding.tar.gz && \
+    echo "0e95b27b8b6196e2cf0a0c9ec143fe2219b82e54c5bb4ee064e76398cbe69ae9 pg_embedding.tar.gz" | sha256sum --check && \
     mkdir pg_embedding-src && cd pg_embedding-src && tar xvzf ../pg_embedding.tar.gz --strip-components=1 -C . && \
     make -j $(getconf _NPROCESSORS_ONLN) && \
     make -j $(getconf _NPROCESSORS_ONLN) install && \
@@ -553,16 +567,17 @@ RUN wget https://github.com/neondatabase/pg_embedding/archive/eeb3ba7c3a60c95b26
 FROM build-deps AS pg-anon-pg-build
 COPY --from=pg-build /usr/local/pgsql/ /usr/local/pgsql/
 
-# Kaniko doesn't allow to do `${from#/usr/local/pgsql/}`, so we use `${from:17}` instead
 ENV PATH "/usr/local/pgsql/bin/:$PATH"
 RUN wget https://gitlab.com/dalibo/postgresql_anonymizer/-/archive/1.1.0/postgresql_anonymizer-1.1.0.tar.gz -O pg_anon.tar.gz && \
     echo "08b09d2ff9b962f96c60db7e6f8e79cf7253eb8772516998fc35ece08633d3ad pg_anon.tar.gz" | sha256sum --check && \
     mkdir pg_anon-src && cd pg_anon-src && tar xvzf ../pg_anon.tar.gz --strip-components=1 -C . && \
-    find /usr/local/pgsql -type f | sort  > /before.txt && \
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /before.txt &&\
     make -j $(getconf _NPROCESSORS_ONLN) install PG_CONFIG=/usr/local/pgsql/bin/pg_config && \
     echo 'trusted = true' >> /usr/local/pgsql/share/extension/anon.control && \
-    find /usr/local/pgsql -type f | sort  > /after.txt && \
-    /bin/bash -c 'for from in $(comm -13 /before.txt /after.txt); do to=/extensions/anon/${from:17} && mkdir -p $(dirname ${to}) && cp -a ${from} ${to}; done'
+    find /usr/local/pgsql -type f | sed 's|^/usr/local/pgsql/||' > /after.txt &&\
+    mkdir -p /extensions/anon && cp /usr/local/pgsql/share/extension/anon.control /extensions/anon && \
+    sort -o /before.txt /before.txt && sort -o /after.txt /after.txt && \
+    comm -13 /before.txt /after.txt | tar --directory=/usr/local/pgsql --zstd -cf /extensions/anon.tar.zst -T -
 
 #########################################################################################
 #
@@ -754,16 +769,23 @@ RUN rm /usr/local/pgsql/lib/lib*.a
 # Extenstion only
 #
 #########################################################################################
+FROM python:3.9-slim-bullseye AS generate-ext-index
+ARG PG_VERSION
+ARG BUILD_TAG
+RUN apt update && apt install -y zstd
+
+# copy the control files here
+COPY --from=kq-imcx-pg-build /extensions/ /extensions/
+COPY --from=pg-anon-pg-build /extensions/ /extensions/
+COPY --from=postgis-build /extensions/ /extensions/
+COPY scripts/combine_control_files.py ./combine_control_files.py
+RUN python3 ./combine_control_files.py ${PG_VERSION} ${BUILD_TAG} --public_extensions="anon,postgis"
+
 FROM scratch AS postgres-extensions
 # After the transition this layer will include all extensitons.
-# As for now, it's only for new custom ones
-#
-# # Default extensions
-# COPY --from=postgres-cleanup-layer /usr/local/pgsql/share/extension /usr/local/pgsql/share/extension
-# COPY --from=postgres-cleanup-layer /usr/local/pgsql/lib             /usr/local/pgsql/lib
-# Custom extensions
-COPY --from=pg-anon-pg-build /extensions/anon/lib/ /extensions/anon/lib
-COPY --from=pg-anon-pg-build /extensions/anon/share/extension /extensions/anon/share/extension
+# As for now, it's only a couple for testing purposses
+COPY --from=generate-ext-index /extensions/*.tar.zst /extensions/
+COPY --from=generate-ext-index /ext_index.json /ext_index.json
 
 #########################################################################################
 #
@@ -794,6 +816,7 @@ COPY --from=compute-tools --chown=postgres /home/nonroot/target/release-line-deb
 # libxml2, libxslt1.1 for xml2
 # libzstd1 for zstd
 # libboost*, libfreetype6, and zlib1g for rdkit
+# ca-certificates for communicating with s3 by compute_ctl
 RUN apt update &&  \
     apt install --no-install-recommends -y \
         gdb \
@@ -817,7 +840,8 @@ RUN apt update &&  \
         libcurl4-openssl-dev \
         locales \
         procps \
-        zlib1g && \
+        zlib1g \
+        ca-certificates && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
     localedef -i en_US -c -f UTF-8 -A /usr/share/locale/locale.alias en_US.UTF-8
 

Makefile

@@ -108,6 +108,8 @@ postgres-%: postgres-configure-% \
 	$(MAKE) -C $(POSTGRES_INSTALL_DIR)/build/$*/contrib/pg_buffercache install
 	+@echo "Compiling pageinspect $*"
 	$(MAKE) -C $(POSTGRES_INSTALL_DIR)/build/$*/contrib/pageinspect install
+	+@echo "Compiling amcheck $*"
+	$(MAKE) -C $(POSTGRES_INSTALL_DIR)/build/$*/contrib/amcheck install
 
 .PHONY: postgres-clean-%
 postgres-clean-%:

README.md

@@ -29,13 +29,13 @@ See developer documentation in [SUMMARY.md](/docs/SUMMARY.md) for more informati
 ```bash
 apt install build-essential libtool libreadline-dev zlib1g-dev flex bison libseccomp-dev \
 libssl-dev clang pkg-config libpq-dev cmake postgresql-client protobuf-compiler \
-libcurl4-openssl-dev
+libcurl4-openssl-dev openssl python-poetry
 ```
 * On Fedora, these packages are needed:
 ```bash
 dnf install flex bison readline-devel zlib-devel openssl-devel \
   libseccomp-devel perl clang cmake postgresql postgresql-contrib protobuf-compiler \
-  protobuf-devel libcurl-devel
+  protobuf-devel libcurl-devel openssl poetry
 ```
 * On Arch based systems, these packages are needed:
 ```bash
@@ -235,6 +235,13 @@ CARGO_BUILD_FLAGS="--features=testing" make
 ./scripts/pytest
 ```
 
+By default, this runs both debug and release modes, and all supported postgres versions. When
+testing locally, it is convenient to run just run one set of permutations, like this:
+
+```sh
+DEFAULT_PG_VERSION=15 BUILD_TYPE=release ./scripts/pytest
+```
+
 ## Documentation
 
 [docs](/docs) Contains a top-level overview of all available markdown documentation.

compute_tools/Cargo.toml

@@ -32,3 +32,6 @@ url.workspace = true
 compute_api.workspace = true
 utils.workspace = true
 workspace_hack.workspace = true
+toml_edit.workspace = true
+remote_storage = { version = "0.1", path = "../libs/remote_storage/" }
+zstd = "0.12.4"

compute_tools/src/bin/compute_ctl.rs

@@ -5,6 +5,8 @@
 //! - `compute_ctl` accepts cluster (compute node) specification as a JSON file.
 //! - Every start is a fresh start, so the data directory is removed and
 //!   initialized again on each run.
+//! - If remote_extension_config is provided, it will be used to fetch extensions list
+//!  and download `shared_preload_libraries` from the remote storage.
 //! - Next it will put configuration files into the `PGDATA` directory.
 //! - Sync safekeepers and get commit LSN.
 //! - Get `basebackup` from pageserver using the returned on the previous step LSN.
@@ -27,7 +29,8 @@
 //! compute_ctl -D /var/db/postgres/compute \
 //!             -C 'postgresql://cloud_admin@localhost/postgres' \
 //!             -S /var/db/postgres/specs/current.json \
-//!             -b /usr/local/bin/postgres
+//!             -b /usr/local/bin/postgres \
+//!             -r {"bucket": "neon-dev-extensions-eu-central-1", "region": "eu-central-1"}
 //! ```
 //!
 use std::collections::HashMap;
@@ -35,7 +38,7 @@ use std::fs::File;
 use std::panic;
 use std::path::Path;
 use std::process::exit;
-use std::sync::{mpsc, Arc, Condvar, Mutex};
+use std::sync::{mpsc, Arc, Condvar, Mutex, OnceLock, RwLock};
 use std::{thread, time::Duration};
 
 use anyhow::{Context, Result};
@@ -48,22 +51,33 @@ use compute_api::responses::ComputeStatus;
 
 use compute_tools::compute::{ComputeNode, ComputeState, ParsedSpec};
 use compute_tools::configurator::launch_configurator;
+use compute_tools::extension_server::{get_pg_version, init_remote_storage};
 use compute_tools::http::api::launch_http_server;
 use compute_tools::logger::*;
 use compute_tools::monitor::launch_monitor;
 use compute_tools::params::*;
 use compute_tools::spec::*;
 
-const BUILD_TAG_DEFAULT: &str = "local";
+// this is an arbitrary build tag. Fine as a default / for testing purposes
+// in-case of not-set environment var
+const BUILD_TAG_DEFAULT: &str = "5670669815";
 
 fn main() -> Result<()> {
     init_tracing_and_logging(DEFAULT_LOG_LEVEL)?;
 
-    let build_tag = option_env!("BUILD_TAG").unwrap_or(BUILD_TAG_DEFAULT);
-
+    let build_tag = option_env!("BUILD_TAG")
+        .unwrap_or(BUILD_TAG_DEFAULT)
+        .to_string();
     info!("build_tag: {build_tag}");
 
     let matches = cli().get_matches();
+    let pgbin_default = String::from("postgres");
+    let pgbin = matches.get_one::<String>("pgbin").unwrap_or(&pgbin_default);
+
+    let remote_ext_config = matches.get_one::<String>("remote-ext-config");
+    let ext_remote_storage = remote_ext_config.map(|x| {
+        init_remote_storage(x).expect("cannot initialize remote extension storage from config")
+    });
 
     let http_port = *matches
         .get_one::<u16>("http-port")
@@ -128,9 +142,6 @@ fn main() -> Result<()> {
     let compute_id = matches.get_one::<String>("compute-id");
     let control_plane_uri = matches.get_one::<String>("control-plane-uri");
 
-    // Try to use just 'postgres' if no path is provided
-    let pgbin = matches.get_one::<String>("pgbin").unwrap();
-
     let spec;
     let mut live_config_allowed = false;
     match spec_json {
@@ -168,6 +179,7 @@ fn main() -> Result<()> {
 
     let mut new_state = ComputeState::new();
     let spec_set;
+
     if let Some(spec) = spec {
         let pspec = ParsedSpec::try_from(spec).map_err(|msg| anyhow::anyhow!(msg))?;
         new_state.pspec = Some(pspec);
@@ -179,20 +191,37 @@ fn main() -> Result<()> {
         connstr: Url::parse(connstr).context("cannot parse connstr as a URL")?,
         pgdata: pgdata.to_string(),
         pgbin: pgbin.to_string(),
+        pgversion: get_pg_version(pgbin),
         live_config_allowed,
         state: Mutex::new(new_state),
         state_changed: Condvar::new(),
+        ext_remote_storage,
+        ext_remote_paths: OnceLock::new(),
+        ext_download_progress: RwLock::new(HashMap::new()),
+        library_index: OnceLock::new(),
+        build_tag,
     };
     let compute = Arc::new(compute_node);
 
+    // If this is a pooled VM, prewarm before starting HTTP server and becoming
+    // available for binding. Prewarming helps postgres start quicker later,
+    // because QEMU will already have it's memory allocated from the host, and
+    // the necessary binaries will alreaady be cached.
+    if !spec_set {
+        compute.prewarm_postgres()?;
+    }
+
     // Launch http service first, so we were able to serve control-plane
     // requests, while configuration is still in progress.
     let _http_handle =
         launch_http_server(http_port, &compute).expect("cannot launch http endpoint thread");
 
+    let extension_server_port: u16 = http_port;
+
     if !spec_set {
         // No spec provided, hang waiting for it.
         info!("no compute spec provided, waiting");
+
         let mut state = compute.state.lock().unwrap();
         while state.status != ComputeStatus::ConfigurationPending {
             state = compute.state_changed.wait(state).unwrap();
@@ -229,7 +258,7 @@ fn main() -> Result<()> {
     // Start Postgres
     let mut delay_exit = false;
     let mut exit_code = None;
-    let pg = match compute.start_compute() {
+    let pg = match compute.start_compute(extension_server_port) {
         Ok(pg) => Some(pg),
         Err(err) => {
             error!("could not start the compute node: {:?}", err);
@@ -358,6 +387,12 @@ fn cli() -> clap::Command {
                 .long("control-plane-uri")
                 .value_name("CONTROL_PLANE_API_BASE_URI"),
         )
+        .arg(
+            Arg::new("remote-ext-config")
+                .short('r')
+                .long("remote-ext-config")
+                .value_name("REMOTE_EXT_CONFIG"),
+        )
 }
 
 #[test]

compute_tools/src/compute.rs

@@ -1,16 +1,23 @@
+use std::collections::HashMap;
 use std::fs;
 use std::io::BufRead;
 use std::os::unix::fs::PermissionsExt;
 use std::path::Path;
 use std::process::{Command, Stdio};
 use std::str::FromStr;
-use std::sync::{Condvar, Mutex};
+use std::sync::{Condvar, Mutex, OnceLock, RwLock};
+use std::time::Instant;
 
 use anyhow::{Context, Result};
 use chrono::{DateTime, Utc};
+use futures::future::join_all;
+use futures::stream::FuturesUnordered;
+use futures::StreamExt;
 use postgres::{Client, NoTls};
+use regex::Regex;
+use tokio;
 use tokio_postgres;
-use tracing::{info, instrument, warn};
+use tracing::{error, info, instrument, warn};
 use utils::id::{TenantId, TimelineId};
 use utils::lsn::Lsn;
 
@@ -18,9 +25,12 @@ use compute_api::responses::{ComputeMetrics, ComputeStatus};
 use compute_api::spec::{ComputeMode, ComputeSpec};
 use utils::measured_stream::MeasuredReader;
 
-use crate::config;
+use remote_storage::{DownloadError, GenericRemoteStorage, RemotePath};
+
 use crate::pg_helpers::*;
 use crate::spec::*;
+use crate::sync_sk::{check_if_synced, ping_safekeeper};
+use crate::{config, extension_server};
 
 /// Compute node info shared across several `compute_ctl` threads.
 pub struct ComputeNode {
@@ -28,6 +38,7 @@ pub struct ComputeNode {
     pub connstr: url::Url,
     pub pgdata: String,
     pub pgbin: String,
+    pub pgversion: String,
     /// We should only allow live re- / configuration of the compute node if
     /// it uses 'pull model', i.e. it can go to control-plane and fetch
     /// the latest configuration. Otherwise, there could be a case:
@@ -47,6 +58,24 @@ pub struct ComputeNode {
     pub state: Mutex<ComputeState>,
     /// `Condvar` to allow notifying waiters about state changes.
     pub state_changed: Condvar,
+    ///  the S3 bucket that we search for extensions in
+    pub ext_remote_storage: Option<GenericRemoteStorage>,
+    // (key: extension name, value: path to extension archive in remote storage)
+    pub ext_remote_paths: OnceLock<HashMap<String, RemotePath>>,
+    // (key: library name, value: name of extension containing this library)
+    pub library_index: OnceLock<HashMap<String, String>>,
+    // key: ext_archive_name, value: started download time, download_completed?
+    pub ext_download_progress: RwLock<HashMap<String, (DateTime<Utc>, bool)>>,
+    pub build_tag: String,
+}
+
+// store some metrics about download size that might impact startup time
+#[derive(Clone, Debug)]
+pub struct RemoteExtensionMetrics {
+    num_ext_downloaded: u64,
+    largest_ext_size: u64,
+    total_ext_download_size: u64,
+    prep_extensions_ms: u64,
 }
 
 #[derive(Clone, Debug)]
@@ -86,6 +115,7 @@ pub struct ParsedSpec {
     pub tenant_id: TenantId,
     pub timeline_id: TimelineId,
     pub pageserver_connstr: String,
+    pub safekeeper_connstrings: Vec<String>,
     pub storage_auth_token: Option<String>,
 }
 
@@ -103,6 +133,21 @@ impl TryFrom<ComputeSpec> for ParsedSpec {
             .clone()
             .or_else(|| spec.cluster.settings.find("neon.pageserver_connstring"))
             .ok_or("pageserver connstr should be provided")?;
+        let safekeeper_connstrings = if spec.safekeeper_connstrings.is_empty() {
+            if matches!(spec.mode, ComputeMode::Primary) {
+                spec.cluster
+                    .settings
+                    .find("neon.safekeepers")
+                    .ok_or("safekeeper connstrings should be provided")?
+                    .split(',')
+                    .map(|str| str.to_string())
+                    .collect()
+            } else {
+                vec![]
+            }
+        } else {
+            spec.safekeeper_connstrings.clone()
+        };
         let storage_auth_token = spec.storage_auth_token.clone();
         let tenant_id: TenantId = if let Some(tenant_id) = spec.tenant_id {
             tenant_id
@@ -128,6 +173,7 @@ impl TryFrom<ComputeSpec> for ParsedSpec {
         Ok(ParsedSpec {
             spec,
             pageserver_connstr,
+            safekeeper_connstrings,
             storage_auth_token,
             tenant_id,
             timeline_id,
@@ -240,7 +286,7 @@ impl ComputeNode {
     #[instrument(skip_all, fields(%lsn))]
     fn get_basebackup(&self, compute_state: &ComputeState, lsn: Lsn) -> Result<()> {
         let spec = compute_state.pspec.as_ref().expect("spec must be set");
-        let start_time = Utc::now();
+        let start_time = Instant::now();
 
         let mut config = postgres::Config::from_str(&spec.pageserver_connstr)?;
 
@@ -253,7 +299,10 @@ impl ComputeNode {
             info!("Storage auth token not set");
         }
 
+        // Connect to pageserver
         let mut client = config.connect(NoTls)?;
+        let pageserver_connect_micros = start_time.elapsed().as_micros() as u64;
+
         let basebackup_cmd = match lsn {
             // HACK We don't use compression on first start (Lsn(0)) because there's no API for it
             Lsn(0) => format!("basebackup {} {}", spec.tenant_id, spec.timeline_id),
@@ -299,14 +348,107 @@ impl ComputeNode {
         };
 
         // Report metrics
-        self.state.lock().unwrap().metrics.basebackup_bytes =
-            measured_reader.get_byte_count() as u64;
-        self.state.lock().unwrap().metrics.basebackup_ms = Utc::now()
+        let mut state = self.state.lock().unwrap();
+        state.metrics.pageserver_connect_micros = pageserver_connect_micros;
+        state.metrics.basebackup_bytes = measured_reader.get_byte_count() as u64;
+        state.metrics.basebackup_ms = start_time.elapsed().as_millis() as u64;
+        Ok(())
+    }
+
+    pub async fn check_safekeepers_synced_async(
+        &self,
+        compute_state: &ComputeState,
+    ) -> Result<Option<Lsn>> {
+        // Construct a connection config for each safekeeper
+        let pspec: ParsedSpec = compute_state
+            .pspec
+            .as_ref()
+            .expect("spec must be set")
+            .clone();
+        let sk_connstrs: Vec<String> = pspec.safekeeper_connstrings.clone();
+        let sk_configs = sk_connstrs.into_iter().map(|connstr| {
+            // Format connstr
+            let id = connstr.clone();
+            let connstr = format!("postgresql://no_user@{}", connstr);
+            let options = format!(
+                "-c timeline_id={} tenant_id={}",
+                pspec.timeline_id, pspec.tenant_id
+            );
+
+            // Construct client
+            let mut config = tokio_postgres::Config::from_str(&connstr).unwrap();
+            config.options(&options);
+            if let Some(storage_auth_token) = pspec.storage_auth_token.clone() {
+                config.password(storage_auth_token);
+            }
+
+            (id, config)
+        });
+
+        // Create task set to query all safekeepers
+        let mut tasks = FuturesUnordered::new();
+        let quorum = sk_configs.len() / 2 + 1;
+        for (id, config) in sk_configs {
+            let timeout = tokio::time::Duration::from_millis(100);
+            let task = tokio::time::timeout(timeout, ping_safekeeper(id, config));
+            tasks.push(tokio::spawn(task));
+        }
+
+        // Get a quorum of responses or errors
+        let mut responses = Vec::new();
+        let mut join_errors = Vec::new();
+        let mut task_errors = Vec::new();
+        let mut timeout_errors = Vec::new();
+        while let Some(response) = tasks.next().await {
+            match response {
+                Ok(Ok(Ok(r))) => responses.push(r),
+                Ok(Ok(Err(e))) => task_errors.push(e),
+                Ok(Err(e)) => timeout_errors.push(e),
+                Err(e) => join_errors.push(e),
+            };
+            if responses.len() >= quorum {
+                break;
+            }
+            if join_errors.len() + task_errors.len() + timeout_errors.len() >= quorum {
+                break;
+            }
+        }
+
+        // In case of error, log and fail the check, but don't crash.
+        // We're playing it safe because these errors could be transient
+        // and we don't yet retry. Also being careful here allows us to
+        // be backwards compatible with safekeepers that don't have the
+        // TIMELINE_STATUS API yet.
+        if responses.len() < quorum {
+            error!(
+                "failed sync safekeepers check {:?} {:?} {:?}",
+                join_errors, task_errors, timeout_errors
+            );
+            return Ok(None);
+        }
+
+        Ok(check_if_synced(responses))
+    }
+
+    // Fast path for sync_safekeepers. If they're already synced we get the lsn
+    // in one roundtrip. If not, we should do a full sync_safekeepers.
+    pub fn check_safekeepers_synced(&self, compute_state: &ComputeState) -> Result<Option<Lsn>> {
+        let start_time = Utc::now();
+
+        // Run actual work with new tokio runtime
+        let rt = tokio::runtime::Builder::new_current_thread()
+            .enable_all()
+            .build()
+            .expect("failed to create rt");
+        let result = rt.block_on(self.check_safekeepers_synced_async(compute_state));
+
+        // Record runtime
+        self.state.lock().unwrap().metrics.sync_sk_check_ms = Utc::now()
             .signed_duration_since(start_time)
             .to_std()
             .unwrap()
             .as_millis() as u64;
-        Ok(())
+        result
     }
 
     // Run `postgres` in a special mode with `--sync-safekeepers` argument
@@ -357,24 +499,36 @@ impl ComputeNode {
     /// Do all the preparations like PGDATA directory creation, configuration,
     /// safekeepers sync, basebackup, etc.
     #[instrument(skip_all)]
-    pub fn prepare_pgdata(&self, compute_state: &ComputeState) -> Result<()> {
+    pub fn prepare_pgdata(
+        &self,
+        compute_state: &ComputeState,
+        extension_server_port: u16,
+    ) -> Result<()> {
         let pspec = compute_state.pspec.as_ref().expect("spec must be set");
         let spec = &pspec.spec;
         let pgdata_path = Path::new(&self.pgdata);
 
         // Remove/create an empty pgdata directory and put configuration there.
         self.create_pgdata()?;
-        config::write_postgres_conf(&pgdata_path.join("postgresql.conf"), &pspec.spec)?;
+        config::write_postgres_conf(
+            &pgdata_path.join("postgresql.conf"),
+            &pspec.spec,
+            Some(extension_server_port),
+        )?;
 
         // Syncing safekeepers is only safe with primary nodes: if a primary
         // is already connected it will be kicked out, so a secondary (standby)
         // cannot sync safekeepers.
         let lsn = match spec.mode {
             ComputeMode::Primary => {
-                info!("starting safekeepers syncing");
-                let lsn = self
-                    .sync_safekeepers(pspec.storage_auth_token.clone())
-                    .with_context(|| "failed to sync safekeepers")?;
+                info!("checking if safekeepers are synced");
+                let lsn = if let Ok(Some(lsn)) = self.check_safekeepers_synced(compute_state) {
+                    lsn
+                } else {
+                    info!("starting safekeepers syncing");
+                    self.sync_safekeepers(pspec.storage_auth_token.clone())
+                        .with_context(|| "failed to sync safekeepers")?
+                };
                 info!("safekeepers synced at LSN {}", lsn);
                 lsn
             }
@@ -412,6 +566,50 @@ impl ComputeNode {
         Ok(())
     }
 
+    /// Start and stop a postgres process to warm up the VM for startup.
+    pub fn prewarm_postgres(&self) -> Result<()> {
+        info!("prewarming");
+
+        // Create pgdata
+        let pgdata = &format!("{}.warmup", self.pgdata);
+        create_pgdata(pgdata)?;
+
+        // Run initdb to completion
+        info!("running initdb");
+        let initdb_bin = Path::new(&self.pgbin).parent().unwrap().join("initdb");
+        Command::new(initdb_bin)
+            .args(["-D", pgdata])
+            .output()
+            .expect("cannot start initdb process");
+
+        // Write conf
+        use std::io::Write;
+        let conf_path = Path::new(pgdata).join("postgresql.conf");
+        let mut file = std::fs::File::create(conf_path)?;
+        writeln!(file, "shared_buffers=65536")?;
+        writeln!(file, "port=51055")?; // Nobody should be connecting
+        writeln!(file, "shared_preload_libraries = 'neon'")?;
+
+        // Start postgres
+        info!("starting postgres");
+        let mut pg = Command::new(&self.pgbin)
+            .args(["-D", pgdata])
+            .spawn()
+            .expect("cannot start postgres process");
+
+        // Stop it when it's ready
+        info!("waiting for postgres");
+        wait_for_postgres(&mut pg, Path::new(pgdata))?;
+        pg.kill()?;
+        info!("sent kill signal");
+        pg.wait()?;
+        info!("done prewarming");
+
+        // clean up
+        let _ok = fs::remove_dir_all(pgdata);
+        Ok(())
+    }
+
     /// Start Postgres as a child process and manage DBs/roles.
     /// After that this will hang waiting on the postmaster process to exit.
     #[instrument(skip_all)]
@@ -506,7 +704,7 @@ impl ComputeNode {
 
         // Write new config
         let pgdata_path = Path::new(&self.pgdata);
-        config::write_postgres_conf(&pgdata_path.join("postgresql.conf"), &spec)?;
+        config::write_postgres_conf(&pgdata_path.join("postgresql.conf"), &spec, None)?;
 
         let mut client = Client::connect(self.connstr.as_str(), NoTls)?;
         self.pg_reload_conf(&mut client)?;
@@ -536,7 +734,7 @@ impl ComputeNode {
     }
 
     #[instrument(skip_all)]
-    pub fn start_compute(&self) -> Result<std::process::Child> {
+    pub fn start_compute(&self, extension_server_port: u16) -> Result<std::process::Child> {
         let compute_state = self.state.lock().unwrap().clone();
         let pspec = compute_state.pspec.as_ref().expect("spec must be set");
         info!(
@@ -547,7 +745,31 @@ impl ComputeNode {
             pspec.timeline_id,
         );
 
-        self.prepare_pgdata(&compute_state)?;
+        // This part is sync, because we need to download
+        // remote shared_preload_libraries before postgres start (if any)
+        {
+            let library_load_start_time = Utc::now();
+            let remote_ext_metrics = self.prepare_preload_libraries(&compute_state)?;
+
+            let library_load_time = Utc::now()
+                .signed_duration_since(library_load_start_time)
+                .to_std()
+                .unwrap()
+                .as_millis() as u64;
+            let mut state = self.state.lock().unwrap();
+            state.metrics.load_ext_ms = library_load_time;
+            state.metrics.num_ext_downloaded = remote_ext_metrics.num_ext_downloaded;
+            state.metrics.largest_ext_size = remote_ext_metrics.largest_ext_size;
+            state.metrics.total_ext_download_size = remote_ext_metrics.total_ext_download_size;
+            state.metrics.prep_extensions_ms = remote_ext_metrics.prep_extensions_ms;
+            info!(
+                "Loading shared_preload_libraries took {:?}ms",
+                library_load_time
+            );
+            info!("{:?}", remote_ext_metrics);
+        }
+
+        self.prepare_pgdata(&compute_state, extension_server_port)?;
 
         let start_time = Utc::now();
         let pg = self.start_postgres(pspec.storage_auth_token.clone())?;
@@ -695,4 +917,241 @@ LIMIT 100",
             "{{\"pg_stat_statements\": []}}".to_string()
         }
     }
+
+    // If remote extension storage is configured,
+    // download extension control files
+    pub async fn prepare_external_extensions(&self, compute_state: &ComputeState) -> Result<()> {
+        if let Some(ref ext_remote_storage) = self.ext_remote_storage {
+            let pspec = compute_state.pspec.as_ref().expect("spec must be set");
+            let spec = &pspec.spec;
+            let custom_ext = spec.custom_extensions.clone().unwrap_or(Vec::new());
+            info!("custom extensions: {:?}", &custom_ext);
+
+            let (ext_remote_paths, library_index) = extension_server::get_available_extensions(
+                ext_remote_storage,
+                &self.pgbin,
+                &self.pgversion,
+                &custom_ext,
+                &self.build_tag,
+            )
+            .await?;
+            self.ext_remote_paths
+                .set(ext_remote_paths)
+                .expect("this is the only time we set ext_remote_paths");
+            self.library_index
+                .set(library_index)
+                .expect("this is the only time we set library_index");
+        }
+        Ok(())
+    }
+
+    // download an archive, unzip and place files in correct locations
+    pub async fn download_extension(
+        &self,
+        ext_name: &str,
+        is_library: bool,
+    ) -> Result<u64, DownloadError> {
+        let remote_storage = self
+            .ext_remote_storage
+            .as_ref()
+            .ok_or(DownloadError::BadInput(anyhow::anyhow!(
+                "Remote extensions storage is not configured",
+            )))?;
+
+        let mut real_ext_name = ext_name;
+        if is_library {
+            // sometimes library names might have a suffix like
+            // library.so or library.so.3. We strip this off
+            // because library_index is based on the name without the file extension
+            let strip_lib_suffix = Regex::new(r"\.so.*").unwrap();
+            let lib_raw_name = strip_lib_suffix.replace(real_ext_name, "").to_string();
+
+            real_ext_name = self
+                .library_index
+                .get()
+                .expect("must have already downloaded the library_index")
+                .get(&lib_raw_name)
+                .ok_or(DownloadError::BadInput(anyhow::anyhow!(
+                    "library {} is not found",
+                    lib_raw_name
+                )))?;
+        }
+
+        let ext_path = &self
+            .ext_remote_paths
+            .get()
+            .expect("error accessing ext_remote_paths")
+            .get(real_ext_name)
+            .ok_or(DownloadError::BadInput(anyhow::anyhow!(
+                "real_ext_name {} is not found",
+                real_ext_name
+            )))?;
+
+        let ext_archive_name = ext_path.object_name().expect("bad path");
+
+        let mut first_try = false;
+        if !self
+            .ext_download_progress
+            .read()
+            .expect("lock err")
+            .contains_key(ext_archive_name)
+        {
+            self.ext_download_progress
+                .write()
+                .expect("lock err")
+                .insert(ext_archive_name.to_string(), (Utc::now(), false));
+            first_try = true;
+        }
+        let (download_start, download_completed) =
+            self.ext_download_progress.read().expect("lock err")[ext_archive_name];
+        let start_time_delta = Utc::now()
+            .signed_duration_since(download_start)
+            .to_std()
+            .unwrap()
+            .as_millis() as u64;
+
+        // how long to wait for extension download if it was started by another process
+        const HANG_TIMEOUT: u64 = 3000; // milliseconds
+
+        if download_completed {
+            info!("extension already downloaded, skipping re-download");
+            return Ok(0);
+        } else if start_time_delta < HANG_TIMEOUT && !first_try {
+            info!("download {ext_archive_name} already started by another process, hanging untill completion or timeout");
+            let mut interval = tokio::time::interval(tokio::time::Duration::from_millis(500));
+            loop {
+                info!("waiting for download");
+                interval.tick().await;
+                let (_, download_completed_now) =
+                    self.ext_download_progress.read().expect("lock")[ext_archive_name];
+                if download_completed_now {
+                    info!("download finished by whoever else downloaded it");
+                    return Ok(0);
+                }
+            }
+            // NOTE: the above loop will get terminated
+            // based on the timeout of the download function
+        }
+
+        // if extension hasn't been downloaded before or the previous
+        // attempt to download was at least HANG_TIMEOUT ms ago
+        // then we try to download it here
+        info!("downloading new extension {ext_archive_name}");
+
+        let download_size = extension_server::download_extension(
+            real_ext_name,
+            ext_path,
+            remote_storage,
+            &self.pgbin,
+        )
+        .await
+        .map_err(DownloadError::Other);
+
+        self.ext_download_progress
+            .write()
+            .expect("bad lock")
+            .insert(ext_archive_name.to_string(), (download_start, true));
+
+        download_size
+    }
+
+    #[tokio::main]
+    pub async fn prepare_preload_libraries(
+        &self,
+        compute_state: &ComputeState,
+    ) -> Result<RemoteExtensionMetrics> {
+        if self.ext_remote_storage.is_none() {
+            return Ok(RemoteExtensionMetrics {
+                num_ext_downloaded: 0,
+                largest_ext_size: 0,
+                total_ext_download_size: 0,
+                prep_extensions_ms: 0,
+            });
+        }
+        let pspec = compute_state.pspec.as_ref().expect("spec must be set");
+        let spec = &pspec.spec;
+
+        info!("parse shared_preload_libraries from spec.cluster.settings");
+        let mut libs_vec = Vec::new();
+        if let Some(libs) = spec.cluster.settings.find("shared_preload_libraries") {
+            libs_vec = libs
+                .split(&[',', '\'', ' '])
+                .filter(|s| *s != "neon" && !s.is_empty())
+                .map(str::to_string)
+                .collect();
+        }
+        info!("parse shared_preload_libraries from provided postgresql.conf");
+        // that is used in neon_local and python tests
+        if let Some(conf) = &spec.cluster.postgresql_conf {
+            let conf_lines = conf.split('\n').collect::<Vec<&str>>();
+            let mut shared_preload_libraries_line = "";
+            for line in conf_lines {
+                if line.starts_with("shared_preload_libraries") {
+                    shared_preload_libraries_line = line;
+                }
+            }
+            let mut preload_libs_vec = Vec::new();
+            if let Some(libs) = shared_preload_libraries_line.split("='").nth(1) {
+                preload_libs_vec = libs
+                    .split(&[',', '\'', ' '])
+                    .filter(|s| *s != "neon" && !s.is_empty())
+                    .map(str::to_string)
+                    .collect();
+            }
+            libs_vec.extend(preload_libs_vec);
+        }
+
+        info!("Download ext_index.json, find the extension paths");
+        let prep_ext_start_time = Utc::now();
+        self.prepare_external_extensions(compute_state).await?;
+        let prep_ext_time_delta = Utc::now()
+            .signed_duration_since(prep_ext_start_time)
+            .to_std()
+            .unwrap()
+            .as_millis() as u64;
+        info!("Prepare extensions took {prep_ext_time_delta}ms");
+
+        // Don't try to download libraries that are not in the index.
+        // Assume that they are already present locally.
+        libs_vec.retain(|lib| {
+            self.library_index
+                .get()
+                .expect("error accessing ext_remote_paths")
+                .contains_key(lib)
+        });
+
+        info!("Downloading to shared preload libraries: {:?}", &libs_vec);
+
+        let mut download_tasks = Vec::new();
+        for library in &libs_vec {
+            download_tasks.push(self.download_extension(library, true));
+        }
+        let results = join_all(download_tasks).await;
+
+        let mut remote_ext_metrics = RemoteExtensionMetrics {
+            num_ext_downloaded: 0,
+            largest_ext_size: 0,
+            total_ext_download_size: 0,
+            prep_extensions_ms: prep_ext_time_delta,
+        };
+        for result in results {
+            let download_size = match result {
+                Ok(res) => {
+                    remote_ext_metrics.num_ext_downloaded += 1;
+                    res
+                }
+                Err(err) => {
+                    // if we failed to download an extension, we don't want to fail the whole
+                    // process, but we do want to log the error
+                    error!("Failed to download extension: {}", err);
+                    0
+                }
+            };
+
+            remote_ext_metrics.largest_ext_size =
+                std::cmp::max(remote_ext_metrics.largest_ext_size, download_size);
+            remote_ext_metrics.total_ext_download_size += download_size;
+        }
+        Ok(remote_ext_metrics)
+    }
 }

compute_tools/src/config.rs

@@ -33,7 +33,11 @@ pub fn line_in_file(path: &Path, line: &str) -> Result<bool> {
 }
 
 /// Create or completely rewrite configuration file specified by `path`
-pub fn write_postgres_conf(path: &Path, spec: &ComputeSpec) -> Result<()> {
+pub fn write_postgres_conf(
+    path: &Path,
+    spec: &ComputeSpec,
+    extension_server_port: Option<u16>,
+) -> Result<()> {
     // File::create() destroys the file content if it exists.
     let mut file = File::create(path)?;
 
@@ -87,5 +91,9 @@ pub fn write_postgres_conf(path: &Path, spec: &ComputeSpec) -> Result<()> {
         writeln!(file, "# Managed by compute_ctl: end")?;
     }
 
+    if let Some(port) = extension_server_port {
+        writeln!(file, "neon.extension_server_port={}", port)?;
+    }
+
     Ok(())
 }

compute_tools/src/extension_server.rs

@@ -0,0 +1,281 @@
+// Download extension files from the extension store
+// and put them in the right place in the postgres directory (share / lib)
+/*
+The layout of the S3 bucket is as follows:
+5615610098 // this is an extension build number
+├── v14
+│   ├── extensions
+│   │   ├── anon.tar.zst
+│   │   └── embedding.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   ├── anon.tar.zst
+    │   └── embedding.tar.zst
+    └── ext_index.json
+5615261079
+├── v14
+│   ├── extensions
+│   │   └── anon.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   └── anon.tar.zst
+    └── ext_index.json
+5623261088
+├── v14
+│   ├── extensions
+│   │   └── embedding.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   └── embedding.tar.zst
+    └── ext_index.json
+
+Note that build number cannot be part of prefix because we might need extensions
+from other build numbers.
+
+ext_index.json stores the control files and location of extension archives
+It also stores a list of public extensions and a library_index
+
+We don't need to duplicate extension.tar.zst files.
+We only need to upload a new one if it is updated.
+(Although currently we just upload every time anyways, hopefully will change
+this sometime)
+
+*access* is controlled by spec
+
+More specifically, here is an example ext_index.json
+{
+    "public_extensions": [
+        "anon",
+        "pg_buffercache"
+    ],
+    "library_index": {
+        "anon": "anon",
+        "pg_buffercache": "pg_buffercache"
+    },
+    "extension_data": {
+        "pg_buffercache": {
+            "control_data": {
+                "pg_buffercache.control": "# pg_buffercache extension \ncomment = 'examine the shared buffer cache' \ndefault_version = '1.3' \nmodule_pathname = '$libdir/pg_buffercache' \nrelocatable = true \ntrusted=true"
+            },
+            "archive_path": "5670669815/v14/extensions/pg_buffercache.tar.zst"
+        },
+        "anon": {
+            "control_data": {
+                "anon.control": "# PostgreSQL Anonymizer (anon) extension \ncomment = 'Data anonymization tools' \ndefault_version = '1.1.0' \ndirectory='extension/anon' \nrelocatable = false \nrequires = 'pgcrypto' \nsuperuser = false \nmodule_pathname = '$libdir/anon' \ntrusted = true \n"
+            },
+            "archive_path": "5670669815/v14/extensions/anon.tar.zst"
+        }
+    }
+}
+*/
+use anyhow::Context;
+use anyhow::{self, Result};
+use futures::future::join_all;
+use remote_storage::*;
+use serde_json;
+use std::collections::HashMap;
+use std::io::Read;
+use std::num::{NonZeroU32, NonZeroUsize};
+use std::path::Path;
+use std::str;
+use tar::Archive;
+use tokio::io::AsyncReadExt;
+use tracing::info;
+use tracing::log::warn;
+use zstd::stream::read::Decoder;
+
+fn get_pg_config(argument: &str, pgbin: &str) -> String {
+    // gives the result of `pg_config [argument]`
+    // where argument is a flag like `--version` or `--sharedir`
+    let pgconfig = pgbin
+        .strip_suffix("postgres")
+        .expect("bad pgbin")
+        .to_owned()
+        + "/pg_config";
+    let config_output = std::process::Command::new(pgconfig)
+        .arg(argument)
+        .output()
+        .expect("pg_config error");
+    std::str::from_utf8(&config_output.stdout)
+        .expect("pg_config error")
+        .trim()
+        .to_string()
+}
+
+pub fn get_pg_version(pgbin: &str) -> String {
+    // pg_config --version returns a (platform specific) human readable string
+    // such as "PostgreSQL 15.4". We parse this to v14/v15
+    let human_version = get_pg_config("--version", pgbin);
+    if human_version.contains("15") {
+        return "v15".to_string();
+    } else if human_version.contains("14") {
+        return "v14".to_string();
+    }
+    panic!("Unsuported postgres version {human_version}");
+}
+
+// download control files for enabled_extensions
+// return Hashmaps converting library names to extension names (library_index)
+// and specifying the remote path to the archive for each extension name
+pub async fn get_available_extensions(
+    remote_storage: &GenericRemoteStorage,
+    pgbin: &str,
+    pg_version: &str,
+    custom_extensions: &[String],
+    build_tag: &str,
+) -> Result<(HashMap<String, RemotePath>, HashMap<String, String>)> {
+    let local_sharedir = Path::new(&get_pg_config("--sharedir", pgbin)).join("extension");
+    let index_path = format!("{build_tag}/{pg_version}/ext_index.json");
+    let index_path = RemotePath::new(Path::new(&index_path)).context("error forming path")?;
+    info!("download ext_index.json from: {:?}", &index_path);
+
+    let mut download = remote_storage.download(&index_path).await?;
+    let mut ext_idx_buffer = Vec::new();
+    download
+        .download_stream
+        .read_to_end(&mut ext_idx_buffer)
+        .await?;
+    info!("ext_index downloaded");
+
+    #[derive(Debug, serde::Deserialize)]
+    struct Index {
+        public_extensions: Vec<String>,
+        library_index: HashMap<String, String>,
+        extension_data: HashMap<String, ExtensionData>,
+    }
+
+    #[derive(Debug, serde::Deserialize)]
+    struct ExtensionData {
+        control_data: HashMap<String, String>,
+        archive_path: String,
+    }
+
+    let ext_index_full = serde_json::from_slice::<Index>(&ext_idx_buffer)?;
+    let mut enabled_extensions = ext_index_full.public_extensions;
+    enabled_extensions.extend_from_slice(custom_extensions);
+    let mut library_index = ext_index_full.library_index;
+    let all_extension_data = ext_index_full.extension_data;
+    info!("library_index: {:?}", library_index);
+
+    info!("enabled_extensions: {:?}", enabled_extensions);
+    let mut ext_remote_paths = HashMap::new();
+    let mut file_create_tasks = Vec::new();
+    for extension in enabled_extensions {
+        let ext_data = &all_extension_data[&extension];
+        for (control_file, control_contents) in &ext_data.control_data {
+            let extension_name = control_file
+                .strip_suffix(".control")
+                .expect("control files must end in .control");
+            let control_path = local_sharedir.join(control_file);
+            if !control_path.exists() {
+                ext_remote_paths.insert(
+                    extension_name.to_string(),
+                    RemotePath::from_string(&ext_data.archive_path)?,
+                );
+                info!("writing file {:?}{:?}", control_path, control_contents);
+                file_create_tasks.push(tokio::fs::write(control_path, control_contents));
+            } else {
+                warn!("control file {:?} exists both locally and remotely. ignoring the remote version.", control_file);
+                // also delete this from library index
+                library_index.retain(|_, value| value != extension_name);
+            }
+        }
+    }
+    let results = join_all(file_create_tasks).await;
+    for result in results {
+        result?;
+    }
+    info!("ext_remote_paths {:?}", ext_remote_paths);
+    Ok((ext_remote_paths, library_index))
+}
+
+// download the archive for a given extension,
+// unzip it, and place files in the appropriate locations (share/lib)
+pub async fn download_extension(
+    ext_name: &str,
+    ext_path: &RemotePath,
+    remote_storage: &GenericRemoteStorage,
+    pgbin: &str,
+) -> Result<u64> {
+    info!("Download extension {:?} from {:?}", ext_name, ext_path);
+    let mut download = remote_storage.download(ext_path).await?;
+    let mut download_buffer = Vec::new();
+    download
+        .download_stream
+        .read_to_end(&mut download_buffer)
+        .await?;
+    let download_size = download_buffer.len() as u64;
+    // it's unclear whether it is more performant to decompress into memory or not
+    // TODO: decompressing into memory can be avoided
+    let mut decoder = Decoder::new(download_buffer.as_slice())?;
+    let mut decompress_buffer = Vec::new();
+    decoder.read_to_end(&mut decompress_buffer)?;
+    let mut archive = Archive::new(decompress_buffer.as_slice());
+    let unzip_dest = pgbin
+        .strip_suffix("/bin/postgres")
+        .expect("bad pgbin")
+        .to_string()
+        + "/download_extensions";
+    archive.unpack(&unzip_dest)?;
+    info!("Download + unzip {:?} completed successfully", &ext_path);
+
+    let sharedir_paths = (
+        unzip_dest.to_string() + "/share/extension",
+        Path::new(&get_pg_config("--sharedir", pgbin)).join("extension"),
+    );
+    let libdir_paths = (
+        unzip_dest.to_string() + "/lib",
+        Path::new(&get_pg_config("--pkglibdir", pgbin)).to_path_buf(),
+    );
+    // move contents of the libdir / sharedir in unzipped archive to the correct local paths
+    for paths in [sharedir_paths, libdir_paths] {
+        let (zip_dir, real_dir) = paths;
+        info!("mv {zip_dir:?}/*  {real_dir:?}");
+        for file in std::fs::read_dir(zip_dir)? {
+            let old_file = file?.path();
+            let new_file =
+                Path::new(&real_dir).join(old_file.file_name().context("error parsing file")?);
+            info!("moving {old_file:?} to {new_file:?}");
+
+            // extension download failed: Directory not empty (os error 39)
+            match std::fs::rename(old_file, new_file) {
+                Ok(()) => info!("move succeeded"),
+                Err(e) => {
+                    warn!("move failed, probably because the extension already exists: {e}")
+                }
+            }
+        }
+    }
+    info!("done moving extension {ext_name}");
+    Ok(download_size)
+}
+
+// This function initializes the necessary structs to use remote storage
+pub fn init_remote_storage(remote_ext_config: &str) -> anyhow::Result<GenericRemoteStorage> {
+    #[derive(Debug, serde::Deserialize)]
+    struct RemoteExtJson {
+        bucket: String,
+        region: String,
+        endpoint: Option<String>,
+        prefix: Option<String>,
+    }
+    let remote_ext_json = serde_json::from_str::<RemoteExtJson>(remote_ext_config)?;
+
+    let config = S3Config {
+        bucket_name: remote_ext_json.bucket,
+        bucket_region: remote_ext_json.region,
+        prefix_in_bucket: remote_ext_json.prefix,
+        endpoint: remote_ext_json.endpoint,
+        concurrency_limit: NonZeroUsize::new(100).expect("100 != 0"),
+        max_keys_per_list_response: None,
+    };
+    let config = RemoteStorageConfig {
+        max_concurrent_syncs: NonZeroUsize::new(100).expect("100 != 0"),
+        max_sync_errors: NonZeroU32::new(100).expect("100 != 0"),
+        storage: RemoteStorageKind::AwsS3(config),
+    };
+    GenericRemoteStorage::from_config(&config)
+}

compute_tools/src/http/api.rs

@@ -121,6 +121,46 @@ async fn routes(req: Request<Body>, compute: &Arc<ComputeNode>) -> Response<Body
             }
         }
 
+        // download extension files from S3 on demand
+        (&Method::POST, route) if route.starts_with("/extension_server/") => {
+            info!("serving {:?} POST request", route);
+            info!("req.uri {:?}", req.uri());
+
+            let mut is_library = false;
+            if let Some(params) = req.uri().query() {
+                info!("serving {:?} POST request with params: {}", route, params);
+                if params == "is_library=true" {
+                    is_library = true;
+                } else {
+                    let mut resp = Response::new(Body::from("Wrong request parameters"));
+                    *resp.status_mut() = StatusCode::BAD_REQUEST;
+                    return resp;
+                }
+            }
+
+            let filename = route.split('/').last().unwrap().to_string();
+            info!("serving /extension_server POST request, filename: {filename:?} is_library: {is_library}");
+
+            // don't even try to download extensions
+            // if no remote storage is configured
+            if compute.ext_remote_storage.is_none() {
+                info!("no extensions remote storage configured");
+                let mut resp = Response::new(Body::from("no remote storage configured"));
+                *resp.status_mut() = StatusCode::INTERNAL_SERVER_ERROR;
+                return resp;
+            }
+
+            match compute.download_extension(&filename, is_library).await {
+                Ok(_) => Response::new(Body::from("OK")),
+                Err(e) => {
+                    error!("extension download failed: {}", e);
+                    let mut resp = Response::new(Body::from(e.to_string()));
+                    *resp.status_mut() = StatusCode::INTERNAL_SERVER_ERROR;
+                    resp
+                }
+            }
+        }
+
         // Return the `404 Not Found` for any other routes.
         _ => {
             let mut not_found = Response::new(Body::from("404 Not Found"));

compute_tools/src/http/openapi_spec.yaml

@@ -139,6 +139,34 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/GenericError"
+  /extension_server:
+    post:
+      tags:
+      - Extension
+      summary: Download extension from S3 to local folder.
+      description: ""
+      operationId: downloadExtension
+      responses:
+        200:
+          description: Extension downloaded
+          content:
+            text/plain:
+              schema:
+                type: string
+                description: Error text or 'OK' if download succeeded.
+                example: "OK"
+        400:
+        description: Request is invalid.
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/GenericError"
+        500:
+        description: Extension download request failed.
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/GenericError"
 
 components:
   securitySchemes:

compute_tools/src/lib.rs

@@ -9,7 +9,9 @@ pub mod http;
 #[macro_use]
 pub mod logger;
 pub mod compute;
+pub mod extension_server;
 pub mod monitor;
 pub mod params;
 pub mod pg_helpers;
 pub mod spec;
+pub mod sync_sk;

compute_tools/src/spec.rs

@@ -124,7 +124,7 @@ pub fn get_spec_from_control_plane(
 pub fn handle_configuration(spec: &ComputeSpec, pgdata_path: &Path) -> Result<()> {
     // File `postgresql.conf` is no longer included into `basebackup`, so just
     // always write all config into it creating new file.
-    config::write_postgres_conf(&pgdata_path.join("postgresql.conf"), spec)?;
+    config::write_postgres_conf(&pgdata_path.join("postgresql.conf"), spec, None)?;
 
     update_pg_hba(pgdata_path)?;
 
@@ -270,7 +270,7 @@ pub fn handle_roles(spec: &ComputeSpec, client: &mut Client) -> Result<()> {
             }
             RoleAction::Create => {
                 let mut query: String = format!(
-                    "CREATE ROLE {} CREATEROLE CREATEDB IN ROLE neon_superuser",
+                    "CREATE ROLE {} CREATEROLE CREATEDB BYPASSRLS IN ROLE neon_superuser",
                     name.pg_quote()
                 );
                 info!("role create query: '{}'", &query);

compute_tools/src/sync_sk.rs

@@ -0,0 +1,98 @@
+// Utils for running sync_safekeepers
+use anyhow::Result;
+use tracing::info;
+use utils::lsn::Lsn;
+
+#[derive(Copy, Clone, Debug)]
+pub enum TimelineStatusResponse {
+    NotFound,
+    Ok(TimelineStatusOkResponse),
+}
+
+#[derive(Copy, Clone, Debug)]
+pub struct TimelineStatusOkResponse {
+    flush_lsn: Lsn,
+    commit_lsn: Lsn,
+}
+
+/// Get a safekeeper's metadata for our timeline. The id is only used for logging
+pub async fn ping_safekeeper(
+    id: String,
+    config: tokio_postgres::Config,
+) -> Result<TimelineStatusResponse> {
+    // TODO add retries
+
+    // Connect
+    info!("connecting to {}", id);
+    let (client, conn) = config.connect(tokio_postgres::NoTls).await?;
+    tokio::spawn(async move {
+        if let Err(e) = conn.await {
+            eprintln!("connection error: {}", e);
+        }
+    });
+
+    // Query
+    info!("querying {}", id);
+    let result = client.simple_query("TIMELINE_STATUS").await?;
+
+    // Parse result
+    info!("done with {}", id);
+    if let postgres::SimpleQueryMessage::Row(row) = &result[0] {
+        use std::str::FromStr;
+        let response = TimelineStatusResponse::Ok(TimelineStatusOkResponse {
+            flush_lsn: Lsn::from_str(row.get("flush_lsn").unwrap())?,
+            commit_lsn: Lsn::from_str(row.get("commit_lsn").unwrap())?,
+        });
+        Ok(response)
+    } else {
+        // Timeline doesn't exist
+        Ok(TimelineStatusResponse::NotFound)
+    }
+}
+
+/// Given a quorum of responses, check if safekeepers are synced at some Lsn
+pub fn check_if_synced(responses: Vec<TimelineStatusResponse>) -> Option<Lsn> {
+    // Check if all responses are ok
+    let ok_responses: Vec<TimelineStatusOkResponse> = responses
+        .iter()
+        .filter_map(|r| match r {
+            TimelineStatusResponse::Ok(ok_response) => Some(ok_response),
+            _ => None,
+        })
+        .cloned()
+        .collect();
+    if ok_responses.len() < responses.len() {
+        info!(
+            "not synced. Only {} out of {} know about this timeline",
+            ok_responses.len(),
+            responses.len()
+        );
+        return None;
+    }
+
+    // Get the min and the max of everything
+    let commit: Vec<Lsn> = ok_responses.iter().map(|r| r.commit_lsn).collect();
+    let flush: Vec<Lsn> = ok_responses.iter().map(|r| r.flush_lsn).collect();
+    let commit_max = commit.iter().max().unwrap();
+    let commit_min = commit.iter().min().unwrap();
+    let flush_max = flush.iter().max().unwrap();
+    let flush_min = flush.iter().min().unwrap();
+
+    // Check that all values are equal
+    if commit_min != commit_max {
+        info!("not synced. {:?} {:?}", commit_min, commit_max);
+        return None;
+    }
+    if flush_min != flush_max {
+        info!("not synced. {:?} {:?}", flush_min, flush_max);
+        return None;
+    }
+
+    // Check that commit == flush
+    if commit_max != flush_max {
+        info!("not synced. {:?} {:?}", commit_max, flush_max);
+        return None;
+    }
+
+    Some(*commit_max)
+}

control_plane/Cargo.toml

@@ -32,3 +32,4 @@ utils.workspace = true
 
 compute_api.workspace = true
 workspace_hack.workspace = true
+tracing.workspace = true

control_plane/src/bin/neon_local.rs

@@ -658,6 +658,8 @@ fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<(
                 .get_one::<String>("endpoint_id")
                 .ok_or_else(|| anyhow!("No endpoint ID was provided to start"))?;
 
+            let remote_ext_config = sub_args.get_one::<String>("remote-ext-config");
+
             // If --safekeepers argument is given, use only the listed safekeeper nodes.
             let safekeepers =
                 if let Some(safekeepers_str) = sub_args.get_one::<String>("safekeepers") {
@@ -699,7 +701,7 @@ fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<(
                     _ => {}
                 }
                 println!("Starting existing endpoint {endpoint_id}...");
-                endpoint.start(&auth_token, safekeepers)?;
+                endpoint.start(&auth_token, safekeepers, remote_ext_config)?;
             } else {
                 let branch_name = sub_args
                     .get_one::<String>("branch-name")
@@ -743,7 +745,7 @@ fn handle_endpoint(ep_match: &ArgMatches, env: &local_env::LocalEnv) -> Result<(
                     pg_version,
                     mode,
                 )?;
-                ep.start(&auth_token, safekeepers)?;
+                ep.start(&auth_token, safekeepers, remote_ext_config)?;
             }
         }
         "stop" => {
@@ -1003,6 +1005,12 @@ fn cli() -> Command {
         .help("Additional pageserver's configuration options or overrides, refer to pageserver's 'config-override' CLI parameter docs for more")
         .required(false);
 
+    let remote_ext_config_args = Arg::new("remote-ext-config")
+        .long("remote-ext-config")
+        .num_args(1)
+        .help("Configure the S3 bucket that we search for extensions in.")
+        .required(false);
+
     let lsn_arg = Arg::new("lsn")
         .long("lsn")
         .help("Specify Lsn on the timeline to start from. By default, end of the timeline would be used.")
@@ -1161,6 +1169,7 @@ fn cli() -> Command {
                     .arg(pg_version_arg)
                     .arg(hot_standby_arg)
                     .arg(safekeepers_arg)
+                    .arg(remote_ext_config_args)
                 )
                 .subcommand(
                     Command::new("stop")

control_plane/src/endpoint.rs

@@ -313,7 +313,7 @@ impl Endpoint {
 
                 // TODO: use future host field from safekeeper spec
                 // Pass the list of safekeepers to the replica so that it can connect to any of them,
-                // whichever is availiable.
+                // whichever is available.
                 let sk_ports = self
                     .env
                     .safekeepers
@@ -420,7 +420,12 @@ impl Endpoint {
         Ok(())
     }
 
-    pub fn start(&self, auth_token: &Option<String>, safekeepers: Vec<NodeId>) -> Result<()> {
+    pub fn start(
+        &self,
+        auth_token: &Option<String>,
+        safekeepers: Vec<NodeId>,
+        remote_ext_config: Option<&String>,
+    ) -> Result<()> {
         if self.status() == "running" {
             anyhow::bail!("The endpoint is already running");
         }
@@ -488,6 +493,7 @@ impl Endpoint {
             pageserver_connstring: Some(pageserver_connstring),
             safekeeper_connstrings,
             storage_auth_token: auth_token.clone(),
+            custom_extensions: Some(vec![]),
         };
         let spec_path = self.endpoint_path().join("spec.json");
         std::fs::write(spec_path, serde_json::to_string_pretty(&spec)?)?;
@@ -519,6 +525,11 @@ impl Endpoint {
             .stdin(std::process::Stdio::null())
             .stderr(logfile.try_clone()?)
             .stdout(logfile);
+
+        if let Some(remote_ext_config) = remote_ext_config {
+            cmd.args(["--remote-ext-config", remote_ext_config]);
+        }
+
         let child = cmd.spawn()?;
 
         // Write down the pid so we can wait for it when we want to stop
@@ -564,9 +575,7 @@ impl Endpoint {
                 }
                 Err(e) => {
                     if attempt == MAX_ATTEMPTS {
-                        return Err(e).context(
-                            "timed out waiting to connect to compute_ctl HTTP; last error: {e}",
-                        );
+                        return Err(e).context("timed out waiting to connect to compute_ctl HTTP");
                     }
                 }
             }

docs/rfcs/024-extension-loading.md

@@ -0,0 +1,236 @@
+# Supporting custom user Extensions (Dynamic Extension Loading)
+Created 2023-05-03
+
+## Motivation
+
+There are many extensions in the PostgreSQL ecosystem, and not all extensions
+are of a quality that we can confidently support them. Additionally, our
+current extension inclusion mechanism has several problems because we build all
+extensions into the primary Compute image: We build the extensions every time
+we build the compute image regardless of whether we actually need to rebuild
+the image, and the inclusion of these extensions in the image adds a hard
+dependency on all supported extensions - thus increasing the image size, and
+with it the time it takes to download that image - increasing first start
+latency.
+
+This RFC proposes a dynamic loading mechanism that solves most of these
+problems.
+
+## Summary
+
+`compute_ctl` is made responsible for loading extensions on-demand into
+the container's file system for dynamically loaded extensions, and will also
+make sure that the extensions in `shared_preload_libraries` are downloaded
+before the compute node starts.
+
+## Components
+
+compute_ctl, PostgreSQL, neon (extension), Compute Host Node, Extension Store
+
+## Requirements
+
+Compute nodes with no extra extensions should not be negatively impacted by
+the existence of support for many extensions.
+
+Installing an extension into PostgreSQL should be easy.
+
+Non-preloaded extensions shouldn't impact startup latency.
+
+Uninstalled extensions shouldn't impact query latency.
+
+A small latency penalty for dynamically loaded extensions is acceptable in
+the first seconds of compute startup, but not in steady-state operations.
+
+## Proposed implementation
+
+### On-demand, JIT-loading of extensions
+
+Before postgres starts we download 
+- control files for all extensions available to that compute node;
+- all `shared_preload_libraries`;
+
+After postgres is running, `compute_ctl` listens for requests to load files.
+When PostgreSQL requests a file, `compute_ctl` downloads it.
+
+PostgreSQL requests files in the following cases:
+- When loading a preload library set in `local_preload_libraries`
+- When explicitly loading a library with `LOAD`
+- Wnen creating extension with `CREATE EXTENSION` (download sql scripts, (optional) extension data files and (optional) library files)))
+
+
+#### Summary
+
+Pros:
+ - Startup is only as slow as it takes to load all (shared_)preload_libraries
+ - Supports BYO Extension
+
+Cons:
+ - O(sizeof(extensions)) IO requirement for loading all extensions.
+
+### Alternative solutions
+
+1. Allow users to add their extensions to the base image
+   
+   Pros:
+    - Easy to deploy
+
+   Cons:
+    - Doesn't scale - first start size is dependent on image size;
+    - All extensions are shared across all users: It doesn't allow users to
+      bring their own restrictive-licensed extensions
+
+2. Bring Your Own compute image
+   
+   Pros:
+    - Still easy to deploy
+    - User can bring own patched version of PostgreSQL
+
+   Cons:
+    - First start latency is O(sizeof(extensions image))
+    - Warm instance pool for skipping pod schedule latency is not feasible with
+      O(n) custom images
+    - Support channels are difficult to manage
+
+3. Download all user extensions in bulk on compute start
+   
+   Pros:
+    - Easy to deploy
+    - No startup latency issues for "clean" users.
+    - Warm instance pool for skipping pod schedule latency is possible
+
+   Cons:
+    - Downloading all extensions in advance takes a lot of time, thus startup
+      latency issues
+
+4. Store user's extensions in persistent storage
+   
+   Pros:
+    - Easy to deploy
+    - No startup latency issues
+    - Warm instance pool for skipping pod schedule latency is possible
+
+   Cons:
+    - EC2 instances have only limited number of attachments shared between EBS
+      volumes, direct-attached NVMe drives, and ENIs.
+    - Compute instance migration isn't trivially solved for EBS mounts (e.g.
+      the device is unavailable whilst moving the mount between instances).
+    - EBS can only mount on one instance at a time (except the expensive IO2
+      device type).
+
+5. Store user's extensions in network drive
+   
+   Pros:
+    - Easy to deploy
+    - Few startup latency issues
+    - Warm instance pool for skipping pod schedule latency is possible
+
+   Cons:
+    - We'd need networked drives, and a lot of them, which would store many
+      duplicate extensions.
+    - **UNCHECKED:** Compute instance migration may not work nicely with
+      networked IOs
+
+
+### Idea extensions
+
+The extension store does not have to be S3 directly, but could be a Node-local
+caching service on top of S3. This would reduce the load on the network for
+popular extensions.
+
+## Extension Storage implementation
+
+The layout of the S3 bucket is as follows:
+```
+5615610098 // this is an extension build number
+├── v14
+│   ├── extensions
+│   │   ├── anon.tar.zst
+│   │   └── embedding.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   ├── anon.tar.zst
+    │   └── embedding.tar.zst
+    └── ext_index.json
+5615261079
+├── v14
+│   ├── extensions
+│   │   └── anon.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   └── anon.tar.zst
+    └── ext_index.json
+5623261088
+├── v14
+│   ├── extensions
+│   │   └── embedding.tar.zst
+│   └── ext_index.json
+└── v15
+    ├── extensions
+    │   └── embedding.tar.zst
+    └── ext_index.json
+```
+
+Note that build number cannot be part of prefix because we might need extensions
+from other build numbers.
+
+`ext_index.json` stores the control files and location of extension archives. 
+It also stores a list of public extensions and a library_index
+
+We don't need to duplicate `extension.tar.zst`` files.
+We only need to upload a new one if it is updated.
+(Although currently we just upload every time anyways, hopefully will change
+this sometime)
+
+*access* is controlled by spec
+
+More specifically, here is an example ext_index.json
+```
+{
+    "public_extensions": [
+        "anon",
+        "pg_buffercache"
+    ],
+    "library_index": {
+        "anon": "anon",
+        "pg_buffercache": "pg_buffercache"
+        // for more complex extensions like postgis
+        // we might have something like:
+        // address_standardizer: postgis
+        // postgis_tiger: postgis
+    },
+    "extension_data": {
+        "pg_buffercache": {
+            "control_data": {
+                "pg_buffercache.control": "# pg_buffercache extension \ncomment = 'examine the shared buffer cache' \ndefault_version = '1.3' \nmodule_pathname = '$libdir/pg_buffercache' \nrelocatable = true \ntrusted=true"
+            },
+            "archive_path": "5670669815/v14/extensions/pg_buffercache.tar.zst"
+        },
+        "anon": {
+            "control_data": {
+                "anon.control": "# PostgreSQL Anonymizer (anon) extension \ncomment = 'Data anonymization tools' \ndefault_version = '1.1.0' \ndirectory='extension/anon' \nrelocatable = false \nrequires = 'pgcrypto' \nsuperuser = false \nmodule_pathname = '$libdir/anon' \ntrusted = true \n"
+            },
+            "archive_path": "5670669815/v14/extensions/anon.tar.zst"
+        }
+    }
+}
+```
+
+### How to add new extension to the Extension Storage?
+
+Simply upload build artifacts to the S3 bucket.
+Implement a CI step for that. Splitting it from compute-node-image build.
+
+### How do we deal with extension versions and updates?
+
+Currently, we rebuild extensions on every compute-node-image build and store them in the <build-version> prefix.
+This is needed to ensure that `/share` and `/lib` files are in sync.
+
+For extension updates, we rely on the PostgreSQL extension versioning mechanism (sql update scripts) and extension authors to not break backwards compatibility within one major version of PostgreSQL.
+
+### Alternatives
+
+For extensions written on trusted languages we can also adopt
+`dbdev` PostgreSQL Package Manager based on `pg_tle` by Supabase.
+This will increase the amount supported extensions and decrease the amount of work required to support them.

libs/compute_api/src/responses.rs

@@ -68,13 +68,46 @@ where
 /// Response of the /metrics.json API
 #[derive(Clone, Debug, Default, Serialize)]
 pub struct ComputeMetrics {
+    /// Time spent waiting in pool
     pub wait_for_spec_ms: u64,
+
+    /// Time spent checking if safekeepers are synced
+    pub sync_sk_check_ms: u64,
+
+    /// Time spent syncing safekeepers (walproposer.c).
+    /// In most cases this should be zero.
     pub sync_safekeepers_ms: u64,
+
+    /// Time it took to establish a pg connection to the pageserver.
+    /// This is two roundtrips, so it's a good proxy for compute-pageserver
+    /// latency. The latency is usually 0.2ms, but it's not safe to assume
+    /// that.
+    pub pageserver_connect_micros: u64,
+
+    /// Time to get basebackup from pageserver and write it to disk.
     pub basebackup_ms: u64,
+
+    /// Compressed size of basebackup received.
     pub basebackup_bytes: u64,
+
+    /// Time spent starting potgres. This includes initialization of shared
+    /// buffers, preloading extensions, and other pg operations.
     pub start_postgres_ms: u64,
+
+    /// Time spent applying pg catalog updates that were made in the console
+    /// UI. This should be 0 when startup time matters, since cplane tries
+    /// to do these updates eagerly, and passes the skip_pg_catalog_updates
+    /// when it's safe to skip this step.
     pub config_ms: u64,
+
+    /// Total time, from when we receive the spec to when we're ready to take
+    /// pg connections.
     pub total_startup_ms: u64,
+    pub load_ext_ms: u64,
+    pub num_ext_downloaded: u64,
+    pub largest_ext_size: u64, // these are measured in bytes
+    pub total_ext_download_size: u64,
+    pub prep_extensions_ms: u64,
 }
 
 /// Response of the `/computes/{compute_id}/spec` control-plane API.

libs/compute_api/src/spec.rs

@@ -60,6 +60,9 @@ pub struct ComputeSpec {
     /// If set, 'storage_auth_token' is used as the password to authenticate to
     /// the pageserver and safekeepers.
     pub storage_auth_token: Option<String>,
+
+    // list of prefixes to search for custom extensions in remote extension storage
+    pub custom_extensions: Option<Vec<String>>,
 }
 
 #[serde_as]

libs/consumption_metrics/src/lib.rs

@@ -5,7 +5,7 @@ use chrono::{DateTime, Utc};
 use rand::Rng;
 use serde::Serialize;
 
-#[derive(Serialize, Debug, Clone, Eq, PartialEq, Ord, PartialOrd)]
+#[derive(Serialize, Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd)]
 #[serde(tag = "type")]
 pub enum EventType {
     #[serde(rename = "absolute")]
@@ -17,6 +17,32 @@ pub enum EventType {
     },
 }
 
+impl EventType {
+    pub fn absolute_time(&self) -> Option<&DateTime<Utc>> {
+        use EventType::*;
+        match self {
+            Absolute { time } => Some(time),
+            _ => None,
+        }
+    }
+
+    pub fn incremental_timerange(&self) -> Option<std::ops::Range<&DateTime<Utc>>> {
+        // these can most likely be thought of as Range or RangeFull
+        use EventType::*;
+        match self {
+            Incremental {
+                start_time,
+                stop_time,
+            } => Some(start_time..stop_time),
+            _ => None,
+        }
+    }
+
+    pub fn is_incremental(&self) -> bool {
+        matches!(self, EventType::Incremental { .. })
+    }
+}
+
 #[derive(Serialize, Debug, Clone, Eq, PartialEq, Ord, PartialOrd)]
 pub struct Event<Extra> {
     #[serde(flatten)]
@@ -31,7 +57,7 @@ pub struct Event<Extra> {
     pub extra: Extra,
 }
 
-pub fn idempotency_key(node_id: String) -> String {
+pub fn idempotency_key(node_id: &str) -> String {
     format!(
         "{}-{}-{:04}",
         Utc::now(),
@@ -45,6 +71,6 @@ pub const CHUNK_SIZE: usize = 1000;
 // Just a wrapper around a slice of events
 // to serialize it as `{"events" : [ ] }
 #[derive(serde::Serialize)]
-pub struct EventChunk<'a, T> {
-    pub events: &'a [T],
+pub struct EventChunk<'a, T: Clone> {
+    pub events: std::borrow::Cow<'a, [T]>,
 }

libs/pq_proto/src/lib.rs

@@ -179,7 +179,7 @@ pub struct FeExecuteMessage {
 #[derive(Debug)]
 pub struct FeCloseMessage;
 
-/// An error occured while parsing or serializing raw stream into Postgres
+/// An error occurred while parsing or serializing raw stream into Postgres
 /// messages.
 #[derive(thiserror::Error, Debug)]
 pub enum ProtocolError {

libs/remote_storage/Cargo.toml

@@ -20,6 +20,7 @@ tokio = { workspace = true, features = ["sync", "fs", "io-util"] }
 tokio-util.workspace = true
 toml_edit.workspace = true
 tracing.workspace = true
+scopeguard.workspace = true
 metrics.workspace = true
 utils.workspace = true
 pin-project-lite.workspace = true

libs/remote_storage/src/lib.rs

@@ -65,6 +65,10 @@ impl RemotePath {
         Ok(Self(relative_path.to_path_buf()))
     }
 
+    pub fn from_string(relative_path: &str) -> anyhow::Result<Self> {
+        Self::new(Path::new(relative_path))
+    }
+
     pub fn with_base(&self, base_path: &Path) -> PathBuf {
         base_path.join(&self.0)
     }
@@ -190,6 +194,20 @@ pub enum GenericRemoteStorage {
 }
 
 impl GenericRemoteStorage {
+    // A function for listing all the files in a "directory"
+    // Example:
+    // list_files("foo/bar") = ["foo/bar/a.txt", "foo/bar/b.txt"]
+    pub async fn list_files(&self, folder: Option<&RemotePath>) -> anyhow::Result<Vec<RemotePath>> {
+        match self {
+            Self::LocalFs(s) => s.list_files(folder).await,
+            Self::AwsS3(s) => s.list_files(folder).await,
+            Self::Unreliable(s) => s.list_files(folder).await,
+        }
+    }
+
+    // lists common *prefixes*, if any of files
+    // Example:
+    // list_prefixes("foo123","foo567","bar123","bar432") = ["foo", "bar"]
     pub async fn list_prefixes(
         &self,
         prefix: Option<&RemotePath>,
@@ -201,14 +219,6 @@ impl GenericRemoteStorage {
         }
     }
 
-    pub async fn list_files(&self, folder: Option<&RemotePath>) -> anyhow::Result<Vec<RemotePath>> {
-        match self {
-            Self::LocalFs(s) => s.list_files(folder).await,
-            Self::AwsS3(s) => s.list_files(folder).await,
-            Self::Unreliable(s) => s.list_files(folder).await,
-        }
-    }
-
     pub async fn upload(
         &self,
         from: impl io::AsyncRead + Unpin + Send + Sync + 'static,

libs/remote_storage/src/s3_bucket.rs

@@ -10,6 +10,7 @@ use anyhow::Context;
 use aws_config::{
     environment::credentials::EnvironmentVariableCredentialsProvider,
     imds::credentials::ImdsCredentialsProvider, meta::credentials::CredentialsProviderChain,
+    provider_config::ProviderConfig, web_identity_token::WebIdentityTokenCredentialsProvider,
 };
 use aws_credential_types::cache::CredentialsCache;
 use aws_sdk_s3::{
@@ -22,6 +23,7 @@ use aws_sdk_s3::{
 };
 use aws_smithy_http::body::SdkBody;
 use hyper::Body;
+use scopeguard::ScopeGuard;
 use tokio::{
     io::{self, AsyncRead},
     sync::Semaphore,
@@ -36,82 +38,9 @@ use crate::{
 
 const MAX_DELETE_OBJECTS_REQUEST_SIZE: usize = 1000;
 
-pub(super) mod metrics {
-    use metrics::{register_int_counter_vec, IntCounterVec};
-    use once_cell::sync::Lazy;
+pub(super) mod metrics;
 
-    static S3_REQUESTS_COUNT: Lazy<IntCounterVec> = Lazy::new(|| {
-        register_int_counter_vec!(
-            "remote_storage_s3_requests_count",
-            "Number of s3 requests of particular type",
-            &["request_type"],
-        )
-        .expect("failed to define a metric")
-    });
-
-    static S3_REQUESTS_FAIL_COUNT: Lazy<IntCounterVec> = Lazy::new(|| {
-        register_int_counter_vec!(
-            "remote_storage_s3_failures_count",
-            "Number of failed s3 requests of particular type",
-            &["request_type"],
-        )
-        .expect("failed to define a metric")
-    });
-
-    pub fn inc_get_object() {
-        S3_REQUESTS_COUNT.with_label_values(&["get_object"]).inc();
-    }
-
-    pub fn inc_get_object_fail() {
-        S3_REQUESTS_FAIL_COUNT
-            .with_label_values(&["get_object"])
-            .inc();
-    }
-
-    pub fn inc_put_object() {
-        S3_REQUESTS_COUNT.with_label_values(&["put_object"]).inc();
-    }
-
-    pub fn inc_put_object_fail() {
-        S3_REQUESTS_FAIL_COUNT
-            .with_label_values(&["put_object"])
-            .inc();
-    }
-
-    pub fn inc_delete_object() {
-        S3_REQUESTS_COUNT
-            .with_label_values(&["delete_object"])
-            .inc();
-    }
-
-    pub fn inc_delete_objects(count: u64) {
-        S3_REQUESTS_COUNT
-            .with_label_values(&["delete_object"])
-            .inc_by(count);
-    }
-
-    pub fn inc_delete_object_fail() {
-        S3_REQUESTS_FAIL_COUNT
-            .with_label_values(&["delete_object"])
-            .inc();
-    }
-
-    pub fn inc_delete_objects_fail(count: u64) {
-        S3_REQUESTS_FAIL_COUNT
-            .with_label_values(&["delete_object"])
-            .inc_by(count);
-    }
-
-    pub fn inc_list_objects() {
-        S3_REQUESTS_COUNT.with_label_values(&["list_objects"]).inc();
-    }
-
-    pub fn inc_list_objects_fail() {
-        S3_REQUESTS_FAIL_COUNT
-            .with_label_values(&["list_objects"])
-            .inc();
-    }
-}
+use self::metrics::{AttemptOutcome, RequestKind};
 
 /// AWS S3 storage.
 pub struct S3Bucket {
@@ -139,18 +68,29 @@ impl S3Bucket {
             aws_config.bucket_name
         );
 
+        let region = Some(Region::new(aws_config.bucket_region.clone()));
+
         let credentials_provider = {
             // uses "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY"
             CredentialsProviderChain::first_try(
                 "env",
                 EnvironmentVariableCredentialsProvider::new(),
             )
+            // uses "AWS_WEB_IDENTITY_TOKEN_FILE", "AWS_ROLE_ARN", "AWS_ROLE_SESSION_NAME"
+            // needed to access remote extensions bucket
+            .or_else("token", {
+                let provider_conf = ProviderConfig::without_region().with_region(region.clone());
+
+                WebIdentityTokenCredentialsProvider::builder()
+                    .configure(&provider_conf)
+                    .build()
+            })
             // uses imds v2
             .or_else("imds", ImdsCredentialsProvider::builder().build())
         };
 
         let mut config_builder = Config::builder()
-            .region(Region::new(aws_config.bucket_region.clone()))
+            .region(region)
             .credentials_cache(CredentialsCache::lazy())
             .credentials_provider(credentials_provider);
 
@@ -200,25 +140,56 @@ impl S3Bucket {
         )
     }
 
-    fn relative_path_to_s3_object(&self, path: &RemotePath) -> String {
-        let mut full_path = self.prefix_in_bucket.clone().unwrap_or_default();
-        for segment in path.0.iter() {
-            full_path.push(REMOTE_STORAGE_PREFIX_SEPARATOR);
-            full_path.push_str(segment.to_str().unwrap_or_default());
+    pub fn relative_path_to_s3_object(&self, path: &RemotePath) -> String {
+        assert_eq!(std::path::MAIN_SEPARATOR, REMOTE_STORAGE_PREFIX_SEPARATOR);
+        let path_string = path
+            .get_path()
+            .to_string_lossy()
+            .trim_end_matches(REMOTE_STORAGE_PREFIX_SEPARATOR)
+            .to_string();
+        match &self.prefix_in_bucket {
+            Some(prefix) => prefix.clone() + "/" + &path_string,
+            None => path_string,
         }
-        full_path
     }
 
-    async fn download_object(&self, request: GetObjectRequest) -> Result<Download, DownloadError> {
+    async fn permit(&self, kind: RequestKind) -> tokio::sync::SemaphorePermit<'_> {
+        let started_at = start_counting_cancelled_wait(kind);
+        let permit = self
+            .concurrency_limiter
+            .acquire()
+            .await
+            .expect("semaphore is never closed");
+
+        let started_at = ScopeGuard::into_inner(started_at);
+        metrics::BUCKET_METRICS
+            .wait_seconds
+            .observe_elapsed(kind, started_at);
+
+        permit
+    }
+
+    async fn owned_permit(&self, kind: RequestKind) -> tokio::sync::OwnedSemaphorePermit {
+        let started_at = start_counting_cancelled_wait(kind);
         let permit = self
             .concurrency_limiter
             .clone()
             .acquire_owned()
             .await
-            .context("Concurrency limiter semaphore got closed during S3 download")
-            .map_err(DownloadError::Other)?;
+            .expect("semaphore is never closed");
 
-        metrics::inc_get_object();
+        let started_at = ScopeGuard::into_inner(started_at);
+        metrics::BUCKET_METRICS
+            .wait_seconds
+            .observe_elapsed(kind, started_at);
+        permit
+    }
+
+    async fn download_object(&self, request: GetObjectRequest) -> Result<Download, DownloadError> {
+        let kind = RequestKind::Get;
+        let permit = self.owned_permit(kind).await;
+
+        let started_at = start_measuring_requests(kind);
 
         let get_object = self
             .client
@@ -229,26 +200,33 @@ impl S3Bucket {
             .send()
             .await;
 
+        let started_at = ScopeGuard::into_inner(started_at);
+
+        if get_object.is_err() {
+            metrics::BUCKET_METRICS.req_seconds.observe_elapsed(
+                kind,
+                AttemptOutcome::Err,
+                started_at,
+            );
+        }
+
         match get_object {
             Ok(object_output) => {
                 let metadata = object_output.metadata().cloned().map(StorageMetadata);
                 Ok(Download {
                     metadata,
-                    download_stream: Box::pin(io::BufReader::new(RatelimitedAsyncRead::new(
-                        permit,
-                        object_output.body.into_async_read(),
+                    download_stream: Box::pin(io::BufReader::new(TimedDownload::new(
+                        started_at,
+                        RatelimitedAsyncRead::new(permit, object_output.body.into_async_read()),
                     ))),
                 })
             }
             Err(SdkError::ServiceError(e)) if matches!(e.err(), GetObjectError::NoSuchKey(_)) => {
                 Err(DownloadError::NotFound)
             }
-            Err(e) => {
-                metrics::inc_get_object_fail();
-                Err(DownloadError::Other(anyhow::anyhow!(
-                    "Failed to download S3 object: {e}"
-                )))
-            }
+            Err(e) => Err(DownloadError::Other(
+                anyhow::Error::new(e).context("download s3 object"),
+            )),
         }
     }
 }
@@ -279,6 +257,54 @@ impl<S: AsyncRead> AsyncRead for RatelimitedAsyncRead<S> {
     }
 }
 
+pin_project_lite::pin_project! {
+    /// Times and tracks the outcome of the request.
+    struct TimedDownload<S> {
+        started_at: std::time::Instant,
+        outcome: metrics::AttemptOutcome,
+        #[pin]
+        inner: S
+    }
+
+    impl<S> PinnedDrop for TimedDownload<S> {
+        fn drop(mut this: Pin<&mut Self>) {
+            metrics::BUCKET_METRICS.req_seconds.observe_elapsed(RequestKind::Get, this.outcome, this.started_at);
+        }
+    }
+}
+
+impl<S: AsyncRead> TimedDownload<S> {
+    fn new(started_at: std::time::Instant, inner: S) -> Self {
+        TimedDownload {
+            started_at,
+            outcome: metrics::AttemptOutcome::Cancelled,
+            inner,
+        }
+    }
+}
+
+impl<S: AsyncRead> AsyncRead for TimedDownload<S> {
+    fn poll_read(
+        self: std::pin::Pin<&mut Self>,
+        cx: &mut std::task::Context<'_>,
+        buf: &mut io::ReadBuf<'_>,
+    ) -> std::task::Poll<std::io::Result<()>> {
+        let this = self.project();
+        let before = buf.filled().len();
+        let read = std::task::ready!(this.inner.poll_read(cx, buf));
+
+        let read_eof = buf.filled().len() == before;
+
+        match read {
+            Ok(()) if read_eof => *this.outcome = AttemptOutcome::Ok,
+            Ok(()) => { /* still in progress */ }
+            Err(_) => *this.outcome = AttemptOutcome::Err,
+        }
+
+        std::task::Poll::Ready(read)
+    }
+}
+
 #[async_trait::async_trait]
 impl RemoteStorage for S3Bucket {
     /// See the doc for `RemoteStorage::list_prefixes`
@@ -287,6 +313,8 @@ impl RemoteStorage for S3Bucket {
         &self,
         prefix: Option<&RemotePath>,
     ) -> Result<Vec<RemotePath>, DownloadError> {
+        let kind = RequestKind::List;
+
         // get the passed prefix or if it is not set use prefix_in_bucket value
         let list_prefix = prefix
             .map(|p| self.relative_path_to_s3_object(p))
@@ -303,15 +331,10 @@ impl RemoteStorage for S3Bucket {
         let mut document_keys = Vec::new();
 
         let mut continuation_token = None;
-        loop {
-            let _guard = self
-                .concurrency_limiter
-                .acquire()
-                .await
-                .context("Concurrency limiter semaphore got closed during S3 list")
-                .map_err(DownloadError::Other)?;
 
-            metrics::inc_list_objects();
+        loop {
+            let _guard = self.permit(kind).await;
+            let started_at = start_measuring_requests(kind);
 
             let fetch_response = self
                 .client
@@ -323,12 +346,16 @@ impl RemoteStorage for S3Bucket {
                 .set_max_keys(self.max_keys_per_list_response)
                 .send()
                 .await
-                .map_err(|e| {
-                    metrics::inc_list_objects_fail();
-                    e
-                })
                 .context("Failed to list S3 prefixes")
-                .map_err(DownloadError::Other)?;
+                .map_err(DownloadError::Other);
+
+            let started_at = ScopeGuard::into_inner(started_at);
+
+            metrics::BUCKET_METRICS
+                .req_seconds
+                .observe_elapsed(kind, &fetch_response, started_at);
+
+            let fetch_response = fetch_response?;
 
             document_keys.extend(
                 fetch_response
@@ -338,10 +365,10 @@ impl RemoteStorage for S3Bucket {
                     .filter_map(|o| Some(self.s3_object_to_relative_path(o.prefix()?))),
             );
 
-            match fetch_response.next_continuation_token {
-                Some(new_token) => continuation_token = Some(new_token),
+            continuation_token = match fetch_response.next_continuation_token {
+                Some(new_token) => Some(new_token),
                 None => break,
-            }
+            };
         }
 
         Ok(document_keys)
@@ -349,6 +376,8 @@ impl RemoteStorage for S3Bucket {
 
     /// See the doc for `RemoteStorage::list_files`
     async fn list_files(&self, folder: Option<&RemotePath>) -> anyhow::Result<Vec<RemotePath>> {
+        let kind = RequestKind::List;
+
         let folder_name = folder
             .map(|p| self.relative_path_to_s3_object(p))
             .or_else(|| self.prefix_in_bucket.clone());
@@ -357,12 +386,8 @@ impl RemoteStorage for S3Bucket {
         let mut continuation_token = None;
         let mut all_files = vec![];
         loop {
-            let _guard = self
-                .concurrency_limiter
-                .acquire()
-                .await
-                .context("Concurrency limiter semaphore got closed during S3 list_files")?;
-            metrics::inc_list_objects();
+            let _guard = self.permit(kind).await;
+            let started_at = start_measuring_requests(kind);
 
             let response = self
                 .client
@@ -373,11 +398,14 @@ impl RemoteStorage for S3Bucket {
                 .set_max_keys(self.max_keys_per_list_response)
                 .send()
                 .await
-                .map_err(|e| {
-                    metrics::inc_list_objects_fail();
-                    e
-                })
-                .context("Failed to list files in S3 bucket")?;
+                .context("Failed to list files in S3 bucket");
+
+            let started_at = ScopeGuard::into_inner(started_at);
+            metrics::BUCKET_METRICS
+                .req_seconds
+                .observe_elapsed(kind, &response, started_at);
+
+            let response = response?;
 
             for object in response.contents().unwrap_or_default() {
                 let object_path = object.key().expect("response does not contain a key");
@@ -399,18 +427,16 @@ impl RemoteStorage for S3Bucket {
         to: &RemotePath,
         metadata: Option<StorageMetadata>,
     ) -> anyhow::Result<()> {
-        let _guard = self
-            .concurrency_limiter
-            .acquire()
-            .await
-            .context("Concurrency limiter semaphore got closed during S3 upload")?;
+        let kind = RequestKind::Put;
+        let _guard = self.permit(kind).await;
 
-        metrics::inc_put_object();
+        let started_at = start_measuring_requests(kind);
 
         let body = Body::wrap_stream(ReaderStream::new(from));
         let bytes_stream = ByteStream::new(SdkBody::from(body));
 
-        self.client
+        let res = self
+            .client
             .put_object()
             .bucket(self.bucket_name.clone())
             .key(self.relative_path_to_s3_object(to))
@@ -418,19 +444,25 @@ impl RemoteStorage for S3Bucket {
             .content_length(from_size_bytes.try_into()?)
             .body(bytes_stream)
             .send()
-            .await
-            .map_err(|e| {
-                metrics::inc_put_object_fail();
-                e
-            })?;
+            .await;
+
+        let started_at = ScopeGuard::into_inner(started_at);
+        metrics::BUCKET_METRICS
+            .req_seconds
+            .observe_elapsed(kind, &res, started_at);
+
+        res?;
+
         Ok(())
     }
 
     async fn download(&self, from: &RemotePath) -> Result<Download, DownloadError> {
+        // if prefix is not none then download file `prefix/from`
+        // if prefix is none then download file `from`
         self.download_object(GetObjectRequest {
             bucket: self.bucket_name.clone(),
             key: self.relative_path_to_s3_object(from),
-            ..GetObjectRequest::default()
+            range: None,
         })
         .await
     }
@@ -457,11 +489,8 @@ impl RemoteStorage for S3Bucket {
         .await
     }
     async fn delete_objects<'a>(&self, paths: &'a [RemotePath]) -> anyhow::Result<()> {
-        let _guard = self
-            .concurrency_limiter
-            .acquire()
-            .await
-            .context("Concurrency limiter semaphore got closed during S3 delete")?;
+        let kind = RequestKind::Delete;
+        let _guard = self.permit(kind).await;
 
         let mut delete_objects = Vec::with_capacity(paths.len());
         for path in paths {
@@ -472,7 +501,7 @@ impl RemoteStorage for S3Bucket {
         }
 
         for chunk in delete_objects.chunks(MAX_DELETE_OBJECTS_REQUEST_SIZE) {
-            metrics::inc_delete_objects(chunk.len() as u64);
+            let started_at = start_measuring_requests(kind);
 
             let resp = self
                 .client
@@ -482,10 +511,17 @@ impl RemoteStorage for S3Bucket {
                 .send()
                 .await;
 
+            let started_at = ScopeGuard::into_inner(started_at);
+            metrics::BUCKET_METRICS
+                .req_seconds
+                .observe_elapsed(kind, &resp, started_at);
+
             match resp {
                 Ok(resp) => {
+                    metrics::BUCKET_METRICS
+                        .deleted_objects_total
+                        .inc_by(chunk.len() as u64);
                     if let Some(errors) = resp.errors {
-                        metrics::inc_delete_objects_fail(errors.len() as u64);
                         return Err(anyhow::format_err!(
                             "Failed to delete {} objects",
                             errors.len()
@@ -493,7 +529,6 @@ impl RemoteStorage for S3Bucket {
                     }
                 }
                 Err(e) => {
-                    metrics::inc_delete_objects_fail(chunk.len() as u64);
                     return Err(e.into());
                 }
             }
@@ -502,24 +537,89 @@ impl RemoteStorage for S3Bucket {
     }
 
     async fn delete(&self, path: &RemotePath) -> anyhow::Result<()> {
-        let _guard = self
-            .concurrency_limiter
-            .acquire()
-            .await
-            .context("Concurrency limiter semaphore got closed during S3 delete")?;
-
-        metrics::inc_delete_object();
-
-        self.client
-            .delete_object()
-            .bucket(self.bucket_name.clone())
-            .key(self.relative_path_to_s3_object(path))
-            .send()
-            .await
-            .map_err(|e| {
-                metrics::inc_delete_object_fail();
-                e
-            })?;
-        Ok(())
+        let paths = std::array::from_ref(path);
+        self.delete_objects(paths).await
+    }
+}
+
+/// On drop (cancellation) count towards [`metrics::BucketMetrics::cancelled_waits`].
+fn start_counting_cancelled_wait(
+    kind: RequestKind,
+) -> ScopeGuard<std::time::Instant, impl FnOnce(std::time::Instant), scopeguard::OnSuccess> {
+    scopeguard::guard_on_success(std::time::Instant::now(), move |_| {
+        metrics::BUCKET_METRICS.cancelled_waits.get(kind).inc()
+    })
+}
+
+/// On drop (cancellation) add time to [`metrics::BucketMetrics::req_seconds`].
+fn start_measuring_requests(
+    kind: RequestKind,
+) -> ScopeGuard<std::time::Instant, impl FnOnce(std::time::Instant), scopeguard::OnSuccess> {
+    scopeguard::guard_on_success(std::time::Instant::now(), move |started_at| {
+        metrics::BUCKET_METRICS.req_seconds.observe_elapsed(
+            kind,
+            AttemptOutcome::Cancelled,
+            started_at,
+        )
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use std::num::NonZeroUsize;
+    use std::path::Path;
+
+    use crate::{RemotePath, S3Bucket, S3Config};
+
+    #[test]
+    fn relative_path() {
+        let all_paths = vec!["", "some/path", "some/path/"];
+        let all_paths: Vec<RemotePath> = all_paths
+            .iter()
+            .map(|x| RemotePath::new(Path::new(x)).expect("bad path"))
+            .collect();
+        let prefixes = [
+            None,
+            Some(""),
+            Some("test/prefix"),
+            Some("test/prefix/"),
+            Some("/test/prefix/"),
+        ];
+        let expected_outputs = vec![
+            vec!["", "some/path", "some/path"],
+            vec!["/", "/some/path", "/some/path"],
+            vec![
+                "test/prefix/",
+                "test/prefix/some/path",
+                "test/prefix/some/path",
+            ],
+            vec![
+                "test/prefix/",
+                "test/prefix/some/path",
+                "test/prefix/some/path",
+            ],
+            vec![
+                "test/prefix/",
+                "test/prefix/some/path",
+                "test/prefix/some/path",
+            ],
+        ];
+
+        for (prefix_idx, prefix) in prefixes.iter().enumerate() {
+            let config = S3Config {
+                bucket_name: "bucket".to_owned(),
+                bucket_region: "region".to_owned(),
+                prefix_in_bucket: prefix.map(str::to_string),
+                endpoint: None,
+                concurrency_limit: NonZeroUsize::new(100).unwrap(),
+                max_keys_per_list_response: Some(5),
+            };
+            let storage = S3Bucket::new(&config).expect("remote storage init");
+            for (test_path_idx, test_path) in all_paths.iter().enumerate() {
+                let result = storage.relative_path_to_s3_object(test_path);
+                let expected = expected_outputs[prefix_idx][test_path_idx];
+                assert_eq!(result, expected);
+            }
+        }
     }
 }

libs/remote_storage/src/s3_bucket/metrics.rs

@@ -0,0 +1,191 @@
+use metrics::{
+    register_histogram_vec, register_int_counter, register_int_counter_vec, Histogram, IntCounter,
+};
+use once_cell::sync::Lazy;
+
+pub(super) static BUCKET_METRICS: Lazy<BucketMetrics> = Lazy::new(Default::default);
+
+#[derive(Clone, Copy, Debug)]
+pub(super) enum RequestKind {
+    Get = 0,
+    Put = 1,
+    Delete = 2,
+    List = 3,
+}
+
+use RequestKind::*;
+
+impl RequestKind {
+    const fn as_str(&self) -> &'static str {
+        match self {
+            Get => "get_object",
+            Put => "put_object",
+            Delete => "delete_object",
+            List => "list_objects",
+        }
+    }
+    const fn as_index(&self) -> usize {
+        *self as usize
+    }
+}
+
+pub(super) struct RequestTyped<C>([C; 4]);
+
+impl<C> RequestTyped<C> {
+    pub(super) fn get(&self, kind: RequestKind) -> &C {
+        &self.0[kind.as_index()]
+    }
+
+    fn build_with(mut f: impl FnMut(RequestKind) -> C) -> Self {
+        use RequestKind::*;
+        let mut it = [Get, Put, Delete, List].into_iter();
+        let arr = std::array::from_fn::<C, 4, _>(|index| {
+            let next = it.next().unwrap();
+            assert_eq!(index, next.as_index());
+            f(next)
+        });
+
+        if let Some(next) = it.next() {
+            panic!("unexpected {next:?}");
+        }
+
+        RequestTyped(arr)
+    }
+}
+
+impl RequestTyped<Histogram> {
+    pub(super) fn observe_elapsed(&self, kind: RequestKind, started_at: std::time::Instant) {
+        self.get(kind).observe(started_at.elapsed().as_secs_f64())
+    }
+}
+
+pub(super) struct PassFailCancelledRequestTyped<C> {
+    success: RequestTyped<C>,
+    fail: RequestTyped<C>,
+    cancelled: RequestTyped<C>,
+}
+
+#[derive(Debug, Clone, Copy)]
+pub(super) enum AttemptOutcome {
+    Ok,
+    Err,
+    Cancelled,
+}
+
+impl<T, E> From<&Result<T, E>> for AttemptOutcome {
+    fn from(value: &Result<T, E>) -> Self {
+        match value {
+            Ok(_) => AttemptOutcome::Ok,
+            Err(_) => AttemptOutcome::Err,
+        }
+    }
+}
+
+impl AttemptOutcome {
+    pub(super) fn as_str(&self) -> &'static str {
+        match self {
+            AttemptOutcome::Ok => "ok",
+            AttemptOutcome::Err => "err",
+            AttemptOutcome::Cancelled => "cancelled",
+        }
+    }
+}
+
+impl<C> PassFailCancelledRequestTyped<C> {
+    pub(super) fn get(&self, kind: RequestKind, outcome: AttemptOutcome) -> &C {
+        let target = match outcome {
+            AttemptOutcome::Ok => &self.success,
+            AttemptOutcome::Err => &self.fail,
+            AttemptOutcome::Cancelled => &self.cancelled,
+        };
+        target.get(kind)
+    }
+
+    fn build_with(mut f: impl FnMut(RequestKind, AttemptOutcome) -> C) -> Self {
+        let success = RequestTyped::build_with(|kind| f(kind, AttemptOutcome::Ok));
+        let fail = RequestTyped::build_with(|kind| f(kind, AttemptOutcome::Err));
+        let cancelled = RequestTyped::build_with(|kind| f(kind, AttemptOutcome::Cancelled));
+
+        PassFailCancelledRequestTyped {
+            success,
+            fail,
+            cancelled,
+        }
+    }
+}
+
+impl PassFailCancelledRequestTyped<Histogram> {
+    pub(super) fn observe_elapsed(
+        &self,
+        kind: RequestKind,
+        outcome: impl Into<AttemptOutcome>,
+        started_at: std::time::Instant,
+    ) {
+        self.get(kind, outcome.into())
+            .observe(started_at.elapsed().as_secs_f64())
+    }
+}
+
+pub(super) struct BucketMetrics {
+    /// Full request duration until successful completion, error or cancellation.
+    pub(super) req_seconds: PassFailCancelledRequestTyped<Histogram>,
+    /// Total amount of seconds waited on queue.
+    pub(super) wait_seconds: RequestTyped<Histogram>,
+
+    /// Track how many semaphore awaits were cancelled per request type.
+    ///
+    /// This is in case cancellations are happening more than expected.
+    pub(super) cancelled_waits: RequestTyped<IntCounter>,
+
+    /// Total amount of deleted objects in batches or single requests.
+    pub(super) deleted_objects_total: IntCounter,
+}
+
+impl Default for BucketMetrics {
+    fn default() -> Self {
+        let buckets = [0.01, 0.10, 0.5, 1.0, 5.0, 10.0, 50.0, 100.0];
+
+        let req_seconds = register_histogram_vec!(
+            "remote_storage_s3_request_seconds",
+            "Seconds to complete a request",
+            &["request_type", "result"],
+            buckets.to_vec(),
+        )
+        .unwrap();
+        let req_seconds = PassFailCancelledRequestTyped::build_with(|kind, outcome| {
+            req_seconds.with_label_values(&[kind.as_str(), outcome.as_str()])
+        });
+
+        let wait_seconds = register_histogram_vec!(
+            "remote_storage_s3_wait_seconds",
+            "Seconds rate limited",
+            &["request_type"],
+            buckets.to_vec(),
+        )
+        .unwrap();
+        let wait_seconds =
+            RequestTyped::build_with(|kind| wait_seconds.with_label_values(&[kind.as_str()]));
+
+        let cancelled_waits = register_int_counter_vec!(
+            "remote_storage_s3_cancelled_waits_total",
+            "Times a semaphore wait has been cancelled per request type",
+            &["request_type"],
+        )
+        .unwrap();
+        let cancelled_waits =
+            RequestTyped::build_with(|kind| cancelled_waits.with_label_values(&[kind.as_str()]));
+
+        let deleted_objects_total = register_int_counter!(
+            "remote_storage_s3_deleted_objects_total",
+            "Amount of deleted objects in total",
+        )
+        .unwrap();
+
+        Self {
+            req_seconds,
+            wait_seconds,
+            cancelled_waits,
+            deleted_objects_total,
+        }
+    }
+}

libs/remote_storage/tests/test_real_s3.rs

@@ -19,7 +19,7 @@ static LOGGING_DONE: OnceCell<()> = OnceCell::new();
 
 const ENABLE_REAL_S3_REMOTE_STORAGE_ENV_VAR_NAME: &str = "ENABLE_REAL_S3_REMOTE_STORAGE";
 
-const BASE_PREFIX: &str = "test/";
+const BASE_PREFIX: &str = "test";
 
 /// Tests that S3 client can list all prefixes, even if the response come paginated and requires multiple S3 queries.
 /// Uses real S3 and requires [`ENABLE_REAL_S3_REMOTE_STORAGE_ENV_VAR_NAME`] and related S3 cred env vars specified.

libs/utils/src/backoff.rs

@@ -0,0 +1,188 @@
+use std::fmt::{Debug, Display};
+
+use futures::Future;
+
+pub const DEFAULT_BASE_BACKOFF_SECONDS: f64 = 0.1;
+pub const DEFAULT_MAX_BACKOFF_SECONDS: f64 = 3.0;
+
+pub async fn exponential_backoff(n: u32, base_increment: f64, max_seconds: f64) {
+    let backoff_duration_seconds =
+        exponential_backoff_duration_seconds(n, base_increment, max_seconds);
+    if backoff_duration_seconds > 0.0 {
+        tracing::info!(
+            "Backoff: waiting {backoff_duration_seconds} seconds before processing with the task",
+        );
+        tokio::time::sleep(std::time::Duration::from_secs_f64(backoff_duration_seconds)).await;
+    }
+}
+
+pub fn exponential_backoff_duration_seconds(n: u32, base_increment: f64, max_seconds: f64) -> f64 {
+    if n == 0 {
+        0.0
+    } else {
+        (1.0 + base_increment).powf(f64::from(n)).min(max_seconds)
+    }
+}
+
+/// retries passed operation until one of the following conditions are met:
+/// Encountered error is considered as permanent (non-retryable)
+/// Retries have been exhausted.
+/// `is_permanent` closure should be used to provide distinction between permanent/non-permanent errors
+/// When attempts cross `warn_threshold` function starts to emit log warnings.
+/// `description` argument is added to log messages. Its value should identify the `op` is doing
+pub async fn retry<T, O, F, E>(
+    mut op: O,
+    is_permanent: impl Fn(&E) -> bool,
+    warn_threshold: u32,
+    max_retries: u32,
+    description: &str,
+) -> Result<T, E>
+where
+    // Not std::error::Error because anyhow::Error doesnt implement it.
+    // For context see https://github.com/dtolnay/anyhow/issues/63
+    E: Display + Debug,
+    O: FnMut() -> F,
+    F: Future<Output = Result<T, E>>,
+{
+    let mut attempts = 0;
+    loop {
+        let result = op().await;
+        match result {
+            Ok(_) => {
+                if attempts > 0 {
+                    tracing::info!("{description} succeeded after {attempts} retries");
+                }
+                return result;
+            }
+
+            // These are "permanent" errors that should not be retried.
+            Err(ref e) if is_permanent(e) => {
+                return result;
+            }
+            // Assume that any other failure might be transient, and the operation might
+            // succeed if we just keep trying.
+            Err(err) if attempts < warn_threshold => {
+                tracing::info!("{description} failed, will retry (attempt {attempts}): {err:#}");
+            }
+            Err(err) if attempts < max_retries => {
+                tracing::warn!("{description} failed, will retry (attempt {attempts}): {err:#}");
+            }
+            Err(ref err) => {
+                // Operation failed `max_attempts` times. Time to give up.
+                tracing::warn!(
+                    "{description} still failed after {attempts} retries, giving up: {err:?}"
+                );
+                return result;
+            }
+        }
+        // sleep and retry
+        exponential_backoff(
+            attempts,
+            DEFAULT_BASE_BACKOFF_SECONDS,
+            DEFAULT_MAX_BACKOFF_SECONDS,
+        )
+        .await;
+        attempts += 1;
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::io;
+
+    use tokio::sync::Mutex;
+
+    use super::*;
+
+    #[test]
+    fn backoff_defaults_produce_growing_backoff_sequence() {
+        let mut current_backoff_value = None;
+
+        for i in 0..10_000 {
+            let new_backoff_value = exponential_backoff_duration_seconds(
+                i,
+                DEFAULT_BASE_BACKOFF_SECONDS,
+                DEFAULT_MAX_BACKOFF_SECONDS,
+            );
+
+            if let Some(old_backoff_value) = current_backoff_value.replace(new_backoff_value) {
+                assert!(
+                    old_backoff_value <= new_backoff_value,
+                    "{i}th backoff value {new_backoff_value} is smaller than the previous one {old_backoff_value}"
+                )
+            }
+        }
+
+        assert_eq!(
+            current_backoff_value.expect("Should have produced backoff values to compare"),
+            DEFAULT_MAX_BACKOFF_SECONDS,
+            "Given big enough of retries, backoff should reach its allowed max value"
+        );
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn retry_always_error() {
+        let count = Mutex::new(0);
+        let err_result = retry(
+            || async {
+                *count.lock().await += 1;
+                Result::<(), io::Error>::Err(io::Error::from(io::ErrorKind::Other))
+            },
+            |_e| false,
+            1,
+            1,
+            "work",
+        )
+        .await;
+
+        assert!(err_result.is_err());
+
+        assert_eq!(*count.lock().await, 2);
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn retry_ok_after_err() {
+        let count = Mutex::new(0);
+        retry(
+            || async {
+                let mut locked = count.lock().await;
+                if *locked > 1 {
+                    Ok(())
+                } else {
+                    *locked += 1;
+                    Err(io::Error::from(io::ErrorKind::Other))
+                }
+            },
+            |_e| false,
+            2,
+            2,
+            "work",
+        )
+        .await
+        .unwrap();
+    }
+
+    #[tokio::test(start_paused = true)]
+    async fn dont_retry_permanent_errors() {
+        let count = Mutex::new(0);
+        let _ = retry(
+            || async {
+                let mut locked = count.lock().await;
+                if *locked > 1 {
+                    Ok(())
+                } else {
+                    *locked += 1;
+                    Err(io::Error::from(io::ErrorKind::Other))
+                }
+            },
+            |_e| true,
+            2,
+            2,
+            "work",
+        )
+        .await
+        .unwrap_err();
+
+        assert_eq!(*count.lock().await, 1);
+    }
+}

libs/utils/src/fs_ext.rs

@@ -24,11 +24,42 @@ pub async fn is_directory_empty(path: impl AsRef<Path>) -> anyhow::Result<bool>
     Ok(dir.next_entry().await?.is_none())
 }
 
+pub async fn list_dir(path: impl AsRef<Path>) -> anyhow::Result<Vec<String>> {
+    let mut dir = tokio::fs::read_dir(&path)
+        .await
+        .context(format!("read_dir({})", path.as_ref().display()))?;
+
+    let mut content = vec![];
+    while let Some(next) = dir.next_entry().await? {
+        let file_name = next.file_name();
+        content.push(file_name.to_string_lossy().to_string());
+    }
+
+    Ok(content)
+}
+
+pub fn ignore_not_found(e: io::Error) -> io::Result<()> {
+    if e.kind() == io::ErrorKind::NotFound {
+        Ok(())
+    } else {
+        Err(e)
+    }
+}
+
+pub fn ignore_absent_files<F>(fs_operation: F) -> io::Result<()>
+where
+    F: Fn() -> io::Result<()>,
+{
+    fs_operation().or_else(ignore_not_found)
+}
+
 #[cfg(test)]
 mod test {
     use std::path::PathBuf;
 
-    use crate::fs_ext::is_directory_empty;
+    use crate::fs_ext::{is_directory_empty, list_dir};
+
+    use super::ignore_absent_files;
 
     #[test]
     fn is_empty_dir() {
@@ -75,4 +106,42 @@ mod test {
         std::fs::remove_file(&file_path).unwrap();
         assert!(is_directory_empty(file_path).await.is_err());
     }
+
+    #[test]
+    fn ignore_absent_files_works() {
+        let dir = tempfile::tempdir().unwrap();
+        let dir_path = dir.path();
+
+        let file_path: PathBuf = dir_path.join("testfile");
+
+        ignore_absent_files(|| std::fs::remove_file(&file_path)).expect("should execute normally");
+
+        let f = std::fs::File::create(&file_path).unwrap();
+        drop(f);
+
+        ignore_absent_files(|| std::fs::remove_file(&file_path)).expect("should execute normally");
+
+        assert!(!file_path.exists());
+    }
+
+    #[tokio::test]
+    async fn list_dir_works() {
+        let dir = tempfile::tempdir().unwrap();
+        let dir_path = dir.path();
+
+        assert!(list_dir(dir_path).await.unwrap().is_empty());
+
+        let file_path: PathBuf = dir_path.join("testfile");
+        let _ = std::fs::File::create(&file_path).unwrap();
+
+        assert_eq!(&list_dir(dir_path).await.unwrap(), &["testfile"]);
+
+        let another_dir_path: PathBuf = dir_path.join("testdir");
+        std::fs::create_dir(another_dir_path).unwrap();
+
+        let expected = &["testdir", "testfile"];
+        let mut actual = list_dir(dir_path).await.unwrap();
+        actual.sort();
+        assert_eq!(actual, expected);
+    }
 }

libs/utils/src/id.rs

@@ -1,5 +1,7 @@
+use std::ffi::OsStr;
 use std::{fmt, str::FromStr};
 
+use anyhow::Context;
 use hex::FromHex;
 use rand::Rng;
 use serde::{Deserialize, Serialize};
@@ -213,6 +215,18 @@ pub struct TimelineId(Id);
 
 id_newtype!(TimelineId);
 
+impl TryFrom<Option<&OsStr>> for TimelineId {
+    type Error = anyhow::Error;
+
+    fn try_from(value: Option<&OsStr>) -> Result<Self, Self::Error> {
+        value
+            .and_then(OsStr::to_str)
+            .unwrap_or_default()
+            .parse::<TimelineId>()
+            .with_context(|| format!("Could not parse timeline id from {:?}", value))
+    }
+}
+
 /// Neon Tenant Id represents identifiar of a particular tenant.
 /// Is used for distinguishing requests and data belonging to different users.
 ///

libs/utils/src/lib.rs

@@ -1,6 +1,8 @@
 //! `utils` is intended to be a place to put code that is shared
 //! between other crates in this repository.
 
+pub mod backoff;
+
 /// `Lsn` type implements common tasks on Log Sequence Numbers
 pub mod lsn;
 /// SeqWait allows waiting for a future sequence number to arrive

pageserver/Cargo.toml

@@ -35,6 +35,8 @@ humantime-serde.workspace = true
 hyper.workspace = true
 itertools.workspace = true
 nix.workspace = true
+# hack to get the number of worker threads tokio uses
+num_cpus = { version = "1.15" }
 num-traits.workspace = true
 once_cell.workspace = true
 pin-project-lite.workspace = true

pageserver/ctl/Cargo.toml

@@ -13,6 +13,7 @@ clap = { workspace = true, features = ["string"] }
 git-version.workspace = true
 pageserver = { path = ".." }
 postgres_ffi.workspace = true
+tokio.workspace = true
 utils.workspace = true
 svg_fmt.workspace = true
 workspace_hack.workspace = true

pageserver/ctl/src/draw_timeline_dir.rs

@@ -23,6 +23,7 @@
 //!      <https://grafana.com/tutorials/build-a-panel-plugin/>
 use anyhow::Result;
 use pageserver::repository::Key;
+use pageserver::METADATA_FILE_NAME;
 use std::cmp::Ordering;
 use std::io::{self, BufRead};
 use std::path::PathBuf;
@@ -71,6 +72,10 @@ pub fn main() -> Result<()> {
         let line = PathBuf::from_str(&line).unwrap();
         let filename = line.file_name().unwrap();
         let filename = filename.to_str().unwrap();
+        if filename == METADATA_FILE_NAME {
+            // Don't try and parse "metadata" like a key-lsn range
+            continue;
+        }
         let range = parse_filename(filename);
         ranges.push(range);
     }

pageserver/ctl/src/layer_map_analyzer.rs

@@ -95,7 +95,7 @@ pub(crate) fn parse_filename(name: &str) -> Option<LayerFile> {
 }
 
 // Finds the max_holes largest holes, ignoring any that are smaller than MIN_HOLE_LENGTH"
-fn get_holes(path: &Path, max_holes: usize) -> Result<Vec<Hole>> {
+async fn get_holes(path: &Path, max_holes: usize) -> Result<Vec<Hole>> {
     let file = FileBlockReader::new(VirtualFile::open(path)?);
     let summary_blk = file.read_blk(0)?;
     let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
@@ -107,29 +107,31 @@ fn get_holes(path: &Path, max_holes: usize) -> Result<Vec<Hole>> {
     // min-heap (reserve space for one more element added before eviction)
     let mut heap: BinaryHeap<Hole> = BinaryHeap::with_capacity(max_holes + 1);
     let mut prev_key: Option<Key> = None;
-    tree_reader.visit(
-        &[0u8; DELTA_KEY_SIZE],
-        VisitDirection::Forwards,
-        |key, _value| {
-            let curr = Key::from_slice(&key[..KEY_SIZE]);
-            if let Some(prev) = prev_key {
-                if curr.to_i128() - prev.to_i128() >= MIN_HOLE_LENGTH {
-                    heap.push(Hole(prev..curr));
-                    if heap.len() > max_holes {
-                        heap.pop(); // remove smallest hole
+    tree_reader
+        .visit(
+            &[0u8; DELTA_KEY_SIZE],
+            VisitDirection::Forwards,
+            |key, _value| {
+                let curr = Key::from_slice(&key[..KEY_SIZE]);
+                if let Some(prev) = prev_key {
+                    if curr.to_i128() - prev.to_i128() >= MIN_HOLE_LENGTH {
+                        heap.push(Hole(prev..curr));
+                        if heap.len() > max_holes {
+                            heap.pop(); // remove smallest hole
+                        }
                     }
                 }
-            }
-            prev_key = Some(curr.next());
-            true
-        },
-    )?;
+                prev_key = Some(curr.next());
+                true
+            },
+        )
+        .await?;
     let mut holes = heap.into_vec();
     holes.sort_by_key(|hole| hole.0.start);
     Ok(holes)
 }
 
-pub(crate) fn main(cmd: &AnalyzeLayerMapCmd) -> Result<()> {
+pub(crate) async fn main(cmd: &AnalyzeLayerMapCmd) -> Result<()> {
     let storage_path = &cmd.path;
     let max_holes = cmd.max_holes.unwrap_or(DEFAULT_MAX_HOLES);
 
@@ -160,7 +162,7 @@ pub(crate) fn main(cmd: &AnalyzeLayerMapCmd) -> Result<()> {
                     parse_filename(&layer.file_name().into_string().unwrap())
                 {
                     if layer_file.is_delta {
-                        layer_file.holes = get_holes(&layer.path(), max_holes)?;
+                        layer_file.holes = get_holes(&layer.path(), max_holes).await?;
                         n_deltas += 1;
                     }
                     layers.push(layer_file);

pageserver/ctl/src/layers.rs

@@ -43,8 +43,7 @@ pub(crate) enum LayerCmd {
     },
 }
 
-fn read_delta_file(path: impl AsRef<Path>) -> Result<()> {
-    use pageserver::tenant::blob_io::BlobCursor;
+async fn read_delta_file(path: impl AsRef<Path>) -> Result<()> {
     use pageserver::tenant::block_io::BlockReader;
 
     let path = path.as_ref();
@@ -60,25 +59,27 @@ fn read_delta_file(path: impl AsRef<Path>) -> Result<()> {
     );
     // TODO(chi): dedup w/ `delta_layer.rs` by exposing the API.
     let mut all = vec![];
-    tree_reader.visit(
-        &[0u8; DELTA_KEY_SIZE],
-        VisitDirection::Forwards,
-        |key, value_offset| {
-            let curr = Key::from_slice(&key[..KEY_SIZE]);
-            all.push((curr, BlobRef(value_offset)));
-            true
-        },
-    )?;
-    let mut cursor = BlockCursor::new(&file);
+    tree_reader
+        .visit(
+            &[0u8; DELTA_KEY_SIZE],
+            VisitDirection::Forwards,
+            |key, value_offset| {
+                let curr = Key::from_slice(&key[..KEY_SIZE]);
+                all.push((curr, BlobRef(value_offset)));
+                true
+            },
+        )
+        .await?;
+    let cursor = BlockCursor::new(&file);
     for (k, v) in all {
-        let value = cursor.read_blob(v.pos())?;
+        let value = cursor.read_blob(v.pos()).await?;
         println!("key:{} value_len:{}", k, value.len());
     }
     // TODO(chi): special handling for last key?
     Ok(())
 }
 
-pub(crate) fn main(cmd: &LayerCmd) -> Result<()> {
+pub(crate) async fn main(cmd: &LayerCmd) -> Result<()> {
     match cmd {
         LayerCmd::List { path } => {
             for tenant in fs::read_dir(path.join("tenants"))? {
@@ -153,7 +154,7 @@ pub(crate) fn main(cmd: &LayerCmd) -> Result<()> {
                         );
 
                         if layer_file.is_delta {
-                            read_delta_file(layer.path())?;
+                            read_delta_file(layer.path()).await?;
                         } else {
                             anyhow::bail!("not supported yet :(");
                         }

pageserver/ctl/src/main.rs

@@ -72,12 +72,13 @@ struct AnalyzeLayerMapCmd {
     max_holes: Option<usize>,
 }
 
-fn main() -> anyhow::Result<()> {
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
     let cli = CliOpts::parse();
 
     match cli.command {
         Commands::Layer(cmd) => {
-            layers::main(&cmd)?;
+            layers::main(&cmd).await?;
         }
         Commands::Metadata(cmd) => {
             handle_metadata(&cmd)?;
@@ -86,7 +87,7 @@ fn main() -> anyhow::Result<()> {
             draw_timeline_dir::main()?;
         }
         Commands::AnalyzeLayerMap(cmd) => {
-            layer_map_analyzer::main(&cmd)?;
+            layer_map_analyzer::main(&cmd).await?;
         }
         Commands::PrintLayerFile(cmd) => {
             if let Err(e) = read_pg_control_file(&cmd.path) {
@@ -94,7 +95,7 @@ fn main() -> anyhow::Result<()> {
                     "Failed to read input file as a pg control one: {e:#}\n\
                     Attempting to read it as layer file"
                 );
-                print_layerfile(&cmd.path)?;
+                print_layerfile(&cmd.path).await?;
             }
         }
     };
@@ -113,12 +114,12 @@ fn read_pg_control_file(control_file_path: &Path) -> anyhow::Result<()> {
     Ok(())
 }
 
-fn print_layerfile(path: &Path) -> anyhow::Result<()> {
+async fn print_layerfile(path: &Path) -> anyhow::Result<()> {
     // Basic initialization of things that don't change after startup
     virtual_file::init(10);
     page_cache::init(100);
     let ctx = RequestContext::new(TaskKind::DebugTool, DownloadBehavior::Error);
-    dump_layerfile_from_path(path, true, &ctx)
+    dump_layerfile_from_path(path, true, &ctx).await
 }
 
 fn handle_metadata(

pageserver/src/bin/pageserver.rs

@@ -9,8 +9,10 @@ use clap::{Arg, ArgAction, Command};
 use fail::FailScenario;
 use metrics::launch_timestamp::{set_launch_timestamp_metric, LaunchTimestamp};
 use pageserver::disk_usage_eviction_task::{self, launch_disk_usage_global_eviction_task};
+use pageserver::metrics::{STARTUP_DURATION, STARTUP_IS_LOADING};
 use pageserver::task_mgr::WALRECEIVER_RUNTIME;
 use remote_storage::GenericRemoteStorage;
+use tokio::time::Instant;
 use tracing::*;
 
 use metrics::set_build_info_metric;
@@ -38,8 +40,6 @@ const PID_FILE_NAME: &str = "pageserver.pid";
 const FEATURES: &[&str] = &[
     #[cfg(feature = "testing")]
     "testing",
-    #[cfg(feature = "fail/failpoints")]
-    "fail/failpoints",
 ];
 
 fn version() -> String {
@@ -226,6 +226,19 @@ fn start_pageserver(
     launch_ts: &'static LaunchTimestamp,
     conf: &'static PageServerConf,
 ) -> anyhow::Result<()> {
+    // Monotonic time for later calculating startup duration
+    let started_startup_at = Instant::now();
+
+    let startup_checkpoint = move |phase: &str, human_phase: &str| {
+        let elapsed = started_startup_at.elapsed();
+        let secs = elapsed.as_secs_f64();
+        STARTUP_DURATION.with_label_values(&[phase]).set(secs);
+        info!(
+            elapsed_ms = elapsed.as_millis(),
+            "{human_phase} ({secs:.3}s since start)"
+        )
+    };
+
     // Print version and launch timestamp to the log,
     // and expose them as prometheus metrics.
     // A changed version string indicates changed software.
@@ -335,6 +348,11 @@ fn start_pageserver(
     // Set up remote storage client
     let remote_storage = create_remote_storage_client(conf)?;
 
+    // Up to this point no significant I/O has been done: this should have been fast.  Record
+    // duration prior to starting I/O intensive phase of startup.
+    startup_checkpoint("initial", "Starting loading tenants");
+    STARTUP_IS_LOADING.set(1);
+
     // Startup staging or optimizing:
     //
     // We want to minimize downtime for `page_service` connections, and trying not to overload
@@ -355,12 +373,11 @@ fn start_pageserver(
     let order = pageserver::InitializationOrder {
         initial_tenant_load: Some(init_done_tx),
         initial_logical_size_can_start: init_done_rx.clone(),
-        initial_logical_size_attempt: init_logical_size_done_tx,
+        initial_logical_size_attempt: Some(init_logical_size_done_tx),
         background_jobs_can_start: background_jobs_barrier.clone(),
     };
 
     // Scan the local 'tenants/' directory and start loading the tenants
-    let init_started_at = std::time::Instant::now();
     let shutdown_pageserver = tokio_util::sync::CancellationToken::new();
 
     BACKGROUND_RUNTIME.block_on(mgr::init_tenant_mgr(
@@ -378,18 +395,13 @@ fn start_pageserver(
             let guard = scopeguard::guard_on_success((), |_| tracing::info!("Cancelled before initial load completed"));
 
             init_done_rx.wait().await;
+            startup_checkpoint("initial_tenant_load", "Initial load completed");
+            STARTUP_IS_LOADING.set(0);
+
             // initial logical sizes can now start, as they were waiting on init_done_rx.
 
             scopeguard::ScopeGuard::into_inner(guard);
 
-            let init_done = std::time::Instant::now();
-            let elapsed = init_done - init_started_at;
-
-            tracing::info!(
-                elapsed_millis = elapsed.as_millis(),
-                "Initial load completed"
-            );
-
             let mut init_sizes_done = std::pin::pin!(init_logical_size_done_rx.wait());
 
             let timeout = conf.background_task_maximum_delay;
@@ -398,12 +410,7 @@ fn start_pageserver(
 
             let init_sizes_done = match tokio::time::timeout(timeout, &mut init_sizes_done).await {
                 Ok(_) => {
-                    let now = std::time::Instant::now();
-                    tracing::info!(
-                        from_init_done_millis = (now - init_done).as_millis(),
-                        from_init_millis = (now - init_started_at).as_millis(),
-                        "Initial logical sizes completed"
-                    );
+                    startup_checkpoint("initial_logical_sizes", "Initial logical sizes completed");
                     None
                 }
                 Err(_) => {
@@ -419,6 +426,7 @@ fn start_pageserver(
 
             // allow background jobs to start
             drop(background_jobs_can_start);
+            startup_checkpoint("background_jobs_can_start", "Starting background jobs");
 
             if let Some(init_sizes_done) = init_sizes_done {
                 // ending up here is not a bug; at the latest logical sizes will be queried by
@@ -428,14 +436,11 @@ fn start_pageserver(
 
                 scopeguard::ScopeGuard::into_inner(guard);
 
-                let now = std::time::Instant::now();
-                tracing::info!(
-                    from_init_done_millis = (now - init_done).as_millis(),
-                    from_init_millis = (now - init_started_at).as_millis(),
-                    "Initial logical sizes completed after timeout (background jobs already started)"
-                );
+                startup_checkpoint("initial_logical_sizes", "Initial logical sizes completed after timeout (background jobs already started)");
 
             }
+
+            startup_checkpoint("complete", "Startup complete");
         };
 
         async move {

pageserver/src/config.rs

@@ -31,9 +31,12 @@ use utils::{
 use crate::disk_usage_eviction_task::DiskUsageEvictionTaskConfig;
 use crate::tenant::config::TenantConf;
 use crate::tenant::config::TenantConfOpt;
-use crate::tenant::{TENANT_ATTACHING_MARKER_FILENAME, TIMELINES_SEGMENT_NAME};
+use crate::tenant::{
+    TENANT_ATTACHING_MARKER_FILENAME, TENANT_DELETED_MARKER_FILE_NAME, TIMELINES_SEGMENT_NAME,
+};
 use crate::{
-    IGNORED_TENANT_FILE_NAME, METADATA_FILE_NAME, TENANT_CONFIG_NAME, TIMELINE_UNINIT_MARK_SUFFIX,
+    IGNORED_TENANT_FILE_NAME, METADATA_FILE_NAME, TENANT_CONFIG_NAME, TIMELINE_DELETE_MARK_SUFFIX,
+    TIMELINE_UNINIT_MARK_SUFFIX,
 };
 
 pub mod defaults {
@@ -601,6 +604,22 @@ impl PageServerConf {
         )
     }
 
+    pub fn timeline_delete_mark_file_path(
+        &self,
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> PathBuf {
+        path_with_suffix_extension(
+            self.timeline_path(&tenant_id, &timeline_id),
+            TIMELINE_DELETE_MARK_SUFFIX,
+        )
+    }
+
+    pub fn tenant_deleted_mark_file_path(&self, tenant_id: &TenantId) -> PathBuf {
+        self.tenant_path(tenant_id)
+            .join(TENANT_DELETED_MARKER_FILE_NAME)
+    }
+
     pub fn traces_path(&self) -> PathBuf {
         self.workdir.join("traces")
     }

pageserver/src/consumption_metrics.rs

@@ -7,27 +7,23 @@ use crate::context::{DownloadBehavior, RequestContext};
 use crate::task_mgr::{self, TaskKind, BACKGROUND_RUNTIME};
 use crate::tenant::{mgr, LogicalSizeCalculationCause};
 use anyhow;
-use chrono::Utc;
+use chrono::{DateTime, Utc};
 use consumption_metrics::{idempotency_key, Event, EventChunk, EventType, CHUNK_SIZE};
 use pageserver_api::models::TenantState;
 use reqwest::Url;
 use serde::Serialize;
 use serde_with::{serde_as, DisplayFromStr};
 use std::collections::HashMap;
-use std::time::Duration;
+use std::sync::Arc;
+use std::time::{Duration, SystemTime};
 use tracing::*;
 use utils::id::{NodeId, TenantId, TimelineId};
-
-const WRITTEN_SIZE: &str = "written_size";
-const SYNTHETIC_STORAGE_SIZE: &str = "synthetic_storage_size";
-const RESIDENT_SIZE: &str = "resident_size";
-const REMOTE_STORAGE_SIZE: &str = "remote_storage_size";
-const TIMELINE_LOGICAL_SIZE: &str = "timeline_logical_size";
+use utils::lsn::Lsn;
 
 const DEFAULT_HTTP_REPORTING_TIMEOUT: Duration = Duration::from_secs(60);
 
 #[serde_as]
-#[derive(Serialize, Debug)]
+#[derive(Serialize, Debug, Clone, Copy)]
 struct Ids {
     #[serde_as(as = "DisplayFromStr")]
     tenant_id: TenantId,
@@ -38,10 +34,142 @@ struct Ids {
 
 /// Key that uniquely identifies the object, this metric describes.
 #[derive(Debug, Clone, PartialEq, Eq, Hash)]
-pub struct PageserverConsumptionMetricsKey {
-    pub tenant_id: TenantId,
-    pub timeline_id: Option<TimelineId>,
-    pub metric: &'static str,
+struct MetricsKey {
+    tenant_id: TenantId,
+    timeline_id: Option<TimelineId>,
+    metric: &'static str,
+}
+
+impl MetricsKey {
+    const fn absolute_values(self) -> AbsoluteValueFactory {
+        AbsoluteValueFactory(self)
+    }
+    const fn incremental_values(self) -> IncrementalValueFactory {
+        IncrementalValueFactory(self)
+    }
+}
+
+/// Helper type which each individual metric kind can return to produce only absolute values.
+struct AbsoluteValueFactory(MetricsKey);
+
+impl AbsoluteValueFactory {
+    fn at(self, time: DateTime<Utc>, val: u64) -> (MetricsKey, (EventType, u64)) {
+        let key = self.0;
+        (key, (EventType::Absolute { time }, val))
+    }
+}
+
+/// Helper type which each individual metric kind can return to produce only incremental values.
+struct IncrementalValueFactory(MetricsKey);
+
+impl IncrementalValueFactory {
+    #[allow(clippy::wrong_self_convention)]
+    fn from_previous_up_to(
+        self,
+        prev_end: DateTime<Utc>,
+        up_to: DateTime<Utc>,
+        val: u64,
+    ) -> (MetricsKey, (EventType, u64)) {
+        let key = self.0;
+        // cannot assert prev_end < up_to because these are realtime clock based
+        (
+            key,
+            (
+                EventType::Incremental {
+                    start_time: prev_end,
+                    stop_time: up_to,
+                },
+                val,
+            ),
+        )
+    }
+
+    fn key(&self) -> &MetricsKey {
+        &self.0
+    }
+}
+
+// the static part of a MetricsKey
+impl MetricsKey {
+    /// Absolute value of [`Timeline::get_last_record_lsn`].
+    ///
+    /// [`Timeline::get_last_record_lsn`]: crate::tenant::Timeline::get_last_record_lsn
+    const fn written_size(tenant_id: TenantId, timeline_id: TimelineId) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: Some(timeline_id),
+            metric: "written_size",
+        }
+        .absolute_values()
+    }
+
+    /// Values will be the difference of the latest [`MetricsKey::written_size`] to what we
+    /// previously sent, starting from the previously sent incremental time range ending at the
+    /// latest absolute measurement.
+    const fn written_size_delta(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> IncrementalValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: Some(timeline_id),
+            // the name here is correctly about data not size, because that is what is wanted by
+            // downstream pipeline
+            metric: "written_data_bytes_delta",
+        }
+        .incremental_values()
+    }
+
+    /// Exact [`Timeline::get_current_logical_size`].
+    ///
+    /// [`Timeline::get_current_logical_size`]: crate::tenant::Timeline::get_current_logical_size
+    const fn timeline_logical_size(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+    ) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: Some(timeline_id),
+            metric: "timeline_logical_size",
+        }
+        .absolute_values()
+    }
+
+    /// [`Tenant::remote_size`]
+    ///
+    /// [`Tenant::remote_size`]: crate::tenant::Tenant::remote_size
+    const fn remote_storage_size(tenant_id: TenantId) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: None,
+            metric: "remote_storage_size",
+        }
+        .absolute_values()
+    }
+
+    /// Sum of [`Timeline::resident_physical_size`] for each `Tenant`.
+    ///
+    /// [`Timeline::resident_physical_size`]: crate::tenant::Timeline::resident_physical_size
+    const fn resident_size(tenant_id: TenantId) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: None,
+            metric: "resident_size",
+        }
+        .absolute_values()
+    }
+
+    /// [`Tenant::cached_synthetic_size`] as refreshed by [`calculate_synthetic_size_worker`].
+    ///
+    /// [`Tenant::cached_synthetic_size`]: crate::tenant::Tenant::cached_synthetic_size
+    const fn synthetic_size(tenant_id: TenantId) -> AbsoluteValueFactory {
+        MetricsKey {
+            tenant_id,
+            timeline_id: None,
+            metric: "synthetic_storage_size",
+        }
+        .absolute_values()
+    }
 }
 
 /// Main thread that serves metrics collection
@@ -79,7 +207,7 @@ pub async fn collect_metrics(
         .timeout(DEFAULT_HTTP_REPORTING_TIMEOUT)
         .build()
         .expect("Failed to create http client with timeout");
-    let mut cached_metrics: HashMap<PageserverConsumptionMetricsKey, u64> = HashMap::new();
+    let mut cached_metrics = HashMap::new();
     let mut prev_iteration_time: std::time::Instant = std::time::Instant::now();
 
     loop {
@@ -119,15 +247,15 @@ pub async fn collect_metrics(
 ///
 /// TODO
 /// - refactor this function (chunking+sending part) to reuse it in proxy module;
-pub async fn collect_metrics_iteration(
+async fn collect_metrics_iteration(
     client: &reqwest::Client,
-    cached_metrics: &mut HashMap<PageserverConsumptionMetricsKey, u64>,
+    cached_metrics: &mut HashMap<MetricsKey, (EventType, u64)>,
     metric_collection_endpoint: &reqwest::Url,
     node_id: NodeId,
     ctx: &RequestContext,
     send_cached: bool,
 ) {
-    let mut current_metrics: Vec<(PageserverConsumptionMetricsKey, u64)> = Vec::new();
+    let mut current_metrics: Vec<(MetricsKey, (EventType, u64))> = Vec::new();
     trace!(
         "starting collect_metrics_iteration. metric_collection_endpoint: {}",
         metric_collection_endpoint
@@ -161,99 +289,65 @@ pub async fn collect_metrics_iteration(
         let mut tenant_resident_size = 0;
 
         // iterate through list of timelines in tenant
-        for timeline in tenant.list_timelines().iter() {
+        for timeline in tenant.list_timelines() {
             // collect per-timeline metrics only for active timelines
-            if timeline.is_active() {
-                let timeline_written_size = u64::from(timeline.get_last_record_lsn());
 
-                current_metrics.push((
-                    PageserverConsumptionMetricsKey {
+            let timeline_id = timeline.timeline_id;
+
+            match TimelineSnapshot::collect(&timeline, ctx) {
+                Ok(Some(snap)) => {
+                    snap.to_metrics(
                         tenant_id,
-                        timeline_id: Some(timeline.timeline_id),
-                        metric: WRITTEN_SIZE,
-                    },
-                    timeline_written_size,
-                ));
-
-                let span = info_span!("collect_metrics_iteration", tenant_id = %timeline.tenant_id, timeline_id = %timeline.timeline_id);
-                match span.in_scope(|| timeline.get_current_logical_size(ctx)) {
-                    // Only send timeline logical size when it is fully calculated.
-                    Ok((size, is_exact)) if is_exact => {
-                        current_metrics.push((
-                            PageserverConsumptionMetricsKey {
-                                tenant_id,
-                                timeline_id: Some(timeline.timeline_id),
-                                metric: TIMELINE_LOGICAL_SIZE,
-                            },
-                            size,
-                        ));
-                    }
-                    Ok((_, _)) => {}
-                    Err(err) => {
-                        error!(
-                            "failed to get current logical size for timeline {}: {err:?}",
-                            timeline.timeline_id
-                        );
-                        continue;
-                    }
-                };
+                        timeline_id,
+                        Utc::now(),
+                        &mut current_metrics,
+                        cached_metrics,
+                    );
+                }
+                Ok(None) => {}
+                Err(e) => {
+                    error!(
+                        "failed to get metrics values for tenant {tenant_id} timeline {}: {e:#?}",
+                        timeline.timeline_id
+                    );
+                    continue;
+                }
             }
 
-            let timeline_resident_size = timeline.get_resident_physical_size();
-            tenant_resident_size += timeline_resident_size;
+            tenant_resident_size += timeline.resident_physical_size();
         }
 
-        match tenant.get_remote_size().await {
-            Ok(tenant_remote_size) => {
-                current_metrics.push((
-                    PageserverConsumptionMetricsKey {
-                        tenant_id,
-                        timeline_id: None,
-                        metric: REMOTE_STORAGE_SIZE,
-                    },
-                    tenant_remote_size,
-                ));
-            }
-            Err(err) => {
-                error!(
-                    "failed to get remote size for tenant {}: {err:?}",
-                    tenant_id
-                );
-            }
-        }
+        current_metrics
+            .push(MetricsKey::remote_storage_size(tenant_id).at(Utc::now(), tenant.remote_size()));
 
-        current_metrics.push((
-            PageserverConsumptionMetricsKey {
-                tenant_id,
-                timeline_id: None,
-                metric: RESIDENT_SIZE,
-            },
-            tenant_resident_size,
-        ));
+        current_metrics
+            .push(MetricsKey::resident_size(tenant_id).at(Utc::now(), tenant_resident_size));
 
         // Note that this metric is calculated in a separate bgworker
         // Here we only use cached value, which may lag behind the real latest one
-        let tenant_synthetic_size = tenant.get_cached_synthetic_size();
+        let synthetic_size = tenant.cached_synthetic_size();
 
-        if tenant_synthetic_size != 0 {
+        if synthetic_size != 0 {
             // only send non-zeroes because otherwise these show up as errors in logs
-            current_metrics.push((
-                PageserverConsumptionMetricsKey {
-                    tenant_id,
-                    timeline_id: None,
-                    metric: SYNTHETIC_STORAGE_SIZE,
-                },
-                tenant_synthetic_size,
-            ));
+            current_metrics
+                .push(MetricsKey::synthetic_size(tenant_id).at(Utc::now(), synthetic_size));
         }
     }
 
     // Filter metrics, unless we want to send all metrics, including cached ones.
     // See: https://github.com/neondatabase/neon/issues/3485
     if !send_cached {
-        current_metrics.retain(|(curr_key, curr_val)| match cached_metrics.get(curr_key) {
-            Some(val) => val != curr_val,
-            None => true,
+        current_metrics.retain(|(curr_key, (kind, curr_val))| {
+            if kind.is_incremental() {
+                // incremental values (currently only written_size_delta) should not get any cache
+                // deduplication because they will be used by upstream for "is still alive."
+                true
+            } else {
+                match cached_metrics.get(curr_key) {
+                    Some((_, val)) => val != curr_val,
+                    None => true,
+                }
+            }
         });
     }
 
@@ -268,14 +362,16 @@ pub async fn collect_metrics_iteration(
 
     let mut chunk_to_send: Vec<Event<Ids>> = Vec::with_capacity(CHUNK_SIZE);
 
+    let node_id = node_id.to_string();
+
     for chunk in chunks {
         chunk_to_send.clear();
 
         // enrich metrics with type,timestamp and idempotency key before sending
-        chunk_to_send.extend(chunk.iter().map(|(curr_key, curr_val)| Event {
-            kind: EventType::Absolute { time: Utc::now() },
+        chunk_to_send.extend(chunk.iter().map(|(curr_key, (when, curr_val))| Event {
+            kind: *when,
             metric: curr_key.metric,
-            idempotency_key: idempotency_key(node_id.to_string()),
+            idempotency_key: idempotency_key(&node_id),
             value: *curr_val,
             extra: Ids {
                 tenant_id: curr_key.tenant_id,
@@ -283,17 +379,14 @@ pub async fn collect_metrics_iteration(
             },
         }));
 
-        let chunk_json = serde_json::value::to_raw_value(&EventChunk {
-            events: &chunk_to_send,
-        })
-        .expect("PageserverConsumptionMetric should not fail serialization");
-
         const MAX_RETRIES: u32 = 3;
 
         for attempt in 0..MAX_RETRIES {
             let res = client
                 .post(metric_collection_endpoint.clone())
-                .json(&chunk_json)
+                .json(&EventChunk {
+                    events: (&chunk_to_send).into(),
+                })
                 .send()
                 .await;
 
@@ -329,6 +422,130 @@ pub async fn collect_metrics_iteration(
     }
 }
 
+/// Internal type to make timeline metric production testable.
+///
+/// As this value type contains all of the information needed from a timeline to produce the
+/// metrics, it can easily be created with different values in test.
+struct TimelineSnapshot {
+    loaded_at: (Lsn, SystemTime),
+    last_record_lsn: Lsn,
+    current_exact_logical_size: Option<u64>,
+}
+
+impl TimelineSnapshot {
+    /// Collect the metrics from an actual timeline.
+    ///
+    /// Fails currently only when [`Timeline::get_current_logical_size`] fails.
+    ///
+    /// [`Timeline::get_current_logical_size`]: crate::tenant::Timeline::get_current_logical_size
+    fn collect(
+        t: &Arc<crate::tenant::Timeline>,
+        ctx: &RequestContext,
+    ) -> anyhow::Result<Option<Self>> {
+        use anyhow::Context;
+
+        if !t.is_active() {
+            // no collection for broken or stopping needed, we will still keep the cached values
+            // though at the caller.
+            Ok(None)
+        } else {
+            let loaded_at = t.loaded_at;
+            let last_record_lsn = t.get_last_record_lsn();
+
+            let current_exact_logical_size = {
+                let span = info_span!("collect_metrics_iteration", tenant_id = %t.tenant_id, timeline_id = %t.timeline_id);
+                let res = span
+                    .in_scope(|| t.get_current_logical_size(ctx))
+                    .context("get_current_logical_size");
+                match res? {
+                    // Only send timeline logical size when it is fully calculated.
+                    (size, is_exact) if is_exact => Some(size),
+                    (_, _) => None,
+                }
+            };
+
+            Ok(Some(TimelineSnapshot {
+                loaded_at,
+                last_record_lsn,
+                current_exact_logical_size,
+            }))
+        }
+    }
+
+    /// Produce the timeline consumption metrics into the `metrics` argument.
+    fn to_metrics(
+        &self,
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+        now: DateTime<Utc>,
+        metrics: &mut Vec<(MetricsKey, (EventType, u64))>,
+        cache: &HashMap<MetricsKey, (EventType, u64)>,
+    ) {
+        let timeline_written_size = u64::from(self.last_record_lsn);
+
+        let (key, written_size_now) =
+            MetricsKey::written_size(tenant_id, timeline_id).at(now, timeline_written_size);
+
+        // last_record_lsn can only go up, right now at least, TODO: #2592 or related
+        // features might change this.
+
+        let written_size_delta_key = MetricsKey::written_size_delta(tenant_id, timeline_id);
+
+        // use this when available, because in a stream of incremental values, it will be
+        // accurate where as when last_record_lsn stops moving, we will only cache the last
+        // one of those.
+        let last_stop_time = cache
+            .get(written_size_delta_key.key())
+            .map(|(until, _val)| {
+                until
+                    .incremental_timerange()
+                    .expect("never create EventType::Absolute for written_size_delta")
+                    .end
+            });
+
+        // by default, use the last sent written_size as the basis for
+        // calculating the delta. if we don't yet have one, use the load time value.
+        let prev = cache
+            .get(&key)
+            .map(|(prev_at, prev)| {
+                // use the prev time from our last incremental update, or default to latest
+                // absolute update on the first round.
+                let prev_at = prev_at
+                    .absolute_time()
+                    .expect("never create EventType::Incremental for written_size");
+                let prev_at = last_stop_time.unwrap_or(prev_at);
+                (*prev_at, *prev)
+            })
+            .unwrap_or_else(|| {
+                // if we don't have a previous point of comparison, compare to the load time
+                // lsn.
+                let (disk_consistent_lsn, loaded_at) = &self.loaded_at;
+                (DateTime::from(*loaded_at), disk_consistent_lsn.0)
+            });
+
+        // written_size_bytes_delta
+        metrics.extend(
+            if let Some(delta) = written_size_now.1.checked_sub(prev.1) {
+                let up_to = written_size_now
+                    .0
+                    .absolute_time()
+                    .expect("never create EventType::Incremental for written_size");
+                let key_value = written_size_delta_key.from_previous_up_to(prev.0, *up_to, delta);
+                Some(key_value)
+            } else {
+                None
+            },
+        );
+
+        // written_size
+        metrics.push((key, written_size_now));
+
+        if let Some(size) = self.current_exact_logical_size {
+            metrics.push(MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, size));
+        }
+    }
+}
+
 /// Caclculate synthetic size for each active tenant
 pub async fn calculate_synthetic_size_worker(
     synthetic_size_calculation_interval: Duration,
@@ -343,7 +560,7 @@ pub async fn calculate_synthetic_size_worker(
             _ = task_mgr::shutdown_watcher() => {
                 return Ok(());
             },
-        tick_at = ticker.tick() => {
+            tick_at = ticker.tick() => {
 
                 let tenants = match mgr::list_tenants().await {
                     Ok(tenants) => tenants,
@@ -379,3 +596,149 @@ pub async fn calculate_synthetic_size_worker(
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashMap;
+
+    use std::time::SystemTime;
+    use utils::{
+        id::{TenantId, TimelineId},
+        lsn::Lsn,
+    };
+
+    use crate::consumption_metrics::MetricsKey;
+
+    use super::TimelineSnapshot;
+    use chrono::{DateTime, Utc};
+
+    #[test]
+    fn startup_collected_timeline_metrics_before_advancing() {
+        let tenant_id = TenantId::generate();
+        let timeline_id = TimelineId::generate();
+
+        let mut metrics = Vec::new();
+        let cache = HashMap::new();
+
+        let initdb_lsn = Lsn(0x10000);
+        let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+
+        let snap = TimelineSnapshot {
+            loaded_at: (disk_consistent_lsn, SystemTime::now()),
+            last_record_lsn: disk_consistent_lsn,
+            current_exact_logical_size: Some(0x42000),
+        };
+
+        let now = DateTime::<Utc>::from(SystemTime::now());
+
+        snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+        assert_eq!(
+            metrics,
+            &[
+                MetricsKey::written_size_delta(tenant_id, timeline_id).from_previous_up_to(
+                    snap.loaded_at.1.into(),
+                    now,
+                    0
+                ),
+                MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
+                MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            ]
+        );
+    }
+
+    #[test]
+    fn startup_collected_timeline_metrics_second_round() {
+        let tenant_id = TenantId::generate();
+        let timeline_id = TimelineId::generate();
+
+        let [now, before, init] = time_backwards();
+
+        let now = DateTime::<Utc>::from(now);
+        let before = DateTime::<Utc>::from(before);
+
+        let initdb_lsn = Lsn(0x10000);
+        let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+
+        let mut metrics = Vec::new();
+        let cache = HashMap::from([
+            MetricsKey::written_size(tenant_id, timeline_id).at(before, disk_consistent_lsn.0)
+        ]);
+
+        let snap = TimelineSnapshot {
+            loaded_at: (disk_consistent_lsn, init),
+            last_record_lsn: disk_consistent_lsn,
+            current_exact_logical_size: Some(0x42000),
+        };
+
+        snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+        assert_eq!(
+            metrics,
+            &[
+                MetricsKey::written_size_delta(tenant_id, timeline_id)
+                    .from_previous_up_to(before, now, 0),
+                MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
+                MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            ]
+        );
+    }
+
+    #[test]
+    fn startup_collected_timeline_metrics_nth_round_at_same_lsn() {
+        let tenant_id = TenantId::generate();
+        let timeline_id = TimelineId::generate();
+
+        let [now, just_before, before, init] = time_backwards();
+
+        let now = DateTime::<Utc>::from(now);
+        let just_before = DateTime::<Utc>::from(just_before);
+        let before = DateTime::<Utc>::from(before);
+
+        let initdb_lsn = Lsn(0x10000);
+        let disk_consistent_lsn = Lsn(initdb_lsn.0 * 2);
+
+        let mut metrics = Vec::new();
+        let cache = HashMap::from([
+            // at t=before was the last time the last_record_lsn changed
+            MetricsKey::written_size(tenant_id, timeline_id).at(before, disk_consistent_lsn.0),
+            // end time of this event is used for the next ones
+            MetricsKey::written_size_delta(tenant_id, timeline_id).from_previous_up_to(
+                before,
+                just_before,
+                0,
+            ),
+        ]);
+
+        let snap = TimelineSnapshot {
+            loaded_at: (disk_consistent_lsn, init),
+            last_record_lsn: disk_consistent_lsn,
+            current_exact_logical_size: Some(0x42000),
+        };
+
+        snap.to_metrics(tenant_id, timeline_id, now, &mut metrics, &cache);
+
+        assert_eq!(
+            metrics,
+            &[
+                MetricsKey::written_size_delta(tenant_id, timeline_id).from_previous_up_to(
+                    just_before,
+                    now,
+                    0
+                ),
+                MetricsKey::written_size(tenant_id, timeline_id).at(now, disk_consistent_lsn.0),
+                MetricsKey::timeline_logical_size(tenant_id, timeline_id).at(now, 0x42000)
+            ]
+        );
+    }
+
+    fn time_backwards<const N: usize>() -> [std::time::SystemTime; N] {
+        let mut times = [std::time::SystemTime::UNIX_EPOCH; N];
+        times[0] = std::time::SystemTime::now();
+        for behind in 1..N {
+            times[behind] = times[0] - std::time::Duration::from_secs(behind as u64);
+        }
+
+        times
+    }
+}

pageserver/src/context.rs

@@ -85,6 +85,7 @@
 //! The solution is that all code paths are infected with precisely one
 //! [`RequestContext`] argument. Functions in the middle of the call chain
 //! only need to pass it on.
+
 use crate::task_mgr::TaskKind;
 
 // The main structure of this module, see module-level comment.
@@ -92,6 +93,7 @@ use crate::task_mgr::TaskKind;
 pub struct RequestContext {
     task_kind: TaskKind,
     download_behavior: DownloadBehavior,
+    access_stats_behavior: AccessStatsBehavior,
 }
 
 /// Desired behavior if the operation requires an on-demand download
@@ -109,6 +111,67 @@ pub enum DownloadBehavior {
     Error,
 }
 
+/// Whether this request should update access times used in LRU eviction
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub(crate) enum AccessStatsBehavior {
+    /// Update access times: this request's access to data should be taken
+    /// as a hint that the accessed layer is likely to be accessed again
+    Update,
+
+    /// Do not update access times: this request is accessing the layer
+    /// but does not want to indicate that the layer should be retained in cache,
+    /// perhaps because the requestor is a compaction routine that will soon cover
+    /// this layer with another.
+    Skip,
+}
+
+pub struct RequestContextBuilder {
+    inner: RequestContext,
+}
+
+impl RequestContextBuilder {
+    /// A new builder with default settings
+    pub fn new(task_kind: TaskKind) -> Self {
+        Self {
+            inner: RequestContext {
+                task_kind,
+                download_behavior: DownloadBehavior::Download,
+                access_stats_behavior: AccessStatsBehavior::Update,
+            },
+        }
+    }
+
+    pub fn extend(original: &RequestContext) -> Self {
+        Self {
+            // This is like a Copy, but avoid implementing Copy because ordinary users of
+            // RequestContext should always move or ref it.
+            inner: RequestContext {
+                task_kind: original.task_kind,
+                download_behavior: original.download_behavior,
+                access_stats_behavior: original.access_stats_behavior,
+            },
+        }
+    }
+
+    /// Configure the DownloadBehavior of the context: whether to
+    /// download missing layers, and/or warn on the download.
+    pub fn download_behavior(mut self, b: DownloadBehavior) -> Self {
+        self.inner.download_behavior = b;
+        self
+    }
+
+    /// Configure the AccessStatsBehavior of the context: whether layer
+    /// accesses should update the access time of the layer.
+    pub(crate) fn access_stats_behavior(mut self, b: AccessStatsBehavior) -> Self {
+        self.inner.access_stats_behavior = b;
+        self
+    }
+
+    pub fn build(self) -> RequestContext {
+        self.inner
+    }
+}
+
 impl RequestContext {
     /// Create a new RequestContext that has no parent.
     ///
@@ -123,10 +186,9 @@ impl RequestContext {
     /// because someone explicitly canceled it.
     /// It has no parent, so it cannot inherit cancellation from there.
     pub fn new(task_kind: TaskKind, download_behavior: DownloadBehavior) -> Self {
-        RequestContext {
-            task_kind,
-            download_behavior,
-        }
+        RequestContextBuilder::new(task_kind)
+            .download_behavior(download_behavior)
+            .build()
     }
 
     /// Create a detached child context for a task that may outlive `self`.
@@ -187,10 +249,7 @@ impl RequestContext {
     }
 
     fn child_impl(&self, task_kind: TaskKind, download_behavior: DownloadBehavior) -> Self {
-        RequestContext {
-            task_kind,
-            download_behavior,
-        }
+        Self::new(task_kind, download_behavior)
     }
 
     pub fn task_kind(&self) -> TaskKind {
@@ -200,4 +259,8 @@ impl RequestContext {
     pub fn download_behavior(&self) -> DownloadBehavior {
         self.download_behavior
     }
+
+    pub(crate) fn access_stats_behavior(&self) -> AccessStatsBehavior {
+        self.access_stats_behavior
+    }
 }

pageserver/src/disk_usage_eviction_task.rs

@@ -304,17 +304,18 @@ pub async fn disk_usage_eviction_task_iteration_impl<U: Usage>(
     // Debug-log the list of candidates
     let now = SystemTime::now();
     for (i, (partition, candidate)) in candidates.iter().enumerate() {
+        let desc = candidate.layer.layer_desc();
         debug!(
             "cand {}/{}: size={}, no_access_for={}us, partition={:?}, {}/{}/{}",
             i + 1,
             candidates.len(),
-            candidate.layer.file_size(),
+            desc.file_size,
             now.duration_since(candidate.last_activity_ts)
                 .unwrap()
                 .as_micros(),
             partition,
-            candidate.layer.get_tenant_id(),
-            candidate.layer.get_timeline_id(),
+            desc.tenant_id,
+            desc.timeline_id,
             candidate.layer,
         );
     }
@@ -346,7 +347,7 @@ pub async fn disk_usage_eviction_task_iteration_impl<U: Usage>(
             warned = Some(usage_planned);
         }
 
-        usage_planned.add_available_bytes(candidate.layer.file_size());
+        usage_planned.add_available_bytes(candidate.layer.layer_desc().file_size);
 
         batched
             .entry(TimelineKey(candidate.timeline))
@@ -389,15 +390,16 @@ pub async fn disk_usage_eviction_task_iteration_impl<U: Usage>(
                 Ok(results) => {
                     assert_eq!(results.len(), batch.len());
                     for (result, layer) in results.into_iter().zip(batch.iter()) {
+                        let file_size = layer.layer_desc().file_size;
                         match result {
                             Some(Ok(())) => {
-                                usage_assumed.add_available_bytes(layer.file_size());
+                                usage_assumed.add_available_bytes(file_size);
                             }
                             Some(Err(EvictionError::CannotEvictRemoteLayer)) => {
                                 unreachable!("get_local_layers_for_disk_usage_eviction finds only local layers")
                             }
                             Some(Err(EvictionError::FileNotFound)) => {
-                                evictions_failed.file_sizes += layer.file_size();
+                                evictions_failed.file_sizes += file_size;
                                 evictions_failed.count += 1;
                             }
                             Some(Err(
@@ -406,7 +408,7 @@ pub async fn disk_usage_eviction_task_iteration_impl<U: Usage>(
                             )) => {
                                 let e = utils::error::report_compact_sources(&e);
                                 warn!(%layer, "failed to evict layer: {e}");
-                                evictions_failed.file_sizes += layer.file_size();
+                                evictions_failed.file_sizes += file_size;
                                 evictions_failed.count += 1;
                             }
                             None => {
@@ -545,12 +547,12 @@ async fn collect_eviction_candidates(
         // We could be better here, e.g., sum of all L0 layers + most recent L1 layer.
         // That's what's typically used by the various background loops.
         //
-        // The default can be overriden with a fixed value in the tenant conf.
+        // The default can be overridden with a fixed value in the tenant conf.
         // A default override can be put in the default tenant conf in the pageserver.toml.
         let min_resident_size = if let Some(s) = tenant.get_min_resident_size_override() {
             debug!(
                 tenant_id=%tenant.tenant_id(),
-                overriden_size=s,
+                overridden_size=s,
                 "using overridden min resident size for tenant"
             );
             s

pageserver/src/http/openapi_spec.yml

@@ -93,6 +93,47 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/Error"
+    delete:
+      description: |
+        Attempts to delete specified tenant. 500 and 409 errors should be retried until 404 is retrieved.
+        404 means that deletion successfully finished"
+      responses:
+        "400":
+          description: Error when no tenant id found in path
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+        "401":
+          description: Unauthorized Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UnauthorizedError"
+        "403":
+          description: Forbidden Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ForbiddenError"
+        "404":
+          description: Tenant not found
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/NotFoundError"
+        "409":
+          description: Deletion is already in progress, continue polling
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ConflictError"
+        "500":
+          description: Generic operation error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
 
   /v1/tenant/{tenant_id}/timeline:
     parameters:
@@ -820,6 +861,7 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/Error"
+
   /v1/tenant/config:
     put:
       description: |

pageserver/src/http/routes.rs

@@ -187,7 +187,7 @@ impl From<crate::tenant::DeleteTimelineError> for ApiError {
                 format!("Cannot delete timeline which has child timelines: {children:?}")
                     .into_boxed_str(),
             ),
-            a @ AlreadyInProgress => ApiError::Conflict(a.to_string()),
+            a @ AlreadyInProgress(_) => ApiError::Conflict(a.to_string()),
             Other(e) => ApiError::InternalServerError(e),
         }
     }
@@ -208,6 +208,19 @@ impl From<crate::tenant::mgr::DeleteTimelineError> for ApiError {
     }
 }
 
+impl From<crate::tenant::delete::DeleteTenantError> for ApiError {
+    fn from(value: crate::tenant::delete::DeleteTenantError) -> Self {
+        use crate::tenant::delete::DeleteTenantError::*;
+        match value {
+            Get(g) => ApiError::from(g),
+            e @ AlreadyInProgress => ApiError::Conflict(e.to_string()),
+            Timeline(t) => ApiError::from(t),
+            Other(o) => ApiError::InternalServerError(o),
+            e @ InvalidState(_) => ApiError::PreconditionFailed(e.to_string().into_boxed_str()),
+        }
+    }
+}
+
 // Helper function to construct a TimelineInfo struct for a timeline
 async fn build_timeline_info(
     timeline: &Arc<Timeline>,
@@ -617,6 +630,23 @@ async fn tenant_status(
     json_response(StatusCode::OK, tenant_info)
 }
 
+async fn tenant_delete_handler(
+    request: Request<Body>,
+    _cancel: CancellationToken,
+) -> Result<Response<Body>, ApiError> {
+    // TODO openapi spec
+    let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
+    check_permission(&request, Some(tenant_id))?;
+
+    let state = get_state(&request);
+
+    mgr::delete_tenant(state.conf, state.remote_storage.clone(), tenant_id)
+        .instrument(info_span!("tenant_delete_handler", %tenant_id))
+        .await?;
+
+    json_response(StatusCode::ACCEPTED, ())
+}
+
 /// HTTP endpoint to query the current tenant_size of a tenant.
 ///
 /// This is not used by consumption metrics under [`crate::consumption_metrics`], but can be used
@@ -994,31 +1024,29 @@ async fn timeline_gc_handler(
 // Run compaction immediately on given timeline.
 async fn timeline_compact_handler(
     request: Request<Body>,
-    _cancel: CancellationToken,
+    cancel: CancellationToken,
 ) -> Result<Response<Body>, ApiError> {
     let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
     check_permission(&request, Some(tenant_id))?;
 
-    let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
-    let result_receiver = mgr::immediate_compact(tenant_id, timeline_id, &ctx)
-        .await
-        .context("spawn compaction task")
-        .map_err(ApiError::InternalServerError)?;
-
-    let result: anyhow::Result<()> = result_receiver
-        .await
-        .context("receive compaction result")
-        .map_err(ApiError::InternalServerError)?;
-    result.map_err(ApiError::InternalServerError)?;
-
-    json_response(StatusCode::OK, ())
+    async {
+        let ctx = RequestContext::new(TaskKind::MgmtRequest, DownloadBehavior::Download);
+        let timeline = active_timeline_of_active_tenant(tenant_id, timeline_id).await?;
+        timeline
+            .compact(&cancel, &ctx)
+            .await
+            .map_err(ApiError::InternalServerError)?;
+        json_response(StatusCode::OK, ())
+    }
+    .instrument(info_span!("manual_compaction", %tenant_id, %timeline_id))
+    .await
 }
 
 // Run checkpoint immediately on given timeline.
 async fn timeline_checkpoint_handler(
     request: Request<Body>,
-    _cancel: CancellationToken,
+    cancel: CancellationToken,
 ) -> Result<Response<Body>, ApiError> {
     let tenant_id: TenantId = parse_request_param(&request, "tenant_id")?;
     let timeline_id: TimelineId = parse_request_param(&request, "timeline_id")?;
@@ -1031,13 +1059,13 @@ async fn timeline_checkpoint_handler(
             .await
             .map_err(ApiError::InternalServerError)?;
         timeline
-            .compact(&ctx)
+            .compact(&cancel, &ctx)
             .await
             .map_err(ApiError::InternalServerError)?;
 
         json_response(StatusCode::OK, ())
     }
-    .instrument(info_span!("manual_checkpoint", tenant_id = %tenant_id, timeline_id = %timeline_id))
+    .instrument(info_span!("manual_checkpoint", %tenant_id, %timeline_id))
     .await
 }
 
@@ -1347,6 +1375,9 @@ pub fn make_router(
         .get("/v1/tenant", |r| api_handler(r, tenant_list_handler))
         .post("/v1/tenant", |r| api_handler(r, tenant_create_handler))
         .get("/v1/tenant/:tenant_id", |r| api_handler(r, tenant_status))
+        .delete("/v1/tenant/:tenant_id", |r| {
+            api_handler(r, tenant_delete_handler)
+        })
         .get("/v1/tenant/:tenant_id/synthetic_size", |r| {
             api_handler(r, tenant_size_handler)
         })

pageserver/src/lib.rs

@@ -7,7 +7,7 @@ pub mod disk_usage_eviction_task;
 pub mod http;
 pub mod import_datadir;
 pub mod keyspace;
-pub(crate) mod metrics;
+pub mod metrics;
 pub mod page_cache;
 pub mod page_service;
 pub mod pgdatadir_mapping;
@@ -47,50 +47,54 @@ pub use crate::metrics::preinitialize_metrics;
 
 #[tracing::instrument]
 pub async fn shutdown_pageserver(exit_code: i32) {
+    use std::time::Duration;
     // Shut down the libpq endpoint task. This prevents new connections from
     // being accepted.
-    task_mgr::shutdown_tasks(Some(TaskKind::LibpqEndpointListener), None, None).await;
+    timed(
+        task_mgr::shutdown_tasks(Some(TaskKind::LibpqEndpointListener), None, None),
+        "shutdown LibpqEndpointListener",
+        Duration::from_secs(1),
+    )
+    .await;
 
     // Shut down any page service tasks.
-    task_mgr::shutdown_tasks(Some(TaskKind::PageRequestHandler), None, None).await;
+    timed(
+        task_mgr::shutdown_tasks(Some(TaskKind::PageRequestHandler), None, None),
+        "shutdown PageRequestHandlers",
+        Duration::from_secs(1),
+    )
+    .await;
 
     // Shut down all the tenants. This flushes everything to disk and kills
     // the checkpoint and GC tasks.
-    tenant::mgr::shutdown_all_tenants().await;
+    timed(
+        tenant::mgr::shutdown_all_tenants(),
+        "shutdown all tenants",
+        Duration::from_secs(5),
+    )
+    .await;
 
     // Shut down the HTTP endpoint last, so that you can still check the server's
     // status while it's shutting down.
     // FIXME: We should probably stop accepting commands like attach/detach earlier.
-    task_mgr::shutdown_tasks(Some(TaskKind::HttpEndpointListener), None, None).await;
+    timed(
+        task_mgr::shutdown_tasks(Some(TaskKind::HttpEndpointListener), None, None),
+        "shutdown http",
+        Duration::from_secs(1),
+    )
+    .await;
 
     // There should be nothing left, but let's be sure
-    task_mgr::shutdown_tasks(None, None, None).await;
+    timed(
+        task_mgr::shutdown_tasks(None, None, None),
+        "shutdown leftovers",
+        Duration::from_secs(1),
+    )
+    .await;
     info!("Shut down successfully completed");
     std::process::exit(exit_code);
 }
 
-const DEFAULT_BASE_BACKOFF_SECONDS: f64 = 0.1;
-const DEFAULT_MAX_BACKOFF_SECONDS: f64 = 3.0;
-
-async fn exponential_backoff(n: u32, base_increment: f64, max_seconds: f64) {
-    let backoff_duration_seconds =
-        exponential_backoff_duration_seconds(n, base_increment, max_seconds);
-    if backoff_duration_seconds > 0.0 {
-        info!(
-            "Backoff: waiting {backoff_duration_seconds} seconds before processing with the task",
-        );
-        tokio::time::sleep(std::time::Duration::from_secs_f64(backoff_duration_seconds)).await;
-    }
-}
-
-pub fn exponential_backoff_duration_seconds(n: u32, base_increment: f64, max_seconds: f64) -> f64 {
-    if n == 0 {
-        0.0
-    } else {
-        (1.0 + base_increment).powf(f64::from(n)).min(max_seconds)
-    }
-}
-
 /// The name of the metadata file pageserver creates per timeline.
 /// Full path: `tenants/<tenant_id>/timelines/<timeline_id>/metadata`.
 pub const METADATA_FILE_NAME: &str = "metadata";
@@ -109,6 +113,8 @@ pub const TEMP_FILE_SUFFIX: &str = "___temp";
 /// Full path: `tenants/<tenant_id>/timelines/<timeline_id>___uninit`.
 pub const TIMELINE_UNINIT_MARK_SUFFIX: &str = "___uninit";
 
+pub const TIMELINE_DELETE_MARK_SUFFIX: &str = "___delete";
+
 /// A marker file to prevent pageserver from loading a certain tenant on restart.
 /// Different from [`TIMELINE_UNINIT_MARK_SUFFIX`] due to semantics of the corresponding
 /// `ignore` management API command, that expects the ignored tenant to be properly loaded
@@ -123,15 +129,30 @@ pub fn is_temporary(path: &Path) -> bool {
     }
 }
 
-pub fn is_uninit_mark(path: &Path) -> bool {
+fn ends_with_suffix(path: &Path, suffix: &str) -> bool {
     match path.file_name() {
-        Some(name) => name
-            .to_string_lossy()
-            .ends_with(TIMELINE_UNINIT_MARK_SUFFIX),
+        Some(name) => name.to_string_lossy().ends_with(suffix),
         None => false,
     }
 }
 
+pub fn is_uninit_mark(path: &Path) -> bool {
+    ends_with_suffix(path, TIMELINE_UNINIT_MARK_SUFFIX)
+}
+
+pub fn is_delete_mark(path: &Path) -> bool {
+    ends_with_suffix(path, TIMELINE_DELETE_MARK_SUFFIX)
+}
+
+fn is_walkdir_io_not_found(e: &walkdir::Error) -> bool {
+    if let Some(e) = e.io_error() {
+        if e.kind() == std::io::ErrorKind::NotFound {
+            return true;
+        }
+    }
+    false
+}
+
 /// During pageserver startup, we need to order operations not to exhaust tokio worker threads by
 /// blocking.
 ///
@@ -147,7 +168,7 @@ pub struct InitializationOrder {
 
     /// Each timeline owns a clone of this to be consumed on the initial logical size calculation
     /// attempt. It is important to drop this once the attempt has completed.
-    pub initial_logical_size_attempt: utils::completion::Completion,
+    pub initial_logical_size_attempt: Option<utils::completion::Completion>,
 
     /// Barrier for when we can start any background jobs.
     ///
@@ -155,33 +176,75 @@ pub struct InitializationOrder {
     pub background_jobs_can_start: utils::completion::Barrier,
 }
 
-#[cfg(test)]
-mod backoff_defaults_tests {
-    use super::*;
+/// Time the future with a warning when it exceeds a threshold.
+async fn timed<Fut: std::future::Future>(
+    fut: Fut,
+    name: &str,
+    warn_at: std::time::Duration,
+) -> <Fut as std::future::Future>::Output {
+    let started = std::time::Instant::now();
 
-    #[test]
-    fn backoff_defaults_produce_growing_backoff_sequence() {
-        let mut current_backoff_value = None;
+    let mut fut = std::pin::pin!(fut);
 
-        for i in 0..10_000 {
-            let new_backoff_value = exponential_backoff_duration_seconds(
-                i,
-                DEFAULT_BASE_BACKOFF_SECONDS,
-                DEFAULT_MAX_BACKOFF_SECONDS,
+    match tokio::time::timeout(warn_at, &mut fut).await {
+        Ok(ret) => {
+            tracing::info!(
+                task = name,
+                elapsed_ms = started.elapsed().as_millis(),
+                "completed"
+            );
+            ret
+        }
+        Err(_) => {
+            tracing::info!(
+                task = name,
+                elapsed_ms = started.elapsed().as_millis(),
+                "still waiting, taking longer than expected..."
             );
 
-            if let Some(old_backoff_value) = current_backoff_value.replace(new_backoff_value) {
-                assert!(
-                    old_backoff_value <= new_backoff_value,
-                    "{i}th backoff value {new_backoff_value} is smaller than the previous one {old_backoff_value}"
-                )
-            }
-        }
+            let ret = fut.await;
 
-        assert_eq!(
-            current_backoff_value.expect("Should have produced backoff values to compare"),
-            DEFAULT_MAX_BACKOFF_SECONDS,
-            "Given big enough of retries, backoff should reach its allowed max value"
-        );
+            // this has a global allowed_errors
+            tracing::warn!(
+                task = name,
+                elapsed_ms = started.elapsed().as_millis(),
+                "completed, took longer than expected"
+            );
+
+            ret
+        }
+    }
+}
+
+#[cfg(test)]
+mod timed_tests {
+    use super::timed;
+    use std::time::Duration;
+
+    #[tokio::test]
+    async fn timed_completes_when_inner_future_completes() {
+        // A future that completes on time should have its result returned
+        let r1 = timed(
+            async move {
+                tokio::time::sleep(Duration::from_millis(10)).await;
+                123
+            },
+            "test 1",
+            Duration::from_millis(50),
+        )
+        .await;
+        assert_eq!(r1, 123);
+
+        // A future that completes too slowly should also have its result returned
+        let r1 = timed(
+            async move {
+                tokio::time::sleep(Duration::from_millis(50)).await;
+                456
+            },
+            "test 1",
+            Duration::from_millis(10),
+        )
+        .await;
+        assert_eq!(r1, 456);
     }
 }

pageserver/src/metrics.rs

@@ -1,12 +1,11 @@
 use metrics::metric_vec_duration::DurationResultObserver;
 use metrics::{
-    register_counter_vec, register_histogram, register_histogram_vec, register_int_counter,
-    register_int_counter_vec, register_int_gauge, register_int_gauge_vec, register_uint_gauge,
-    register_uint_gauge_vec, Counter, CounterVec, Histogram, HistogramVec, IntCounter,
-    IntCounterVec, IntGauge, IntGaugeVec, UIntGauge, UIntGaugeVec,
+    register_counter_vec, register_gauge_vec, register_histogram, register_histogram_vec,
+    register_int_counter, register_int_counter_vec, register_int_gauge, register_int_gauge_vec,
+    register_uint_gauge, register_uint_gauge_vec, Counter, CounterVec, GaugeVec, Histogram,
+    HistogramVec, IntCounter, IntCounterVec, IntGauge, IntGaugeVec, UIntGauge, UIntGaugeVec,
 };
 use once_cell::sync::Lazy;
-use pageserver_api::models::TenantState;
 use strum::VariantNames;
 use strum_macros::{EnumVariantNames, IntoStaticStr};
 use utils::id::{TenantId, TimelineId};
@@ -74,7 +73,7 @@ pub static STORAGE_TIME_COUNT_PER_TIMELINE: Lazy<IntCounterVec> = Lazy::new(|| {
 // Buckets for background operations like compaction, GC, size calculation
 const STORAGE_OP_BUCKETS: &[f64] = &[0.010, 0.100, 1.0, 10.0, 100.0, 1000.0];
 
-pub static STORAGE_TIME_GLOBAL: Lazy<HistogramVec> = Lazy::new(|| {
+pub(crate) static STORAGE_TIME_GLOBAL: Lazy<HistogramVec> = Lazy::new(|| {
     register_histogram_vec!(
         "pageserver_storage_operations_seconds_global",
         "Time spent on storage operations",
@@ -84,18 +83,17 @@ pub static STORAGE_TIME_GLOBAL: Lazy<HistogramVec> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-static READ_NUM_FS_LAYERS: Lazy<HistogramVec> = Lazy::new(|| {
-    register_histogram_vec!(
+pub(crate) static READ_NUM_FS_LAYERS: Lazy<Histogram> = Lazy::new(|| {
+    register_histogram!(
         "pageserver_read_num_fs_layers",
         "Number of persistent layers accessed for processing a read request, including those in the cache",
-        &["tenant_id", "timeline_id"],
         vec![1.0, 2.0, 3.0, 4.0, 5.0, 6.0, 10.0, 20.0, 50.0, 100.0],
     )
     .expect("failed to define a metric")
 });
 
 // Metrics collected on operations on the storage repository.
-pub static RECONSTRUCT_TIME: Lazy<Histogram> = Lazy::new(|| {
+pub(crate) static RECONSTRUCT_TIME: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "pageserver_getpage_reconstruct_seconds",
         "Time spent in reconstruct_value (reconstruct a page from deltas)",
@@ -104,7 +102,7 @@ pub static RECONSTRUCT_TIME: Lazy<Histogram> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static MATERIALIZED_PAGE_CACHE_HIT_DIRECT: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static MATERIALIZED_PAGE_CACHE_HIT_DIRECT: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_materialized_cache_hits_direct_total",
         "Number of cache hits from materialized page cache without redo",
@@ -112,17 +110,16 @@ pub static MATERIALIZED_PAGE_CACHE_HIT_DIRECT: Lazy<IntCounter> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-static GET_RECONSTRUCT_DATA_TIME: Lazy<HistogramVec> = Lazy::new(|| {
-    register_histogram_vec!(
+pub(crate) static GET_RECONSTRUCT_DATA_TIME: Lazy<Histogram> = Lazy::new(|| {
+    register_histogram!(
         "pageserver_getpage_get_reconstruct_data_seconds",
         "Time spent in get_reconstruct_value_data",
-        &["tenant_id", "timeline_id"],
         CRITICAL_OP_BUCKETS.into(),
     )
     .expect("failed to define a metric")
 });
 
-pub static MATERIALIZED_PAGE_CACHE_HIT: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static MATERIALIZED_PAGE_CACHE_HIT: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_materialized_cache_hits_total",
         "Number of cache hits from materialized page cache",
@@ -246,11 +243,10 @@ pub static PAGE_CACHE_SIZE: Lazy<PageCacheSizeMetrics> = Lazy::new(|| PageCacheS
     },
 });
 
-static WAIT_LSN_TIME: Lazy<HistogramVec> = Lazy::new(|| {
-    register_histogram_vec!(
+pub(crate) static WAIT_LSN_TIME: Lazy<Histogram> = Lazy::new(|| {
+    register_histogram!(
         "pageserver_wait_lsn_seconds",
         "Time spent waiting for WAL to arrive",
-        &["tenant_id", "timeline_id"],
         CRITICAL_OP_BUCKETS.into(),
     )
     .expect("failed to define a metric")
@@ -284,7 +280,7 @@ static REMOTE_PHYSICAL_SIZE: Lazy<UIntGaugeVec> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static REMOTE_ONDEMAND_DOWNLOADED_LAYERS: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static REMOTE_ONDEMAND_DOWNLOADED_LAYERS: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_remote_ondemand_downloaded_layers_total",
         "Total on-demand downloaded layers"
@@ -292,7 +288,7 @@ pub static REMOTE_ONDEMAND_DOWNLOADED_LAYERS: Lazy<IntCounter> = Lazy::new(|| {
     .unwrap()
 });
 
-pub static REMOTE_ONDEMAND_DOWNLOADED_BYTES: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static REMOTE_ONDEMAND_DOWNLOADED_BYTES: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_remote_ondemand_downloaded_bytes_total",
         "Total bytes of layers on-demand downloaded",
@@ -309,16 +305,29 @@ static CURRENT_LOGICAL_SIZE: Lazy<UIntGaugeVec> = Lazy::new(|| {
     .expect("failed to define current logical size metric")
 });
 
-pub static TENANT_STATE_METRIC: Lazy<UIntGaugeVec> = Lazy::new(|| {
+pub(crate) static TENANT_STATE_METRIC: Lazy<UIntGaugeVec> = Lazy::new(|| {
     register_uint_gauge_vec!(
         "pageserver_tenant_states_count",
         "Count of tenants per state",
-        &["tenant_id", "state"]
+        &["state"]
     )
     .expect("Failed to register pageserver_tenant_states_count metric")
 });
 
-pub static TENANT_SYNTHETIC_SIZE_METRIC: Lazy<UIntGaugeVec> = Lazy::new(|| {
+/// A set of broken tenants.
+///
+/// These are expected to be so rare that a set is fine. Set as in a new timeseries per each broken
+/// tenant.
+pub(crate) static BROKEN_TENANTS_SET: Lazy<UIntGaugeVec> = Lazy::new(|| {
+    register_uint_gauge_vec!(
+        "pageserver_broken_tenants_count",
+        "Set of broken tenants",
+        &["tenant_id"]
+    )
+    .expect("Failed to register pageserver_tenant_states_count metric")
+});
+
+pub(crate) static TENANT_SYNTHETIC_SIZE_METRIC: Lazy<UIntGaugeVec> = Lazy::new(|| {
     register_uint_gauge_vec!(
         "pageserver_tenant_synthetic_cached_size_bytes",
         "Synthetic size of each tenant in bytes",
@@ -376,7 +385,7 @@ static EVICTIONS_WITH_LOW_RESIDENCE_DURATION: Lazy<IntCounterVec> = Lazy::new(||
     .expect("failed to define a metric")
 });
 
-pub static UNEXPECTED_ONDEMAND_DOWNLOADS: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static UNEXPECTED_ONDEMAND_DOWNLOADS: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_unexpected_ondemand_downloads_count",
         "Number of unexpected on-demand downloads. \
@@ -385,6 +394,35 @@ pub static UNEXPECTED_ONDEMAND_DOWNLOADS: Lazy<IntCounter> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
+/// How long did we take to start up?  Broken down by labels to describe
+/// different phases of startup.
+pub static STARTUP_DURATION: Lazy<GaugeVec> = Lazy::new(|| {
+    register_gauge_vec!(
+        "pageserver_startup_duration_seconds",
+        "Time taken by phases of pageserver startup, in seconds",
+        &["phase"]
+    )
+    .expect("Failed to register pageserver_startup_duration_seconds metric")
+});
+
+pub static STARTUP_IS_LOADING: Lazy<UIntGauge> = Lazy::new(|| {
+    register_uint_gauge!(
+        "pageserver_startup_is_loading",
+        "1 while in initial startup load of tenants, 0 at other times"
+    )
+    .expect("Failed to register pageserver_startup_is_loading")
+});
+
+/// How long did tenants take to go from construction to active state?
+pub(crate) static TENANT_ACTIVATION: Lazy<Histogram> = Lazy::new(|| {
+    register_histogram!(
+        "pageserver_tenant_activation_seconds",
+        "Time taken by tenants to activate, in seconds",
+        CRITICAL_OP_BUCKETS.into()
+    )
+    .expect("Failed to register pageserver_tenant_activation_seconds metric")
+});
+
 /// Each `Timeline`'s  [`EVICTIONS_WITH_LOW_RESIDENCE_DURATION`] metric.
 #[derive(Debug)]
 pub struct EvictionsWithLowResidenceDuration {
@@ -499,23 +537,31 @@ const STORAGE_IO_TIME_BUCKETS: &[f64] = &[
     30.000,   // 30000 ms
 ];
 
-const STORAGE_IO_TIME_OPERATIONS: &[&str] = &[
-    "open", "close", "read", "write", "seek", "fsync", "gc", "metadata",
-];
-
-const STORAGE_IO_SIZE_OPERATIONS: &[&str] = &["read", "write"];
-
-pub static STORAGE_IO_TIME: Lazy<HistogramVec> = Lazy::new(|| {
+/// Tracks time taken by fs operations near VirtualFile.
+///
+/// Operations:
+/// - open ([`std::fs::OpenOptions::open`])
+/// - close (dropping [`std::fs::File`])
+/// - close-by-replace (close by replacement algorithm)
+/// - read (`read_at`)
+/// - write (`write_at`)
+/// - seek (modify internal position or file length query)
+/// - fsync ([`std::fs::File::sync_all`])
+/// - metadata ([`std::fs::File::metadata`])
+pub(crate) static STORAGE_IO_TIME: Lazy<HistogramVec> = Lazy::new(|| {
     register_histogram_vec!(
         "pageserver_io_operations_seconds",
         "Time spent in IO operations",
-        &["operation", "tenant_id", "timeline_id"],
+        &["operation"],
         STORAGE_IO_TIME_BUCKETS.into()
     )
     .expect("failed to define a metric")
 });
 
-pub static STORAGE_IO_SIZE: Lazy<IntGaugeVec> = Lazy::new(|| {
+const STORAGE_IO_SIZE_OPERATIONS: &[&str] = &["read", "write"];
+
+// Needed for the https://neonprod.grafana.net/d/5uK9tHL4k/picking-tenant-for-relocation?orgId=1
+pub(crate) static STORAGE_IO_SIZE: Lazy<IntGaugeVec> = Lazy::new(|| {
     register_int_gauge_vec!(
         "pageserver_io_operations_bytes_total",
         "Total amount of bytes read/written in IO operations",
@@ -605,7 +651,7 @@ static REMOTE_TIMELINE_CLIENT_CALLS_STARTED_HIST: Lazy<HistogramVec> = Lazy::new
          at a given instant. It gives you a better idea of the queue depth \
          than plotting the gauge directly, since operations may complete faster \
          than the sampling interval.",
-        &["tenant_id", "timeline_id", "file_kind", "op_kind"],
+        &["file_kind", "op_kind"],
         // The calls_unfinished gauge is an integer gauge, hence we have integer buckets.
         vec![0.0, 1.0, 2.0, 4.0, 6.0, 8.0, 10.0, 15.0, 20.0, 40.0, 60.0, 80.0, 100.0, 500.0],
     )
@@ -662,18 +708,18 @@ impl RemoteOpFileKind {
     }
 }
 
-pub static REMOTE_OPERATION_TIME: Lazy<HistogramVec> = Lazy::new(|| {
+pub(crate) static REMOTE_OPERATION_TIME: Lazy<HistogramVec> = Lazy::new(|| {
     register_histogram_vec!(
         "pageserver_remote_operation_seconds",
         "Time spent on remote storage operations. \
         Grouped by tenant, timeline, operation_kind and status. \
         Does not account for time spent waiting in remote timeline client's queues.",
-        &["tenant_id", "timeline_id", "file_kind", "op_kind", "status"]
+        &["file_kind", "op_kind", "status"]
     )
     .expect("failed to define a metric")
 });
 
-pub static TENANT_TASK_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
+pub(crate) static TENANT_TASK_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
         "pageserver_tenant_task_events",
         "Number of task start/stop/fail events.",
@@ -682,7 +728,7 @@ pub static TENANT_TASK_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
     .expect("Failed to register tenant_task_events metric")
 });
 
-pub static BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT: Lazy<IntCounterVec> = Lazy::new(|| {
+pub(crate) static BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
         "pageserver_background_loop_period_overrun_count",
         "Incremented whenever warn_when_period_overrun() logs a warning.",
@@ -693,7 +739,7 @@ pub static BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT: Lazy<IntCounterVec> = Lazy::new
 
 // walreceiver metrics
 
-pub static WALRECEIVER_STARTED_CONNECTIONS: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static WALRECEIVER_STARTED_CONNECTIONS: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_walreceiver_started_connections_total",
         "Number of started walreceiver connections"
@@ -701,7 +747,7 @@ pub static WALRECEIVER_STARTED_CONNECTIONS: Lazy<IntCounter> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WALRECEIVER_ACTIVE_MANAGERS: Lazy<IntGauge> = Lazy::new(|| {
+pub(crate) static WALRECEIVER_ACTIVE_MANAGERS: Lazy<IntGauge> = Lazy::new(|| {
     register_int_gauge!(
         "pageserver_walreceiver_active_managers",
         "Number of active walreceiver managers"
@@ -709,7 +755,7 @@ pub static WALRECEIVER_ACTIVE_MANAGERS: Lazy<IntGauge> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WALRECEIVER_SWITCHES: Lazy<IntCounterVec> = Lazy::new(|| {
+pub(crate) static WALRECEIVER_SWITCHES: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
         "pageserver_walreceiver_switches_total",
         "Number of walreceiver manager change_connection calls",
@@ -718,7 +764,7 @@ pub static WALRECEIVER_SWITCHES: Lazy<IntCounterVec> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WALRECEIVER_BROKER_UPDATES: Lazy<IntCounter> = Lazy::new(|| {
+pub(crate) static WALRECEIVER_BROKER_UPDATES: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_walreceiver_broker_updates_total",
         "Number of received broker updates in walreceiver"
@@ -726,7 +772,7 @@ pub static WALRECEIVER_BROKER_UPDATES: Lazy<IntCounter> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WALRECEIVER_CANDIDATES_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
+pub(crate) static WALRECEIVER_CANDIDATES_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
     register_int_counter_vec!(
         "pageserver_walreceiver_candidates_events_total",
         "Number of walreceiver candidate events",
@@ -735,10 +781,10 @@ pub static WALRECEIVER_CANDIDATES_EVENTS: Lazy<IntCounterVec> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WALRECEIVER_CANDIDATES_ADDED: Lazy<IntCounter> =
+pub(crate) static WALRECEIVER_CANDIDATES_ADDED: Lazy<IntCounter> =
     Lazy::new(|| WALRECEIVER_CANDIDATES_EVENTS.with_label_values(&["add"]));
 
-pub static WALRECEIVER_CANDIDATES_REMOVED: Lazy<IntCounter> =
+pub(crate) static WALRECEIVER_CANDIDATES_REMOVED: Lazy<IntCounter> =
     Lazy::new(|| WALRECEIVER_CANDIDATES_EVENTS.with_label_values(&["remove"]));
 
 // Metrics collected on WAL redo operations
@@ -785,7 +831,7 @@ macro_rules! redo_bytes_histogram_count_buckets {
     };
 }
 
-pub static WAL_REDO_TIME: Lazy<Histogram> = Lazy::new(|| {
+pub(crate) static WAL_REDO_TIME: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "pageserver_wal_redo_seconds",
         "Time spent on WAL redo",
@@ -794,7 +840,7 @@ pub static WAL_REDO_TIME: Lazy<Histogram> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WAL_REDO_WAIT_TIME: Lazy<Histogram> = Lazy::new(|| {
+pub(crate) static WAL_REDO_WAIT_TIME: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "pageserver_wal_redo_wait_seconds",
         "Time spent waiting for access to the Postgres WAL redo process",
@@ -803,7 +849,7 @@ pub static WAL_REDO_WAIT_TIME: Lazy<Histogram> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WAL_REDO_RECORDS_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
+pub(crate) static WAL_REDO_RECORDS_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "pageserver_wal_redo_records_histogram",
         "Histogram of number of records replayed per redo in the Postgres WAL redo process",
@@ -812,7 +858,7 @@ pub static WAL_REDO_RECORDS_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WAL_REDO_BYTES_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
+pub(crate) static WAL_REDO_BYTES_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
     register_histogram!(
         "pageserver_wal_redo_bytes_histogram",
         "Histogram of number of records replayed per redo sent to Postgres",
@@ -821,7 +867,8 @@ pub static WAL_REDO_BYTES_HISTOGRAM: Lazy<Histogram> = Lazy::new(|| {
     .expect("failed to define a metric")
 });
 
-pub static WAL_REDO_RECORD_COUNTER: Lazy<IntCounter> = Lazy::new(|| {
+// FIXME: isn't this already included by WAL_REDO_RECORDS_HISTOGRAM which has _count?
+pub(crate) static WAL_REDO_RECORD_COUNTER: Lazy<IntCounter> = Lazy::new(|| {
     register_int_counter!(
         "pageserver_replayed_wal_records_total",
         "Number of WAL records replayed in WAL redo process"
@@ -897,7 +944,6 @@ impl StorageTimeMetrics {
 pub struct TimelineMetrics {
     tenant_id: String,
     timeline_id: String,
-    pub get_reconstruct_data_time_histo: Histogram,
     pub flush_time_histo: StorageTimeMetrics,
     pub compact_time_histo: StorageTimeMetrics,
     pub create_images_time_histo: StorageTimeMetrics,
@@ -906,9 +952,7 @@ pub struct TimelineMetrics {
     pub load_layer_map_histo: StorageTimeMetrics,
     pub garbage_collect_histo: StorageTimeMetrics,
     pub last_record_gauge: IntGauge,
-    pub wait_lsn_time_histo: Histogram,
     pub resident_physical_size_gauge: UIntGauge,
-    pub read_num_fs_layers: Histogram,
     /// copy of LayeredTimeline.current_logical_size
     pub current_logical_size_gauge: UIntGauge,
     pub num_persistent_files_created: IntCounter,
@@ -925,9 +969,6 @@ impl TimelineMetrics {
     ) -> Self {
         let tenant_id = tenant_id.to_string();
         let timeline_id = timeline_id.to_string();
-        let get_reconstruct_data_time_histo = GET_RECONSTRUCT_DATA_TIME
-            .get_metric_with_label_values(&[&tenant_id, &timeline_id])
-            .unwrap();
         let flush_time_histo =
             StorageTimeMetrics::new(StorageTimeOperation::LayerFlush, &tenant_id, &timeline_id);
         let compact_time_histo =
@@ -948,9 +989,6 @@ impl TimelineMetrics {
         let last_record_gauge = LAST_RECORD_LSN
             .get_metric_with_label_values(&[&tenant_id, &timeline_id])
             .unwrap();
-        let wait_lsn_time_histo = WAIT_LSN_TIME
-            .get_metric_with_label_values(&[&tenant_id, &timeline_id])
-            .unwrap();
         let resident_physical_size_gauge = RESIDENT_PHYSICAL_SIZE
             .get_metric_with_label_values(&[&tenant_id, &timeline_id])
             .unwrap();
@@ -966,16 +1004,12 @@ impl TimelineMetrics {
         let evictions = EVICTIONS
             .get_metric_with_label_values(&[&tenant_id, &timeline_id])
             .unwrap();
-        let read_num_fs_layers = READ_NUM_FS_LAYERS
-            .get_metric_with_label_values(&[&tenant_id, &timeline_id])
-            .unwrap();
         let evictions_with_low_residence_duration =
             evictions_with_low_residence_duration_builder.build(&tenant_id, &timeline_id);
 
         TimelineMetrics {
             tenant_id,
             timeline_id,
-            get_reconstruct_data_time_histo,
             flush_time_histo,
             compact_time_histo,
             create_images_time_histo,
@@ -984,7 +1018,6 @@ impl TimelineMetrics {
             garbage_collect_histo,
             load_layer_map_histo,
             last_record_gauge,
-            wait_lsn_time_histo,
             resident_physical_size_gauge,
             current_logical_size_gauge,
             num_persistent_files_created,
@@ -993,7 +1026,6 @@ impl TimelineMetrics {
             evictions_with_low_residence_duration: std::sync::RwLock::new(
                 evictions_with_low_residence_duration,
             ),
-            read_num_fs_layers,
         }
     }
 }
@@ -1002,15 +1034,12 @@ impl Drop for TimelineMetrics {
     fn drop(&mut self) {
         let tenant_id = &self.tenant_id;
         let timeline_id = &self.timeline_id;
-        let _ = GET_RECONSTRUCT_DATA_TIME.remove_label_values(&[tenant_id, timeline_id]);
         let _ = LAST_RECORD_LSN.remove_label_values(&[tenant_id, timeline_id]);
-        let _ = WAIT_LSN_TIME.remove_label_values(&[tenant_id, timeline_id]);
         let _ = RESIDENT_PHYSICAL_SIZE.remove_label_values(&[tenant_id, timeline_id]);
         let _ = CURRENT_LOGICAL_SIZE.remove_label_values(&[tenant_id, timeline_id]);
         let _ = NUM_PERSISTENT_FILES_CREATED.remove_label_values(&[tenant_id, timeline_id]);
         let _ = PERSISTENT_BYTES_WRITTEN.remove_label_values(&[tenant_id, timeline_id]);
         let _ = EVICTIONS.remove_label_values(&[tenant_id, timeline_id]);
-        let _ = READ_NUM_FS_LAYERS.remove_label_values(&[tenant_id, timeline_id]);
 
         self.evictions_with_low_residence_duration
             .write()
@@ -1022,9 +1051,6 @@ impl Drop for TimelineMetrics {
             let _ =
                 STORAGE_TIME_COUNT_PER_TIMELINE.remove_label_values(&[op, tenant_id, timeline_id]);
         }
-        for op in STORAGE_IO_TIME_OPERATIONS {
-            let _ = STORAGE_IO_TIME.remove_label_values(&[op, tenant_id, timeline_id]);
-        }
 
         for op in STORAGE_IO_SIZE_OPERATIONS {
             let _ = STORAGE_IO_SIZE.remove_label_values(&[op, tenant_id, timeline_id]);
@@ -1039,9 +1065,7 @@ impl Drop for TimelineMetrics {
 pub fn remove_tenant_metrics(tenant_id: &TenantId) {
     let tid = tenant_id.to_string();
     let _ = TENANT_SYNTHETIC_SIZE_METRIC.remove_label_values(&[&tid]);
-    for state in TenantState::VARIANTS {
-        let _ = TENANT_STATE_METRIC.remove_label_values(&[&tid, state]);
-    }
+    // we leave the BROKEN_TENANTS_SET entry if any
 }
 
 use futures::Future;
@@ -1056,9 +1080,7 @@ pub struct RemoteTimelineClientMetrics {
     tenant_id: String,
     timeline_id: String,
     remote_physical_size_gauge: Mutex<Option<UIntGauge>>,
-    remote_operation_time: Mutex<HashMap<(&'static str, &'static str, &'static str), Histogram>>,
     calls_unfinished_gauge: Mutex<HashMap<(&'static str, &'static str), IntGauge>>,
-    calls_started_hist: Mutex<HashMap<(&'static str, &'static str), Histogram>>,
     bytes_started_counter: Mutex<HashMap<(&'static str, &'static str), IntCounter>>,
     bytes_finished_counter: Mutex<HashMap<(&'static str, &'static str), IntCounter>>,
 }
@@ -1068,14 +1090,13 @@ impl RemoteTimelineClientMetrics {
         RemoteTimelineClientMetrics {
             tenant_id: tenant_id.to_string(),
             timeline_id: timeline_id.to_string(),
-            remote_operation_time: Mutex::new(HashMap::default()),
             calls_unfinished_gauge: Mutex::new(HashMap::default()),
-            calls_started_hist: Mutex::new(HashMap::default()),
             bytes_started_counter: Mutex::new(HashMap::default()),
             bytes_finished_counter: Mutex::new(HashMap::default()),
             remote_physical_size_gauge: Mutex::new(None),
         }
     }
+
     pub fn remote_physical_size_gauge(&self) -> UIntGauge {
         let mut guard = self.remote_physical_size_gauge.lock().unwrap();
         guard
@@ -1089,26 +1110,17 @@ impl RemoteTimelineClientMetrics {
             })
             .clone()
     }
+
     pub fn remote_operation_time(
         &self,
         file_kind: &RemoteOpFileKind,
         op_kind: &RemoteOpKind,
         status: &'static str,
     ) -> Histogram {
-        let mut guard = self.remote_operation_time.lock().unwrap();
         let key = (file_kind.as_str(), op_kind.as_str(), status);
-        let metric = guard.entry(key).or_insert_with(move || {
-            REMOTE_OPERATION_TIME
-                .get_metric_with_label_values(&[
-                    &self.tenant_id.to_string(),
-                    &self.timeline_id.to_string(),
-                    key.0,
-                    key.1,
-                    key.2,
-                ])
-                .unwrap()
-        });
-        metric.clone()
+        REMOTE_OPERATION_TIME
+            .get_metric_with_label_values(&[key.0, key.1, key.2])
+            .unwrap()
     }
 
     fn calls_unfinished_gauge(
@@ -1136,19 +1148,10 @@ impl RemoteTimelineClientMetrics {
         file_kind: &RemoteOpFileKind,
         op_kind: &RemoteOpKind,
     ) -> Histogram {
-        let mut guard = self.calls_started_hist.lock().unwrap();
         let key = (file_kind.as_str(), op_kind.as_str());
-        let metric = guard.entry(key).or_insert_with(move || {
-            REMOTE_TIMELINE_CLIENT_CALLS_STARTED_HIST
-                .get_metric_with_label_values(&[
-                    &self.tenant_id.to_string(),
-                    &self.timeline_id.to_string(),
-                    key.0,
-                    key.1,
-                ])
-                .unwrap()
-        });
-        metric.clone()
+        REMOTE_TIMELINE_CLIENT_CALLS_STARTED_HIST
+            .get_metric_with_label_values(&[key.0, key.1])
+            .unwrap()
     }
 
     fn bytes_started_counter(
@@ -1328,15 +1331,10 @@ impl Drop for RemoteTimelineClientMetrics {
             tenant_id,
             timeline_id,
             remote_physical_size_gauge,
-            remote_operation_time,
             calls_unfinished_gauge,
-            calls_started_hist,
             bytes_started_counter,
             bytes_finished_counter,
         } = self;
-        for ((a, b, c), _) in remote_operation_time.get_mut().unwrap().drain() {
-            let _ = REMOTE_OPERATION_TIME.remove_label_values(&[tenant_id, timeline_id, a, b, c]);
-        }
         for ((a, b), _) in calls_unfinished_gauge.get_mut().unwrap().drain() {
             let _ = REMOTE_TIMELINE_CLIENT_CALLS_UNFINISHED_GAUGE.remove_label_values(&[
                 tenant_id,
@@ -1345,14 +1343,6 @@ impl Drop for RemoteTimelineClientMetrics {
                 b,
             ]);
         }
-        for ((a, b), _) in calls_started_hist.get_mut().unwrap().drain() {
-            let _ = REMOTE_TIMELINE_CLIENT_CALLS_STARTED_HIST.remove_label_values(&[
-                tenant_id,
-                timeline_id,
-                a,
-                b,
-            ]);
-        }
         for ((a, b), _) in bytes_started_counter.get_mut().unwrap().drain() {
             let _ = REMOTE_TIMELINE_CLIENT_BYTES_STARTED_COUNTER.remove_label_values(&[
                 tenant_id,
@@ -1434,15 +1424,51 @@ impl<F: Future<Output = Result<O, E>>, O, E> Future for MeasuredRemoteOp<F> {
 }
 
 pub fn preinitialize_metrics() {
-    // We want to alert on this metric increasing.
-    // Initialize it eagerly, so that our alert rule can distinguish absence of the metric from metric value 0.
-    assert_eq!(UNEXPECTED_ONDEMAND_DOWNLOADS.get(), 0);
-    UNEXPECTED_ONDEMAND_DOWNLOADS.reset();
+    // Python tests need these and on some we do alerting.
+    //
+    // FIXME(4813): make it so that we have no top level metrics as this fn will easily fall out of
+    // order:
+    // - global metrics reside in a Lazy<PageserverMetrics>
+    //   - access via crate::metrics::PS_METRICS.materialized_page_cache_hit.inc()
+    // - could move the statics into TimelineMetrics::new()?
 
-    // Same as above for this metric, but, it's a Vec-type metric for which we don't know all the labels.
-    BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT.reset();
+    // counters
+    [
+        &MATERIALIZED_PAGE_CACHE_HIT,
+        &MATERIALIZED_PAGE_CACHE_HIT_DIRECT,
+        &UNEXPECTED_ONDEMAND_DOWNLOADS,
+        &WALRECEIVER_STARTED_CONNECTIONS,
+        &WALRECEIVER_BROKER_UPDATES,
+        &WALRECEIVER_CANDIDATES_ADDED,
+        &WALRECEIVER_CANDIDATES_REMOVED,
+    ]
+    .into_iter()
+    .for_each(|c| {
+        Lazy::force(c);
+    });
 
-    // Python tests need these.
-    MATERIALIZED_PAGE_CACHE_HIT_DIRECT.get();
-    MATERIALIZED_PAGE_CACHE_HIT.get();
+    // countervecs
+    [&BACKGROUND_LOOP_PERIOD_OVERRUN_COUNT]
+        .into_iter()
+        .for_each(|c| {
+            Lazy::force(c);
+        });
+
+    // gauges
+    WALRECEIVER_ACTIVE_MANAGERS.get();
+
+    // histograms
+    [
+        &READ_NUM_FS_LAYERS,
+        &RECONSTRUCT_TIME,
+        &WAIT_LSN_TIME,
+        &WAL_REDO_TIME,
+        &WAL_REDO_WAIT_TIME,
+        &WAL_REDO_RECORDS_HISTOGRAM,
+        &WAL_REDO_BYTES_HISTOGRAM,
+    ]
+    .into_iter()
+    .for_each(|h| {
+        Lazy::force(h);
+    });
 }

pageserver/src/task_mgr.rs

@@ -130,11 +130,25 @@ pub static WALRECEIVER_RUNTIME: Lazy<Runtime> = Lazy::new(|| {
 pub static BACKGROUND_RUNTIME: Lazy<Runtime> = Lazy::new(|| {
     tokio::runtime::Builder::new_multi_thread()
         .thread_name("background op worker")
+        // if you change the number of worker threads please change the constant below
         .enable_all()
         .build()
         .expect("Failed to create background op runtime")
 });
 
+pub(crate) static BACKGROUND_RUNTIME_WORKER_THREADS: Lazy<usize> = Lazy::new(|| {
+    // force init and thus panics
+    let _ = BACKGROUND_RUNTIME.handle();
+    // replicates tokio-1.28.1::loom::sys::num_cpus which is not available publicly
+    // tokio would had already panicked for parsing errors or NotUnicode
+    //
+    // this will be wrong if any of the runtimes gets their worker threads configured to something
+    // else, but that has not been needed in a long time.
+    std::env::var("TOKIO_WORKER_THREADS")
+        .map(|s| s.parse::<usize>().unwrap())
+        .unwrap_or_else(|_e| usize::max(1, num_cpus::get()))
+});
+
 #[derive(Debug, Clone, Copy)]
 pub struct PageserverTaskId(u64);
 
@@ -545,7 +559,7 @@ pub fn current_task_id() -> Option<PageserverTaskId> {
 pub async fn shutdown_watcher() {
     let token = SHUTDOWN_TOKEN
         .try_with(|t| t.clone())
-        .expect("shutdown_requested() called in an unexpected task or thread");
+        .expect("shutdown_watcher() called in an unexpected task or thread");
 
     token.cancelled().await;
 }

pageserver/src/tenant/blob_io.rs

@@ -16,30 +16,20 @@ use crate::tenant::block_io::{BlockCursor, BlockReader};
 use std::cmp::min;
 use std::io::{Error, ErrorKind};
 
-/// For reading
-pub trait BlobCursor {
-    /// Read a blob into a new buffer.
-    fn read_blob(&mut self, offset: u64) -> Result<Vec<u8>, std::io::Error> {
-        let mut buf = Vec::new();
-        self.read_blob_into_buf(offset, &mut buf)?;
-        Ok(buf)
-    }
-
-    /// Read blob into the given buffer. Any previous contents in the buffer
-    /// are overwritten.
-    fn read_blob_into_buf(
-        &mut self,
-        offset: u64,
-        dstbuf: &mut Vec<u8>,
-    ) -> Result<(), std::io::Error>;
-}
-
-impl<R> BlobCursor for BlockCursor<R>
+impl<R> BlockCursor<R>
 where
     R: BlockReader,
 {
-    fn read_blob_into_buf(
-        &mut self,
+    /// Read a blob into a new buffer.
+    pub async fn read_blob(&self, offset: u64) -> Result<Vec<u8>, std::io::Error> {
+        let mut buf = Vec::new();
+        self.read_blob_into_buf(offset, &mut buf).await?;
+        Ok(buf)
+    }
+    /// Read blob into the given buffer. Any previous contents in the buffer
+    /// are overwritten.
+    pub async fn read_blob_into_buf(
+        &self,
         offset: u64,
         dstbuf: &mut Vec<u8>,
     ) -> Result<(), std::io::Error> {

pageserver/src/tenant/block_io.rs

@@ -2,8 +2,7 @@
 //! Low-level Block-oriented I/O functions
 //!
 
-use crate::page_cache;
-use crate::page_cache::{ReadBufResult, PAGE_SZ};
+use crate::page_cache::{self, PageReadGuard, ReadBufResult, PAGE_SZ};
 use bytes::Bytes;
 use std::ops::{Deref, DerefMut};
 use std::os::unix::fs::FileExt;
@@ -15,14 +14,12 @@ use std::sync::atomic::AtomicU64;
 /// There are currently two implementations: EphemeralFile, and FileBlockReader
 /// below.
 pub trait BlockReader {
-    type BlockLease: Deref<Target = [u8; PAGE_SZ]> + 'static;
-
     ///
     /// Read a block. Returns a "lease" object that can be used to
     /// access to the contents of the page. (For the page cache, the
     /// lease object represents a lock on the buffer.)
     ///
-    fn read_blk(&self, blknum: u32) -> Result<Self::BlockLease, std::io::Error>;
+    fn read_blk(&self, blknum: u32) -> Result<BlockLease, std::io::Error>;
 
     ///
     /// Create a new "cursor" for reading from this reader.
@@ -41,13 +38,48 @@ impl<B> BlockReader for &B
 where
     B: BlockReader,
 {
-    type BlockLease = B::BlockLease;
-
-    fn read_blk(&self, blknum: u32) -> Result<Self::BlockLease, std::io::Error> {
+    fn read_blk(&self, blknum: u32) -> Result<BlockLease, std::io::Error> {
         (*self).read_blk(blknum)
     }
 }
 
+/// A block accessible for reading
+///
+/// During builds with `#[cfg(test)]`, this is a proper enum
+/// with two variants to support testing code. During normal
+/// builds, it just has one variant and is thus a cheap newtype
+/// wrapper of [`PageReadGuard`]
+pub enum BlockLease {
+    PageReadGuard(PageReadGuard<'static>),
+    #[cfg(test)]
+    Rc(std::rc::Rc<[u8; PAGE_SZ]>),
+}
+
+impl From<PageReadGuard<'static>> for BlockLease {
+    fn from(value: PageReadGuard<'static>) -> Self {
+        BlockLease::PageReadGuard(value)
+    }
+}
+
+#[cfg(test)]
+impl From<std::rc::Rc<[u8; PAGE_SZ]>> for BlockLease {
+    fn from(value: std::rc::Rc<[u8; PAGE_SZ]>) -> Self {
+        BlockLease::Rc(value)
+    }
+}
+
+impl Deref for BlockLease {
+    type Target = [u8; PAGE_SZ];
+
+    fn deref(&self) -> &Self::Target {
+        match self {
+            BlockLease::PageReadGuard(v) => v.deref(),
+            #[cfg(test)]
+            BlockLease::Rc(v) => v.deref(),
+        }
+    }
+}
+
 ///
 /// A "cursor" for efficiently reading multiple pages from a BlockReader
 ///
@@ -80,7 +112,7 @@ where
         BlockCursor { reader }
     }
 
-    pub fn read_blk(&mut self, blknum: u32) -> Result<R::BlockLease, std::io::Error> {
+    pub fn read_blk(&self, blknum: u32) -> Result<BlockLease, std::io::Error> {
         self.reader.read_blk(blknum)
     }
 }
@@ -118,9 +150,7 @@ impl<F> BlockReader for FileBlockReader<F>
 where
     F: FileExt,
 {
-    type BlockLease = page_cache::PageReadGuard<'static>;
-
-    fn read_blk(&self, blknum: u32) -> Result<Self::BlockLease, std::io::Error> {
+    fn read_blk(&self, blknum: u32) -> Result<BlockLease, std::io::Error> {
         // Look up the right page
         let cache = page_cache::get();
         loop {
@@ -132,7 +162,7 @@ where
                         format!("Failed to read immutable buf: {e:#}"),
                     )
                 })? {
-                ReadBufResult::Found(guard) => break Ok(guard),
+                ReadBufResult::Found(guard) => break Ok(guard.into()),
                 ReadBufResult::NotFound(mut write_guard) => {
                     // Read the page from disk into the buffer
                     self.fill_buffer(write_guard.deref_mut(), blknum)?;

pageserver/src/tenant/delete.rs

@@ -0,0 +1,559 @@
+use std::{
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+
+use anyhow::Context;
+use pageserver_api::models::TenantState;
+use remote_storage::{DownloadError, GenericRemoteStorage, RemotePath};
+use tokio::sync::OwnedMutexGuard;
+use tracing::{error, info, instrument, warn, Instrument, Span};
+
+use utils::{
+    backoff, completion, crashsafe, fs_ext,
+    id::{TenantId, TimelineId},
+};
+
+use crate::{
+    config::PageServerConf,
+    context::RequestContext,
+    task_mgr::{self, TaskKind},
+    InitializationOrder,
+};
+
+use super::{
+    mgr::{GetTenantError, TenantsMap},
+    remote_timeline_client::{FAILED_REMOTE_OP_RETRIES, FAILED_UPLOAD_WARN_THRESHOLD},
+    span,
+    timeline::delete::DeleteTimelineFlow,
+    tree_sort_timelines, DeleteTimelineError, Tenant,
+};
+
+const SHOULD_RESUME_DELETION_FETCH_MARK_ATTEMPTS: u32 = 3;
+
+#[derive(Debug, thiserror::Error)]
+pub enum DeleteTenantError {
+    #[error("GetTenant {0}")]
+    Get(#[from] GetTenantError),
+
+    #[error("Invalid state {0}. Expected Active or Broken")]
+    InvalidState(TenantState),
+
+    #[error("Tenant deletion is already in progress")]
+    AlreadyInProgress,
+
+    #[error("Timeline {0}")]
+    Timeline(#[from] DeleteTimelineError),
+
+    #[error(transparent)]
+    Other(#[from] anyhow::Error),
+}
+
+type DeletionGuard = tokio::sync::OwnedMutexGuard<DeleteTenantFlow>;
+
+fn remote_tenant_delete_mark_path(
+    conf: &PageServerConf,
+    tenant_id: &TenantId,
+) -> anyhow::Result<RemotePath> {
+    let tenant_remote_path = conf
+        .tenant_path(tenant_id)
+        .strip_prefix(&conf.workdir)
+        .context("Failed to strip workdir prefix")
+        .and_then(RemotePath::new)
+        .context("tenant path")?;
+    Ok(tenant_remote_path.join(Path::new("deleted")))
+}
+
+async fn create_remote_delete_mark(
+    conf: &PageServerConf,
+    remote_storage: &GenericRemoteStorage,
+    tenant_id: &TenantId,
+) -> Result<(), DeleteTenantError> {
+    let remote_mark_path = remote_tenant_delete_mark_path(conf, tenant_id)?;
+
+    let data: &[u8] = &[];
+    backoff::retry(
+        || async {
+            remote_storage
+                .upload(data, 0, &remote_mark_path, None)
+                .await
+        },
+        |_e| false,
+        FAILED_UPLOAD_WARN_THRESHOLD,
+        FAILED_REMOTE_OP_RETRIES,
+        "mark_upload",
+    )
+    .await
+    .context("mark_upload")?;
+
+    Ok(())
+}
+
+async fn create_local_delete_mark(
+    conf: &PageServerConf,
+    tenant_id: &TenantId,
+) -> Result<(), DeleteTenantError> {
+    let marker_path = conf.tenant_deleted_mark_file_path(tenant_id);
+
+    // Note: we're ok to replace existing file.
+    let _ = std::fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(&marker_path)
+        .with_context(|| format!("could not create delete marker file {marker_path:?}"))?;
+
+    crashsafe::fsync_file_and_parent(&marker_path).context("sync_mark")?;
+
+    Ok(())
+}
+
+async fn schedule_ordered_timeline_deletions(
+    tenant: &Arc<Tenant>,
+) -> Result<Vec<(Arc<tokio::sync::Mutex<DeleteTimelineFlow>>, TimelineId)>, DeleteTenantError> {
+    // Tenant is stopping at this point. We know it will be deleted.
+    // No new timelines should be created.
+    // Tree sort timelines to delete from leafs to the root.
+    // NOTE: by calling clone we release the mutex which creates a possibility for a race: pending deletion
+    // can complete and remove timeline from the map in between our call to clone
+    // and `DeleteTimelineFlow::run`, so `run` wont find timeline in `timelines` map.
+    // timelines.lock is currently synchronous so we cant hold it across await point.
+    // So just ignore NotFound error if we get it from `run`.
+    // Beware: in case it becomes async and we try to hold it here, `run` also locks it, which can create a deadlock.
+    let timelines = tenant.timelines.lock().unwrap().clone();
+    let sorted =
+        tree_sort_timelines(timelines, |t| t.get_ancestor_timeline_id()).context("tree sort")?;
+
+    let mut already_running_deletions = vec![];
+
+    for (timeline_id, _) in sorted.into_iter().rev() {
+        if let Err(e) = DeleteTimelineFlow::run(tenant, timeline_id, true).await {
+            match e {
+                DeleteTimelineError::NotFound => {
+                    // Timeline deletion finished after call to clone above but before call
+                    // to `DeleteTimelineFlow::run` and removed timeline from the map.
+                    continue;
+                }
+                DeleteTimelineError::AlreadyInProgress(guard) => {
+                    already_running_deletions.push((guard, timeline_id));
+                    continue;
+                }
+                e => return Err(DeleteTenantError::Timeline(e)),
+            }
+        }
+    }
+
+    Ok(already_running_deletions)
+}
+
+async fn ensure_timelines_dir_empty(timelines_path: &Path) -> Result<(), DeleteTenantError> {
+    // Assert timelines dir is empty.
+    if !fs_ext::is_directory_empty(timelines_path).await? {
+        // Display first 10 items in directory
+        let list = &fs_ext::list_dir(timelines_path).await.context("list_dir")?[..10];
+        return Err(DeleteTenantError::Other(anyhow::anyhow!(
+            "Timelines directory is not empty after all timelines deletion: {list:?}"
+        )));
+    }
+
+    Ok(())
+}
+
+async fn remove_tenant_remote_delete_mark(
+    conf: &PageServerConf,
+    remote_storage: Option<&GenericRemoteStorage>,
+    tenant_id: &TenantId,
+) -> Result<(), DeleteTenantError> {
+    if let Some(remote_storage) = remote_storage {
+        let path = remote_tenant_delete_mark_path(conf, tenant_id)?;
+        backoff::retry(
+            || async { remote_storage.delete(&path).await },
+            |_e| false,
+            FAILED_UPLOAD_WARN_THRESHOLD,
+            FAILED_REMOTE_OP_RETRIES,
+            "remove_tenant_remote_delete_mark",
+        )
+        .await
+        .context("remove_tenant_remote_delete_mark")?;
+    }
+    Ok(())
+}
+
+// Cleanup fs traces: tenant config, timelines dir local delete mark, tenant dir
+async fn cleanup_remaining_fs_traces(
+    conf: &PageServerConf,
+    tenant_id: &TenantId,
+) -> Result<(), DeleteTenantError> {
+    let rm = |p: PathBuf, is_dir: bool| async move {
+        if is_dir {
+            tokio::fs::remove_dir(&p).await
+        } else {
+            tokio::fs::remove_file(&p).await
+        }
+        .or_else(fs_ext::ignore_not_found)
+        .with_context(|| {
+            let to_display = p.display();
+            format!("failed to delete {to_display}")
+        })
+    };
+
+    rm(conf.tenant_config_path(tenant_id), false).await?;
+
+    fail::fail_point!("tenant-delete-before-remove-timelines-dir", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: tenant-delete-before-remove-timelines-dir"
+        ))?
+    });
+
+    rm(conf.timelines_path(tenant_id), true).await?;
+
+    fail::fail_point!("tenant-delete-before-remove-deleted-mark", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: tenant-delete-before-remove-deleted-mark"
+        ))?
+    });
+
+    rm(conf.tenant_deleted_mark_file_path(tenant_id), false).await?;
+
+    fail::fail_point!("tenant-delete-before-remove-tenant-dir", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: tenant-delete-before-remove-tenant-dir"
+        ))?
+    });
+
+    rm(conf.tenant_path(tenant_id), true).await?;
+
+    Ok(())
+}
+
+/// Orchestrates tenant shut down of all tasks, removes its in-memory structures,
+/// and deletes its data from both disk and s3.
+/// The sequence of steps:
+/// 1. Upload remote deletion mark.
+/// 2. Create local mark file.
+/// 3. Shutdown tasks
+/// 4. Run ordered timeline deletions
+/// 5. Wait for timeline deletion operations that were scheduled before tenant deletion was requested
+/// 6. Remove remote mark
+/// 7. Cleanup remaining fs traces, tenant dir, config, timelines dir, local delete mark
+/// It is resumable from any step in case a crash/restart occurs.
+/// There are three entrypoints to the process:
+/// 1. [`DeleteTenantFlow::run`] this is the main one called by a management api handler.
+/// 2. [`DeleteTenantFlow::resume`] is called during restarts when local or remote deletion marks are still there.
+/// Note the only other place that messes around timeline delete mark is the `Tenant::spawn_load` function.
+#[derive(Default)]
+pub enum DeleteTenantFlow {
+    #[default]
+    NotStarted,
+    InProgress,
+    Finished,
+}
+
+impl DeleteTenantFlow {
+    // These steps are run in the context of management api request handler.
+    // Long running steps are continued to run in the background.
+    // NB: If this fails half-way through, and is retried, the retry will go through
+    // all the same steps again. Make sure the code here is idempotent, and don't
+    // error out if some of the shutdown tasks have already been completed!
+    // NOTE: static needed for background part.
+    // We assume that calling code sets up the span with tenant_id.
+    #[instrument(skip_all)]
+    pub(crate) async fn run(
+        conf: &'static PageServerConf,
+        remote_storage: Option<GenericRemoteStorage>,
+        tenants: &'static tokio::sync::RwLock<TenantsMap>,
+        tenant_id: TenantId,
+    ) -> Result<(), DeleteTenantError> {
+        span::debug_assert_current_span_has_tenant_id();
+
+        let (tenant, mut guard) = Self::prepare(tenants, tenant_id).await?;
+
+        if let Err(e) = Self::run_inner(&mut guard, conf, remote_storage.as_ref(), &tenant).await {
+            tenant.set_broken(format!("{e:#}")).await;
+            return Err(e);
+        }
+
+        Self::schedule_background(guard, conf, remote_storage, tenants, tenant);
+
+        Ok(())
+    }
+
+    // Helper function needed to be able to match once on returned error and transition tenant into broken state.
+    // This is needed because tenant.shutwodn is not idempotent. If tenant state is set to stopping another call to tenant.shutdown
+    // will result in an error, but here we need to be able to retry shutdown when tenant deletion is retried.
+    // So the solution is to set tenant state to broken.
+    async fn run_inner(
+        guard: &mut OwnedMutexGuard<Self>,
+        conf: &'static PageServerConf,
+        remote_storage: Option<&GenericRemoteStorage>,
+        tenant: &Tenant,
+    ) -> Result<(), DeleteTenantError> {
+        guard.mark_in_progress()?;
+
+        fail::fail_point!("tenant-delete-before-create-remote-mark", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: tenant-delete-before-create-remote-mark"
+            ))?
+        });
+
+        // IDEA: implement detach as delete without remote storage. Then they would use the same lock (deletion_progress) so wont contend.
+        // Though sounds scary, different mark name?
+        // Detach currently uses remove_dir_all so in case of a crash we can end up in a weird state.
+        if let Some(remote_storage) = &remote_storage {
+            create_remote_delete_mark(conf, remote_storage, &tenant.tenant_id)
+                .await
+                .context("remote_mark")?
+        }
+
+        fail::fail_point!("tenant-delete-before-create-local-mark", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: tenant-delete-before-create-local-mark"
+            ))?
+        });
+
+        create_local_delete_mark(conf, &tenant.tenant_id)
+            .await
+            .context("local delete mark")?;
+
+        fail::fail_point!("tenant-delete-before-background", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: tenant-delete-before-background"
+            ))?
+        });
+
+        Ok(())
+    }
+
+    fn mark_in_progress(&mut self) -> anyhow::Result<()> {
+        match self {
+            Self::Finished => anyhow::bail!("Bug. Is in finished state"),
+            Self::InProgress { .. } => { /* We're in a retry */ }
+            Self::NotStarted => { /* Fresh start */ }
+        }
+
+        *self = Self::InProgress;
+
+        Ok(())
+    }
+
+    pub async fn should_resume_deletion(
+        conf: &'static PageServerConf,
+        remote_storage: Option<&GenericRemoteStorage>,
+        tenant: &Tenant,
+    ) -> Result<Option<DeletionGuard>, DeleteTenantError> {
+        let acquire = |t: &Tenant| {
+            Some(
+                Arc::clone(&t.delete_progress)
+                    .try_lock_owned()
+                    .expect("we're the only owner during init"),
+            )
+        };
+
+        let tenant_id = tenant.tenant_id;
+        // Check local mark first, if its there there is no need to go to s3 to check whether remote one exists.
+        if conf.tenant_deleted_mark_file_path(&tenant_id).exists() {
+            return Ok(acquire(tenant));
+        }
+
+        let remote_storage = match remote_storage {
+            Some(remote_storage) => remote_storage,
+            None => return Ok(None),
+        };
+
+        // If remote storage is there we rely on it
+        let remote_mark_path = remote_tenant_delete_mark_path(conf, &tenant_id)?;
+
+        let result = backoff::retry(
+            || async { remote_storage.download(&remote_mark_path).await },
+            |e| matches!(e, DownloadError::NotFound),
+            SHOULD_RESUME_DELETION_FETCH_MARK_ATTEMPTS,
+            SHOULD_RESUME_DELETION_FETCH_MARK_ATTEMPTS,
+            "fetch_tenant_deletion_mark",
+        )
+        .await;
+
+        match result {
+            Ok(_) => Ok(acquire(tenant)),
+            Err(DownloadError::NotFound) => Ok(None),
+            Err(e) => Err(anyhow::anyhow!(e)).context("should_resume_deletion")?,
+        }
+    }
+
+    pub(crate) async fn resume(
+        guard: DeletionGuard,
+        tenant: &Arc<Tenant>,
+        init_order: Option<&InitializationOrder>,
+        tenants: &'static tokio::sync::RwLock<TenantsMap>,
+        ctx: &RequestContext,
+    ) -> Result<(), DeleteTenantError> {
+        let (_, progress) = completion::channel();
+
+        tenant
+            .set_stopping(progress, true)
+            .await
+            .expect("cant be stopping or broken");
+
+        // Do not consume valuable resources during the load phase, continue deletion once init phase is complete.
+        let background_jobs_can_start = init_order.as_ref().map(|x| &x.background_jobs_can_start);
+        if let Some(background) = background_jobs_can_start {
+            info!("waiting for backgound jobs barrier");
+            background.clone().wait().await;
+            info!("ready for backgound jobs barrier");
+        }
+
+        // Tenant may not be loadable if we fail late in cleanup_remaining_fs_traces (e g remove timelines dir)
+        let timelines_path = tenant.conf.timelines_path(&tenant.tenant_id);
+        if timelines_path.exists() {
+            tenant.load(init_order, ctx).await.context("load")?;
+        }
+
+        Self::background(
+            guard,
+            tenant.conf,
+            tenant.remote_storage.clone(),
+            tenants,
+            tenant,
+        )
+        .await
+    }
+
+    async fn prepare(
+        tenants: &tokio::sync::RwLock<TenantsMap>,
+        tenant_id: TenantId,
+    ) -> Result<(Arc<Tenant>, tokio::sync::OwnedMutexGuard<Self>), DeleteTenantError> {
+        let m = tenants.read().await;
+
+        let tenant = m
+            .get(&tenant_id)
+            .ok_or(GetTenantError::NotFound(tenant_id))?;
+
+        // FIXME: unsure about active only. Our init jobs may not be cancellable properly,
+        // so at least for now allow deletions only for active tenants. TODO recheck
+        // Broken and Stopping is needed for retries.
+        if !matches!(
+            tenant.current_state(),
+            TenantState::Active | TenantState::Broken { .. }
+        ) {
+            return Err(DeleteTenantError::InvalidState(tenant.current_state()));
+        }
+
+        let guard = Arc::clone(&tenant.delete_progress)
+            .try_lock_owned()
+            .map_err(|_| DeleteTenantError::AlreadyInProgress)?;
+
+        fail::fail_point!("tenant-delete-before-shutdown", |_| {
+            Err(anyhow::anyhow!("failpoint: tenant-delete-before-shutdown"))?
+        });
+
+        // make pageserver shutdown not to wait for our completion
+        let (_, progress) = completion::channel();
+
+        // It would be good to only set stopping here and continue shutdown in the background, but shutdown is not idempotent.
+        // i e it is an error to do:
+        // tenant.set_stopping
+        // tenant.shutdown
+        // Its also bad that we're holding tenants.read here.
+        // TODO relax set_stopping to be idempotent?
+        if tenant.shutdown(progress, false).await.is_err() {
+            return Err(DeleteTenantError::Other(anyhow::anyhow!(
+                "tenant shutdown is already in progress"
+            )));
+        }
+
+        Ok((Arc::clone(tenant), guard))
+    }
+
+    fn schedule_background(
+        guard: OwnedMutexGuard<Self>,
+        conf: &'static PageServerConf,
+        remote_storage: Option<GenericRemoteStorage>,
+        tenants: &'static tokio::sync::RwLock<TenantsMap>,
+        tenant: Arc<Tenant>,
+    ) {
+        let tenant_id = tenant.tenant_id;
+
+        task_mgr::spawn(
+            task_mgr::BACKGROUND_RUNTIME.handle(),
+            TaskKind::TimelineDeletionWorker,
+            Some(tenant_id),
+            None,
+            "tenant_delete",
+            false,
+            async move {
+                if let Err(err) =
+                    Self::background(guard, conf, remote_storage, tenants, &tenant).await
+                {
+                    error!("Error: {err:#}");
+                    tenant.set_broken(format!("{err:#}")).await;
+                };
+                Ok(())
+            }
+            .instrument({
+                let span = tracing::info_span!(parent: None, "delete_tenant", tenant_id=%tenant_id);
+                span.follows_from(Span::current());
+                span
+            }),
+        );
+    }
+
+    async fn background(
+        mut guard: OwnedMutexGuard<Self>,
+        conf: &PageServerConf,
+        remote_storage: Option<GenericRemoteStorage>,
+        tenants: &'static tokio::sync::RwLock<TenantsMap>,
+        tenant: &Arc<Tenant>,
+    ) -> Result<(), DeleteTenantError> {
+        // Tree sort timelines, schedule delete for them. Mention retries from the console side.
+        // Note that if deletion fails we dont mark timelines as broken,
+        // the whole tenant will become broken as by `Self::schedule_background` logic
+        let already_running_timeline_deletions = schedule_ordered_timeline_deletions(tenant)
+            .await
+            .context("schedule_ordered_timeline_deletions")?;
+
+        fail::fail_point!("tenant-delete-before-polling-ongoing-deletions", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: tenant-delete-before-polling-ongoing-deletions"
+            ))?
+        });
+
+        // Wait for deletions that were already running at the moment when tenant deletion was requested.
+        // When we can lock deletion guard it means that corresponding timeline deletion finished.
+        for (guard, timeline_id) in already_running_timeline_deletions {
+            let flow = guard.lock().await;
+            if !flow.is_finished() {
+                return Err(DeleteTenantError::Other(anyhow::anyhow!(
+                    "already running timeline deletion failed: {timeline_id}"
+                )));
+            }
+        }
+
+        let timelines_path = conf.timelines_path(&tenant.tenant_id);
+        // May not exist if we fail in cleanup_remaining_fs_traces after removing it
+        if timelines_path.exists() {
+            // sanity check to guard against layout changes
+            ensure_timelines_dir_empty(&timelines_path)
+                .await
+                .context("timelines dir not empty")?;
+        }
+
+        remove_tenant_remote_delete_mark(conf, remote_storage.as_ref(), &tenant.tenant_id).await?;
+
+        fail::fail_point!("tenant-delete-before-cleanup-remaining-fs-traces", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: tenant-delete-before-cleanup-remaining-fs-traces"
+            ))?
+        });
+
+        cleanup_remaining_fs_traces(conf, &tenant.tenant_id)
+            .await
+            .context("cleanup_remaining_fs_traces")?;
+
+        let mut locked = tenants.write().await;
+        if locked.remove(&tenant.tenant_id).is_none() {
+            warn!("Tenant got removed from tenants map during deletion");
+        };
+
+        *guard = Self::Finished;
+
+        Ok(())
+    }
+}

pageserver/src/tenant/disk_btree.rs

@@ -20,6 +20,7 @@
 //!
 use byteorder::{ReadBytesExt, BE};
 use bytes::{BufMut, Bytes, BytesMut};
+use either::Either;
 use hex;
 use std::{cmp::Ordering, io, result};
 use thiserror::Error;
@@ -230,14 +231,15 @@ where
     ///
     /// Read the value for given key. Returns the value, or None if it doesn't exist.
     ///
-    pub fn get(&self, search_key: &[u8; L]) -> Result<Option<u64>> {
+    pub async fn get(&self, search_key: &[u8; L]) -> Result<Option<u64>> {
         let mut result: Option<u64> = None;
         self.visit(search_key, VisitDirection::Forwards, |key, value| {
             if key == search_key {
                 result = Some(value);
             }
             false
-        })?;
+        })
+        .await?;
         Ok(result)
     }
 
@@ -246,7 +248,7 @@ where
     /// will be called for every key >= 'search_key' (or <= 'search_key', if scanning
     /// backwards)
     ///
-    pub fn visit<V>(
+    pub async fn visit<V>(
         &self,
         search_key: &[u8; L],
         dir: VisitDirection,
@@ -255,117 +257,77 @@ where
     where
         V: FnMut(&[u8], u64) -> bool,
     {
-        self.search_recurse(self.root_blk, search_key, dir, &mut visitor)
-    }
+        let mut stack = Vec::new();
+        stack.push((self.root_blk, None));
+        while let Some((node_blknum, opt_iter)) = stack.pop() {
+            // Locate the node.
+            let node_buf = self.reader.read_blk(self.start_blk + node_blknum)?;
 
-    fn search_recurse<V>(
-        &self,
-        node_blknum: u32,
-        search_key: &[u8; L],
-        dir: VisitDirection,
-        visitor: &mut V,
-    ) -> Result<bool>
-    where
-        V: FnMut(&[u8], u64) -> bool,
-    {
-        // Locate the node.
-        let blk = self.reader.read_blk(self.start_blk + node_blknum)?;
+            let node = OnDiskNode::deparse(node_buf.as_ref())?;
+            let prefix_len = node.prefix_len as usize;
+            let suffix_len = node.suffix_len as usize;
 
-        // Search all entries on this node
-        self.search_node(blk.as_ref(), search_key, dir, visitor)
-    }
+            assert!(node.num_children > 0);
 
-    fn search_node<V>(
-        &self,
-        node_buf: &[u8],
-        search_key: &[u8; L],
-        dir: VisitDirection,
-        visitor: &mut V,
-    ) -> Result<bool>
-    where
-        V: FnMut(&[u8], u64) -> bool,
-    {
-        let node = OnDiskNode::deparse(node_buf)?;
-        let prefix_len = node.prefix_len as usize;
-        let suffix_len = node.suffix_len as usize;
+            let mut keybuf = Vec::new();
+            keybuf.extend(node.prefix);
+            keybuf.resize(prefix_len + suffix_len, 0);
 
-        assert!(node.num_children > 0);
-
-        let mut keybuf = Vec::new();
-        keybuf.extend(node.prefix);
-        keybuf.resize(prefix_len + suffix_len, 0);
-
-        if dir == VisitDirection::Forwards {
-            // Locate the first match
-            let mut idx = match node.binary_search(search_key, keybuf.as_mut_slice()) {
-                Ok(idx) => idx,
-                Err(idx) => {
-                    if node.level == 0 {
-                        // Imagine that the node contains the following keys:
-                        //
-                        // 1
-                        // 3  <-- idx
-                        // 5
-                        //
-                        // If the search key is '2' and there is exact match,
-                        // the binary search would return the index of key
-                        // '3'. That's cool, '3' is the first key to return.
+            let mut iter = if let Some(iter) = opt_iter {
+                iter
+            } else if dir == VisitDirection::Forwards {
+                // Locate the first match
+                let idx = match node.binary_search(search_key, keybuf.as_mut_slice()) {
+                    Ok(idx) => idx,
+                    Err(idx) => {
+                        if node.level == 0 {
+                            // Imagine that the node contains the following keys:
+                            //
+                            // 1
+                            // 3  <-- idx
+                            // 5
+                            //
+                            // If the search key is '2' and there is exact match,
+                            // the binary search would return the index of key
+                            // '3'. That's cool, '3' is the first key to return.
+                            idx
+                        } else {
+                            // This is an internal page, so each key represents a lower
+                            // bound for what's in the child page. If there is no exact
+                            // match, we have to return the *previous* entry.
+                            //
+                            // 1  <-- return this
+                            // 3  <-- idx
+                            // 5
+                            idx.saturating_sub(1)
+                        }
+                    }
+                };
+                Either::Left(idx..node.num_children.into())
+            } else {
+                let idx = match node.binary_search(search_key, keybuf.as_mut_slice()) {
+                    Ok(idx) => {
+                        // Exact match. That's the first entry to return, and walk
+                        // backwards from there.
                         idx
-                    } else {
-                        // This is an internal page, so each key represents a lower
-                        // bound for what's in the child page. If there is no exact
-                        // match, we have to return the *previous* entry.
-                        //
-                        // 1  <-- return this
-                        // 3  <-- idx
-                        // 5
-                        idx.saturating_sub(1)
                     }
-                }
-            };
-            // idx points to the first match now. Keep going from there
-            let mut key_off = idx * suffix_len;
-            while idx < node.num_children as usize {
-                let suffix = &node.keys[key_off..key_off + suffix_len];
-                keybuf[prefix_len..].copy_from_slice(suffix);
-                let value = node.value(idx);
-                #[allow(clippy::collapsible_if)]
-                if node.level == 0 {
-                    // leaf
-                    if !visitor(&keybuf, value.to_u64()) {
-                        return Ok(false);
+                    Err(idx) => {
+                        // No exact match. The binary search returned the index of the
+                        // first key that's > search_key. Back off by one, and walk
+                        // backwards from there.
+                        if let Some(idx) = idx.checked_sub(1) {
+                            idx
+                        } else {
+                            return Ok(false);
+                        }
                     }
-                } else {
-                    #[allow(clippy::collapsible_if)]
-                    if !self.search_recurse(value.to_blknum(), search_key, dir, visitor)? {
-                        return Ok(false);
-                    }
-                }
-                idx += 1;
-                key_off += suffix_len;
-            }
-        } else {
-            let mut idx = match node.binary_search(search_key, keybuf.as_mut_slice()) {
-                Ok(idx) => {
-                    // Exact match. That's the first entry to return, and walk
-                    // backwards from there. (The loop below starts from 'idx -
-                    // 1', so add one here to compensate.)
-                    idx + 1
-                }
-                Err(idx) => {
-                    // No exact match. The binary search returned the index of the
-                    // first key that's > search_key. Back off by one, and walk
-                    // backwards from there. (The loop below starts from idx - 1,
-                    // so we don't need to subtract one here)
-                    idx
-                }
+                };
+                Either::Right((0..=idx).rev())
             };
 
-            // idx points to the first match + 1 now. Keep going from there.
-            let mut key_off = idx * suffix_len;
-            while idx > 0 {
-                idx -= 1;
-                key_off -= suffix_len;
+            // idx points to the first match now. Keep going from there
+            while let Some(idx) = iter.next() {
+                let key_off = idx * suffix_len;
                 let suffix = &node.keys[key_off..key_off + suffix_len];
                 keybuf[prefix_len..].copy_from_slice(suffix);
                 let value = node.value(idx);
@@ -376,12 +338,8 @@ where
                         return Ok(false);
                     }
                 } else {
-                    #[allow(clippy::collapsible_if)]
-                    if !self.search_recurse(value.to_blknum(), search_key, dir, visitor)? {
-                        return Ok(false);
-                    }
-                }
-                if idx == 0 {
+                    stack.push((node_blknum, Some(iter)));
+                    stack.push((value.to_blknum(), None));
                     break;
                 }
             }
@@ -390,39 +348,42 @@ where
     }
 
     #[allow(dead_code)]
-    pub fn dump(&self) -> Result<()> {
-        self.dump_recurse(self.root_blk, &[], 0)
-    }
+    pub async fn dump(&self) -> Result<()> {
+        let mut stack = Vec::new();
 
-    fn dump_recurse(&self, blknum: u32, path: &[u8], depth: usize) -> Result<()> {
-        let blk = self.reader.read_blk(self.start_blk + blknum)?;
-        let buf: &[u8] = blk.as_ref();
+        stack.push((self.root_blk, String::new(), 0, 0, 0));
 
-        let node = OnDiskNode::<L>::deparse(buf)?;
+        while let Some((blknum, path, depth, child_idx, key_off)) = stack.pop() {
+            let blk = self.reader.read_blk(self.start_blk + blknum)?;
+            let buf: &[u8] = blk.as_ref();
+            let node = OnDiskNode::<L>::deparse(buf)?;
 
-        print!("{:indent$}", "", indent = depth * 2);
-        println!(
-            "blk #{}: path {}: prefix {}, suffix_len {}",
-            blknum,
-            hex::encode(path),
-            hex::encode(node.prefix),
-            node.suffix_len
-        );
+            if child_idx == 0 {
+                print!("{:indent$}", "", indent = depth * 2);
+                let path_prefix = stack
+                    .iter()
+                    .map(|(_blknum, path, ..)| path.as_str())
+                    .collect::<String>();
+                println!(
+                    "blk #{blknum}: path {path_prefix}{path}: prefix {}, suffix_len {}",
+                    hex::encode(node.prefix),
+                    node.suffix_len
+                );
+            }
 
-        let mut idx = 0;
-        let mut key_off = 0;
-        while idx < node.num_children {
+            if child_idx + 1 < node.num_children {
+                let key_off = key_off + node.suffix_len as usize;
+                stack.push((blknum, path.clone(), depth, child_idx + 1, key_off));
+            }
             let key = &node.keys[key_off..key_off + node.suffix_len as usize];
-            let val = node.value(idx as usize);
+            let val = node.value(child_idx as usize);
+
             print!("{:indent$}", "", indent = depth * 2 + 2);
             println!("{}: {}", hex::encode(key), hex::encode(val.0));
 
             if node.level > 0 {
-                let child_path = [path, node.prefix].concat();
-                self.dump_recurse(val.to_blknum(), &child_path, depth + 1)?;
+                stack.push((val.to_blknum(), hex::encode(node.prefix), depth + 1, 0, 0));
             }
-            idx += 1;
-            key_off += node.suffix_len as usize;
         }
         Ok(())
     }
@@ -724,6 +685,7 @@ impl<const L: usize> BuildNode<L> {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::tenant::block_io::BlockLease;
     use rand::Rng;
     use std::collections::BTreeMap;
     use std::sync::atomic::{AtomicUsize, Ordering};
@@ -738,12 +700,10 @@ mod tests {
         }
     }
     impl BlockReader for TestDisk {
-        type BlockLease = std::rc::Rc<[u8; PAGE_SZ]>;
-
-        fn read_blk(&self, blknum: u32) -> io::Result<Self::BlockLease> {
+        fn read_blk(&self, blknum: u32) -> io::Result<BlockLease> {
             let mut buf = [0u8; PAGE_SZ];
             buf.copy_from_slice(&self.blocks[blknum as usize]);
-            Ok(std::rc::Rc::new(buf))
+            Ok(std::rc::Rc::new(buf).into())
         }
     }
     impl BlockWriter for &mut TestDisk {
@@ -754,8 +714,8 @@ mod tests {
         }
     }
 
-    #[test]
-    fn basic() -> Result<()> {
+    #[tokio::test]
+    async fn basic() -> Result<()> {
         let mut disk = TestDisk::new();
         let mut writer = DiskBtreeBuilder::<_, 6>::new(&mut disk);
 
@@ -775,16 +735,16 @@ mod tests {
 
         let reader = DiskBtreeReader::new(0, root_offset, disk);
 
-        reader.dump()?;
+        reader.dump().await?;
 
         // Test the `get` function on all the keys.
         for (key, val) in all_data.iter() {
-            assert_eq!(reader.get(key)?, Some(*val));
+            assert_eq!(reader.get(key).await?, Some(*val));
         }
         // And on some keys that don't exist
-        assert_eq!(reader.get(b"aaaaaa")?, None);
-        assert_eq!(reader.get(b"zzzzzz")?, None);
-        assert_eq!(reader.get(b"xaaabx")?, None);
+        assert_eq!(reader.get(b"aaaaaa").await?, None);
+        assert_eq!(reader.get(b"zzzzzz").await?, None);
+        assert_eq!(reader.get(b"xaaabx").await?, None);
 
         // Test search with `visit` function
         let search_key = b"xabaaa";
@@ -795,10 +755,12 @@ mod tests {
             .collect();
 
         let mut data = Vec::new();
-        reader.visit(search_key, VisitDirection::Forwards, |key, value| {
-            data.push((key.to_vec(), value));
-            true
-        })?;
+        reader
+            .visit(search_key, VisitDirection::Forwards, |key, value| {
+                data.push((key.to_vec(), value));
+                true
+            })
+            .await?;
         assert_eq!(data, expected);
 
         // Test a backwards scan
@@ -809,16 +771,20 @@ mod tests {
             .collect();
         expected.reverse();
         let mut data = Vec::new();
-        reader.visit(search_key, VisitDirection::Backwards, |key, value| {
-            data.push((key.to_vec(), value));
-            true
-        })?;
+        reader
+            .visit(search_key, VisitDirection::Backwards, |key, value| {
+                data.push((key.to_vec(), value));
+                true
+            })
+            .await?;
         assert_eq!(data, expected);
 
         // Backward scan where nothing matches
-        reader.visit(b"aaaaaa", VisitDirection::Backwards, |key, value| {
-            panic!("found unexpected key {}: {}", hex::encode(key), value);
-        })?;
+        reader
+            .visit(b"aaaaaa", VisitDirection::Backwards, |key, value| {
+                panic!("found unexpected key {}: {}", hex::encode(key), value);
+            })
+            .await?;
 
         // Full scan
         let expected: Vec<(Vec<u8>, u64)> = all_data
@@ -826,17 +792,19 @@ mod tests {
             .map(|(key, value)| (key.to_vec(), *value))
             .collect();
         let mut data = Vec::new();
-        reader.visit(&[0u8; 6], VisitDirection::Forwards, |key, value| {
-            data.push((key.to_vec(), value));
-            true
-        })?;
+        reader
+            .visit(&[0u8; 6], VisitDirection::Forwards, |key, value| {
+                data.push((key.to_vec(), value));
+                true
+            })
+            .await?;
         assert_eq!(data, expected);
 
         Ok(())
     }
 
-    #[test]
-    fn lots_of_keys() -> Result<()> {
+    #[tokio::test]
+    async fn lots_of_keys() -> Result<()> {
         let mut disk = TestDisk::new();
         let mut writer = DiskBtreeBuilder::<_, 8>::new(&mut disk);
 
@@ -856,7 +824,7 @@ mod tests {
 
         let reader = DiskBtreeReader::new(0, root_offset, disk);
 
-        reader.dump()?;
+        reader.dump().await?;
 
         use std::sync::Mutex;
 
@@ -877,13 +845,15 @@ mod tests {
         for search_key_int in 0..(NUM_KEYS * 2 + 10) {
             let search_key = u64::to_be_bytes(search_key_int);
             assert_eq!(
-                reader.get(&search_key)?,
+                reader.get(&search_key).await?,
                 all_data.get(&search_key_int).cloned()
             );
 
             // Test a forward scan starting with this key
             result.lock().unwrap().clear();
-            reader.visit(&search_key, VisitDirection::Forwards, take_ten)?;
+            reader
+                .visit(&search_key, VisitDirection::Forwards, take_ten)
+                .await?;
             let expected = all_data
                 .range(search_key_int..)
                 .take(10)
@@ -893,7 +863,9 @@ mod tests {
 
             // And a backwards scan
             result.lock().unwrap().clear();
-            reader.visit(&search_key, VisitDirection::Backwards, take_ten)?;
+            reader
+                .visit(&search_key, VisitDirection::Backwards, take_ten)
+                .await?;
             let expected = all_data
                 .range(..=search_key_int)
                 .rev()
@@ -907,7 +879,9 @@ mod tests {
         let search_key = u64::to_be_bytes(0);
         limit.store(usize::MAX, Ordering::Relaxed);
         result.lock().unwrap().clear();
-        reader.visit(&search_key, VisitDirection::Forwards, take_ten)?;
+        reader
+            .visit(&search_key, VisitDirection::Forwards, take_ten)
+            .await?;
         let expected = all_data
             .iter()
             .map(|(&key, &val)| (key, val))
@@ -918,7 +892,9 @@ mod tests {
         let search_key = u64::to_be_bytes(u64::MAX);
         limit.store(usize::MAX, Ordering::Relaxed);
         result.lock().unwrap().clear();
-        reader.visit(&search_key, VisitDirection::Backwards, take_ten)?;
+        reader
+            .visit(&search_key, VisitDirection::Backwards, take_ten)
+            .await?;
         let expected = all_data
             .iter()
             .rev()
@@ -929,8 +905,8 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn random_data() -> Result<()> {
+    #[tokio::test]
+    async fn random_data() -> Result<()> {
         // Generate random keys with exponential distribution, to
         // exercise the prefix compression
         const NUM_KEYS: usize = 100000;
@@ -957,19 +933,23 @@ mod tests {
         // Test get() operation on all the keys
         for (&key, &val) in all_data.iter() {
             let search_key = u128::to_be_bytes(key);
-            assert_eq!(reader.get(&search_key)?, Some(val));
+            assert_eq!(reader.get(&search_key).await?, Some(val));
         }
 
         // Test get() operations on random keys, most of which will not exist
         for _ in 0..100000 {
             let key_int = rand::thread_rng().gen::<u128>();
             let search_key = u128::to_be_bytes(key_int);
-            assert!(reader.get(&search_key)? == all_data.get(&key_int).cloned());
+            assert!(reader.get(&search_key).await? == all_data.get(&key_int).cloned());
         }
 
         // Test boundary cases
-        assert!(reader.get(&u128::to_be_bytes(u128::MIN))? == all_data.get(&u128::MIN).cloned());
-        assert!(reader.get(&u128::to_be_bytes(u128::MAX))? == all_data.get(&u128::MAX).cloned());
+        assert!(
+            reader.get(&u128::to_be_bytes(u128::MIN)).await? == all_data.get(&u128::MIN).cloned()
+        );
+        assert!(
+            reader.get(&u128::to_be_bytes(u128::MAX)).await? == all_data.get(&u128::MAX).cloned()
+        );
 
         Ok(())
     }
@@ -994,8 +974,8 @@ mod tests {
     ///
     /// This test contains a particular data set, see disk_btree_test_data.rs
     ///
-    #[test]
-    fn particular_data() -> Result<()> {
+    #[tokio::test]
+    async fn particular_data() -> Result<()> {
         // Build a tree from it
         let mut disk = TestDisk::new();
         let mut writer = DiskBtreeBuilder::<_, 26>::new(&mut disk);
@@ -1011,18 +991,20 @@ mod tests {
 
         // Test get() operation on all the keys
         for (key, val) in disk_btree_test_data::TEST_DATA {
-            assert_eq!(reader.get(&key)?, Some(val));
+            assert_eq!(reader.get(&key).await?, Some(val));
         }
 
         // Test full scan
         let mut count = 0;
-        reader.visit(&[0u8; 26], VisitDirection::Forwards, |_key, _value| {
-            count += 1;
-            true
-        })?;
+        reader
+            .visit(&[0u8; 26], VisitDirection::Forwards, |_key, _value| {
+                count += 1;
+                true
+            })
+            .await?;
         assert_eq!(count, disk_btree_test_data::TEST_DATA.len());
 
-        reader.dump()?;
+        reader.dump().await?;
 
         Ok(())
     }

pageserver/src/tenant/ephemeral_file.rs

@@ -4,7 +4,7 @@
 use crate::config::PageServerConf;
 use crate::page_cache::{self, ReadBufResult, WriteBufResult, PAGE_SZ};
 use crate::tenant::blob_io::BlobWriter;
-use crate::tenant::block_io::BlockReader;
+use crate::tenant::block_io::{BlockLease, BlockReader};
 use crate::virtual_file::VirtualFile;
 use once_cell::sync::Lazy;
 use std::cmp::min;
@@ -266,11 +266,17 @@ impl Drop for EphemeralFile {
         // unlink the file
         let res = std::fs::remove_file(&self.file.path);
         if let Err(e) = res {
-            warn!(
-                "could not remove ephemeral file '{}': {}",
-                self.file.path.display(),
-                e
-            );
+            if e.kind() != std::io::ErrorKind::NotFound {
+                // just never log the not found errors, we cannot do anything for them; on detach
+                // the tenant directory is already gone.
+                //
+                // not found files might also be related to https://github.com/neondatabase/neon/issues/2442
+                error!(
+                    "could not remove ephemeral file '{}': {}",
+                    self.file.path.display(),
+                    e
+                );
+            }
         }
     }
 }
@@ -297,9 +303,7 @@ pub fn writeback(file_id: u64, blkno: u32, buf: &[u8]) -> Result<(), io::Error>
 }
 
 impl BlockReader for EphemeralFile {
-    type BlockLease = page_cache::PageReadGuard<'static>;
-
-    fn read_blk(&self, blknum: u32) -> Result<Self::BlockLease, io::Error> {
+    fn read_blk(&self, blknum: u32) -> Result<BlockLease, io::Error> {
         // Look up the right page
         let cache = page_cache::get();
         loop {
@@ -307,7 +311,7 @@ impl BlockReader for EphemeralFile {
                 .read_ephemeral_buf(self.file_id, blknum)
                 .map_err(|e| to_io_error(e, "Failed to read ephemeral buf"))?
             {
-                ReadBufResult::Found(guard) => return Ok(guard),
+                ReadBufResult::Found(guard) => return Ok(guard.into()),
                 ReadBufResult::NotFound(mut write_guard) => {
                     // Read the page from disk into the buffer
                     self.fill_buffer(write_guard.deref_mut(), blknum)?;
@@ -328,7 +332,7 @@ fn to_io_error(e: anyhow::Error, context: &str) -> io::Error {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::tenant::blob_io::{BlobCursor, BlobWriter};
+    use crate::tenant::blob_io::BlobWriter;
     use crate::tenant::block_io::BlockCursor;
     use rand::{seq::SliceRandom, thread_rng, RngCore};
     use std::fs;
@@ -395,17 +399,26 @@ mod tests {
         Ok(())
     }
 
-    #[test]
-    fn test_ephemeral_blobs() -> Result<(), io::Error> {
+    #[tokio::test]
+    async fn test_ephemeral_blobs() -> Result<(), io::Error> {
         let (conf, tenant_id, timeline_id) = harness("ephemeral_blobs")?;
 
         let mut file = EphemeralFile::create(conf, tenant_id, timeline_id)?;
 
         let pos_foo = file.write_blob(b"foo")?;
-        assert_eq!(b"foo", file.block_cursor().read_blob(pos_foo)?.as_slice());
+        assert_eq!(
+            b"foo",
+            file.block_cursor().read_blob(pos_foo).await?.as_slice()
+        );
         let pos_bar = file.write_blob(b"bar")?;
-        assert_eq!(b"foo", file.block_cursor().read_blob(pos_foo)?.as_slice());
-        assert_eq!(b"bar", file.block_cursor().read_blob(pos_bar)?.as_slice());
+        assert_eq!(
+            b"foo",
+            file.block_cursor().read_blob(pos_foo).await?.as_slice()
+        );
+        assert_eq!(
+            b"bar",
+            file.block_cursor().read_blob(pos_bar).await?.as_slice()
+        );
 
         let mut blobs = Vec::new();
         for i in 0..10000 {
@@ -420,9 +433,9 @@ mod tests {
             blobs.push((pos, data));
         }
 
-        let mut cursor = BlockCursor::new(&file);
+        let cursor = BlockCursor::new(&file);
         for (pos, expected) in blobs {
-            let actual = cursor.read_blob(pos)?;
+            let actual = cursor.read_blob(pos).await?;
             assert_eq!(actual, expected);
         }
 
@@ -431,7 +444,7 @@ mod tests {
         large_data.resize(20000, 0);
         thread_rng().fill_bytes(&mut large_data);
         let pos_large = file.write_blob(&large_data)?;
-        let result = file.block_cursor().read_blob(pos_large)?;
+        let result = file.block_cursor().read_blob(pos_large).await?;
         assert_eq!(result, large_data);
 
         Ok(())

pageserver/src/tenant/layer_map.rs

@@ -121,7 +121,7 @@ impl BatchedUpdates<'_> {
     ///
     /// This should be called when the corresponding file on disk has been deleted.
     ///
-    pub fn remove_historic(&mut self, layer_desc: PersistentLayerDesc) {
+    pub fn remove_historic(&mut self, layer_desc: &PersistentLayerDesc) {
         self.layer_map.remove_historic_noflush(layer_desc)
     }
 
@@ -253,11 +253,11 @@ impl LayerMap {
     ///
     /// Helper function for BatchedUpdates::remove_historic
     ///
-    pub fn remove_historic_noflush(&mut self, layer_desc: PersistentLayerDesc) {
+    pub fn remove_historic_noflush(&mut self, layer_desc: &PersistentLayerDesc) {
         self.historic
-            .remove(historic_layer_coverage::LayerKey::from(&layer_desc));
+            .remove(historic_layer_coverage::LayerKey::from(layer_desc));
         let layer_key = layer_desc.key();
-        if Self::is_l0(&layer_desc) {
+        if Self::is_l0(layer_desc) {
             let len_before = self.l0_delta_layers.len();
             let mut l0_delta_layers = std::mem::take(&mut self.l0_delta_layers);
             l0_delta_layers.retain(|other| other.key() != layer_key);
@@ -626,17 +626,17 @@ impl LayerMap {
 
     /// debugging function to print out the contents of the layer map
     #[allow(unused)]
-    pub fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
+    pub async fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
         println!("Begin dump LayerMap");
 
         println!("open_layer:");
         if let Some(open_layer) = &self.open_layer {
-            open_layer.dump(verbose, ctx)?;
+            open_layer.dump(verbose, ctx).await?;
         }
 
         println!("frozen_layers:");
         for frozen_layer in self.frozen_layers.iter() {
-            frozen_layer.dump(verbose, ctx)?;
+            frozen_layer.dump(verbose, ctx).await?;
         }
 
         println!("historic_layers:");
@@ -766,8 +766,7 @@ mod tests {
                 expected_in_counts
             );
 
-            map.batch_update()
-                .remove_historic(downloaded.layer_desc().clone());
+            map.batch_update().remove_historic(downloaded.layer_desc());
             assert_eq!(count_layer_in(&map, downloaded.layer_desc()), (0, 0));
         }
 

pageserver/src/tenant/metadata.rs

@@ -9,10 +9,11 @@
 //! [`remote_timeline_client`]: super::remote_timeline_client
 
 use std::fs::{File, OpenOptions};
-use std::io::Write;
+use std::io::{self, Write};
 
 use anyhow::{bail, ensure, Context};
 use serde::{Deserialize, Serialize};
+use thiserror::Error;
 use tracing::info_span;
 use utils::bin_ser::SerializeError;
 use utils::{
@@ -267,24 +268,24 @@ pub fn save_metadata(
     Ok(())
 }
 
+#[derive(Error, Debug)]
+pub enum LoadMetadataError {
+    #[error(transparent)]
+    Read(#[from] io::Error),
+
+    #[error(transparent)]
+    Decode(#[from] anyhow::Error),
+}
+
 pub fn load_metadata(
     conf: &'static PageServerConf,
     tenant_id: &TenantId,
     timeline_id: &TimelineId,
-) -> anyhow::Result<TimelineMetadata> {
+) -> Result<TimelineMetadata, LoadMetadataError> {
     let metadata_path = conf.metadata_path(tenant_id, timeline_id);
-    let metadata_bytes = std::fs::read(&metadata_path).with_context(|| {
-        format!(
-            "Failed to read metadata bytes from path {}",
-            metadata_path.display()
-        )
-    })?;
-    TimelineMetadata::from_bytes(&metadata_bytes).with_context(|| {
-        format!(
-            "Failed to parse metadata bytes from path {}",
-            metadata_path.display()
-        )
-    })
+    let metadata_bytes = std::fs::read(metadata_path)?;
+
+    Ok(TimelineMetadata::from_bytes(&metadata_bytes)?)
 }
 
 #[cfg(test)]

pageserver/src/tenant/mgr.rs

@@ -20,15 +20,19 @@ use crate::config::PageServerConf;
 use crate::context::{DownloadBehavior, RequestContext};
 use crate::task_mgr::{self, TaskKind};
 use crate::tenant::config::TenantConfOpt;
+use crate::tenant::delete::DeleteTenantFlow;
 use crate::tenant::{create_tenant_files, CreateTenantFilesMode, Tenant, TenantState};
 use crate::{InitializationOrder, IGNORED_TENANT_FILE_NAME};
 
 use utils::fs_ext::PathExt;
 use utils::id::{TenantId, TimelineId};
 
+use super::delete::DeleteTenantError;
+use super::timeline::delete::DeleteTimelineFlow;
+
 /// The tenants known to the pageserver.
 /// The enum variants are used to distinguish the different states that the pageserver can be in.
-enum TenantsMap {
+pub(crate) enum TenantsMap {
     /// [`init_tenant_mgr`] is not done yet.
     Initializing,
     /// [`init_tenant_mgr`] is done, all on-disk tenants have been loaded.
@@ -40,13 +44,13 @@ enum TenantsMap {
 }
 
 impl TenantsMap {
-    fn get(&self, tenant_id: &TenantId) -> Option<&Arc<Tenant>> {
+    pub(crate) fn get(&self, tenant_id: &TenantId) -> Option<&Arc<Tenant>> {
         match self {
             TenantsMap::Initializing => None,
             TenantsMap::Open(m) | TenantsMap::ShuttingDown(m) => m.get(tenant_id),
         }
     }
-    fn remove(&mut self, tenant_id: &TenantId) -> Option<Arc<Tenant>> {
+    pub(crate) fn remove(&mut self, tenant_id: &TenantId) -> Option<Arc<Tenant>> {
         match self {
             TenantsMap::Initializing => None,
             TenantsMap::Open(m) | TenantsMap::ShuttingDown(m) => m.remove(tenant_id),
@@ -95,7 +99,9 @@ pub async fn init_tenant_mgr(
                         );
                     }
                 } else {
-                    // This case happens if we crash during attach before creating the attach marker file
+                    // This case happens if we:
+                    // * crash during attach before creating the attach marker file
+                    // * crash during tenant delete before removing tenant directory
                     let is_empty = tenant_dir_path.is_empty_dir().with_context(|| {
                         format!("Failed to check whether {tenant_dir_path:?} is an empty dir")
                     })?;
@@ -122,6 +128,7 @@ pub async fn init_tenant_mgr(
                         broker_client.clone(),
                         remote_storage.clone(),
                         Some(init_order.clone()),
+                        &TENANTS,
                         &ctx,
                     ) {
                         Ok(tenant) => {
@@ -152,12 +159,13 @@ pub async fn init_tenant_mgr(
     Ok(())
 }
 
-pub fn schedule_local_tenant_processing(
+pub(crate) fn schedule_local_tenant_processing(
     conf: &'static PageServerConf,
     tenant_path: &Path,
     broker_client: storage_broker::BrokerClientChannel,
     remote_storage: Option<GenericRemoteStorage>,
     init_order: Option<InitializationOrder>,
+    tenants: &'static tokio::sync::RwLock<TenantsMap>,
     ctx: &RequestContext,
 ) -> anyhow::Result<Arc<Tenant>> {
     anyhow::ensure!(
@@ -217,6 +225,7 @@ pub fn schedule_local_tenant_processing(
             broker_client,
             remote_storage,
             init_order,
+            tenants,
             ctx,
         )
     };
@@ -264,71 +273,77 @@ async fn shutdown_all_tenants0(tenants: &tokio::sync::RwLock<TenantsMap>) {
         }
     };
 
+    let started_at = std::time::Instant::now();
     let mut join_set = JoinSet::new();
     for (tenant_id, tenant) in tenants_to_shut_down {
         join_set.spawn(
             async move {
-                // ordering shouldn't matter for this, either we store true right away or never
-                let ordering = std::sync::atomic::Ordering::Relaxed;
-                let joined_other = std::sync::atomic::AtomicBool::new(false);
+                let freeze_and_flush = true;
 
-                let mut shutdown = std::pin::pin!(async {
-                    let freeze_and_flush = true;
-
-                    let res = {
-                        let (_guard, shutdown_progress) = completion::channel();
-                        tenant.shutdown(shutdown_progress, freeze_and_flush).await
-                    };
-
-                    if let Err(other_progress) = res {
-                        // join the another shutdown in progress
-                        joined_other.store(true, ordering);
-                        other_progress.wait().await;
-                    }
-                });
-
-                // in practice we might not have a lot time to go, since systemd is going to
-                // SIGKILL us at 10s, but we can try. delete tenant might take a while, so put out
-                // a warning.
-                let warning = std::time::Duration::from_secs(5);
-                let mut warning = std::pin::pin!(tokio::time::sleep(warning));
-
-                tokio::select! {
-                    _ = &mut shutdown => {},
-                    _ = &mut warning => {
-                        let joined_other = joined_other.load(ordering);
-                        warn!(%joined_other, "waiting for the shutdown to complete");
-                        shutdown.await;
-                    }
+                let res = {
+                    let (_guard, shutdown_progress) = completion::channel();
+                    tenant.shutdown(shutdown_progress, freeze_and_flush).await
                 };
 
+                if let Err(other_progress) = res {
+                    // join the another shutdown in progress
+                    other_progress.wait().await;
+                }
+
+                // we cannot afford per tenant logging here, because if s3 is degraded, we are
+                // going to log too many lines
+
                 debug!("tenant successfully stopped");
             }
             .instrument(info_span!("shutdown", %tenant_id)),
         );
     }
 
+    let total = join_set.len();
     let mut panicked = 0;
+    let mut buffering = true;
+    const BUFFER_FOR: std::time::Duration = std::time::Duration::from_millis(500);
+    let mut buffered = std::pin::pin!(tokio::time::sleep(BUFFER_FOR));
 
-    while let Some(res) = join_set.join_next().await {
-        match res {
-            Ok(()) => {}
-            Err(join_error) if join_error.is_cancelled() => {
-                unreachable!("we are not cancelling any of the futures");
-            }
-            Err(join_error) if join_error.is_panic() => {
-                // cannot really do anything, as this panic is likely a bug
-                panicked += 1;
-            }
-            Err(join_error) => {
-                warn!("unknown kind of JoinError: {join_error}");
+    while !join_set.is_empty() {
+        tokio::select! {
+            Some(joined) = join_set.join_next() => {
+                match joined {
+                    Ok(()) => {}
+                    Err(join_error) if join_error.is_cancelled() => {
+                        unreachable!("we are not cancelling any of the futures");
+                    }
+                    Err(join_error) if join_error.is_panic() => {
+                        // cannot really do anything, as this panic is likely a bug
+                        panicked += 1;
+                    }
+                    Err(join_error) => {
+                        warn!("unknown kind of JoinError: {join_error}");
+                    }
+                }
+                if !buffering {
+                    // buffer so that every 500ms since the first update (or starting) we'll log
+                    // how far away we are; this is because we will get SIGKILL'd at 10s, and we
+                    // are not able to log *then*.
+                    buffering = true;
+                    buffered.as_mut().reset(tokio::time::Instant::now() + BUFFER_FOR);
+                }
+            },
+            _ = &mut buffered, if buffering => {
+                buffering = false;
+                info!(remaining = join_set.len(), total, elapsed_ms = started_at.elapsed().as_millis(), "waiting for tenants to shutdown");
             }
         }
     }
 
     if panicked > 0 {
-        warn!(panicked, "observed panicks while shutting down tenants");
+        warn!(
+            panicked,
+            total, "observed panicks while shutting down tenants"
+        );
     }
+
+    // caller will log how long we took
 }
 
 pub async fn create_tenant(
@@ -348,7 +363,7 @@ pub async fn create_tenant(
         //       See https://github.com/neondatabase/neon/issues/4233
 
         let created_tenant =
-            schedule_local_tenant_processing(conf, &tenant_directory, broker_client, remote_storage, None, ctx)?;
+            schedule_local_tenant_processing(conf, &tenant_directory, broker_client, remote_storage, None, &TENANTS, ctx)?;
         // TODO: tenant object & its background loops remain, untracked in tenant map, if we fail here.
         //      See https://github.com/neondatabase/neon/issues/4233
 
@@ -409,6 +424,14 @@ pub async fn get_tenant(
     }
 }
 
+pub async fn delete_tenant(
+    conf: &'static PageServerConf,
+    remote_storage: Option<GenericRemoteStorage>,
+    tenant_id: TenantId,
+) -> Result<(), DeleteTenantError> {
+    DeleteTenantFlow::run(conf, remote_storage, &TENANTS, tenant_id).await
+}
+
 #[derive(Debug, thiserror::Error)]
 pub enum DeleteTimelineError {
     #[error("Tenant {0}")]
@@ -421,12 +444,10 @@ pub enum DeleteTimelineError {
 pub async fn delete_timeline(
     tenant_id: TenantId,
     timeline_id: TimelineId,
-    ctx: &RequestContext,
+    _ctx: &RequestContext,
 ) -> Result<(), DeleteTimelineError> {
     let tenant = get_tenant(tenant_id, true).await?;
-    tenant
-        .prepare_and_schedule_delete_timeline(timeline_id, ctx)
-        .await?;
+    DeleteTimelineFlow::run(&tenant, timeline_id, false).await?;
     Ok(())
 }
 
@@ -501,7 +522,7 @@ pub async fn load_tenant(
                 .with_context(|| format!("Failed to remove tenant ignore mark {tenant_ignore_mark:?} during tenant loading"))?;
         }
 
-        let new_tenant = schedule_local_tenant_processing(conf, &tenant_path, broker_client, remote_storage, None, ctx)
+        let new_tenant = schedule_local_tenant_processing(conf, &tenant_path, broker_client, remote_storage, None, &TENANTS, ctx)
             .with_context(|| {
                 format!("Failed to schedule tenant processing in path {tenant_path:?}")
             })?;
@@ -582,7 +603,7 @@ pub async fn attach_tenant(
             .context("check for attach marker file existence")?;
         anyhow::ensure!(marker_file_exists, "create_tenant_files should have created the attach marker file");
 
-        let attached_tenant = schedule_local_tenant_processing(conf, &tenant_dir, broker_client, Some(remote_storage), None, ctx)?;
+        let attached_tenant = schedule_local_tenant_processing(conf, &tenant_dir, broker_client, Some(remote_storage), None, &TENANTS, ctx)?;
         // TODO: tenant object & its background loops remain, untracked in tenant map, if we fail here.
         //      See https://github.com/neondatabase/neon/issues/4233
 
@@ -768,55 +789,6 @@ pub async fn immediate_gc(
     Ok(wait_task_done)
 }
 
-pub async fn immediate_compact(
-    tenant_id: TenantId,
-    timeline_id: TimelineId,
-    ctx: &RequestContext,
-) -> Result<tokio::sync::oneshot::Receiver<anyhow::Result<()>>, ApiError> {
-    let guard = TENANTS.read().await;
-
-    let tenant = guard
-        .get(&tenant_id)
-        .map(Arc::clone)
-        .with_context(|| format!("tenant {tenant_id}"))
-        .map_err(|e| ApiError::NotFound(e.into()))?;
-
-    let timeline = tenant
-        .get_timeline(timeline_id, true)
-        .map_err(|e| ApiError::NotFound(e.into()))?;
-
-    // Run in task_mgr to avoid race with tenant_detach operation
-    let ctx = ctx.detached_child(TaskKind::Compaction, DownloadBehavior::Download);
-    let (task_done, wait_task_done) = tokio::sync::oneshot::channel();
-    task_mgr::spawn(
-        &tokio::runtime::Handle::current(),
-        TaskKind::Compaction,
-        Some(tenant_id),
-        Some(timeline_id),
-        &format!(
-            "timeline_compact_handler compaction run for tenant {tenant_id} timeline {timeline_id}"
-        ),
-        false,
-        async move {
-            let result = timeline
-                .compact(&ctx)
-                .instrument(info_span!("manual_compact", %tenant_id, %timeline_id))
-                .await;
-
-            match task_done.send(result) {
-                Ok(_) => (),
-                Err(result) => error!("failed to send compaction result: {result:?}"),
-            }
-            Ok(())
-        },
-    );
-
-    // drop the guard until after we've spawned the task so that timeline shutdown will wait for the task
-    drop(guard);
-
-    Ok(wait_task_done)
-}
-
 #[cfg(test)]
 mod tests {
     use std::collections::HashMap;

pageserver/src/tenant/remote_timeline_client.rs

@@ -211,6 +211,9 @@ use chrono::{NaiveDateTime, Utc};
 // re-export these
 pub use download::{is_temp_download_file, list_remote_timelines};
 use scopeguard::ScopeGuard;
+use utils::backoff::{
+    self, exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS,
+};
 
 use std::collections::{HashMap, VecDeque};
 use std::path::Path;
@@ -241,7 +244,6 @@ use crate::{
     tenant::upload_queue::{
         UploadOp, UploadQueue, UploadQueueInitialized, UploadQueueStopped, UploadTask,
     },
-    {exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS},
 };
 
 use utils::id::{TenantId, TimelineId};
@@ -256,12 +258,12 @@ use super::upload_queue::SetDeletedFlagProgress;
 // But after FAILED_DOWNLOAD_WARN_THRESHOLD retries, we start to log it at WARN
 // level instead, as repeated failures can mean a more serious problem. If it
 // fails more than FAILED_DOWNLOAD_RETRIES times, we give up
-const FAILED_DOWNLOAD_WARN_THRESHOLD: u32 = 3;
-const FAILED_DOWNLOAD_RETRIES: u32 = 10;
+pub(crate) const FAILED_DOWNLOAD_WARN_THRESHOLD: u32 = 3;
+pub(crate) const FAILED_REMOTE_OP_RETRIES: u32 = 10;
 
 // Similarly log failed uploads and deletions at WARN level, after this many
 // retries. Uploads and deletions are retried forever, though.
-const FAILED_UPLOAD_WARN_THRESHOLD: u32 = 3;
+pub(crate) const FAILED_UPLOAD_WARN_THRESHOLD: u32 = 3;
 
 pub enum MaybeDeletedIndexPart {
     IndexPart(IndexPart),
@@ -514,7 +516,7 @@ impl RemoteTimelineClient {
     /// updated metadata.
     ///
     /// The upload will be added to the queue immediately, but it
-    /// won't be performed until all previosuly scheduled layer file
+    /// won't be performed until all previously scheduled layer file
     /// upload operations have completed successfully.  This is to
     /// ensure that when the index file claims that layers X, Y and Z
     /// exist in remote storage, they really do. To wait for the upload
@@ -625,7 +627,7 @@ impl RemoteTimelineClient {
     /// Note: This schedules an index file upload before the deletions.  The
     /// deletion won't actually be performed, until any previously scheduled
     /// upload operations, and the index file upload, have completed
-    /// succesfully.
+    /// successfully.
     pub fn schedule_layer_file_deletion(
         self: &Arc<Self>,
         names: &[LayerFileName],
@@ -752,12 +754,24 @@ impl RemoteTimelineClient {
 
         pausable_failpoint!("persist_deleted_index_part");
 
-        upload::upload_index_part(
-            self.conf,
-            &self.storage_impl,
-            &self.tenant_id,
-            &self.timeline_id,
-            &index_part_with_deleted_at,
+        backoff::retry(
+            || async {
+                upload::upload_index_part(
+                    self.conf,
+                    &self.storage_impl,
+                    &self.tenant_id,
+                    &self.timeline_id,
+                    &index_part_with_deleted_at,
+                )
+                .await
+            },
+            |_e| false,
+            1,
+            // have just a couple of attempts
+            // when executed as part of timeline deletion this happens in context of api call
+            // when executed as part of tenant deletion this happens in the background
+            2,
+            "persist_index_part_with_deleted_flag",
         )
         .await?;
 
@@ -827,17 +841,26 @@ impl RemoteTimelineClient {
             )
         };
 
-        receiver.changed().await?;
+        receiver.changed().await.context("upload queue shut down")?;
 
         // 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
         let timeline_path = self.conf.timeline_path(&self.tenant_id, &self.timeline_id);
         let timeline_storage_path = self.conf.remote_path(&timeline_path)?;
 
-        let remaining = self
-            .storage_impl
-            .list_prefixes(Some(&timeline_storage_path))
-            .await?;
+        let remaining = backoff::retry(
+            || async {
+                self.storage_impl
+                    .list_prefixes(Some(&timeline_storage_path))
+                    .await
+            },
+            |_e| false,
+            FAILED_DOWNLOAD_WARN_THRESHOLD,
+            FAILED_REMOTE_OP_RETRIES,
+            "list_prefixes",
+        )
+        .await
+        .context("list prefixes")?;
 
         let remaining: Vec<RemotePath> = remaining
             .into_iter()
@@ -852,13 +875,42 @@ impl RemoteTimelineClient {
             .collect();
 
         if !remaining.is_empty() {
-            self.storage_impl.delete_objects(&remaining).await?;
+            backoff::retry(
+                || async { self.storage_impl.delete_objects(&remaining).await },
+                |_e| false,
+                FAILED_UPLOAD_WARN_THRESHOLD,
+                FAILED_REMOTE_OP_RETRIES,
+                "delete_objects",
+            )
+            .await
+            .context("delete_objects")?;
         }
 
+        fail::fail_point!("timeline-delete-before-index-delete", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: timeline-delete-before-index-delete"
+            ))?
+        });
+
         let index_file_path = timeline_storage_path.join(Path::new(IndexPart::FILE_NAME));
 
         debug!("deleting index part");
-        self.storage_impl.delete(&index_file_path).await?;
+
+        backoff::retry(
+            || async { self.storage_impl.delete(&index_file_path).await },
+            |_e| false,
+            FAILED_UPLOAD_WARN_THRESHOLD,
+            FAILED_REMOTE_OP_RETRIES,
+            "delete_index",
+        )
+        .await
+        .context("delete_index")?;
+
+        fail::fail_point!("timeline-delete-after-index-delete", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: timeline-delete-after-index-delete"
+            ))?
+        });
 
         info!(prefix=%timeline_storage_path, referenced=deletions_queued, not_referenced=%remaining.len(), "done deleting in timeline prefix, including index_part.json");
 
@@ -1105,7 +1157,7 @@ impl RemoteTimelineClient {
             debug!("remote task {} completed successfully", task.op);
         }
 
-        // The task has completed succesfully. Remove it from the in-progress list.
+        // The task has completed successfully. Remove it from the in-progress list.
         {
             let mut upload_queue_guard = self.upload_queue.lock().unwrap();
             let upload_queue = match upload_queue_guard.deref_mut() {

pageserver/src/tenant/remote_timeline_client/download.rs

@@ -11,19 +11,17 @@ use std::time::Duration;
 use anyhow::{anyhow, Context};
 use tokio::fs;
 use tokio::io::AsyncWriteExt;
-
-use tracing::{info, warn};
+use utils::backoff;
 
 use crate::config::PageServerConf;
 use crate::tenant::storage_layer::LayerFileName;
 use crate::tenant::timeline::span::debug_assert_current_span_has_tenant_and_timeline_id;
-use crate::{exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS};
 use remote_storage::{DownloadError, GenericRemoteStorage};
 use utils::crashsafe::path_with_suffix_extension;
 use utils::id::{TenantId, TimelineId};
 
 use super::index::{IndexPart, LayerFileMetadata};
-use super::{FAILED_DOWNLOAD_RETRIES, FAILED_DOWNLOAD_WARN_THRESHOLD};
+use super::{FAILED_DOWNLOAD_WARN_THRESHOLD, FAILED_REMOTE_OP_RETRIES};
 
 async fn fsync_path(path: impl AsRef<std::path::Path>) -> Result<(), std::io::Error> {
     fs::File::open(path).await?.sync_all().await
@@ -268,7 +266,6 @@ pub(super) async fn download_index_part(
     Ok(index_part)
 }
 
-///
 /// Helper function to handle retries for a download operation.
 ///
 /// Remote operations can fail due to rate limits (IAM, S3), spurious network
@@ -276,47 +273,17 @@ pub(super) async fn download_index_part(
 /// with backoff.
 ///
 /// (See similar logic for uploads in `perform_upload_task`)
-async fn download_retry<T, O, F>(mut op: O, description: &str) -> Result<T, DownloadError>
+async fn download_retry<T, O, F>(op: O, description: &str) -> Result<T, DownloadError>
 where
     O: FnMut() -> F,
     F: Future<Output = Result<T, DownloadError>>,
 {
-    let mut attempts = 0;
-    loop {
-        let result = op().await;
-        match result {
-            Ok(_) => {
-                if attempts > 0 {
-                    info!("{description} succeeded after {attempts} retries");
-                }
-                return result;
-            }
-
-            // These are "permanent" errors that should not be retried.
-            Err(DownloadError::BadInput(_)) | Err(DownloadError::NotFound) => {
-                return result;
-            }
-            // Assume that any other failure might be transient, and the operation might
-            // succeed if we just keep trying.
-            Err(DownloadError::Other(err)) if attempts < FAILED_DOWNLOAD_WARN_THRESHOLD => {
-                info!("{description} failed, will retry (attempt {attempts}): {err:#}");
-            }
-            Err(DownloadError::Other(err)) if attempts < FAILED_DOWNLOAD_RETRIES => {
-                warn!("{description} failed, will retry (attempt {attempts}): {err:#}");
-            }
-            Err(DownloadError::Other(ref err)) => {
-                // Operation failed FAILED_DOWNLOAD_RETRIES times. Time to give up.
-                warn!("{description} still failed after {attempts} retries, giving up: {err:?}");
-                return result;
-            }
-        }
-        // sleep and retry
-        exponential_backoff(
-            attempts,
-            DEFAULT_BASE_BACKOFF_SECONDS,
-            DEFAULT_MAX_BACKOFF_SECONDS,
-        )
-        .await;
-        attempts += 1;
-    }
+    backoff::retry(
+        op,
+        |e| matches!(e, DownloadError::BadInput(_) | DownloadError::NotFound),
+        FAILED_DOWNLOAD_WARN_THRESHOLD,
+        FAILED_REMOTE_OP_RETRIES,
+        description,
+    )
+    .await
 }

pageserver/src/tenant/remote_timeline_client/index.rs

@@ -223,6 +223,45 @@ mod tests {
         assert_eq!(part, expected);
     }
 
+    #[test]
+    fn v2_indexpart_is_parsed_with_deleted_at() {
+        let example = r#"{
+            "version":2,
+            "timeline_layers":["000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__0000000001696070-00000000016960E9"],
+            "missing_layers":["This shouldn't fail deserialization"],
+            "layer_metadata":{
+                "000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__0000000001696070-00000000016960E9": { "file_size": 25600000 },
+                "000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000016B59D8-00000000016B5A51": { "file_size": 9007199254741001 }
+            },
+            "disk_consistent_lsn":"0/16960E8",
+            "metadata_bytes":[112,11,159,210,0,54,0,4,0,0,0,0,1,105,96,232,1,0,0,0,0,1,105,96,112,0,0,0,0,0,0,0,0,0,0,0,0,0,1,105,96,112,0,0,0,0,1,105,96,112,0,0,0,14,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],
+            "deleted_at": "2023-07-31T09:00:00.123"
+        }"#;
+
+        let expected = IndexPart {
+            // note this is not verified, could be anything, but exists for humans debugging.. could be the git version instead?
+            version: 2,
+            timeline_layers: HashSet::from(["000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__0000000001696070-00000000016960E9".parse().unwrap()]),
+            layer_metadata: HashMap::from([
+                ("000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__0000000001696070-00000000016960E9".parse().unwrap(), IndexLayerMetadata {
+                    file_size: 25600000,
+                }),
+                ("000000000000000000000000000000000000-FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF__00000000016B59D8-00000000016B5A51".parse().unwrap(), IndexLayerMetadata {
+                    // serde_json should always parse this but this might be a double with jq for
+                    // example.
+                    file_size: 9007199254741001,
+                })
+            ]),
+            disk_consistent_lsn: "0/16960E8".parse::<Lsn>().unwrap(),
+            metadata_bytes: [112,11,159,210,0,54,0,4,0,0,0,0,1,105,96,232,1,0,0,0,0,1,105,96,112,0,0,0,0,0,0,0,0,0,0,0,0,0,1,105,96,112,0,0,0,0,1,105,96,112,0,0,0,14,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0].to_vec(),
+            deleted_at: Some(chrono::NaiveDateTime::parse_from_str(
+                "2023-07-31T09:00:00.123000000", "%Y-%m-%dT%H:%M:%S.%f").unwrap())
+        };
+
+        let part = serde_json::from_str::<IndexPart>(example).unwrap();
+        assert_eq!(part, expected);
+    }
+
     #[test]
     fn empty_layers_are_parsed() {
         let empty_layers_json = r#"{

pageserver/src/tenant/storage_layer.rs

@@ -8,8 +8,8 @@ mod layer_desc;
 mod remote_layer;
 
 use crate::config::PageServerConf;
-use crate::context::RequestContext;
-use crate::repository::{Key, Value};
+use crate::context::{AccessStatsBehavior, RequestContext};
+use crate::repository::Key;
 use crate::task_mgr::TaskKind;
 use crate::walrecord::NeonWalRecord;
 use anyhow::Result;
@@ -34,7 +34,7 @@ use utils::{
     lsn::Lsn,
 };
 
-pub use delta_layer::{DeltaLayer, DeltaLayerWriter};
+pub use delta_layer::{DeltaLayer, DeltaLayerWriter, ValueRef};
 pub use filename::{DeltaFileName, ImageFileName, LayerFileName};
 pub use image_layer::{ImageLayer, ImageLayerWriter};
 pub use inmemory_layer::InMemoryLayer;
@@ -241,10 +241,14 @@ impl LayerAccessStats {
         });
     }
 
-    fn record_access(&self, access_kind: LayerAccessKind, task_kind: TaskKind) {
+    fn record_access(&self, access_kind: LayerAccessKind, ctx: &RequestContext) {
+        if ctx.access_stats_behavior() == AccessStatsBehavior::Skip {
+            return;
+        }
+
         let this_access = LayerAccessStatFullDetails {
             when: SystemTime::now(),
-            task_kind,
+            task_kind: ctx.task_kind(),
             access_kind,
         };
 
@@ -252,7 +256,7 @@ impl LayerAccessStats {
         locked.iter_mut().for_each(|inner| {
             inner.first_access.get_or_insert(this_access);
             inner.count_by_access_kind[access_kind] += 1;
-            inner.task_kind_flag |= task_kind;
+            inner.task_kind_flag |= ctx.task_kind();
             inner.last_accesses.write(this_access);
         })
     }
@@ -338,7 +342,8 @@ impl LayerAccessStats {
 /// All layers should implement a minimal `std::fmt::Debug` without tenant or
 /// timeline names, because those are known in the context of which the layers
 /// are used in (timeline).
-pub trait Layer: std::fmt::Debug + std::fmt::Display + Send + Sync {
+#[async_trait::async_trait]
+pub trait Layer: std::fmt::Debug + std::fmt::Display + Send + Sync + 'static {
     /// Range of keys that this layer covers
     fn get_key_range(&self) -> Range<Key>;
 
@@ -368,7 +373,7 @@ pub trait Layer: std::fmt::Debug + std::fmt::Display + Send + Sync {
     /// is available. If this returns ValueReconstructResult::Continue, look up
     /// the predecessor layer and call again with the same 'reconstruct_data' to
     /// collect more data.
-    fn get_value_reconstruct_data(
+    async fn get_value_reconstruct_data(
         &self,
         key: Key,
         lsn_range: Range<Lsn>,
@@ -377,15 +382,9 @@ pub trait Layer: std::fmt::Debug + std::fmt::Display + Send + Sync {
     ) -> Result<ValueReconstructResult>;
 
     /// Dump summary of the contents of the layer to stdout
-    fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()>;
+    async fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()>;
 }
 
-/// Returned by [`PersistentLayer::iter`]
-pub type LayerIter<'i> = Box<dyn Iterator<Item = Result<(Key, Lsn, Value)>> + 'i + Send>;
-
-/// Returned by [`PersistentLayer::key_iter`]
-pub type LayerKeyIter<'i> = Box<dyn Iterator<Item = (Key, Lsn, u64)> + 'i + Send>;
-
 /// Get a layer descriptor from a layer.
 pub trait AsLayerDesc {
     /// Get the layer descriptor.
@@ -406,16 +405,6 @@ pub trait AsLayerDesc {
 /// An image layer is a snapshot of all the data in a key-range, at a single
 /// LSN.
 pub trait PersistentLayer: Layer + AsLayerDesc {
-    /// Identify the tenant this layer belongs to
-    fn get_tenant_id(&self) -> TenantId {
-        self.layer_desc().tenant_id
-    }
-
-    /// Identify the timeline this layer belongs to
-    fn get_timeline_id(&self) -> TimelineId {
-        self.layer_desc().timeline_id
-    }
-
     /// File name used for this layer, both in the pageserver's local filesystem
     /// state as well as in the remote storage.
     fn filename(&self) -> LayerFileName {
@@ -426,15 +415,6 @@ pub trait PersistentLayer: Layer + AsLayerDesc {
     // `None` for `RemoteLayer`.
     fn local_path(&self) -> Option<PathBuf>;
 
-    /// Iterate through all keys and values stored in the layer
-    fn iter(&self, ctx: &RequestContext) -> Result<LayerIter<'_>>;
-
-    /// Iterate through all keys stored in the layer. Returns key, lsn and value size
-    /// It is used only for compaction and so is currently implemented only for DeltaLayer
-    fn key_iter(&self, _ctx: &RequestContext) -> Result<LayerKeyIter<'_>> {
-        panic!("Not implemented")
-    }
-
     /// Permanently remove this layer from disk.
     fn delete_resident_layer_file(&self) -> Result<()>;
 
@@ -450,14 +430,6 @@ pub trait PersistentLayer: Layer + AsLayerDesc {
         false
     }
 
-    /// Returns None if the layer file size is not known.
-    ///
-    /// Should not change over the lifetime of the layer object because
-    /// current_physical_size is computed as the som of this value.
-    fn file_size(&self) -> u64 {
-        self.layer_desc().file_size
-    }
-
     fn info(&self, reset: LayerAccessStatsReset) -> HistoricLayerInfo;
 
     fn access_stats(&self) -> &LayerAccessStats;

pageserver/src/tenant/storage_layer/delta_layer.rs

@@ -29,10 +29,10 @@
 //!
 use crate::config::PageServerConf;
 use crate::context::RequestContext;
-use crate::page_cache::{PageReadGuard, PAGE_SZ};
+use crate::page_cache::PAGE_SZ;
 use crate::repository::{Key, Value, KEY_SIZE};
-use crate::tenant::blob_io::{BlobCursor, BlobWriter, WriteBlobWriter};
-use crate::tenant::block_io::{BlockBuf, BlockCursor, BlockReader, FileBlockReader};
+use crate::tenant::blob_io::{BlobWriter, WriteBlobWriter};
+use crate::tenant::block_io::{BlockBuf, BlockCursor, BlockLease, BlockReader, FileBlockReader};
 use crate::tenant::disk_btree::{DiskBtreeBuilder, DiskBtreeReader, VisitDirection};
 use crate::tenant::storage_layer::{
     PersistentLayer, ValueReconstructResult, ValueReconstructState,
@@ -41,7 +41,6 @@ use crate::virtual_file::VirtualFile;
 use crate::{walrecord, TEMP_FILE_SUFFIX};
 use crate::{DELTA_FILE_MAGIC, STORAGE_FORMAT_VERSION};
 use anyhow::{bail, ensure, Context, Result};
-use once_cell::sync::OnceCell;
 use pageserver_api::models::{HistoricLayerInfo, LayerAccessKind};
 use rand::{distributions::Alphanumeric, Rng};
 use serde::{Deserialize, Serialize};
@@ -52,6 +51,8 @@ use std::ops::Range;
 use std::os::unix::fs::FileExt;
 use std::path::{Path, PathBuf};
 use std::sync::Arc;
+use tokio::runtime::Handle;
+use tokio::sync::OnceCell;
 use tracing::*;
 
 use utils::{
@@ -61,8 +62,8 @@ use utils::{
 };
 
 use super::{
-    AsLayerDesc, DeltaFileName, Layer, LayerAccessStats, LayerAccessStatsReset, LayerIter,
-    LayerKeyIter, PathOrConf, PersistentLayerDesc,
+    AsLayerDesc, DeltaFileName, Layer, LayerAccessStats, LayerAccessStatsReset, PathOrConf,
+    PersistentLayerDesc,
 };
 
 ///
@@ -90,14 +91,30 @@ pub struct Summary {
 
 impl From<&DeltaLayer> for Summary {
     fn from(layer: &DeltaLayer) -> Self {
+        Self::expected(
+            layer.desc.tenant_id,
+            layer.desc.timeline_id,
+            layer.desc.key_range.clone(),
+            layer.desc.lsn_range.clone(),
+        )
+    }
+}
+
+impl Summary {
+    pub(super) fn expected(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+        keys: Range<Key>,
+        lsns: Range<Lsn>,
+    ) -> Self {
         Self {
             magic: DELTA_FILE_MAGIC,
             format_version: STORAGE_FORMAT_VERSION,
 
-            tenant_id: layer.desc.tenant_id,
-            timeline_id: layer.desc.timeline_id,
-            key_range: layer.desc.key_range.clone(),
-            lsn_range: layer.desc.lsn_range.clone(),
+            tenant_id,
+            timeline_id,
+            key_range: keys,
+            lsn_range: lsns,
 
             index_start_blk: 0,
             index_root_blk: 0,
@@ -108,12 +125,10 @@ impl From<&DeltaLayer> for Summary {
 // Flag indicating that this version initialize the page
 const WILL_INIT: u64 = 1;
 
-///
 /// Struct representing reference to BLOB in layers. Reference contains BLOB
 /// offset, and for WAL records it also contains `will_init` flag. The flag
 /// helps to determine the range of records that needs to be applied, without
 /// reading/deserializing records themselves.
-///
 #[derive(Debug, Serialize, Deserialize, Copy, Clone)]
 pub struct BlobRef(pub u64);
 
@@ -138,10 +153,8 @@ impl BlobRef {
 pub const DELTA_KEY_SIZE: usize = KEY_SIZE + 8;
 struct DeltaKey([u8; DELTA_KEY_SIZE]);
 
-///
 /// This is the key of the B-tree index stored in the delta layer. It consists
 /// of the serialized representation of a Key and LSN.
-///
 impl DeltaKey {
     fn from_slice(buf: &[u8]) -> Self {
         let mut bytes: [u8; DELTA_KEY_SIZE] = [0u8; DELTA_KEY_SIZE];
@@ -189,7 +202,7 @@ pub struct DeltaLayer {
 
     access_stats: LayerAccessStats,
 
-    inner: OnceCell<DeltaLayerInner>,
+    inner: OnceCell<Arc<DeltaLayerInner>>,
 }
 
 impl std::fmt::Debug for DeltaLayer {
@@ -214,6 +227,12 @@ pub struct DeltaLayerInner {
     file: FileBlockReader<VirtualFile>,
 }
 
+impl AsRef<DeltaLayerInner> for DeltaLayerInner {
+    fn as_ref(&self) -> &DeltaLayerInner {
+        self
+    }
+}
+
 impl std::fmt::Debug for DeltaLayerInner {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("DeltaLayerInner")
@@ -223,9 +242,10 @@ impl std::fmt::Debug for DeltaLayerInner {
     }
 }
 
+#[async_trait::async_trait]
 impl Layer for DeltaLayer {
     /// debugging function to print out the contents of the layer
-    fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
+    async fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
         println!(
             "----- delta layer for ten {} tli {} keys {}-{} lsn {}-{} size {} ----",
             self.desc.tenant_id,
@@ -241,7 +261,7 @@ impl Layer for DeltaLayer {
             return Ok(());
         }
 
-        let inner = self.load(LayerAccessKind::Dump, ctx)?;
+        let inner = self.load(LayerAccessKind::Dump, ctx).await?;
 
         println!(
             "index_start_blk: {}, root {}",
@@ -255,13 +275,14 @@ impl Layer for DeltaLayer {
             file,
         );
 
-        tree_reader.dump()?;
+        tree_reader.dump().await?;
 
-        let mut cursor = file.block_cursor();
+        let cursor = file.block_cursor();
 
         // A subroutine to dump a single blob
-        let mut dump_blob = |blob_ref: BlobRef| -> anyhow::Result<String> {
-            let buf = cursor.read_blob(blob_ref.pos())?;
+        let dump_blob = |blob_ref: BlobRef| -> anyhow::Result<String> {
+            // TODO this is not ideal, but on the other hand we are in dumping code...
+            let buf = Handle::current().block_on(cursor.read_blob(blob_ref.pos()))?;
             let val = Value::des(&buf)?;
             let desc = match val {
                 Value::Image(img) => {
@@ -280,27 +301,29 @@ impl Layer for DeltaLayer {
             Ok(desc)
         };
 
-        tree_reader.visit(
-            &[0u8; DELTA_KEY_SIZE],
-            VisitDirection::Forwards,
-            |delta_key, val| {
-                let blob_ref = BlobRef(val);
-                let key = DeltaKey::extract_key_from_buf(delta_key);
-                let lsn = DeltaKey::extract_lsn_from_buf(delta_key);
+        tree_reader
+            .visit(
+                &[0u8; DELTA_KEY_SIZE],
+                VisitDirection::Forwards,
+                |delta_key, val| {
+                    let blob_ref = BlobRef(val);
+                    let key = DeltaKey::extract_key_from_buf(delta_key);
+                    let lsn = DeltaKey::extract_lsn_from_buf(delta_key);
 
-                let desc = match dump_blob(blob_ref) {
-                    Ok(desc) => desc,
-                    Err(err) => format!("ERROR: {}", err),
-                };
-                println!("  key {} at {}: {}", key, lsn, desc);
-                true
-            },
-        )?;
+                    let desc = match dump_blob(blob_ref) {
+                        Ok(desc) => desc,
+                        Err(err) => format!("ERROR: {}", err),
+                    };
+                    println!("  key {} at {}: {}", key, lsn, desc);
+                    true
+                },
+            )
+            .await?;
 
         Ok(())
     }
 
-    fn get_value_reconstruct_data(
+    async fn get_value_reconstruct_data(
         &self,
         key: Key,
         lsn_range: Range<Lsn>,
@@ -308,82 +331,15 @@ impl Layer for DeltaLayer {
         ctx: &RequestContext,
     ) -> anyhow::Result<ValueReconstructResult> {
         ensure!(lsn_range.start >= self.desc.lsn_range.start);
-        let mut need_image = true;
 
         ensure!(self.desc.key_range.contains(&key));
 
-        {
-            // Open the file and lock the metadata in memory
-            let inner = self.load(LayerAccessKind::GetValueReconstructData, ctx)?;
-
-            // Scan the page versions backwards, starting from `lsn`.
-            let file = &inner.file;
-            let tree_reader = DiskBtreeReader::<_, DELTA_KEY_SIZE>::new(
-                inner.index_start_blk,
-                inner.index_root_blk,
-                file,
-            );
-            let search_key = DeltaKey::from_key_lsn(&key, Lsn(lsn_range.end.0 - 1));
-
-            let mut offsets: Vec<(Lsn, u64)> = Vec::new();
-
-            tree_reader.visit(&search_key.0, VisitDirection::Backwards, |key, value| {
-                let blob_ref = BlobRef(value);
-                if key[..KEY_SIZE] != search_key.0[..KEY_SIZE] {
-                    return false;
-                }
-                let entry_lsn = DeltaKey::extract_lsn_from_buf(key);
-                if entry_lsn < lsn_range.start {
-                    return false;
-                }
-                offsets.push((entry_lsn, blob_ref.pos()));
-
-                !blob_ref.will_init()
-            })?;
-
-            // Ok, 'offsets' now contains the offsets of all the entries we need to read
-            let mut cursor = file.block_cursor();
-            let mut buf = Vec::new();
-            for (entry_lsn, pos) in offsets {
-                cursor.read_blob_into_buf(pos, &mut buf).with_context(|| {
-                    format!(
-                        "Failed to read blob from virtual file {}",
-                        file.file.path.display()
-                    )
-                })?;
-                let val = Value::des(&buf).with_context(|| {
-                    format!(
-                        "Failed to deserialize file blob from virtual file {}",
-                        file.file.path.display()
-                    )
-                })?;
-                match val {
-                    Value::Image(img) => {
-                        reconstruct_state.img = Some((entry_lsn, img));
-                        need_image = false;
-                        break;
-                    }
-                    Value::WalRecord(rec) => {
-                        let will_init = rec.will_init();
-                        reconstruct_state.records.push((entry_lsn, rec));
-                        if will_init {
-                            // This WAL record initializes the page, so no need to go further back
-                            need_image = false;
-                            break;
-                        }
-                    }
-                }
-            }
-            // release metadata lock and close the file
-        }
-
-        // If an older page image is needed to reconstruct the page, let the
-        // caller know.
-        if need_image {
-            Ok(ValueReconstructResult::Continue)
-        } else {
-            Ok(ValueReconstructResult::Complete)
-        }
+        let inner = self
+            .load(LayerAccessKind::GetValueReconstructData, ctx)
+            .await?;
+        inner
+            .get_value_reconstruct_data(key, lsn_range, reconstruct_state)
+            .await
     }
 
     /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
@@ -423,23 +379,6 @@ impl PersistentLayer for DeltaLayer {
         Some(self.path())
     }
 
-    fn iter(&self, ctx: &RequestContext) -> Result<LayerIter<'_>> {
-        let inner = self
-            .load(LayerAccessKind::KeyIter, ctx)
-            .context("load delta layer")?;
-        Ok(match DeltaValueIter::new(inner) {
-            Ok(iter) => Box::new(iter),
-            Err(err) => Box::new(std::iter::once(Err(err))),
-        })
-    }
-
-    fn key_iter(&self, ctx: &RequestContext) -> Result<LayerKeyIter<'_>> {
-        let inner = self.load(LayerAccessKind::KeyIter, ctx)?;
-        Ok(Box::new(
-            DeltaKeyIter::new(inner).context("Layer index is corrupted")?,
-        ))
-    }
-
     fn delete_resident_layer_file(&self) -> Result<()> {
         // delete underlying file
         fs::remove_file(self.path())?;
@@ -509,55 +448,43 @@ impl DeltaLayer {
     /// Open the underlying file and read the metadata into memory, if it's
     /// not loaded already.
     ///
-    fn load(&self, access_kind: LayerAccessKind, ctx: &RequestContext) -> Result<&DeltaLayerInner> {
-        self.access_stats
-            .record_access(access_kind, ctx.task_kind());
+    async fn load(
+        &self,
+        access_kind: LayerAccessKind,
+        ctx: &RequestContext,
+    ) -> Result<&Arc<DeltaLayerInner>> {
+        self.access_stats.record_access(access_kind, ctx);
         // Quick exit if already loaded
         self.inner
             .get_or_try_init(|| self.load_inner())
+            .await
             .with_context(|| format!("Failed to load delta layer {}", self.path().display()))
     }
 
-    fn load_inner(&self) -> Result<DeltaLayerInner> {
+    async fn load_inner(&self) -> Result<Arc<DeltaLayerInner>> {
         let path = self.path();
 
-        let file = VirtualFile::open(&path)
-            .with_context(|| format!("Failed to open file '{}'", path.display()))?;
-        let file = FileBlockReader::new(file);
+        let summary = match &self.path_or_conf {
+            PathOrConf::Conf(_) => Some(Summary::from(self)),
+            PathOrConf::Path(_) => None,
+        };
 
-        let summary_blk = file.read_blk(0)?;
-        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
+        let loaded = DeltaLayerInner::load(&path, summary)?;
 
-        match &self.path_or_conf {
-            PathOrConf::Conf(_) => {
-                let mut expected_summary = Summary::from(self);
-                expected_summary.index_start_blk = actual_summary.index_start_blk;
-                expected_summary.index_root_blk = actual_summary.index_root_blk;
-                if actual_summary != expected_summary {
-                    bail!("in-file summary does not match expected summary. actual = {:?} expected = {:?}", actual_summary, expected_summary);
-                }
-            }
-            PathOrConf::Path(path) => {
-                let actual_filename = path.file_name().unwrap().to_str().unwrap().to_owned();
-                let expected_filename = self.filename().file_name();
+        if let PathOrConf::Path(ref path) = self.path_or_conf {
+            // not production code
 
-                if actual_filename != expected_filename {
-                    println!(
-                        "warning: filename does not match what is expected from in-file summary"
-                    );
-                    println!("actual: {:?}", actual_filename);
-                    println!("expected: {:?}", expected_filename);
-                }
+            let actual_filename = path.file_name().unwrap().to_str().unwrap().to_owned();
+            let expected_filename = self.filename().file_name();
+
+            if actual_filename != expected_filename {
+                println!("warning: filename does not match what is expected from in-file summary");
+                println!("actual: {:?}", actual_filename);
+                println!("expected: {:?}", expected_filename);
             }
         }
 
-        debug!("loaded from {}", &path.display());
-
-        Ok(DeltaLayerInner {
-            file,
-            index_start_blk: actual_summary.index_start_blk,
-            index_root_blk: actual_summary.index_root_blk,
-        })
+        Ok(Arc::new(loaded))
     }
 
     /// Create a DeltaLayer struct representing an existing file on disk.
@@ -579,7 +506,7 @@ impl DeltaLayer {
                 file_size,
             ),
             access_stats,
-            inner: once_cell::sync::OnceCell::new(),
+            inner: OnceCell::new(),
         }
     }
 
@@ -606,7 +533,7 @@ impl DeltaLayer {
                 metadata.len(),
             ),
             access_stats: LayerAccessStats::empty_will_record_residence_event_later(),
-            inner: once_cell::sync::OnceCell::new(),
+            inner: OnceCell::new(),
         })
     }
 
@@ -622,6 +549,33 @@ impl DeltaLayer {
             &self.layer_name(),
         )
     }
+
+    /// Obtains all keys and value references stored in the layer
+    ///
+    /// The value can be obtained via the [`ValueRef::load`] function.
+    pub async fn load_val_refs(
+        &self,
+        ctx: &RequestContext,
+    ) -> Result<Vec<(Key, Lsn, ValueRef<Arc<DeltaLayerInner>>)>> {
+        let inner = self
+            .load(LayerAccessKind::Iter, ctx)
+            .await
+            .context("load delta layer")?;
+        DeltaLayerInner::load_val_refs(inner)
+            .await
+            .context("Layer index is corrupted")
+    }
+
+    /// Loads all keys stored in the layer. Returns key, lsn and value size.
+    pub async fn load_keys(&self, ctx: &RequestContext) -> Result<Vec<(Key, Lsn, u64)>> {
+        let inner = self
+            .load(LayerAccessKind::KeyIter, ctx)
+            .await
+            .context("load delta layer keys")?;
+        DeltaLayerInner::load_keys(inner)
+            .await
+            .context("Layer index is corrupted")
+    }
 }
 
 /// A builder object for constructing a new delta layer.
@@ -770,7 +724,7 @@ impl DeltaLayerWriterInner {
                 metadata.len(),
             ),
             access_stats: LayerAccessStats::empty_will_record_residence_event_later(),
-            inner: once_cell::sync::OnceCell::new(),
+            inner: OnceCell::new(),
         };
 
         // fsync the file
@@ -892,168 +846,202 @@ impl Drop for DeltaLayerWriter {
     }
 }
 
-///
-/// Iterator over all key-value pairse stored in a delta layer
-///
-/// FIXME: This creates a Vector to hold the offsets of all key value pairs.
-/// That takes up quite a lot of memory. Should do this in a more streaming
-/// fashion.
-///
-struct DeltaValueIter<'a> {
-    all_offsets: Vec<(DeltaKey, BlobRef)>,
-    next_idx: usize,
-    reader: BlockCursor<Adapter<'a>>,
-}
+impl DeltaLayerInner {
+    pub(super) fn load(path: &std::path::Path, summary: Option<Summary>) -> anyhow::Result<Self> {
+        let file = VirtualFile::open(path)
+            .with_context(|| format!("Failed to open file '{}'", path.display()))?;
+        let file = FileBlockReader::new(file);
 
-struct Adapter<'a>(&'a DeltaLayerInner);
+        let summary_blk = file.read_blk(0)?;
+        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
 
-impl<'a> BlockReader for Adapter<'a> {
-    type BlockLease = PageReadGuard<'static>;
+        if let Some(mut expected_summary) = summary {
+            // production code path
+            expected_summary.index_start_blk = actual_summary.index_start_blk;
+            expected_summary.index_root_blk = actual_summary.index_root_blk;
+            if actual_summary != expected_summary {
+                bail!(
+                    "in-file summary does not match expected summary. actual = {:?} expected = {:?}",
+                    actual_summary,
+                    expected_summary
+                );
+            }
+        }
 
-    fn read_blk(&self, blknum: u32) -> Result<Self::BlockLease, std::io::Error> {
-        self.0.file.read_blk(blknum)
+        Ok(DeltaLayerInner {
+            file,
+            index_start_blk: actual_summary.index_start_blk,
+            index_root_blk: actual_summary.index_root_blk,
+        })
     }
-}
 
-impl<'a> Iterator for DeltaValueIter<'a> {
-    type Item = Result<(Key, Lsn, Value)>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.next_res().transpose()
-    }
-}
-
-impl<'a> DeltaValueIter<'a> {
-    fn new(inner: &'a DeltaLayerInner) -> Result<Self> {
-        let file = &inner.file;
+    pub(super) async fn get_value_reconstruct_data(
+        &self,
+        key: Key,
+        lsn_range: Range<Lsn>,
+        reconstruct_state: &mut ValueReconstructState,
+    ) -> anyhow::Result<ValueReconstructResult> {
+        let mut need_image = true;
+        // Scan the page versions backwards, starting from `lsn`.
+        let file = &self.file;
         let tree_reader = DiskBtreeReader::<_, DELTA_KEY_SIZE>::new(
-            inner.index_start_blk,
-            inner.index_root_blk,
+            self.index_start_blk,
+            self.index_root_blk,
             file,
         );
+        let search_key = DeltaKey::from_key_lsn(&key, Lsn(lsn_range.end.0 - 1));
 
-        let mut all_offsets: Vec<(DeltaKey, BlobRef)> = Vec::new();
-        tree_reader.visit(
-            &[0u8; DELTA_KEY_SIZE],
-            VisitDirection::Forwards,
-            |key, value| {
-                all_offsets.push((DeltaKey::from_slice(key), BlobRef(value)));
-                true
-            },
-        )?;
+        let mut offsets: Vec<(Lsn, u64)> = Vec::new();
 
-        let iter = DeltaValueIter {
-            all_offsets,
-            next_idx: 0,
-            reader: BlockCursor::new(Adapter(inner)),
-        };
+        tree_reader
+            .visit(&search_key.0, VisitDirection::Backwards, |key, value| {
+                let blob_ref = BlobRef(value);
+                if key[..KEY_SIZE] != search_key.0[..KEY_SIZE] {
+                    return false;
+                }
+                let entry_lsn = DeltaKey::extract_lsn_from_buf(key);
+                if entry_lsn < lsn_range.start {
+                    return false;
+                }
+                offsets.push((entry_lsn, blob_ref.pos()));
 
-        Ok(iter)
-    }
+                !blob_ref.will_init()
+            })
+            .await?;
 
-    fn next_res(&mut self) -> Result<Option<(Key, Lsn, Value)>> {
-        if self.next_idx < self.all_offsets.len() {
-            let (delta_key, blob_ref) = &self.all_offsets[self.next_idx];
-
-            let key = delta_key.key();
-            let lsn = delta_key.lsn();
-
-            let buf = self.reader.read_blob(blob_ref.pos())?;
-            let val = Value::des(&buf)?;
-            self.next_idx += 1;
-            Ok(Some((key, lsn, val)))
-        } else {
-            Ok(None)
-        }
-    }
-}
-///
-/// Iterator over all keys stored in a delta layer
-///
-/// FIXME: This creates a Vector to hold all keys.
-/// That takes up quite a lot of memory. Should do this in a more streaming
-/// fashion.
-///
-struct DeltaKeyIter {
-    all_keys: Vec<(DeltaKey, u64)>,
-    next_idx: usize,
-}
-
-impl Iterator for DeltaKeyIter {
-    type Item = (Key, Lsn, u64);
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.next_idx < self.all_keys.len() {
-            let (delta_key, size) = &self.all_keys[self.next_idx];
-
-            let key = delta_key.key();
-            let lsn = delta_key.lsn();
-
-            self.next_idx += 1;
-            Some((key, lsn, *size))
-        } else {
-            None
-        }
-    }
-}
-
-impl<'a> DeltaKeyIter {
-    fn new(inner: &'a DeltaLayerInner) -> Result<Self> {
-        let file = &inner.file;
-        let tree_reader = DiskBtreeReader::<_, DELTA_KEY_SIZE>::new(
-            inner.index_start_blk,
-            inner.index_root_blk,
-            file,
-        );
-
-        let mut all_keys: Vec<(DeltaKey, u64)> = Vec::new();
-        tree_reader.visit(
-            &[0u8; DELTA_KEY_SIZE],
-            VisitDirection::Forwards,
-            |key, value| {
-                let delta_key = DeltaKey::from_slice(key);
-                let pos = BlobRef(value).pos();
-                if let Some(last) = all_keys.last_mut() {
-                    if last.0.key() == delta_key.key() {
-                        return true;
-                    } else {
-                        // subtract offset of new key BLOB and first blob of this key
-                        // to get total size if values associated with this key
-                        let first_pos = last.1;
-                        last.1 = pos - first_pos;
+        // Ok, 'offsets' now contains the offsets of all the entries we need to read
+        let cursor = file.block_cursor();
+        let mut buf = Vec::new();
+        for (entry_lsn, pos) in offsets {
+            cursor
+                .read_blob_into_buf(pos, &mut buf)
+                .await
+                .with_context(|| {
+                    format!(
+                        "Failed to read blob from virtual file {}",
+                        file.file.path.display()
+                    )
+                })?;
+            let val = Value::des(&buf).with_context(|| {
+                format!(
+                    "Failed to deserialize file blob from virtual file {}",
+                    file.file.path.display()
+                )
+            })?;
+            match val {
+                Value::Image(img) => {
+                    reconstruct_state.img = Some((entry_lsn, img));
+                    need_image = false;
+                    break;
+                }
+                Value::WalRecord(rec) => {
+                    let will_init = rec.will_init();
+                    reconstruct_state.records.push((entry_lsn, rec));
+                    if will_init {
+                        // This WAL record initializes the page, so no need to go further back
+                        need_image = false;
+                        break;
                     }
                 }
-                all_keys.push((delta_key, pos));
-                true
-            },
-        )?;
+            }
+        }
+
+        // If an older page image is needed to reconstruct the page, let the
+        // caller know.
+        if need_image {
+            Ok(ValueReconstructResult::Continue)
+        } else {
+            Ok(ValueReconstructResult::Complete)
+        }
+    }
+
+    pub(super) async fn load_val_refs<T: AsRef<DeltaLayerInner> + Clone>(
+        this: &T,
+    ) -> Result<Vec<(Key, Lsn, ValueRef<T>)>> {
+        let dl = this.as_ref();
+        let file = &dl.file;
+        let tree_reader =
+            DiskBtreeReader::<_, DELTA_KEY_SIZE>::new(dl.index_start_blk, dl.index_root_blk, file);
+
+        let mut all_offsets = Vec::<(Key, Lsn, ValueRef<T>)>::new();
+        tree_reader
+            .visit(
+                &[0u8; DELTA_KEY_SIZE],
+                VisitDirection::Forwards,
+                |key, value| {
+                    let delta_key = DeltaKey::from_slice(key);
+                    let val_ref = ValueRef {
+                        blob_ref: BlobRef(value),
+                        reader: BlockCursor::new(Adapter(this.clone())),
+                    };
+                    all_offsets.push((delta_key.key(), delta_key.lsn(), val_ref));
+                    true
+                },
+            )
+            .await?;
+
+        Ok(all_offsets)
+    }
+
+    pub(super) async fn load_keys(&self) -> Result<Vec<(Key, Lsn, u64)>> {
+        let file = &self.file;
+        let tree_reader = DiskBtreeReader::<_, DELTA_KEY_SIZE>::new(
+            self.index_start_blk,
+            self.index_root_blk,
+            file,
+        );
+
+        let mut all_keys: Vec<(Key, Lsn, u64)> = Vec::new();
+        tree_reader
+            .visit(
+                &[0u8; DELTA_KEY_SIZE],
+                VisitDirection::Forwards,
+                |key, value| {
+                    let delta_key = DeltaKey::from_slice(key);
+                    let pos = BlobRef(value).pos();
+                    if let Some(last) = all_keys.last_mut() {
+                        if last.0 == delta_key.key() {
+                            return true;
+                        } else {
+                            // subtract offset of new key BLOB and first blob of this key
+                            // to get total size if values associated with this key
+                            let first_pos = last.2;
+                            last.2 = pos - first_pos;
+                        }
+                    }
+                    all_keys.push((delta_key.key(), delta_key.lsn(), pos));
+                    true
+                },
+            )
+            .await?;
         if let Some(last) = all_keys.last_mut() {
             // Last key occupies all space till end of layer
-            last.1 = std::fs::metadata(&file.file.path)?.len() - last.1;
+            last.2 = std::fs::metadata(&file.file.path)?.len() - last.2;
         }
-        let iter = DeltaKeyIter {
-            all_keys,
-            next_idx: 0,
-        };
-
-        Ok(iter)
+        Ok(all_keys)
     }
 }
 
-#[cfg(test)]
-mod test {
-    use super::DeltaKeyIter;
-    use super::DeltaLayer;
-    use super::DeltaValueIter;
+/// Reference to an on-disk value
+pub struct ValueRef<T: AsRef<DeltaLayerInner>> {
+    blob_ref: BlobRef,
+    reader: BlockCursor<Adapter<T>>,
+}
 
-    // We will soon need the iters to be send in the compaction code.
-    // Cf https://github.com/neondatabase/neon/pull/4462#issuecomment-1587398883
-    // Cf https://github.com/neondatabase/neon/issues/4471
-    #[test]
-    fn is_send() {
-        fn assert_send<T: Send>() {}
-        assert_send::<DeltaLayer>();
-        assert_send::<DeltaValueIter>();
-        assert_send::<DeltaKeyIter>();
+impl<T: AsRef<DeltaLayerInner>> ValueRef<T> {
+    /// Loads the value from disk
+    pub async fn load(&self) -> Result<Value> {
+        // theoretically we *could* record an access time for each, but it does not really matter
+        let buf = self.reader.read_blob(self.blob_ref.pos()).await?;
+        let val = Value::des(&buf)?;
+        Ok(val)
+    }
+}
+
+struct Adapter<T: AsRef<DeltaLayerInner>>(T);
+
+impl<T: AsRef<DeltaLayerInner>> BlockReader for Adapter<T> {
+    fn read_blk(&self, blknum: u32) -> Result<BlockLease, std::io::Error> {
+        self.0.as_ref().file.read_blk(blknum)
     }
 }

pageserver/src/tenant/storage_layer/image_layer.rs

@@ -27,7 +27,7 @@ use crate::config::PageServerConf;
 use crate::context::RequestContext;
 use crate::page_cache::PAGE_SZ;
 use crate::repository::{Key, KEY_SIZE};
-use crate::tenant::blob_io::{BlobCursor, BlobWriter, WriteBlobWriter};
+use crate::tenant::blob_io::{BlobWriter, WriteBlobWriter};
 use crate::tenant::block_io::{BlockBuf, BlockReader, FileBlockReader};
 use crate::tenant::disk_btree::{DiskBtreeBuilder, DiskBtreeReader, VisitDirection};
 use crate::tenant::storage_layer::{
@@ -47,7 +47,7 @@ use std::io::{Seek, SeekFrom};
 use std::ops::Range;
 use std::os::unix::prelude::FileExt;
 use std::path::{Path, PathBuf};
-use std::sync::{RwLock, RwLockReadGuard};
+use tokio::sync::OnceCell;
 use tracing::*;
 
 use utils::{
@@ -57,9 +57,7 @@ use utils::{
 };
 
 use super::filename::ImageFileName;
-use super::{
-    AsLayerDesc, Layer, LayerAccessStatsReset, LayerIter, PathOrConf, PersistentLayerDesc,
-};
+use super::{AsLayerDesc, Layer, LayerAccessStatsReset, PathOrConf, PersistentLayerDesc};
 
 ///
 /// Header stored in the beginning of the file
@@ -68,7 +66,7 @@ use super::{
 /// the 'index' starts at the block indicated by 'index_start_blk'
 ///
 #[derive(Debug, Serialize, Deserialize, PartialEq, Eq)]
-struct Summary {
+pub(super) struct Summary {
     /// Magic value to identify this as a neon image file. Always IMAGE_FILE_MAGIC.
     magic: u16,
     format_version: u16,
@@ -87,13 +85,29 @@ struct Summary {
 
 impl From<&ImageLayer> for Summary {
     fn from(layer: &ImageLayer) -> Self {
+        Self::expected(
+            layer.desc.tenant_id,
+            layer.desc.timeline_id,
+            layer.desc.key_range.clone(),
+            layer.lsn,
+        )
+    }
+}
+
+impl Summary {
+    pub(super) fn expected(
+        tenant_id: TenantId,
+        timeline_id: TimelineId,
+        key_range: Range<Key>,
+        lsn: Lsn,
+    ) -> Self {
         Self {
             magic: IMAGE_FILE_MAGIC,
             format_version: STORAGE_FORMAT_VERSION,
-            tenant_id: layer.desc.tenant_id,
-            timeline_id: layer.desc.timeline_id,
-            key_range: layer.desc.key_range.clone(),
-            lsn: layer.lsn,
+            tenant_id,
+            timeline_id,
+            key_range,
+            lsn,
 
             index_start_blk: 0,
             index_root_blk: 0,
@@ -117,7 +131,7 @@ pub struct ImageLayer {
 
     access_stats: LayerAccessStats,
 
-    inner: RwLock<ImageLayerInner>,
+    inner: OnceCell<ImageLayerInner>,
 }
 
 impl std::fmt::Debug for ImageLayer {
@@ -134,30 +148,29 @@ impl std::fmt::Debug for ImageLayer {
 }
 
 pub struct ImageLayerInner {
-    /// If false, the 'index' has not been loaded into memory yet.
-    loaded: bool,
-
     // values copied from summary
     index_start_blk: u32,
     index_root_blk: u32,
 
-    /// Reader object for reading blocks from the file. (None if not loaded yet)
-    file: Option<FileBlockReader<VirtualFile>>,
+    lsn: Lsn,
+
+    /// Reader object for reading blocks from the file.
+    file: FileBlockReader<VirtualFile>,
 }
 
 impl std::fmt::Debug for ImageLayerInner {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("ImageLayerInner")
-            .field("loaded", &self.loaded)
             .field("index_start_blk", &self.index_start_blk)
             .field("index_root_blk", &self.index_root_blk)
             .finish()
     }
 }
 
+#[async_trait::async_trait]
 impl Layer for ImageLayer {
     /// debugging function to print out the contents of the layer
-    fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
+    async fn dump(&self, verbose: bool, ctx: &RequestContext) -> Result<()> {
         println!(
             "----- image layer for ten {} tli {} key {}-{} at {} is_incremental {} size {} ----",
             self.desc.tenant_id,
@@ -173,23 +186,25 @@ impl Layer for ImageLayer {
             return Ok(());
         }
 
-        let inner = self.load(LayerAccessKind::Dump, ctx)?;
-        let file = inner.file.as_ref().unwrap();
+        let inner = self.load(LayerAccessKind::Dump, ctx).await?;
+        let file = &inner.file;
         let tree_reader =
             DiskBtreeReader::<_, KEY_SIZE>::new(inner.index_start_blk, inner.index_root_blk, file);
 
-        tree_reader.dump()?;
+        tree_reader.dump().await?;
 
-        tree_reader.visit(&[0u8; KEY_SIZE], VisitDirection::Forwards, |key, value| {
-            println!("key: {} offset {}", hex::encode(key), value);
-            true
-        })?;
+        tree_reader
+            .visit(&[0u8; KEY_SIZE], VisitDirection::Forwards, |key, value| {
+                println!("key: {} offset {}", hex::encode(key), value);
+                true
+            })
+            .await?;
 
         Ok(())
     }
 
     /// Look up given page in the file
-    fn get_value_reconstruct_data(
+    async fn get_value_reconstruct_data(
         &self,
         key: Key,
         lsn_range: Range<Lsn>,
@@ -200,28 +215,14 @@ impl Layer for ImageLayer {
         assert!(lsn_range.start >= self.lsn);
         assert!(lsn_range.end >= self.lsn);
 
-        let inner = self.load(LayerAccessKind::GetValueReconstructData, ctx)?;
-
-        let file = inner.file.as_ref().unwrap();
-        let tree_reader = DiskBtreeReader::new(inner.index_start_blk, inner.index_root_blk, file);
-
-        let mut keybuf: [u8; KEY_SIZE] = [0u8; KEY_SIZE];
-        key.write_to_byte_slice(&mut keybuf);
-        if let Some(offset) = tree_reader.get(&keybuf)? {
-            let blob = file.block_cursor().read_blob(offset).with_context(|| {
-                format!(
-                    "failed to read value from data file {} at offset {}",
-                    self.path().display(),
-                    offset
-                )
-            })?;
-            let value = Bytes::from(blob);
-
-            reconstruct_state.img = Some((self.lsn, value));
-            Ok(ValueReconstructResult::Complete)
-        } else {
-            Ok(ValueReconstructResult::Missing)
-        }
+        let inner = self
+            .load(LayerAccessKind::GetValueReconstructData, ctx)
+            .await?;
+        inner
+            .get_value_reconstruct_data(key, reconstruct_state)
+            .await
+            // FIXME: makes no sense to dump paths
+            .with_context(|| format!("read {}", self.path().display()))
     }
 
     /// Boilerplate to implement the Layer trait, always use layer_desc for persistent layers.
@@ -258,10 +259,6 @@ impl PersistentLayer for ImageLayer {
         Some(self.path())
     }
 
-    fn iter(&self, _ctx: &RequestContext) -> Result<LayerIter<'_>> {
-        unimplemented!();
-    }
-
     fn delete_resident_layer_file(&self) -> Result<()> {
         // delete underlying file
         fs::remove_file(self.path())?;
@@ -321,83 +318,41 @@ impl ImageLayer {
     /// Open the underlying file and read the metadata into memory, if it's
     /// not loaded already.
     ///
-    fn load(
+    async fn load(
         &self,
         access_kind: LayerAccessKind,
         ctx: &RequestContext,
-    ) -> Result<RwLockReadGuard<ImageLayerInner>> {
-        self.access_stats
-            .record_access(access_kind, ctx.task_kind());
-        loop {
-            // Quick exit if already loaded
-            let inner = self.inner.read().unwrap();
-            if inner.loaded {
-                return Ok(inner);
-            }
-
-            // Need to open the file and load the metadata. Upgrade our lock to
-            // a write lock. (Or rather, release and re-lock in write mode.)
-            drop(inner);
-            let mut inner = self.inner.write().unwrap();
-            if !inner.loaded {
-                self.load_inner(&mut inner).with_context(|| {
-                    format!("Failed to load image layer {}", self.path().display())
-                })?
-            } else {
-                // Another thread loaded it while we were not holding the lock.
-            }
-
-            // We now have the file open and loaded. There's no function to do
-            // that in the std library RwLock, so we have to release and re-lock
-            // in read mode. (To be precise, the lock guard was moved in the
-            // above call to `load_inner`, so it's already been released). And
-            // while we do that, another thread could unload again, so we have
-            // to re-check and retry if that happens.
-            drop(inner);
-        }
+    ) -> Result<&ImageLayerInner> {
+        self.access_stats.record_access(access_kind, ctx);
+        self.inner
+            .get_or_try_init(|| self.load_inner())
+            .await
+            .with_context(|| format!("Failed to load image layer {}", self.path().display()))
     }
 
-    fn load_inner(&self, inner: &mut ImageLayerInner) -> Result<()> {
+    async fn load_inner(&self) -> Result<ImageLayerInner> {
         let path = self.path();
 
-        // Open the file if it's not open already.
-        if inner.file.is_none() {
-            let file = VirtualFile::open(&path)
-                .with_context(|| format!("Failed to open file '{}'", path.display()))?;
-            inner.file = Some(FileBlockReader::new(file));
-        }
-        let file = inner.file.as_mut().unwrap();
-        let summary_blk = file.read_blk(0)?;
-        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
+        let expected_summary = match &self.path_or_conf {
+            PathOrConf::Conf(_) => Some(Summary::from(self)),
+            PathOrConf::Path(_) => None,
+        };
 
-        match &self.path_or_conf {
-            PathOrConf::Conf(_) => {
-                let mut expected_summary = Summary::from(self);
-                expected_summary.index_start_blk = actual_summary.index_start_blk;
-                expected_summary.index_root_blk = actual_summary.index_root_blk;
+        let loaded = ImageLayerInner::load(&path, self.desc.image_layer_lsn(), expected_summary)?;
 
-                if actual_summary != expected_summary {
-                    bail!("in-file summary does not match expected summary. actual = {:?} expected = {:?}", actual_summary, expected_summary);
-                }
-            }
-            PathOrConf::Path(path) => {
-                let actual_filename = path.file_name().unwrap().to_str().unwrap().to_owned();
-                let expected_filename = self.filename().file_name();
+        if let PathOrConf::Path(ref path) = self.path_or_conf {
+            // not production code
+            let actual_filename = path.file_name().unwrap().to_str().unwrap().to_owned();
+            let expected_filename = self.filename().file_name();
 
-                if actual_filename != expected_filename {
-                    println!(
-                        "warning: filename does not match what is expected from in-file summary"
-                    );
-                    println!("actual: {:?}", actual_filename);
-                    println!("expected: {:?}", expected_filename);
-                }
+            if actual_filename != expected_filename {
+                println!("warning: filename does not match what is expected from in-file summary");
+                println!("actual: {:?}", actual_filename);
+                println!("expected: {:?}", expected_filename);
             }
         }
 
-        inner.index_start_blk = actual_summary.index_start_blk;
-        inner.index_root_blk = actual_summary.index_root_blk;
-        inner.loaded = true;
-        Ok(())
+        Ok(loaded)
     }
 
     /// Create an ImageLayer struct representing an existing file on disk
@@ -421,12 +376,7 @@ impl ImageLayer {
             ), // Now we assume image layer ALWAYS covers the full range. This may change in the future.
             lsn: filename.lsn,
             access_stats,
-            inner: RwLock::new(ImageLayerInner {
-                loaded: false,
-                file: None,
-                index_start_blk: 0,
-                index_root_blk: 0,
-            }),
+            inner: OnceCell::new(),
         }
     }
 
@@ -453,12 +403,7 @@ impl ImageLayer {
             ), // Now we assume image layer ALWAYS covers the full range. This may change in the future.
             lsn: summary.lsn,
             access_stats: LayerAccessStats::empty_will_record_residence_event_later(),
-            inner: RwLock::new(ImageLayerInner {
-                file: None,
-                loaded: false,
-                index_start_blk: 0,
-                index_root_blk: 0,
-            }),
+            inner: OnceCell::new(),
         })
     }
 
@@ -477,6 +422,66 @@ impl ImageLayer {
     }
 }
 
+impl ImageLayerInner {
+    pub(super) fn load(
+        path: &std::path::Path,
+        lsn: Lsn,
+        summary: Option<Summary>,
+    ) -> anyhow::Result<Self> {
+        let file = VirtualFile::open(path)
+            .with_context(|| format!("Failed to open file '{}'", path.display()))?;
+        let file = FileBlockReader::new(file);
+        let summary_blk = file.read_blk(0)?;
+        let actual_summary = Summary::des_prefix(summary_blk.as_ref())?;
+
+        if let Some(mut expected_summary) = summary {
+            // production code path
+            expected_summary.index_start_blk = actual_summary.index_start_blk;
+            expected_summary.index_root_blk = actual_summary.index_root_blk;
+
+            if actual_summary != expected_summary {
+                bail!(
+                    "in-file summary does not match expected summary. actual = {:?} expected = {:?}",
+                    actual_summary,
+                    expected_summary
+                );
+            }
+        }
+
+        Ok(ImageLayerInner {
+            index_start_blk: actual_summary.index_start_blk,
+            index_root_blk: actual_summary.index_root_blk,
+            lsn,
+            file,
+        })
+    }
+
+    pub(super) async fn get_value_reconstruct_data(
+        &self,
+        key: Key,
+        reconstruct_state: &mut ValueReconstructState,
+    ) -> anyhow::Result<ValueReconstructResult> {
+        let file = &self.file;
+        let tree_reader = DiskBtreeReader::new(self.index_start_blk, self.index_root_blk, file);
+
+        let mut keybuf: [u8; KEY_SIZE] = [0u8; KEY_SIZE];
+        key.write_to_byte_slice(&mut keybuf);
+        if let Some(offset) = tree_reader.get(&keybuf).await? {
+            let blob = file
+                .block_cursor()
+                .read_blob(offset)
+                .await
+                .with_context(|| format!("failed to read value from offset {}", offset))?;
+            let value = Bytes::from(blob);
+
+            reconstruct_state.img = Some((self.lsn, value));
+            Ok(ValueReconstructResult::Complete)
+        } else {
+            Ok(ValueReconstructResult::Missing)
+        }
+    }
+}
+
 /// A builder object for constructing a new image layer.
 ///
 /// Usage:
@@ -619,12 +624,7 @@ impl ImageLayerWriterInner {
             desc,
             lsn: self.lsn,
             access_stats: LayerAccessStats::empty_will_record_residence_event_later(),
-            inner: RwLock::new(ImageLayerInner {
-                loaded: false,
-                file: None,
-                index_start_blk,
-                index_root_blk,
-            }),
+            inner: OnceCell::new(),
         };
 
         // fsync the file

pageserver/src/tenant/storage_layer/inmemory_layer.rs

@@ -7,7 +7,7 @@
 use crate::config::PageServerConf;
 use crate::context::RequestContext;
 use crate::repository::{Key, Value};
-use crate::tenant::blob_io::{BlobCursor, BlobWriter};
+use crate::tenant::blob_io::BlobWriter;
 use crate::tenant::block_io::BlockReader;
 use crate::tenant::ephemeral_file::EphemeralFile;
 use crate::tenant::storage_layer::{ValueReconstructResult, ValueReconstructState};
@@ -16,6 +16,7 @@ use anyhow::{ensure, Result};
 use pageserver_api::models::InMemoryLayerInfo;
 use std::cell::RefCell;
 use std::collections::HashMap;
+use std::sync::OnceLock;
 use tracing::*;
 use utils::{
     bin_ser::BeSer,
@@ -27,7 +28,7 @@ use utils::{
 // while being able to use std::fmt::Write's methods
 use std::fmt::Write as _;
 use std::ops::Range;
-use std::sync::RwLock;
+use tokio::sync::RwLock;
 
 use super::{DeltaLayer, DeltaLayerWriter, Layer};
 
@@ -42,14 +43,16 @@ pub struct InMemoryLayer {
     tenant_id: TenantId,
     timeline_id: TimelineId,
 
-    ///
     /// This layer contains all the changes from 'start_lsn'. The
     /// start is inclusive.
-    ///
     start_lsn: Lsn,
 
-    /// The above fields never change. The parts that do change are in 'inner',
-    /// and protected by mutex.
+    /// Frozen layers have an exclusive end LSN.
+    /// Writes are only allowed when this is `None`.
+    end_lsn: OnceLock<Lsn>,
+
+    /// The above fields never change, except for `end_lsn`, which is only set once.
+    /// All other changing parts are in `inner`, and protected by a mutex.
     inner: RwLock<InMemoryLayerInner>,
 }
 
@@ -57,21 +60,16 @@ impl std::fmt::Debug for InMemoryLayer {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("InMemoryLayer")
             .field("start_lsn", &self.start_lsn)
+            .field("end_lsn", &self.end_lsn)
             .field("inner", &self.inner)
             .finish()
     }
 }
 
 pub struct InMemoryLayerInner {
-    /// Frozen layers have an exclusive end LSN.
-    /// Writes are only allowed when this is None
-    end_lsn: Option<Lsn>,
-
-    ///
     /// All versions of all pages in the layer are kept here.  Indexed
     /// by block number and LSN. The value is an offset into the
     /// ephemeral file where the page version is stored.
-    ///
     index: HashMap<Key, VecMap<Lsn, u64>>,
 
     /// The values are stored in a serialized format in this file.
@@ -82,15 +80,7 @@ pub struct InMemoryLayerInner {
 
 impl std::fmt::Debug for InMemoryLayerInner {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_struct("InMemoryLayerInner")
-            .field("end_lsn", &self.end_lsn)
-            .finish()
-    }
-}
-
-impl InMemoryLayerInner {
-    fn assert_writeable(&self) {
-        assert!(self.end_lsn.is_none());
+        f.debug_struct("InMemoryLayerInner").finish()
     }
 }
 
@@ -101,29 +91,31 @@ impl InMemoryLayer {
 
     pub fn info(&self) -> InMemoryLayerInfo {
         let lsn_start = self.start_lsn;
-        let lsn_end = self.inner.read().unwrap().end_lsn;
 
-        match lsn_end {
-            Some(lsn_end) => InMemoryLayerInfo::Frozen { lsn_start, lsn_end },
-            None => InMemoryLayerInfo::Open { lsn_start },
+        if let Some(&lsn_end) = self.end_lsn.get() {
+            InMemoryLayerInfo::Frozen { lsn_start, lsn_end }
+        } else {
+            InMemoryLayerInfo::Open { lsn_start }
         }
     }
+
+    fn assert_writable(&self) {
+        assert!(self.end_lsn.get().is_none());
+    }
+
+    fn end_lsn_or_max(&self) -> Lsn {
+        self.end_lsn.get().copied().unwrap_or(Lsn::MAX)
+    }
 }
 
+#[async_trait::async_trait]
 impl Layer for InMemoryLayer {
     fn get_key_range(&self) -> Range<Key> {
         Key::MIN..Key::MAX
     }
 
     fn get_lsn_range(&self) -> Range<Lsn> {
-        let inner = self.inner.read().unwrap();
-
-        let end_lsn = if let Some(end_lsn) = inner.end_lsn {
-            end_lsn
-        } else {
-            Lsn(u64::MAX)
-        };
-        self.start_lsn..end_lsn
+        self.start_lsn..self.end_lsn_or_max()
     }
 
     fn is_incremental(&self) -> bool {
@@ -132,14 +124,10 @@ impl Layer for InMemoryLayer {
     }
 
     /// debugging function to print out the contents of the layer
-    fn dump(&self, verbose: bool, _ctx: &RequestContext) -> Result<()> {
-        let inner = self.inner.read().unwrap();
+    async fn dump(&self, verbose: bool, _ctx: &RequestContext) -> Result<()> {
+        let inner = self.inner.read().await;
 
-        let end_str = inner
-            .end_lsn
-            .as_ref()
-            .map(Lsn::to_string)
-            .unwrap_or_default();
+        let end_str = self.end_lsn_or_max();
 
         println!(
             "----- in-memory layer for tli {} LSNs {}-{} ----",
@@ -150,12 +138,12 @@ impl Layer for InMemoryLayer {
             return Ok(());
         }
 
-        let mut cursor = inner.file.block_cursor();
+        let cursor = inner.file.block_cursor();
         let mut buf = Vec::new();
         for (key, vec_map) in inner.index.iter() {
             for (lsn, pos) in vec_map.as_slice() {
                 let mut desc = String::new();
-                cursor.read_blob_into_buf(*pos, &mut buf)?;
+                cursor.read_blob_into_buf(*pos, &mut buf).await?;
                 let val = Value::des(&buf);
                 match val {
                     Ok(Value::Image(img)) => {
@@ -183,7 +171,7 @@ impl Layer for InMemoryLayer {
     }
 
     /// Look up given value in the layer.
-    fn get_value_reconstruct_data(
+    async fn get_value_reconstruct_data(
         &self,
         key: Key,
         lsn_range: Range<Lsn>,
@@ -193,15 +181,15 @@ impl Layer for InMemoryLayer {
         ensure!(lsn_range.start >= self.start_lsn);
         let mut need_image = true;
 
-        let inner = self.inner.read().unwrap();
+        let inner = self.inner.read().await;
 
-        let mut reader = inner.file.block_cursor();
+        let reader = inner.file.block_cursor();
 
         // Scan the page versions backwards, starting from `lsn`.
         if let Some(vec_map) = inner.index.get(&key) {
             let slice = vec_map.slice_range(lsn_range);
             for (entry_lsn, pos) in slice.iter().rev() {
-                let buf = reader.read_blob(*pos)?;
+                let buf = reader.read_blob(*pos).await?;
                 let value = Value::des(&buf)?;
                 match value {
                     Value::Image(img) => {
@@ -235,9 +223,7 @@ impl Layer for InMemoryLayer {
 
 impl std::fmt::Display for InMemoryLayer {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let inner = self.inner.read().unwrap();
-
-        let end_lsn = inner.end_lsn.unwrap_or(Lsn(u64::MAX));
+        let end_lsn = self.end_lsn_or_max();
         write!(f, "inmem-{:016X}-{:016X}", self.start_lsn.0, end_lsn.0)
     }
 }
@@ -246,8 +232,8 @@ impl InMemoryLayer {
     ///
     /// Get layer size on the disk
     ///
-    pub fn size(&self) -> Result<u64> {
-        let inner = self.inner.read().unwrap();
+    pub async fn size(&self) -> Result<u64> {
+        let inner = self.inner.read().await;
         Ok(inner.file.size)
     }
 
@@ -269,8 +255,8 @@ impl InMemoryLayer {
             timeline_id,
             tenant_id,
             start_lsn,
+            end_lsn: OnceLock::new(),
             inner: RwLock::new(InMemoryLayerInner {
-                end_lsn: None,
                 index: HashMap::new(),
                 file,
             }),
@@ -281,10 +267,10 @@ impl InMemoryLayer {
 
     /// Common subroutine of the public put_wal_record() and put_page_image() functions.
     /// Adds the page version to the in-memory tree
-    pub fn put_value(&self, key: Key, lsn: Lsn, val: &Value) -> Result<()> {
+    pub async fn put_value(&self, key: Key, lsn: Lsn, val: &Value) -> Result<()> {
         trace!("put_value key {} at {}/{}", key, self.timeline_id, lsn);
-        let mut inner = self.inner.write().unwrap();
-        inner.assert_writeable();
+        let mut inner = self.inner.write().await;
+        self.assert_writable();
 
         let off = {
             SER_BUFFER.with(|x| -> Result<_> {
@@ -315,11 +301,11 @@ impl InMemoryLayer {
     /// Make the layer non-writeable. Only call once.
     /// Records the end_lsn for non-dropped layers.
     /// `end_lsn` is exclusive
-    pub fn freeze(&self, end_lsn: Lsn) {
-        let mut inner = self.inner.write().unwrap();
+    pub async fn freeze(&self, end_lsn: Lsn) {
+        let inner = self.inner.write().await;
 
         assert!(self.start_lsn < end_lsn);
-        inner.end_lsn = Some(end_lsn);
+        self.end_lsn.set(end_lsn).expect("end_lsn set only once");
 
         for vec_map in inner.index.values() {
             for (lsn, _pos) in vec_map.as_slice() {
@@ -331,7 +317,7 @@ impl InMemoryLayer {
     /// Write this frozen in-memory layer to disk.
     ///
     /// Returns a new delta layer with all the same data as this in-memory layer
-    pub fn write_to_disk(&self) -> Result<DeltaLayer> {
+    pub async fn write_to_disk(&self) -> Result<DeltaLayer> {
         // Grab the lock in read-mode. We hold it over the I/O, but because this
         // layer is not writeable anymore, no one should be trying to acquire the
         // write lock on it, so we shouldn't block anyone. There's one exception
@@ -341,19 +327,21 @@ impl InMemoryLayer {
         // lock, it will see that it's not writeable anymore and retry, but it
         // would have to wait until we release it. That race condition is very
         // rare though, so we just accept the potential latency hit for now.
-        let inner = self.inner.read().unwrap();
+        let inner = self.inner.read().await;
+
+        let end_lsn = *self.end_lsn.get().unwrap();
 
         let mut delta_layer_writer = DeltaLayerWriter::new(
             self.conf,
             self.timeline_id,
             self.tenant_id,
             Key::MIN,
-            self.start_lsn..inner.end_lsn.unwrap(),
+            self.start_lsn..end_lsn,
         )?;
 
         let mut buf = Vec::new();
 
-        let mut cursor = inner.file.block_cursor();
+        let cursor = inner.file.block_cursor();
 
         let mut keys: Vec<(&Key, &VecMap<Lsn, u64>)> = inner.index.iter().collect();
         keys.sort_by_key(|k| k.0);
@@ -362,7 +350,7 @@ impl InMemoryLayer {
             let key = **key;
             // Write all page versions
             for (lsn, pos) in vec_map.as_slice() {
-                cursor.read_blob_into_buf(*pos, &mut buf)?;
+                cursor.read_blob_into_buf(*pos, &mut buf).await?;
                 let will_init = Value::des(&buf)?.will_init();
                 delta_layer_writer.put_value_bytes(key, *lsn, &buf, will_init)?;
             }

pageserver/src/tenant/storage_layer/remote_layer.rs

@@ -20,8 +20,8 @@ use utils::{
 
 use super::filename::{DeltaFileName, ImageFileName};
 use super::{
-    AsLayerDesc, DeltaLayer, ImageLayer, LayerAccessStats, LayerAccessStatsReset, LayerIter,
-    LayerKeyIter, LayerResidenceStatus, PersistentLayer, PersistentLayerDesc,
+    AsLayerDesc, DeltaLayer, ImageLayer, LayerAccessStats, LayerAccessStatsReset,
+    LayerResidenceStatus, PersistentLayer, PersistentLayerDesc,
 };
 
 /// RemoteLayer is a not yet downloaded [`ImageLayer`] or
@@ -65,8 +65,9 @@ impl std::fmt::Debug for RemoteLayer {
     }
 }
 
+#[async_trait::async_trait]
 impl Layer for RemoteLayer {
-    fn get_value_reconstruct_data(
+    async fn get_value_reconstruct_data(
         &self,
         _key: Key,
         _lsn_range: Range<Lsn>,
@@ -77,7 +78,7 @@ impl Layer for RemoteLayer {
     }
 
     /// debugging function to print out the contents of the layer
-    fn dump(&self, _verbose: bool, _ctx: &RequestContext) -> Result<()> {
+    async fn dump(&self, _verbose: bool, _ctx: &RequestContext) -> Result<()> {
         println!(
             "----- remote layer for ten {} tli {} keys {}-{} lsn {}-{} is_delta {} is_incremental {} size {} ----",
             self.desc.tenant_id,
@@ -128,14 +129,6 @@ impl PersistentLayer for RemoteLayer {
         None
     }
 
-    fn iter(&self, _ctx: &RequestContext) -> Result<LayerIter<'_>> {
-        bail!("cannot iterate a remote layer");
-    }
-
-    fn key_iter(&self, _ctx: &RequestContext) -> Result<LayerKeyIter<'_>> {
-        bail!("cannot iterate a remote layer");
-    }
-
     fn delete_resident_layer_file(&self) -> Result<()> {
         bail!("remote layer has no layer file");
     }

pageserver/src/tenant/tasks.rs

@@ -73,17 +73,13 @@ pub fn start_background_loops(
 ///
 async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
     let wait_duration = Duration::from_secs(2);
-    info!("starting");
     TENANT_TASK_EVENTS.with_label_values(&["start"]).inc();
     async {
         let ctx = RequestContext::todo_child(TaskKind::Compaction, DownloadBehavior::Download);
         let mut first = true;
         loop {
-            trace!("waking up");
-
             tokio::select! {
                 _ = cancel.cancelled() => {
-                    info!("received cancellation request");
                     return;
                 },
                 tenant_wait_result = wait_for_active_tenant(&tenant) => match tenant_wait_result {
@@ -111,7 +107,7 @@ async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
                 Duration::from_secs(10)
             } else {
                 // Run compaction
-                if let Err(e) = tenant.compaction_iteration(&ctx).await {
+                if let Err(e) = tenant.compaction_iteration(&cancel, &ctx).await {
                     error!("Compaction failed, retrying in {:?}: {e:?}", wait_duration);
                     wait_duration
                 } else {
@@ -126,15 +122,12 @@ async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
                 .await
                 .is_ok()
             {
-                info!("received cancellation request during idling");
                 break;
             }
         }
     }
     .await;
     TENANT_TASK_EVENTS.with_label_values(&["stop"]).inc();
-
-    trace!("compaction loop stopped.");
 }
 
 ///
@@ -142,7 +135,6 @@ async fn compaction_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
 ///
 async fn gc_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
     let wait_duration = Duration::from_secs(2);
-    info!("starting");
     TENANT_TASK_EVENTS.with_label_values(&["start"]).inc();
     async {
         // GC might require downloading, to find the cutoff LSN that corresponds to the
@@ -151,11 +143,8 @@ async fn gc_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
             RequestContext::todo_child(TaskKind::GarbageCollector, DownloadBehavior::Download);
         let mut first = true;
         loop {
-            trace!("waking up");
-
             tokio::select! {
                 _ = cancel.cancelled() => {
-                    info!("received cancellation request");
                     return;
                 },
                 tenant_wait_result = wait_for_active_tenant(&tenant) => match tenant_wait_result {
@@ -200,14 +189,12 @@ async fn gc_loop(tenant: Arc<Tenant>, cancel: CancellationToken) {
                 .await
                 .is_ok()
             {
-                info!("received cancellation request during idling");
                 break;
             }
         }
     }
     .await;
     TENANT_TASK_EVENTS.with_label_values(&["stop"]).inc();
-    trace!("GC loop stopped.");
 }
 
 async fn wait_for_active_tenant(tenant: &Arc<Tenant>) -> ControlFlow<()> {
@@ -232,7 +219,6 @@ async fn wait_for_active_tenant(tenant: &Arc<Tenant>) -> ControlFlow<()> {
                     }
                 }
                 Err(_sender_dropped_error) => {
-                    info!("Tenant dropped the state updates sender, quitting waiting for tenant and the task loop");
                     return ControlFlow::Break(());
                 }
             }

pageserver/src/tenant/timeline.rs

@@ -1,3 +1,4 @@
+pub mod delete;
 mod eviction_task;
 pub mod layer_manager;
 mod logical_size;
@@ -18,6 +19,7 @@ use pageserver_api::models::{
 use remote_storage::GenericRemoteStorage;
 use serde_with::serde_as;
 use storage_broker::BrokerClientChannel;
+use tokio::runtime::Handle;
 use tokio::sync::{oneshot, watch, TryAcquireError};
 use tokio_util::sync::CancellationToken;
 use tracing::*;
@@ -33,7 +35,9 @@ use std::sync::atomic::Ordering as AtomicOrdering;
 use std::sync::{Arc, Mutex, RwLock, Weak};
 use std::time::{Duration, Instant, SystemTime};
 
-use crate::context::{DownloadBehavior, RequestContext};
+use crate::context::{
+    AccessStatsBehavior, DownloadBehavior, RequestContext, RequestContextBuilder,
+};
 use crate::tenant::remote_timeline_client::{self, index::LayerFileMetadata};
 use crate::tenant::storage_layer::{
     DeltaFileName, DeltaLayerWriter, ImageFileName, ImageLayerWriter, InMemoryLayer,
@@ -79,6 +83,7 @@ use crate::METADATA_FILE_NAME;
 use crate::ZERO_PAGE;
 use crate::{is_temporary, task_mgr};
 
+use self::delete::DeleteTimelineFlow;
 pub(super) use self::eviction_task::EvictionTaskTenantState;
 use self::eviction_task::EvictionTaskTimelineState;
 use self::layer_manager::LayerManager;
@@ -237,11 +242,10 @@ pub struct Timeline {
 
     /// Layer removal lock.
     /// A lock to ensure that no layer of the timeline is removed concurrently by other tasks.
-    /// This lock is acquired in [`Timeline::gc`], [`Timeline::compact`],
-    /// and [`Tenant::delete_timeline`]. This is an `Arc<Mutex>` lock because we need an owned
+    /// This lock is acquired in [`Timeline::gc`] and [`Timeline::compact`].
+    /// This is an `Arc<Mutex>` lock because we need an owned
     /// lock guard in functions that will be spawned to tokio I/O pool (which requires `'static`).
-    ///
-    /// [`Tenant::delete_timeline`]: super::Tenant::delete_timeline
+    /// Note that [`DeleteTimelineFlow`] uses `delete_progress` field.
     pub(super) layer_removal_cs: Arc<tokio::sync::Mutex<()>>,
 
     // Needed to ensure that we can't create a branch at a point that was already garbage collected
@@ -283,7 +287,7 @@ pub struct Timeline {
 
     /// 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_lock: Arc<tokio::sync::Mutex<bool>>,
+    pub delete_progress: Arc<tokio::sync::Mutex<DeleteTimelineFlow>>,
 
     eviction_task_timeline_state: tokio::sync::Mutex<EvictionTaskTimelineState>,
 
@@ -293,6 +297,10 @@ pub struct Timeline {
     /// Completion shared between all timelines loaded during startup; used to delay heavier
     /// background tasks until some logical sizes have been calculated.
     initial_logical_size_attempt: Mutex<Option<completion::Completion>>,
+
+    /// Load or creation time information about the disk_consistent_lsn and when the loading
+    /// happened. Used for consumption metrics.
+    pub(crate) loaded_at: (Lsn, SystemTime),
 }
 
 pub struct WalReceiverInfo {
@@ -334,7 +342,7 @@ pub struct GcInfo {
 #[derive(thiserror::Error)]
 pub enum PageReconstructError {
     #[error(transparent)]
-    Other(#[from] anyhow::Error), // source and Display delegate to anyhow::Error
+    Other(#[from] anyhow::Error),
 
     /// The operation would require downloading a layer that is missing locally.
     NeedsDownload(TenantTimelineId, LayerFileName),
@@ -475,7 +483,7 @@ impl Timeline {
             img: cached_page_img,
         };
 
-        let timer = self.metrics.get_reconstruct_data_time_histo.start_timer();
+        let timer = crate::metrics::GET_RECONSTRUCT_DATA_TIME.start_timer();
         self.get_reconstruct_data(key, lsn, &mut reconstruct_state, ctx)
             .await?;
         timer.stop_and_record();
@@ -523,7 +531,7 @@ impl Timeline {
         size
     }
 
-    pub fn get_resident_physical_size(&self) -> u64 {
+    pub fn resident_physical_size(&self) -> u64 {
         self.metrics.resident_physical_size_gauge.get()
     }
 
@@ -555,7 +563,7 @@ impl Timeline {
             "wait_lsn cannot be called in WAL receiver"
         );
 
-        let _timer = self.metrics.wait_lsn_time_histo.start_timer();
+        let _timer = crate::metrics::WAIT_LSN_TIME.start_timer();
 
         match self
             .last_record_lsn
@@ -611,9 +619,46 @@ impl Timeline {
     }
 
     /// Outermost timeline compaction operation; downloads needed layers.
-    pub async fn compact(self: &Arc<Self>, ctx: &RequestContext) -> anyhow::Result<()> {
+    pub async fn compact(
+        self: &Arc<Self>,
+        cancel: &CancellationToken,
+        ctx: &RequestContext,
+    ) -> anyhow::Result<()> {
         const ROUNDS: usize = 2;
 
+        static CONCURRENT_COMPACTIONS: once_cell::sync::Lazy<tokio::sync::Semaphore> =
+            once_cell::sync::Lazy::new(|| {
+                let total_threads = *task_mgr::BACKGROUND_RUNTIME_WORKER_THREADS;
+                let permits = usize::max(
+                    1,
+                    // while a lot of the work is done on spawn_blocking, we still do
+                    // repartitioning in the async context. this should give leave us some workers
+                    // unblocked to be blocked on other work, hopefully easing any outside visible
+                    // effects of restarts.
+                    //
+                    // 6/8 is a guess; previously we ran with unlimited 8 and more from
+                    // spawn_blocking.
+                    (total_threads * 3).checked_div(4).unwrap_or(0),
+                );
+                assert_ne!(permits, 0, "we will not be adding in permits later");
+                assert!(
+                    permits < total_threads,
+                    "need threads avail for shorter work"
+                );
+                tokio::sync::Semaphore::new(permits)
+            });
+
+        // this wait probably never needs any "long time spent" logging, because we already nag if
+        // compaction task goes over it's period (20s) which is quite often in production.
+        let _permit = tokio::select! {
+            permit = CONCURRENT_COMPACTIONS.acquire() => {
+                permit
+            },
+            _ = cancel.cancelled() => {
+                return Ok(());
+            }
+        };
+
         let last_record_lsn = self.get_last_record_lsn();
 
         // Last record Lsn could be zero in case the timeline was just created
@@ -655,6 +700,9 @@ impl Timeline {
                 Err(CompactionError::DownloadRequired(rls)) => {
                     anyhow::bail!("Compaction requires downloading multiple times (last was {} layers), possibly battling against eviction", rls.len())
                 }
+                Err(CompactionError::ShuttingDown) => {
+                    return Ok(());
+                }
                 Err(CompactionError::Other(e)) => {
                     return Err(e);
                 }
@@ -671,11 +719,9 @@ impl Timeline {
 
             let mut failed = 0;
 
-            let mut cancelled = pin!(task_mgr::shutdown_watcher());
-
             loop {
                 tokio::select! {
-                    _ = &mut cancelled => anyhow::bail!("Cancelled while downloading remote layers"),
+                    _ = cancel.cancelled() => anyhow::bail!("Cancelled while downloading remote layers"),
                     res = downloads.next() => {
                         match res {
                             Some(Ok(())) => {},
@@ -738,7 +784,8 @@ impl Timeline {
         let layer_removal_cs = Arc::new(self.layer_removal_cs.clone().lock_owned().await);
         // Is the timeline being deleted?
         if self.is_stopping() {
-            return Err(anyhow::anyhow!("timeline is Stopping").into());
+            trace!("Dropping out of compaction on timeline shutdown");
+            return Err(CompactionError::ShuttingDown);
         }
 
         let target_file_size = self.get_checkpoint_distance();
@@ -754,10 +801,15 @@ impl Timeline {
             .await
         {
             Ok((partitioning, lsn)) => {
+                // Disables access_stats updates, so that the files we read remain candidates for eviction after we're done with them
+                let image_ctx = RequestContextBuilder::extend(ctx)
+                    .access_stats_behavior(AccessStatsBehavior::Skip)
+                    .build();
+
                 // 2. Create new image layers for partitions that have been modified
                 // "enough".
                 let layer_paths_to_upload = self
-                    .create_image_layers(&partitioning, lsn, false, ctx)
+                    .create_image_layers(&partitioning, lsn, false, &image_ctx)
                     .await
                     .map_err(anyhow::Error::from)?;
                 if let Some(remote_client) = &self.remote_client {
@@ -830,7 +882,7 @@ impl Timeline {
             let Some(open_layer) = layers.open_layer.as_ref() else {
                 return Ok(());
             };
-            open_layer.size()?
+            open_layer.size().await?
         };
         let last_freeze_at = self.last_freeze_at.load();
         let last_freeze_ts = *(self.last_freeze_ts.read().unwrap());
@@ -874,7 +926,7 @@ impl Timeline {
     pub fn set_state(&self, new_state: TimelineState) {
         match (self.current_state(), new_state) {
             (equal_state_1, equal_state_2) if equal_state_1 == equal_state_2 => {
-                warn!("Ignoring new state, equal to the existing one: {equal_state_2:?}");
+                info!("Ignoring new state, equal to the existing one: {equal_state_2:?}");
             }
             (st, TimelineState::Loading) => {
                 error!("ignoring transition from {st:?} into Loading state");
@@ -890,7 +942,7 @@ impl Timeline {
                     new_state,
                     TimelineState::Stopping | TimelineState::Broken { .. }
                 ) {
-                    // drop the copmletion guard, if any; it might be holding off the completion
+                    // drop the completion guard, if any; it might be holding off the completion
                     // forever needlessly
                     self.initial_logical_size_attempt
                         .lock()
@@ -1115,7 +1167,7 @@ impl Timeline {
             return Err(EvictionError::CannotEvictRemoteLayer);
         }
 
-        let layer_file_size = local_layer.file_size();
+        let layer_file_size = local_layer.layer_desc().file_size;
 
         let local_layer_mtime = local_layer
             .local_path()
@@ -1325,9 +1377,10 @@ impl Timeline {
         pg_version: u32,
         initial_logical_size_can_start: Option<completion::Barrier>,
         initial_logical_size_attempt: Option<completion::Completion>,
+        state: TimelineState,
     ) -> Arc<Self> {
         let disk_consistent_lsn = metadata.disk_consistent_lsn();
-        let (state, _) = watch::channel(TimelineState::Loading);
+        let (state, _) = watch::channel(state);
 
         let (layer_flush_start_tx, _) = tokio::sync::watch::channel(0);
         let (layer_flush_done_tx, _) = tokio::sync::watch::channel((0, Ok(())));
@@ -1367,6 +1420,8 @@ impl Timeline {
                 last_freeze_at: AtomicLsn::new(disk_consistent_lsn.0),
                 last_freeze_ts: RwLock::new(Instant::now()),
 
+                loaded_at: (disk_consistent_lsn, SystemTime::now()),
+
                 ancestor_timeline: ancestor,
                 ancestor_lsn: metadata.ancestor_lsn(),
 
@@ -1418,7 +1473,7 @@ impl Timeline {
                 eviction_task_timeline_state: tokio::sync::Mutex::new(
                     EvictionTaskTimelineState::default(),
                 ),
-                delete_lock: Arc::new(tokio::sync::Mutex::new(false)),
+                delete_progress: Arc::new(tokio::sync::Mutex::new(DeleteTimelineFlow::default())),
 
                 initial_logical_size_can_start,
                 initial_logical_size_attempt: Mutex::new(initial_logical_size_attempt),
@@ -1542,7 +1597,6 @@ impl Timeline {
     ///
     pub(super) async fn load_layer_map(&self, disk_consistent_lsn: Lsn) -> anyhow::Result<()> {
         let mut guard = self.layers.write().await;
-        let mut num_layers = 0;
 
         let timer = self.metrics.load_layer_map_histo.start_timer();
 
@@ -1560,12 +1614,12 @@ impl Timeline {
             let fname = direntry.file_name();
             let fname = fname.to_string_lossy();
 
-            if let Some(imgfilename) = ImageFileName::parse_str(&fname) {
+            if let Some(filename) = ImageFileName::parse_str(&fname) {
                 // create an ImageLayer struct for each image file.
-                if imgfilename.lsn > disk_consistent_lsn {
-                    warn!(
+                if filename.lsn > disk_consistent_lsn {
+                    info!(
                         "found future image layer {} on timeline {} disk_consistent_lsn is {}",
-                        imgfilename, self.timeline_id, disk_consistent_lsn
+                        filename, self.timeline_id, disk_consistent_lsn
                     );
 
                     rename_to_backup(&direntry_path)?;
@@ -1573,31 +1627,31 @@ impl Timeline {
                 }
 
                 let file_size = direntry_path.metadata()?.len();
+                let stats =
+                    LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Resident);
 
                 let layer = ImageLayer::new(
                     self.conf,
                     self.timeline_id,
                     self.tenant_id,
-                    &imgfilename,
+                    &filename,
                     file_size,
-                    LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Resident),
+                    stats,
                 );
 
-                trace!("found layer {}", layer.path().display());
                 total_physical_size += file_size;
                 loaded_layers.push(Arc::new(layer));
-                num_layers += 1;
-            } else if let Some(deltafilename) = DeltaFileName::parse_str(&fname) {
+            } else if let Some(filename) = DeltaFileName::parse_str(&fname) {
                 // Create a DeltaLayer struct for each delta file.
                 // The end-LSN is exclusive, while disk_consistent_lsn is
                 // inclusive. For example, if disk_consistent_lsn is 100, it is
                 // OK for a delta layer to have end LSN 101, but if the end LSN
                 // is 102, then it might not have been fully flushed to disk
                 // before crash.
-                if deltafilename.lsn_range.end > disk_consistent_lsn + 1 {
-                    warn!(
+                if filename.lsn_range.end > disk_consistent_lsn + 1 {
+                    info!(
                         "found future delta layer {} on timeline {} disk_consistent_lsn is {}",
-                        deltafilename, self.timeline_id, disk_consistent_lsn
+                        filename, self.timeline_id, disk_consistent_lsn
                     );
 
                     rename_to_backup(&direntry_path)?;
@@ -1605,20 +1659,20 @@ impl Timeline {
                 }
 
                 let file_size = direntry_path.metadata()?.len();
+                let stats =
+                    LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Resident);
 
                 let layer = DeltaLayer::new(
                     self.conf,
                     self.timeline_id,
                     self.tenant_id,
-                    &deltafilename,
+                    &filename,
                     file_size,
-                    LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Resident),
+                    stats,
                 );
 
-                trace!("found layer {}", layer.path().display());
                 total_physical_size += file_size;
                 loaded_layers.push(Arc::new(layer));
-                num_layers += 1;
             } else if fname == METADATA_FILE_NAME || fname.ends_with(".old") {
                 // ignore these
             } else if remote_timeline_client::is_temp_download_file(&direntry_path) {
@@ -1643,6 +1697,7 @@ impl Timeline {
             }
         }
 
+        let num_layers = loaded_layers.len();
         guard.initialize_local_layers(loaded_layers, Lsn(disk_consistent_lsn.0) + 1);
 
         info!(
@@ -1737,19 +1792,21 @@ impl Timeline {
             match remote_layer_name {
                 LayerFileName::Image(imgfilename) => {
                     if imgfilename.lsn > up_to_date_disk_consistent_lsn {
-                        warn!(
+                        info!(
                         "found future image layer {} on timeline {} remote_consistent_lsn is {}",
                         imgfilename, self.timeline_id, up_to_date_disk_consistent_lsn
                     );
                         continue;
                     }
+                    let stats =
+                        LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Evicted);
 
                     let remote_layer = RemoteLayer::new_img(
                         self.tenant_id,
                         self.timeline_id,
                         imgfilename,
                         &remote_layer_metadata,
-                        LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Evicted),
+                        stats,
                     );
                     let remote_layer = Arc::new(remote_layer);
                     added_remote_layers.push(remote_layer);
@@ -1762,18 +1819,21 @@ impl Timeline {
                     // is 102, then it might not have been fully flushed to disk
                     // before crash.
                     if deltafilename.lsn_range.end > up_to_date_disk_consistent_lsn + 1 {
-                        warn!(
+                        info!(
                             "found future delta layer {} on timeline {} remote_consistent_lsn is {}",
                             deltafilename, self.timeline_id, up_to_date_disk_consistent_lsn
                         );
                         continue;
                     }
+                    let stats =
+                        LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Evicted);
+
                     let remote_layer = RemoteLayer::new_delta(
                         self.tenant_id,
                         self.timeline_id,
                         deltafilename,
                         &remote_layer_metadata,
-                        LayerAccessStats::for_loading_layer(&guard, LayerResidenceStatus::Evicted),
+                        stats,
                     );
                     let remote_layer = Arc::new(remote_layer);
                     added_remote_layers.push(remote_layer);
@@ -1883,6 +1943,15 @@ impl Timeline {
     }
 
     fn try_spawn_size_init_task(self: &Arc<Self>, lsn: Lsn, ctx: &RequestContext) {
+        let state = self.current_state();
+        if matches!(
+            state,
+            TimelineState::Broken { .. } | TimelineState::Stopping
+        ) {
+            // Can happen when timeline detail endpoint is used when deletion is ongoing (or its broken).
+            return;
+        }
+
         let permit = match Arc::clone(&self.current_logical_size.initial_size_computation)
             .try_acquire_owned()
         {
@@ -2212,15 +2281,16 @@ trait TraversalLayerExt {
 
 impl TraversalLayerExt for Arc<dyn PersistentLayer> {
     fn traversal_id(&self) -> TraversalId {
+        let timeline_id = self.layer_desc().timeline_id;
         match self.local_path() {
             Some(local_path) => {
-                debug_assert!(local_path.to_str().unwrap().contains(&format!("{}", self.get_timeline_id())),
+                debug_assert!(local_path.to_str().unwrap().contains(&format!("{}", timeline_id)),
                     "need timeline ID to uniquely identify the layer when traversal crosses ancestor boundary",
                 );
                 format!("{}", local_path.display())
             }
             None => {
-                format!("remote {}/{self}", self.get_timeline_id())
+                format!("remote {}/{self}", timeline_id)
             }
         }
     }
@@ -2252,8 +2322,9 @@ impl Timeline {
         let mut timeline_owned;
         let mut timeline = self;
 
-        let mut read_count =
-            scopeguard::guard(0, |cnt| self.metrics.read_num_fs_layers.observe(cnt as f64));
+        let mut read_count = scopeguard::guard(0, |cnt| {
+            crate::metrics::READ_NUM_FS_LAYERS.observe(cnt as f64)
+        });
 
         // For debugging purposes, collect the path of layers that we traversed
         // through. It's included in the error message if we fail to find the key.
@@ -2387,12 +2458,15 @@ impl Timeline {
                             // Get all the data needed to reconstruct the page version from this layer.
                             // But if we have an older cached page image, no need to go past that.
                             let lsn_floor = max(cached_lsn + 1, start_lsn);
-                            result = match open_layer.get_value_reconstruct_data(
-                                key,
-                                lsn_floor..cont_lsn,
-                                reconstruct_state,
-                                ctx,
-                            ) {
+                            result = match open_layer
+                                .get_value_reconstruct_data(
+                                    key,
+                                    lsn_floor..cont_lsn,
+                                    reconstruct_state,
+                                    ctx,
+                                )
+                                .await
+                            {
                                 Ok(result) => result,
                                 Err(e) => return Err(PageReconstructError::from(e)),
                             };
@@ -2414,12 +2488,15 @@ impl Timeline {
                         if cont_lsn > start_lsn {
                             //info!("CHECKING for {} at {} on frozen layer {}", key, cont_lsn, frozen_layer.filename().display());
                             let lsn_floor = max(cached_lsn + 1, start_lsn);
-                            result = match frozen_layer.get_value_reconstruct_data(
-                                key,
-                                lsn_floor..cont_lsn,
-                                reconstruct_state,
-                                ctx,
-                            ) {
+                            result = match frozen_layer
+                                .get_value_reconstruct_data(
+                                    key,
+                                    lsn_floor..cont_lsn,
+                                    reconstruct_state,
+                                    ctx,
+                                )
+                                .await
+                            {
                                 Ok(result) => result,
                                 Err(e) => return Err(PageReconstructError::from(e)),
                             };
@@ -2450,12 +2527,15 @@ impl Timeline {
                             // Get all the data needed to reconstruct the page version from this layer.
                             // But if we have an older cached page image, no need to go past that.
                             let lsn_floor = max(cached_lsn + 1, lsn_floor);
-                            result = match layer.get_value_reconstruct_data(
-                                key,
-                                lsn_floor..cont_lsn,
-                                reconstruct_state,
-                                ctx,
-                            ) {
+                            result = match layer
+                                .get_value_reconstruct_data(
+                                    key,
+                                    lsn_floor..cont_lsn,
+                                    reconstruct_state,
+                                    ctx,
+                                )
+                                .await
+                            {
                                 Ok(result) => result,
                                 Err(e) => return Err(PageReconstructError::from(e)),
                             };
@@ -2574,7 +2654,7 @@ impl Timeline {
     async fn put_value(&self, key: Key, lsn: Lsn, val: &Value) -> anyhow::Result<()> {
         //info!("PUT: key {} at {}", key, lsn);
         let layer = self.get_layer_for_write(lsn).await?;
-        layer.put_value(key, lsn, val)?;
+        layer.put_value(key, lsn, val).await?;
         Ok(())
     }
 
@@ -2600,7 +2680,9 @@ impl Timeline {
             Some(self.write_lock.lock().await)
         };
         let mut guard = self.layers.write().await;
-        guard.try_freeze_in_memory_layer(self.get_last_record_lsn(), &self.last_freeze_at);
+        guard
+            .try_freeze_in_memory_layer(self.get_last_record_lsn(), &self.last_freeze_at)
+            .await;
     }
 
     /// Layer flusher task's main loop.
@@ -2746,7 +2828,10 @@ impl Timeline {
                 // We will remove frozen layer and add delta layer in one atomic operation later.
                 let layer = self.create_delta_layer(&frozen_layer).await?;
                 (
-                    HashMap::from([(layer.filename(), LayerFileMetadata::new(layer.file_size()))]),
+                    HashMap::from([(
+                        layer.filename(),
+                        LayerFileMetadata::new(layer.layer_desc().file_size),
+                    )]),
                     Some(layer),
                 )
             };
@@ -2766,7 +2851,7 @@ impl Timeline {
                 );
 
                 // update metrics
-                let sz = l.file_size();
+                let sz = l.layer_desc().file_size;
                 self.metrics.resident_physical_size_gauge.add(sz);
                 self.metrics.num_persistent_files_created.inc_by(1);
                 self.metrics.persistent_bytes_written.inc_by(sz);
@@ -2879,7 +2964,11 @@ impl Timeline {
             let frozen_layer = Arc::clone(frozen_layer);
             move || {
                 // Write it out
-                let new_delta = frozen_layer.write_to_disk()?;
+                // Keep this inside `spawn_blocking` and `Handle::current`
+                // as long as the write path is still sync and the read impl
+                // is still not fully async. Otherwise executor threads would
+                // be blocked.
+                let new_delta = Handle::current().block_on(frozen_layer.write_to_disk())?;
                 let new_delta_path = new_delta.path();
 
                 // Sync it to disk.
@@ -3173,6 +3262,8 @@ enum CompactionError {
     /// This should not happen repeatedly, but will be retried once by top-level
     /// `Timeline::compact`.
     DownloadRequired(Vec<Arc<RemoteLayer>>),
+    /// The timeline or pageserver is shutting down
+    ShuttingDown,
     /// Compaction cannot be done right now; page reconstruction and so on.
     Other(anyhow::Error),
 }
@@ -3383,14 +3474,14 @@ impl Timeline {
         // "gaps" in the sequence of level 0 files should only happen in case
         // of a crash, partial download from cloud storage, or something like
         // that, so it's not a big deal in practice.
-        level0_deltas.sort_by_key(|l| l.get_lsn_range().start);
+        level0_deltas.sort_by_key(|l| l.layer_desc().lsn_range.start);
         let mut level0_deltas_iter = level0_deltas.iter();
 
         let first_level0_delta = level0_deltas_iter.next().unwrap();
-        let mut prev_lsn_end = first_level0_delta.get_lsn_range().end;
+        let mut prev_lsn_end = first_level0_delta.layer_desc().lsn_range.end;
         let mut deltas_to_compact = vec![Arc::clone(first_level0_delta)];
         for l in level0_deltas_iter {
-            let lsn_range = l.get_lsn_range();
+            let lsn_range = &l.layer_desc().lsn_range;
 
             if lsn_range.start != prev_lsn_end {
                 break;
@@ -3399,8 +3490,13 @@ impl Timeline {
             prev_lsn_end = lsn_range.end;
         }
         let lsn_range = Range {
-            start: deltas_to_compact.first().unwrap().get_lsn_range().start,
-            end: deltas_to_compact.last().unwrap().get_lsn_range().end,
+            start: deltas_to_compact
+                .first()
+                .unwrap()
+                .layer_desc()
+                .lsn_range
+                .start,
+            end: deltas_to_compact.last().unwrap().layer_desc().lsn_range.end,
         };
 
         let remotes = deltas_to_compact
@@ -3450,10 +3546,30 @@ impl Timeline {
         // min-heap (reserve space for one more element added before eviction)
         let mut heap: BinaryHeap<Hole> = BinaryHeap::with_capacity(max_holes + 1);
         let mut prev: Option<Key> = None;
-        for (next_key, _next_lsn, _size) in itertools::process_results(
-            deltas_to_compact.iter().map(|l| l.key_iter(ctx)),
-            |iter_iter| iter_iter.kmerge_by(|a, b| a.0 < b.0),
-        )? {
+
+        let mut all_value_refs = Vec::new();
+        let mut all_keys = Vec::new();
+
+        for l in deltas_to_compact.iter() {
+            // TODO: replace this with an await once we fully go async
+            let delta = l.clone().downcast_delta_layer().expect("delta layer");
+            Handle::current().block_on(async {
+                all_value_refs.extend(delta.load_val_refs(ctx).await?);
+                all_keys.extend(delta.load_keys(ctx).await?);
+                anyhow::Ok(())
+            })?;
+        }
+
+        // The current stdlib sorting implementation is designed in a way where it is
+        // particularly fast where the slice is made up of sorted sub-ranges.
+        all_value_refs.sort_by_key(|(key, lsn, _value_ref)| (*key, *lsn));
+
+        // The current stdlib sorting implementation is designed in a way where it is
+        // particularly fast where the slice is made up of sorted sub-ranges.
+        all_keys.sort_by_key(|(key, lsn, _size)| (*key, *lsn));
+
+        for (next_key, _next_lsn, _size) in all_keys.iter() {
+            let next_key = *next_key;
             if let Some(prev_key) = prev {
                 // just first fast filter
                 if next_key.to_i128() - prev_key.to_i128() >= min_hole_range {
@@ -3486,34 +3602,10 @@ impl Timeline {
 
         // This iterator walks through all key-value pairs from all the layers
         // we're compacting, in key, LSN order.
-        let all_values_iter = itertools::process_results(
-            deltas_to_compact.iter().map(|l| l.iter(ctx)),
-            |iter_iter| {
-                iter_iter.kmerge_by(|a, b| {
-                    if let Ok((a_key, a_lsn, _)) = a {
-                        if let Ok((b_key, b_lsn, _)) = b {
-                            (a_key, a_lsn) < (b_key, b_lsn)
-                        } else {
-                            false
-                        }
-                    } else {
-                        true
-                    }
-                })
-            },
-        )?;
+        let all_values_iter = all_value_refs.into_iter();
 
         // This iterator walks through all keys and is needed to calculate size used by each key
-        let mut all_keys_iter = itertools::process_results(
-            deltas_to_compact.iter().map(|l| l.key_iter(ctx)),
-            |iter_iter| {
-                iter_iter.kmerge_by(|a, b| {
-                    let (a_key, a_lsn, _) = a;
-                    let (b_key, b_lsn, _) = b;
-                    (a_key, a_lsn) < (b_key, b_lsn)
-                })
-            },
-        )?;
+        let mut all_keys_iter = all_keys.into_iter();
 
         stats.prepare_iterators_micros = stats.read_lock_drop_micros.till_now();
 
@@ -3567,98 +3659,105 @@ impl Timeline {
         let mut key_values_total_size = 0u64;
         let mut dup_start_lsn: Lsn = Lsn::INVALID; // start LSN of layer containing values of the single key
         let mut dup_end_lsn: Lsn = Lsn::INVALID; // end LSN of layer containing values of the single key
-        for x in all_values_iter {
-            let (key, lsn, value) = x?;
-            let same_key = prev_key.map_or(false, |prev_key| prev_key == key);
-            // We need to check key boundaries once we reach next key or end of layer with the same key
-            if !same_key || lsn == dup_end_lsn {
-                let mut next_key_size = 0u64;
-                let is_dup_layer = dup_end_lsn.is_valid();
-                dup_start_lsn = Lsn::INVALID;
-                if !same_key {
-                    dup_end_lsn = Lsn::INVALID;
+
+        // TODO remove this block_on wrapper once we fully go async
+        Handle::current().block_on(async {
+            for (key, lsn, value_ref) in all_values_iter {
+                let value = value_ref.load().await?;
+                let same_key = prev_key.map_or(false, |prev_key| prev_key == key);
+                // We need to check key boundaries once we reach next key or end of layer with the same key
+                if !same_key || lsn == dup_end_lsn {
+                    let mut next_key_size = 0u64;
+                    let is_dup_layer = dup_end_lsn.is_valid();
+                    dup_start_lsn = Lsn::INVALID;
+                    if !same_key {
+                        dup_end_lsn = Lsn::INVALID;
+                    }
+                    // Determine size occupied by this key. We stop at next key or when size becomes larger than target_file_size
+                    for (next_key, next_lsn, next_size) in all_keys_iter.by_ref() {
+                        next_key_size = next_size;
+                        if key != next_key {
+                            if dup_end_lsn.is_valid() {
+                                // We are writting segment with duplicates:
+                                // place all remaining values of this key in separate segment
+                                dup_start_lsn = dup_end_lsn; // new segments starts where old stops
+                                dup_end_lsn = lsn_range.end; // there are no more values of this key till end of LSN range
+                            }
+                            break;
+                        }
+                        key_values_total_size += next_size;
+                        // Check if it is time to split segment: if total keys size is larger than target file size.
+                        // We need to avoid generation of empty segments if next_size > target_file_size.
+                        if key_values_total_size > target_file_size && lsn != next_lsn {
+                            // Split key between multiple layers: such layer can contain only single key
+                            dup_start_lsn = if dup_end_lsn.is_valid() {
+                                dup_end_lsn // new segment with duplicates starts where old one stops
+                            } else {
+                                lsn // start with the first LSN for this key
+                            };
+                            dup_end_lsn = next_lsn; // upper LSN boundary is exclusive
+                            break;
+                        }
+                    }
+                    // handle case when loop reaches last key: in this case dup_end is non-zero but dup_start is not set.
+                    if dup_end_lsn.is_valid() && !dup_start_lsn.is_valid() {
+                        dup_start_lsn = dup_end_lsn;
+                        dup_end_lsn = lsn_range.end;
+                    }
+                    if writer.is_some() {
+                        let written_size = writer.as_mut().unwrap().size();
+                        let contains_hole =
+                            next_hole < holes.len() && key >= holes[next_hole].key_range.end;
+                        // check if key cause layer overflow or contains hole...
+                        if is_dup_layer
+                            || dup_end_lsn.is_valid()
+                            || written_size + key_values_total_size > target_file_size
+                            || contains_hole
+                        {
+                            // ... if so, flush previous layer and prepare to write new one
+                            new_layers.push(Arc::new(
+                                writer.take().unwrap().finish(prev_key.unwrap().next())?,
+                            ));
+                            writer = None;
+
+                            if contains_hole {
+                                // skip hole
+                                next_hole += 1;
+                            }
+                        }
+                    }
+                    // Remember size of key value because at next iteration we will access next item
+                    key_values_total_size = next_key_size;
                 }
-                // Determine size occupied by this key. We stop at next key or when size becomes larger than target_file_size
-                for (next_key, next_lsn, next_size) in all_keys_iter.by_ref() {
-                    next_key_size = next_size;
-                    if key != next_key {
+                if writer.is_none() {
+                    // Create writer if not initiaized yet
+                    writer = Some(DeltaLayerWriter::new(
+                        self.conf,
+                        self.timeline_id,
+                        self.tenant_id,
+                        key,
                         if dup_end_lsn.is_valid() {
-                            // We are writting segment with duplicates:
-                            // place all remaining values of this key in separate segment
-                            dup_start_lsn = dup_end_lsn; // new segments starts where old stops
-                            dup_end_lsn = lsn_range.end; // there are no more values of this key till end of LSN range
-                        }
-                        break;
-                    }
-                    key_values_total_size += next_size;
-                    // Check if it is time to split segment: if total keys size is larger than target file size.
-                    // We need to avoid generation of empty segments if next_size > target_file_size.
-                    if key_values_total_size > target_file_size && lsn != next_lsn {
-                        // Split key between multiple layers: such layer can contain only single key
-                        dup_start_lsn = if dup_end_lsn.is_valid() {
-                            dup_end_lsn // new segment with duplicates starts where old one stops
+                            // this is a layer containing slice of values of the same key
+                            debug!("Create new dup layer {}..{}", dup_start_lsn, dup_end_lsn);
+                            dup_start_lsn..dup_end_lsn
                         } else {
-                            lsn // start with the first LSN for this key
-                        };
-                        dup_end_lsn = next_lsn; // upper LSN boundary is exclusive
-                        break;
-                    }
+                            debug!("Create new layer {}..{}", lsn_range.start, lsn_range.end);
+                            lsn_range.clone()
+                        },
+                    )?);
                 }
-                // handle case when loop reaches last key: in this case dup_end is non-zero but dup_start is not set.
-                if dup_end_lsn.is_valid() && !dup_start_lsn.is_valid() {
-                    dup_start_lsn = dup_end_lsn;
-                    dup_end_lsn = lsn_range.end;
-                }
-                if writer.is_some() {
-                    let written_size = writer.as_mut().unwrap().size();
-                    let contains_hole =
-                        next_hole < holes.len() && key >= holes[next_hole].key_range.end;
-                    // check if key cause layer overflow or contains hole...
-                    if is_dup_layer
-                        || dup_end_lsn.is_valid()
-                        || written_size + key_values_total_size > target_file_size
-                        || contains_hole
-                    {
-                        // ... if so, flush previous layer and prepare to write new one
-                        new_layers.push(Arc::new(
-                            writer.take().unwrap().finish(prev_key.unwrap().next())?,
-                        ));
-                        writer = None;
 
-                        if contains_hole {
-                            // skip hole
-                            next_hole += 1;
-                        }
-                    }
-                }
-                // Remember size of key value because at next iteration we will access next item
-                key_values_total_size = next_key_size;
+                fail_point!("delta-layer-writer-fail-before-finish", |_| {
+                    Result::<_>::Err(anyhow::anyhow!(
+                        "failpoint delta-layer-writer-fail-before-finish"
+                    ))
+                });
+
+                writer.as_mut().unwrap().put_value(key, lsn, value)?;
+                prev_key = Some(key);
             }
-            if writer.is_none() {
-                // Create writer if not initiaized yet
-                writer = Some(DeltaLayerWriter::new(
-                    self.conf,
-                    self.timeline_id,
-                    self.tenant_id,
-                    key,
-                    if dup_end_lsn.is_valid() {
-                        // this is a layer containing slice of values of the same key
-                        debug!("Create new dup layer {}..{}", dup_start_lsn, dup_end_lsn);
-                        dup_start_lsn..dup_end_lsn
-                    } else {
-                        debug!("Create new layer {}..{}", lsn_range.start, lsn_range.end);
-                        lsn_range.clone()
-                    },
-                )?);
-            }
-
-            fail_point!("delta-layer-writer-fail-before-finish", |_| {
-                Err(anyhow::anyhow!("failpoint delta-layer-writer-fail-before-finish").into())
-            });
-
-            writer.as_mut().unwrap().put_value(key, lsn, value)?;
-            prev_key = Some(key);
-        }
+            Ok(())
+        })?;
         if let Some(writer) = writer {
             new_layers.push(Arc::new(writer.finish(prev_key.unwrap().next())?));
         }
@@ -4580,7 +4679,7 @@ impl std::fmt::Debug for LocalLayerInfoForDiskUsageEviction {
 
 impl LocalLayerInfoForDiskUsageEviction {
     pub fn file_size(&self) -> u64 {
-        self.layer.file_size()
+        self.layer.layer_desc().file_size
     }
 }
 

pageserver/src/tenant/timeline/delete.rs

@@ -0,0 +1,583 @@
+use std::{
+    ops::{Deref, DerefMut},
+    sync::Arc,
+};
+
+use anyhow::Context;
+use pageserver_api::models::TimelineState;
+use tokio::sync::OwnedMutexGuard;
+use tracing::{debug, error, info, instrument, warn, Instrument, Span};
+use utils::{
+    crashsafe, fs_ext,
+    id::{TenantId, TimelineId},
+};
+
+use crate::{
+    config::PageServerConf,
+    task_mgr::{self, TaskKind},
+    tenant::{
+        metadata::TimelineMetadata,
+        remote_timeline_client::{
+            self, PersistIndexPartWithDeletedFlagError, RemoteTimelineClient,
+        },
+        CreateTimelineCause, DeleteTimelineError, Tenant,
+    },
+    InitializationOrder,
+};
+
+use super::Timeline;
+
+/// Now that the Timeline is in Stopping state, request all the related tasks to shut down.
+async fn stop_tasks(timeline: &Timeline) -> Result<(), DeleteTimelineError> {
+    // Stop the walreceiver first.
+    debug!("waiting for wal receiver to shutdown");
+    let maybe_started_walreceiver = { timeline.walreceiver.lock().unwrap().take() };
+    if let Some(walreceiver) = maybe_started_walreceiver {
+        walreceiver.stop().await;
+    }
+    debug!("wal receiver shutdown confirmed");
+
+    // Prevent new uploads from starting.
+    if let Some(remote_client) = timeline.remote_client.as_ref() {
+        let res = remote_client.stop();
+        match res {
+            Ok(()) => {}
+            Err(e) => match e {
+                remote_timeline_client::StopError::QueueUninitialized => {
+                    // This case shouldn't happen currently because the
+                    // load and attach code bails out if _any_ of the timeline fails to fetch its IndexPart.
+                    // That is, before we declare the Tenant as Active.
+                    // But we only allow calls to delete_timeline on Active tenants.
+                    return Err(DeleteTimelineError::Other(anyhow::anyhow!("upload queue is uninitialized, likely the timeline was in Broken state prior to this call because it failed to fetch IndexPart during load or attach, check the logs")));
+                }
+            },
+        }
+    }
+
+    // Stop & wait for the remaining timeline tasks, including upload tasks.
+    // NB: This and other delete_timeline calls do not run as a task_mgr task,
+    //     so, they are not affected by this shutdown_tasks() call.
+    info!("waiting for timeline tasks to shutdown");
+    task_mgr::shutdown_tasks(None, Some(timeline.tenant_id), Some(timeline.timeline_id)).await;
+
+    fail::fail_point!("timeline-delete-before-index-deleted-at", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: timeline-delete-before-index-deleted-at"
+        ))?
+    });
+    Ok(())
+}
+
+/// Mark timeline as deleted in S3 so we won't pick it up next time
+/// during attach or pageserver restart.
+/// See comment in persist_index_part_with_deleted_flag.
+async fn set_deleted_in_remote_index(timeline: &Timeline) -> Result<(), DeleteTimelineError> {
+    if let Some(remote_client) = timeline.remote_client.as_ref() {
+        match remote_client.persist_index_part_with_deleted_flag().await {
+            // If we (now, or already) marked it successfully as deleted, we can proceed
+            Ok(()) | Err(PersistIndexPartWithDeletedFlagError::AlreadyDeleted(_)) => (),
+            // Bail out otherwise
+            //
+            // AlreadyInProgress shouldn't happen, because the 'delete_lock' prevents
+            // two tasks from performing the deletion at the same time. The first task
+            // that starts deletion should run it to completion.
+            Err(e @ PersistIndexPartWithDeletedFlagError::AlreadyInProgress(_))
+            | Err(e @ PersistIndexPartWithDeletedFlagError::Other(_)) => {
+                return Err(DeleteTimelineError::Other(anyhow::anyhow!(e)));
+            }
+        }
+    }
+    Ok(())
+}
+
+// We delete local files first, so if pageserver restarts after local files deletion then remote deletion is not continued.
+// This can be solved with inversion of these steps. But even if these steps are inverted then, when index_part.json
+// gets deleted there is no way to distinguish between "this timeline is good, we just didnt upload it to remote"
+// and "this timeline is deleted we should continue with removal of local state". So to avoid the ambiguity we use a mark file.
+// After index part is deleted presence of this mark file indentifies that it was a deletion intention.
+// So we can just remove the mark file.
+async fn create_delete_mark(
+    conf: &PageServerConf,
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+) -> Result<(), DeleteTimelineError> {
+    fail::fail_point!("timeline-delete-before-delete-mark", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: timeline-delete-before-delete-mark"
+        ))?
+    });
+    let marker_path = conf.timeline_delete_mark_file_path(tenant_id, timeline_id);
+
+    // Note: we're ok to replace existing file.
+    let _ = std::fs::OpenOptions::new()
+        .write(true)
+        .create(true)
+        .open(&marker_path)
+        .with_context(|| format!("could not create delete marker file {marker_path:?}"))?;
+
+    crashsafe::fsync_file_and_parent(&marker_path).context("sync_mark")?;
+    Ok(())
+}
+
+/// Grab the layer_removal_cs lock, and actually perform the deletion.
+///
+/// This lock prevents prevents GC or compaction from running at the same time.
+/// The GC task doesn't register itself with the timeline it's operating on,
+/// so it might still be running even though we called `shutdown_tasks`.
+///
+/// Note that there are still other race conditions between
+/// GC, compaction and timeline deletion. See
+/// <https://github.com/neondatabase/neon/issues/2671>
+///
+/// No timeout here, GC & Compaction should be responsive to the
+/// `TimelineState::Stopping` change.
+async fn delete_local_layer_files(
+    conf: &PageServerConf,
+    tenant_id: TenantId,
+    timeline: &Timeline,
+) -> anyhow::Result<()> {
+    info!("waiting for layer_removal_cs.lock()");
+    let layer_removal_guard = timeline.layer_removal_cs.lock().await;
+    info!("got layer_removal_cs.lock(), deleting layer files");
+
+    // NB: storage_sync upload tasks that reference these layers have been cancelled
+    //     by the caller.
+
+    let local_timeline_directory = conf.timeline_path(&tenant_id, &timeline.timeline_id);
+
+    fail::fail_point!("timeline-delete-before-rm", |_| {
+        Err(anyhow::anyhow!("failpoint: timeline-delete-before-rm"))?
+    });
+
+    // NB: This need not be atomic because the deleted flag in the IndexPart
+    // will be observed during tenant/timeline load. The deletion will be resumed there.
+    //
+    // For configurations without remote storage, we guarantee crash-safety by persising delete mark file.
+    //
+    // Note that here we do not bail out on std::io::ErrorKind::NotFound.
+    // This can happen if we're called a second time, e.g.,
+    // because of a previous failure/cancellation at/after
+    // failpoint timeline-delete-after-rm.
+    //
+    // It can also happen if we race with tenant detach, because,
+    // it doesn't grab the layer_removal_cs lock.
+    //
+    // For now, log and continue.
+    // warn! level is technically not appropriate for the
+    // first case because we should expect retries to happen.
+    // But the error is so rare, it seems better to get attention if it happens.
+    //
+    // Note that metadata removal is skipped, this is not technically needed,
+    // but allows to reuse timeline loading code during resumed deletion.
+    // (we always expect that metadata is in place when timeline is being loaded)
+
+    #[cfg(feature = "testing")]
+    let mut counter = 0;
+
+    // Timeline directory may not exist if we failed to delete mark file and request was retried.
+    if !local_timeline_directory.exists() {
+        return Ok(());
+    }
+
+    let metadata_path = conf.metadata_path(&tenant_id, &timeline.timeline_id);
+
+    for entry in walkdir::WalkDir::new(&local_timeline_directory).contents_first(true) {
+        #[cfg(feature = "testing")]
+        {
+            counter += 1;
+            if counter == 2 {
+                fail::fail_point!("timeline-delete-during-rm", |_| {
+                    Err(anyhow::anyhow!("failpoint: timeline-delete-during-rm"))?
+                });
+            }
+        }
+
+        let entry = entry?;
+        if entry.path() == metadata_path {
+            debug!("found metadata, skipping");
+            continue;
+        }
+
+        if entry.path() == local_timeline_directory {
+            // Keeping directory because metedata file is still there
+            debug!("found timeline dir itself, skipping");
+            continue;
+        }
+
+        let metadata = match entry.metadata() {
+            Ok(metadata) => metadata,
+            Err(e) => {
+                if crate::is_walkdir_io_not_found(&e) {
+                    warn!(
+                        timeline_dir=?local_timeline_directory,
+                        path=?entry.path().display(),
+                        "got not found err while removing timeline dir, proceeding anyway"
+                    );
+                    continue;
+                }
+                anyhow::bail!(e);
+            }
+        };
+
+        if metadata.is_dir() {
+            warn!(path=%entry.path().display(), "unexpected directory under timeline dir");
+            tokio::fs::remove_dir(entry.path()).await
+        } else {
+            tokio::fs::remove_file(entry.path()).await
+        }
+        .with_context(|| format!("Failed to remove: {}", entry.path().display()))?;
+    }
+
+    info!("finished deleting layer files, releasing layer_removal_cs.lock()");
+    drop(layer_removal_guard);
+
+    fail::fail_point!("timeline-delete-after-rm", |_| {
+        Err(anyhow::anyhow!("failpoint: timeline-delete-after-rm"))?
+    });
+
+    Ok(())
+}
+
+/// Removes remote layers and an index file after them.
+async fn delete_remote_layers_and_index(timeline: &Timeline) -> anyhow::Result<()> {
+    if let Some(remote_client) = &timeline.remote_client {
+        remote_client.delete_all().await.context("delete_all")?
+    };
+
+    Ok(())
+}
+
+// This function removs remaining traces of a timeline on disk.
+// Namely: metadata file, timeline directory, delete mark.
+// Note: io::ErrorKind::NotFound are ignored for metadata and timeline dir.
+// delete mark should be present because it is the last step during deletion.
+// (nothing can fail after its deletion)
+async fn cleanup_remaining_timeline_fs_traces(
+    conf: &PageServerConf,
+    tenant_id: TenantId,
+    timeline_id: TimelineId,
+) -> anyhow::Result<()> {
+    // Remove local metadata
+    tokio::fs::remove_file(conf.metadata_path(&tenant_id, &timeline_id))
+        .await
+        .or_else(fs_ext::ignore_not_found)
+        .context("remove metadata")?;
+
+    fail::fail_point!("timeline-delete-after-rm-metadata", |_| {
+        Err(anyhow::anyhow!(
+            "failpoint: timeline-delete-after-rm-metadata"
+        ))?
+    });
+
+    // Remove timeline dir
+    tokio::fs::remove_dir(conf.timeline_path(&tenant_id, &timeline_id))
+        .await
+        .or_else(fs_ext::ignore_not_found)
+        .context("timeline dir")?;
+
+    fail::fail_point!("timeline-delete-after-rm-dir", |_| {
+        Err(anyhow::anyhow!("failpoint: timeline-delete-after-rm-dir"))?
+    });
+
+    // Remove delete mark
+    tokio::fs::remove_file(conf.timeline_delete_mark_file_path(tenant_id, timeline_id))
+        .await
+        .context("remove delete mark")
+}
+
+/// It is important that this gets called when DeletionGuard is being held.
+/// For more context see comments in [`DeleteTimelineFlow::prepare`]
+async fn remove_timeline_from_tenant(
+    tenant: &Tenant,
+    timeline_id: TimelineId,
+    _: &DeletionGuard, // using it as a witness
+) -> anyhow::Result<()> {
+    // Remove the timeline from the map.
+    let mut timelines = tenant.timelines.lock().unwrap();
+    let children_exist = timelines
+        .iter()
+        .any(|(_, entry)| entry.get_ancestor_timeline_id() == Some(timeline_id));
+    // XXX this can happen because `branch_timeline` doesn't check `TimelineState::Stopping`.
+    // We already deleted the layer files, so it's probably best to panic.
+    // (Ideally, above remove_dir_all is atomic so we don't see this timeline after a restart)
+    if children_exist {
+        panic!("Timeline grew children while we removed layer files");
+    }
+
+    timelines
+        .remove(&timeline_id)
+        .expect("timeline that we were deleting was concurrently removed from 'timelines' map");
+
+    drop(timelines);
+
+    Ok(())
+}
+
+/// Orchestrates timeline shut down of all timeline tasks, removes its in-memory structures,
+/// and deletes its data from both disk and s3.
+/// The sequence of steps:
+/// 1. Set deleted_at in remote index part.
+/// 2. Create local mark file.
+/// 3. Delete local files except metadata (it is simpler this way, to be able to reuse timeline initialization code that expects metadata)
+/// 4. Delete remote layers
+/// 5. Delete index part
+/// 6. Delete meta, timeline directory
+/// 7. Delete mark file
+/// It is resumable from any step in case a crash/restart occurs.
+/// There are three entrypoints to the process:
+/// 1. [`DeleteTimelineFlow::run`] this is the main one called by a management api handler.
+/// 2. [`DeleteTimelineFlow::resume_deletion`] is called during restarts when local metadata is still present
+/// and we possibly neeed to continue deletion of remote files.
+/// 3. [`DeleteTimelineFlow::cleanup_remaining_timeline_fs_traces`] is used when we deleted remote
+/// index but still have local metadata, timeline directory and delete mark.
+/// Note the only other place that messes around timeline delete mark is the logic that scans directory with timelines during tenant load.
+#[derive(Default)]
+pub enum DeleteTimelineFlow {
+    #[default]
+    NotStarted,
+    InProgress,
+    Finished,
+}
+
+impl DeleteTimelineFlow {
+    // These steps are run in the context of management api request handler.
+    // Long running steps are continued to run in the background.
+    // NB: If this fails half-way through, and is retried, the retry will go through
+    // all the same steps again. Make sure the code here is idempotent, and don't
+    // error out if some of the shutdown tasks have already been completed!
+    #[instrument(skip(tenant), fields(tenant_id=%tenant.tenant_id))]
+    pub async fn run(
+        tenant: &Arc<Tenant>,
+        timeline_id: TimelineId,
+        inplace: bool,
+    ) -> Result<(), DeleteTimelineError> {
+        let (timeline, mut guard) = Self::prepare(tenant, timeline_id)?;
+
+        guard.mark_in_progress()?;
+
+        stop_tasks(&timeline).await?;
+
+        set_deleted_in_remote_index(&timeline).await?;
+
+        create_delete_mark(tenant.conf, timeline.tenant_id, timeline.timeline_id).await?;
+
+        fail::fail_point!("timeline-delete-before-schedule", |_| {
+            Err(anyhow::anyhow!(
+                "failpoint: timeline-delete-before-schedule"
+            ))?
+        });
+
+        if inplace {
+            Self::background(guard, tenant.conf, tenant, &timeline).await?
+        } else {
+            Self::schedule_background(guard, tenant.conf, Arc::clone(tenant), timeline);
+        }
+
+        Ok(())
+    }
+
+    fn mark_in_progress(&mut self) -> anyhow::Result<()> {
+        match self {
+            Self::Finished => anyhow::bail!("Bug. Is in finished state"),
+            Self::InProgress { .. } => { /* We're in a retry */ }
+            Self::NotStarted => { /* Fresh start */ }
+        }
+
+        *self = Self::InProgress;
+
+        Ok(())
+    }
+
+    /// Shortcut to create Timeline in stopping state and spawn deletion task.
+    /// See corresponding parts of [`crate::tenant::delete::DeleteTenantFlow`]
+    #[instrument(skip_all, fields(%timeline_id))]
+    pub async fn resume_deletion(
+        tenant: Arc<Tenant>,
+        timeline_id: TimelineId,
+        local_metadata: &TimelineMetadata,
+        remote_client: Option<RemoteTimelineClient>,
+        init_order: Option<&InitializationOrder>,
+    ) -> anyhow::Result<()> {
+        // Note: here we even skip populating layer map. Timeline is essentially uninitialized.
+        // RemoteTimelineClient is the only functioning part.
+        let timeline = tenant
+            .create_timeline_struct(
+                timeline_id,
+                local_metadata,
+                None, // Ancestor is not needed for deletion.
+                remote_client,
+                init_order,
+                // Important. We dont pass ancestor above because it can be missing.
+                // Thus we need to skip the validation here.
+                CreateTimelineCause::Delete,
+            )
+            .context("create_timeline_struct")?;
+
+        let mut guard = DeletionGuard(
+            Arc::clone(&timeline.delete_progress)
+                .try_lock_owned()
+                .expect("cannot happen because we're the only owner"),
+        );
+
+        // We meed to do this because when console retries delete request we shouldnt answer with 404
+        // because 404 means successful deletion.
+        {
+            let mut locked = tenant.timelines.lock().unwrap();
+            locked.insert(timeline_id, Arc::clone(&timeline));
+        }
+
+        guard.mark_in_progress()?;
+
+        // Note that delete mark can be missing on resume
+        // because we create delete mark after we set deleted_at in the index part.
+        create_delete_mark(tenant.conf, tenant.tenant_id, timeline_id).await?;
+
+        Self::schedule_background(guard, tenant.conf, tenant, timeline);
+
+        Ok(())
+    }
+
+    #[instrument(skip_all, fields(%timeline_id))]
+    pub async fn cleanup_remaining_timeline_fs_traces(
+        tenant: &Tenant,
+        timeline_id: TimelineId,
+    ) -> anyhow::Result<()> {
+        let r =
+            cleanup_remaining_timeline_fs_traces(tenant.conf, tenant.tenant_id, timeline_id).await;
+        info!("Done");
+        r
+    }
+
+    fn prepare(
+        tenant: &Tenant,
+        timeline_id: TimelineId,
+    ) -> Result<(Arc<Timeline>, DeletionGuard), DeleteTimelineError> {
+        // Note the interaction between this guard and deletion guard.
+        // Here we attempt to lock deletion guard when we're holding a lock on timelines.
+        // This is important because when you take into account `remove_timeline_from_tenant`
+        // we remove timeline from memory when we still hold the deletion guard.
+        // So here when timeline deletion is finished timeline wont be present in timelines map at all
+        // which makes the following sequence impossible:
+        // T1: get preempted right before the try_lock on `Timeline::delete_progress`
+        // T2: do a full deletion, acquire and drop `Timeline::delete_progress`
+        // T1: acquire deletion lock, do another `DeleteTimelineFlow::run`
+        // For more context see this discussion: `https://github.com/neondatabase/neon/pull/4552#discussion_r1253437346`
+        let timelines = tenant.timelines.lock().unwrap();
+
+        let timeline = match timelines.get(&timeline_id) {
+            Some(t) => t,
+            None => return Err(DeleteTimelineError::NotFound),
+        };
+
+        // Ensure that there are no child timelines **attached to that pageserver**,
+        // because detach removes files, which will break child branches
+        let children: Vec<TimelineId> = timelines
+            .iter()
+            .filter_map(|(id, entry)| {
+                if entry.get_ancestor_timeline_id() == Some(timeline_id) {
+                    Some(*id)
+                } else {
+                    None
+                }
+            })
+            .collect();
+
+        if !children.is_empty() {
+            return Err(DeleteTimelineError::HasChildren(children));
+        }
+
+        // Note that using try_lock here is important to avoid a deadlock.
+        // Here we take lock on timelines and then the deletion guard.
+        // At the end of the operation we're holding the guard and need to lock timelines map
+        // to remove the timeline from it.
+        // Always if you have two locks that are taken in different order this can result in a deadlock.
+
+        let delete_progress = Arc::clone(&timeline.delete_progress);
+        let delete_lock_guard = match delete_progress.try_lock_owned() {
+            Ok(guard) => DeletionGuard(guard),
+            Err(_) => {
+                // Unfortunately if lock fails arc is consumed.
+                return Err(DeleteTimelineError::AlreadyInProgress(Arc::clone(
+                    &timeline.delete_progress,
+                )));
+            }
+        };
+
+        timeline.set_state(TimelineState::Stopping);
+
+        Ok((Arc::clone(timeline), delete_lock_guard))
+    }
+
+    fn schedule_background(
+        guard: DeletionGuard,
+        conf: &'static PageServerConf,
+        tenant: Arc<Tenant>,
+        timeline: Arc<Timeline>,
+    ) {
+        let tenant_id = timeline.tenant_id;
+        let timeline_id = timeline.timeline_id;
+
+        task_mgr::spawn(
+            task_mgr::BACKGROUND_RUNTIME.handle(),
+            TaskKind::TimelineDeletionWorker,
+            Some(tenant_id),
+            Some(timeline_id),
+            "timeline_delete",
+            false,
+            async move {
+                if let Err(err) = Self::background(guard, conf, &tenant, &timeline).await {
+                    error!("Error: {err:#}");
+                    timeline.set_broken(format!("{err:#}"))
+                };
+                Ok(())
+            }
+            .instrument({
+                let span =
+                    tracing::info_span!(parent: None, "delete_timeline", tenant_id=%tenant_id, timeline_id=%timeline_id);
+                span.follows_from(Span::current());
+                span
+            }),
+        );
+    }
+
+    async fn background(
+        mut guard: DeletionGuard,
+        conf: &PageServerConf,
+        tenant: &Tenant,
+        timeline: &Timeline,
+    ) -> Result<(), DeleteTimelineError> {
+        delete_local_layer_files(conf, tenant.tenant_id, timeline).await?;
+
+        delete_remote_layers_and_index(timeline).await?;
+
+        pausable_failpoint!("in_progress_delete");
+
+        cleanup_remaining_timeline_fs_traces(conf, tenant.tenant_id, timeline.timeline_id).await?;
+
+        remove_timeline_from_tenant(tenant, timeline.timeline_id, &guard).await?;
+
+        *guard = Self::Finished;
+
+        Ok(())
+    }
+
+    pub(crate) fn is_finished(&self) -> bool {
+        matches!(self, Self::Finished)
+    }
+}
+
+struct DeletionGuard(OwnedMutexGuard<DeleteTimelineFlow>);
+
+impl Deref for DeletionGuard {
+    type Target = DeleteTimelineFlow;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for DeletionGuard {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}

pageserver/src/tenant/timeline/eviction_task.rs

@@ -78,9 +78,6 @@ impl Timeline {
 
     #[instrument(skip_all, fields(tenant_id = %self.tenant_id, timeline_id = %self.timeline_id))]
     async fn eviction_task(self: Arc<Self>, cancel: CancellationToken) {
-        scopeguard::defer! {
-            info!("eviction task finishing");
-        }
         use crate::tenant::tasks::random_init_delay;
         {
             let policy = self.get_eviction_policy();
@@ -308,8 +305,13 @@ impl Timeline {
         ctx: &RequestContext,
     ) -> ControlFlow<()> {
         let mut state = self.eviction_task_timeline_state.lock().await;
+
+        // Only do the imitate_layer accesses approximately as often as the threshold.  A little
+        // more frequently, to avoid this period racing with the threshold/period-th eviction iteration.
+        let inter_imitate_period = p.threshold.checked_sub(p.period).unwrap_or(p.threshold);
+
         match state.last_layer_access_imitation {
-            Some(ts) if ts.elapsed() < p.threshold => { /* no need to run */ }
+            Some(ts) if ts.elapsed() < inter_imitate_period => { /* no need to run */ }
             _ => {
                 self.imitate_timeline_cached_layer_accesses(cancel, ctx)
                     .await;
@@ -332,7 +334,7 @@ impl Timeline {
         };
         let mut state = tenant.eviction_task_tenant_state.lock().await;
         match state.last_layer_access_imitation {
-            Some(ts) if ts.elapsed() < p.threshold => { /* no need to run */ }
+            Some(ts) if ts.elapsed() < inter_imitate_period => { /* no need to run */ }
             _ => {
                 self.imitate_synthetic_size_calculation_worker(&tenant, ctx, cancel)
                     .await;

pageserver/src/tenant/timeline/layer_manager.rs

@@ -120,10 +120,9 @@ impl LayerManager {
 
         ensure!(
             lsn > last_record_lsn,
-            "cannot modify relation after advancing last_record_lsn (incoming_lsn={}, last_record_lsn={})\n{}",
+            "cannot modify relation after advancing last_record_lsn (incoming_lsn={}, last_record_lsn={})",
             lsn,
             last_record_lsn,
-            std::backtrace::Backtrace::force_capture(),
         );
 
         // Do we have a layer open for writing already?
@@ -164,7 +163,7 @@ impl LayerManager {
     }
 
     /// Called from `freeze_inmem_layer`, returns true if successfully frozen.
-    pub fn try_freeze_in_memory_layer(
+    pub async fn try_freeze_in_memory_layer(
         &mut self,
         Lsn(last_record_lsn): Lsn,
         last_freeze_at: &AtomicLsn,
@@ -174,7 +173,7 @@ impl LayerManager {
         if let Some(open_layer) = &self.layer_map.open_layer {
             let open_layer_rc = Arc::clone(open_layer);
             // Does this layer need freezing?
-            open_layer.freeze(end_lsn);
+            open_layer.freeze(end_lsn).await;
 
             // The layer is no longer open, update the layer map to reflect this.
             // We will replace it with on-disk historics below.
@@ -278,7 +277,7 @@ impl LayerManager {
         updates: &mut BatchedUpdates<'_>,
         mapping: &mut LayerFileManager,
     ) {
-        updates.remove_historic(layer.layer_desc().clone());
+        updates.remove_historic(layer.layer_desc());
         mapping.remove(layer);
     }
 
@@ -292,10 +291,10 @@ impl LayerManager {
         metrics: &TimelineMetrics,
         mapping: &mut LayerFileManager,
     ) -> anyhow::Result<()> {
+        let desc = layer.layer_desc();
         if !layer.is_remote_layer() {
             layer.delete_resident_layer_file()?;
-            let layer_file_size = layer.file_size();
-            metrics.resident_physical_size_gauge.sub(layer_file_size);
+            metrics.resident_physical_size_gauge.sub(desc.file_size);
         }
 
         // TODO Removing from the bottom of the layer map is expensive.
@@ -303,7 +302,7 @@ impl LayerManager {
         //      won't be needed for page reconstruction for this timeline,
         //      and mark what we can't delete yet as deleted from the layer
         //      map index without actually rebuilding the index.
-        updates.remove_historic(layer.layer_desc().clone());
+        updates.remove_historic(desc);
         mapping.remove(layer);
 
         Ok(())

pageserver/src/tenant/timeline/uninit.rs

@@ -2,13 +2,9 @@ use std::{collections::hash_map::Entry, fs, path::PathBuf, sync::Arc};
 
 use anyhow::Context;
 use tracing::{error, info, info_span, warn};
-use utils::{crashsafe, id::TimelineId, lsn::Lsn};
+use utils::{crashsafe, fs_ext, id::TimelineId, lsn::Lsn};
 
-use crate::{
-    context::RequestContext,
-    import_datadir,
-    tenant::{ignore_absent_files, Tenant},
-};
+use crate::{context::RequestContext, import_datadir, tenant::Tenant};
 
 use super::Timeline;
 
@@ -141,7 +137,7 @@ impl Drop for UninitializedTimeline<'_> {
 
 pub(crate) fn cleanup_timeline_directory(uninit_mark: TimelineUninitMark) {
     let timeline_path = &uninit_mark.timeline_path;
-    match ignore_absent_files(|| fs::remove_dir_all(timeline_path)) {
+    match fs_ext::ignore_absent_files(|| fs::remove_dir_all(timeline_path)) {
         Ok(()) => {
             info!("Timeline dir {timeline_path:?} removed successfully, removing the uninit mark")
         }
@@ -185,7 +181,7 @@ impl TimelineUninitMark {
         let uninit_mark_parent = uninit_mark_file
             .parent()
             .with_context(|| format!("Uninit mark file {uninit_mark_file:?} has no parent"))?;
-        ignore_absent_files(|| fs::remove_file(uninit_mark_file)).with_context(|| {
+        fs_ext::ignore_absent_files(|| fs::remove_file(uninit_mark_file)).with_context(|| {
             format!("Failed to remove uninit mark file at path {uninit_mark_file:?}")
         })?;
         crashsafe::fsync(uninit_mark_parent).context("Failed to fsync uninit mark parent")?;

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

@@ -31,14 +31,19 @@ use storage_broker::Streaming;
 use tokio::select;
 use tracing::*;
 
-use crate::{exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS};
 use postgres_connection::{parse_host_port, PgConnectionConfig};
+use utils::backoff::{
+    exponential_backoff, DEFAULT_BASE_BACKOFF_SECONDS, DEFAULT_MAX_BACKOFF_SECONDS,
+};
 use utils::{
     id::{NodeId, TenantTimelineId},
     lsn::Lsn,
 };
 
-use super::{walreceiver_connection::WalConnectionStatus, TaskEvent, TaskHandle};
+use super::{
+    walreceiver_connection::WalConnectionStatus, walreceiver_connection::WalReceiverError,
+    TaskEvent, TaskHandle,
+};
 
 /// Attempts to subscribe for timeline updates, pushed by safekeepers into the broker.
 /// Based on the updates, desides whether to start, keep or stop a WAL receiver task.
@@ -419,13 +424,19 @@ impl ConnectionManagerState {
                 match res {
                     Ok(()) => Ok(()),
                     Err(e) => {
-                        use super::walreceiver_connection::ExpectedError;
-                        if e.is_expected() {
-                            info!("walreceiver connection handling ended: {e:#}");
-                            Ok(())
-                        } else {
-                            // give out an error to have task_mgr give it a really verbose logging
-                            Err(e).context("walreceiver connection handling failure")
+                        match e {
+                            WalReceiverError::SuccessfulCompletion(msg) => {
+                                info!("walreceiver connection handling ended with success: {msg}");
+                                Ok(())
+                            }
+                            WalReceiverError::ExpectedSafekeeperError(e) => {
+                                info!("walreceiver connection handling ended: {e}");
+                                Ok(())
+                            }
+                            WalReceiverError::Other(e) => {
+                                // give out an error to have task_mgr give it a really verbose logging
+                                Err(e).context("walreceiver connection handling failure")
+                            }
                         }
                     }
                 }
@@ -1123,7 +1134,7 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn lsn_wal_over_threshhold_current_candidate() -> anyhow::Result<()> {
+    async fn lsn_wal_over_threshold_current_candidate() -> anyhow::Result<()> {
         let harness = TenantHarness::create("lsn_wal_over_threshcurrent_candidate")?;
         let mut state = dummy_state(&harness).await;
         let current_lsn = Lsn(100_000).align();
@@ -1189,8 +1200,8 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn timeout_connection_threshhold_current_candidate() -> anyhow::Result<()> {
-        let harness = TenantHarness::create("timeout_connection_threshhold_current_candidate")?;
+    async fn timeout_connection_threshold_current_candidate() -> anyhow::Result<()> {
+        let harness = TenantHarness::create("timeout_connection_threshold_current_candidate")?;
         let mut state = dummy_state(&harness).await;
         let current_lsn = Lsn(100_000).align();
         let now = Utc::now().naive_utc();
@@ -1252,8 +1263,8 @@ mod tests {
     }
 
     #[tokio::test]
-    async fn timeout_wal_over_threshhold_current_candidate() -> anyhow::Result<()> {
-        let harness = TenantHarness::create("timeout_wal_over_threshhold_current_candidate")?;
+    async fn timeout_wal_over_threshold_current_candidate() -> anyhow::Result<()> {
+        let harness = TenantHarness::create("timeout_wal_over_threshold_current_candidate")?;
         let mut state = dummy_state(&harness).await;
         let current_lsn = Lsn(100_000).align();
         let new_lsn = Lsn(100_100).align();

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

@@ -8,14 +8,14 @@ use std::{
     time::{Duration, SystemTime},
 };
 
-use anyhow::{bail, ensure, Context};
+use anyhow::{anyhow, Context};
 use bytes::BytesMut;
 use chrono::{NaiveDateTime, Utc};
 use fail::fail_point;
 use futures::StreamExt;
 use postgres::{error::SqlState, SimpleQueryMessage, SimpleQueryRow};
-use postgres_ffi::v14::xlog_utils::normalize_lsn;
 use postgres_ffi::WAL_SEGMENT_SIZE;
+use postgres_ffi::{v14::xlog_utils::normalize_lsn, waldecoder::WalDecodeError};
 use postgres_protocol::message::backend::ReplicationMessage;
 use postgres_types::PgLsn;
 use tokio::{select, sync::watch, time};
@@ -60,6 +60,50 @@ pub(super) struct WalConnectionStatus {
     pub node: NodeId,
 }
 
+pub(super) enum WalReceiverError {
+    /// An error of a type that does not indicate an issue, e.g. a connection closing
+    ExpectedSafekeeperError(postgres::Error),
+    /// An "error" message that carries a SUCCESSFUL_COMPLETION status code.  Carries
+    /// the message part of the original postgres error
+    SuccessfulCompletion(String),
+    /// Generic error
+    Other(anyhow::Error),
+}
+
+impl From<tokio_postgres::Error> for WalReceiverError {
+    fn from(err: tokio_postgres::Error) -> Self {
+        if let Some(dberror) = err.as_db_error().filter(|db_error| {
+            db_error.code() == &SqlState::SUCCESSFUL_COMPLETION
+                && db_error.message().contains("ending streaming")
+        }) {
+            // Strip the outer DbError, which carries a misleading "error" severity
+            Self::SuccessfulCompletion(dberror.message().to_string())
+        } else if err.is_closed()
+            || err
+                .source()
+                .and_then(|source| source.downcast_ref::<std::io::Error>())
+                .map(is_expected_io_error)
+                .unwrap_or(false)
+        {
+            Self::ExpectedSafekeeperError(err)
+        } else {
+            Self::Other(anyhow::Error::new(err))
+        }
+    }
+}
+
+impl From<anyhow::Error> for WalReceiverError {
+    fn from(err: anyhow::Error) -> Self {
+        Self::Other(err)
+    }
+}
+
+impl From<WalDecodeError> for WalReceiverError {
+    fn from(err: WalDecodeError) -> Self {
+        Self::Other(anyhow::Error::new(err))
+    }
+}
+
 /// Open a connection to the given safekeeper and receive WAL, sending back progress
 /// messages as we go.
 pub(super) async fn handle_walreceiver_connection(
@@ -70,7 +114,7 @@ pub(super) async fn handle_walreceiver_connection(
     connect_timeout: Duration,
     ctx: RequestContext,
     node: NodeId,
-) -> anyhow::Result<()> {
+) -> Result<(), WalReceiverError> {
     debug_assert_current_span_has_tenant_and_timeline_id();
 
     WALRECEIVER_STARTED_CONNECTIONS.inc();
@@ -130,11 +174,15 @@ pub(super) async fn handle_walreceiver_connection(
                 connection_result = connection => match connection_result {
                     Ok(()) => debug!("Walreceiver db connection closed"),
                     Err(connection_error) => {
-                        if connection_error.is_expected() {
-                            // silence, because most likely we've already exited the outer call
-                            // with a similar error.
-                        } else {
-                            warn!("Connection aborted: {connection_error:#}")
+                        match WalReceiverError::from(connection_error) {
+                            WalReceiverError::ExpectedSafekeeperError(_) => {
+                                // silence, because most likely we've already exited the outer call
+                                // with a similar error.
+                            },
+                            WalReceiverError::SuccessfulCompletion(_) => {}
+                            WalReceiverError::Other(err) => {
+                                warn!("Connection aborted: {err:#}")
+                            }
                         }
                     }
                 },
@@ -180,7 +228,7 @@ pub(super) async fn handle_walreceiver_connection(
     let mut startpoint = last_rec_lsn;
 
     if startpoint == Lsn(0) {
-        bail!("No previous WAL position");
+        return Err(WalReceiverError::Other(anyhow!("No previous WAL position")));
     }
 
     // There might be some padding after the last full record, skip it.
@@ -262,7 +310,9 @@ pub(super) async fn handle_walreceiver_connection(
                         // 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.
-                        ensure!(lsn.is_aligned());
+                        if !lsn.is_aligned() {
+                            return Err(WalReceiverError::Other(anyhow!("LSN not aligned")));
+                        }
 
                         walingest
                             .ingest_record(recdata, lsn, &mut modification, &mut decoded, &ctx)
@@ -419,51 +469,3 @@ async fn identify_system(client: &mut Client) -> anyhow::Result<IdentifySystem>
         Err(IdentifyError.into())
     }
 }
-
-/// Trait for avoid reporting walreceiver specific expected or "normal" or "ok" errors.
-pub(super) trait ExpectedError {
-    /// Test if this error is an ok error.
-    ///
-    /// We don't want to report connectivity problems as real errors towards connection manager because
-    /// 1. they happen frequently enough to make server logs hard to read and
-    /// 2. the connection manager can retry other safekeeper.
-    ///
-    /// If this function returns `true`, it's such an error.
-    /// The caller should log it at info level and then report to connection manager that we're done handling this connection.
-    /// Connection manager will then handle reconnections.
-    ///
-    /// If this function returns an `false` the error should be propagated and the connection manager
-    /// will log the error at ERROR level.
-    fn is_expected(&self) -> bool;
-}
-
-impl ExpectedError for postgres::Error {
-    fn is_expected(&self) -> bool {
-        self.is_closed()
-            || self
-                .source()
-                .and_then(|source| source.downcast_ref::<std::io::Error>())
-                .map(is_expected_io_error)
-                .unwrap_or(false)
-            || self
-                .as_db_error()
-                .filter(|db_error| {
-                    db_error.code() == &SqlState::SUCCESSFUL_COMPLETION
-                        && db_error.message().contains("ending streaming")
-                })
-                .is_some()
-    }
-}
-
-impl ExpectedError for anyhow::Error {
-    fn is_expected(&self) -> bool {
-        let head = self.downcast_ref::<postgres::Error>();
-
-        let tail = self
-            .chain()
-            .filter_map(|e| e.downcast_ref::<postgres::Error>());
-
-        // check if self or any of the chained/sourced errors are expected
-        head.into_iter().chain(tail).any(|e| e.is_expected())
-    }
-}

pageserver/src/virtual_file.rs

@@ -53,6 +53,9 @@ pub struct VirtualFile {
     pub path: PathBuf,
     open_options: OpenOptions,
 
+    // These are strings becase we only use them for metrics, and those expect strings.
+    // It makes no sense for us to constantly turn the `TimelineId` and `TenantId` into
+    // strings.
     tenant_id: String,
     timeline_id: String,
 }
@@ -149,12 +152,10 @@ impl OpenFiles {
         // old file.
         //
         if let Some(old_file) = slot_guard.file.take() {
-            // We do not have information about tenant_id/timeline_id of evicted file.
-            // It is possible to store path together with file or use filepath crate,
-            // but as far as close() is not expected to be fast, it is not so critical to gather
-            // precise per-tenant statistic here.
+            // the normal path of dropping VirtualFile uses "close", use "close-by-replace" here to
+            // distinguish the two.
             STORAGE_IO_TIME
-                .with_label_values(&["close", "-", "-"])
+                .with_label_values(&["close-by-replace"])
                 .observe_closure_duration(|| drop(old_file));
         }
 
@@ -208,7 +209,7 @@ impl VirtualFile {
         }
         let (handle, mut slot_guard) = get_open_files().find_victim_slot();
         let file = STORAGE_IO_TIME
-            .with_label_values(&["open", &tenant_id, &timeline_id])
+            .with_label_values(&["open"])
             .observe_closure_duration(|| open_options.open(path))?;
 
         // Strip all options other than read and write.
@@ -271,7 +272,7 @@ impl VirtualFile {
                             // Found a cached file descriptor.
                             slot.recently_used.store(true, Ordering::Relaxed);
                             return Ok(STORAGE_IO_TIME
-                                .with_label_values(&[op, &self.tenant_id, &self.timeline_id])
+                                .with_label_values(&[op])
                                 .observe_closure_duration(|| func(file)));
                         }
                     }
@@ -298,12 +299,12 @@ impl VirtualFile {
 
         // Open the physical file
         let file = STORAGE_IO_TIME
-            .with_label_values(&["open", &self.tenant_id, &self.timeline_id])
+            .with_label_values(&["open"])
             .observe_closure_duration(|| self.open_options.open(&self.path))?;
 
         // Perform the requested operation on it
         let result = STORAGE_IO_TIME
-            .with_label_values(&[op, &self.tenant_id, &self.timeline_id])
+            .with_label_values(&[op])
             .observe_closure_duration(|| func(&file));
 
         // Store the File in the slot and update the handle in the VirtualFile
@@ -333,13 +334,11 @@ impl Drop for VirtualFile {
         let mut slot_guard = slot.inner.write().unwrap();
         if slot_guard.tag == handle.tag {
             slot.recently_used.store(false, Ordering::Relaxed);
-            // Unlike files evicted by replacement algorithm, here
-            // we group close time by tenant_id/timeline_id.
-            // At allows to compare number/time of "normal" file closes
-            // with file eviction.
+            // there is also operation "close-by-replace" for closes done on eviction for
+            // comparison.
             STORAGE_IO_TIME
-                .with_label_values(&["close", &self.tenant_id, &self.timeline_id])
-                .observe_closure_duration(|| slot_guard.file.take());
+                .with_label_values(&["close"])
+                .observe_closure_duration(|| drop(slot_guard.file.take()));
         }
     }
 }

pgxn/neon/Makefile

@@ -4,6 +4,7 @@
 MODULE_big = neon
 OBJS = \
 	$(WIN32RES) \
+	extension_server.o \
 	file_cache.o \
 	libpagestore.o \
 	libpqwalproposer.o \

pgxn/neon/extension_server.c

@@ -0,0 +1,103 @@
+
+/*-------------------------------------------------------------------------
+ *
+ * extension_server.c
+ *	  Request compute_ctl to download extension files.
+ *
+ * IDENTIFICATION
+ *	 contrib/neon/extension_server.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres.h"
+#include "tcop/pquery.h"
+#include "tcop/utility.h"
+#include "access/xact.h"
+#include "utils/hsearch.h"
+#include "utils/memutils.h"
+#include "commands/defrem.h"
+#include "miscadmin.h"
+#include "utils/acl.h"
+#include "fmgr.h"
+#include "utils/guc.h"
+#include "port.h"
+#include "fmgr.h"
+
+#include <curl/curl.h>
+
+static int extension_server_port = 0;
+
+static download_extension_file_hook_type prev_download_extension_file_hook = NULL;
+
+// to download all SQL (and data) files for an extension:
+// curl -X POST http://localhost:8080/extension_server/postgis
+// it covers two possible extension files layouts:
+// 1. extension_name--version--platform.sql
+// 2. extension_name/extension_name--version.sql
+//    extension_name/extra_files.csv
+//
+// to download specific library file:
+// curl -X POST http://localhost:8080/extension_server/postgis-3.so?is_library=true
+static bool
+neon_download_extension_file_http(const char *filename, bool is_library)
+{
+    CURL *curl;
+    CURLcode res;
+    char *compute_ctl_url;
+    char *postdata;
+    bool ret = false;
+
+    if ((curl = curl_easy_init()) == NULL)
+    {
+        elog(ERROR, "Failed to initialize curl handle");
+    }
+
+    compute_ctl_url = psprintf("http://localhost:%d/extension_server/%s%s",
+                               extension_server_port, filename, is_library ? "?is_library=true" : "");
+
+    elog(LOG, "Sending request to compute_ctl: %s", compute_ctl_url);
+
+    curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, "POST");
+    curl_easy_setopt(curl, CURLOPT_URL, compute_ctl_url);
+    curl_easy_setopt(curl, CURLOPT_TIMEOUT, 3L /* seconds */);
+
+    if (curl)
+    {
+        /* Perform the request, res will get the return code */
+        res = curl_easy_perform(curl);
+        /* Check for errors */
+        if (res == CURLE_OK)
+        {
+            ret = true;
+        }
+        else
+        {
+            // Don't error here because postgres will try to find the file
+            // and will fail with some proper error message if it's not found.
+            elog(WARNING, "neon_download_extension_file_http failed: %s\n", curl_easy_strerror(res));
+        }
+
+        /* always cleanup */
+        curl_easy_cleanup(curl);
+    }
+
+    return ret;
+}
+
+void pg_init_extension_server()
+{
+    // Port to connect to compute_ctl on localhost
+    // to request extension files.
+    DefineCustomIntVariable("neon.extension_server_port",
+                            "connection string to the compute_ctl",
+                            NULL,
+                            &extension_server_port,
+                            0, 0, INT_MAX,
+                            PGC_POSTMASTER,
+                            0, /* no flags required */
+                            NULL, NULL, NULL);
+
+    // set download_extension_file_hook
+    prev_download_extension_file_hook = download_extension_file_hook;
+    download_extension_file_hook = neon_download_extension_file_http;
+}

pgxn/neon/file_cache.c

@@ -172,7 +172,7 @@ lfc_change_limit_hook(int newval, void *extra)
 	{
 		lfc_desc = BasicOpenFile(lfc_path, O_RDWR|O_CREAT);
 		if (lfc_desc < 0) {
-			elog(LOG, "Failed to open file cache %s: %m", lfc_path);
+			elog(WARNING, "Failed to open file cache %s: %m, disabling file cache", lfc_path);
 			lfc_size_limit = 0; /* disable file cache */
 			return;
 		}
@@ -557,7 +557,7 @@ lfc_write(RelFileNode rnode, ForkNumber forkNum, BlockNumber blkno,
 			Assert(victim->access_count == 0);
 			entry->offset = victim->offset; /* grab victim's chunk */
 			hash_search(lfc_hash, &victim->key, HASH_REMOVE, NULL);
-			elog(LOG, "Swap file cache page");
+			elog(DEBUG2, "Swap file cache page");
 		}
 		else
 		{
@@ -574,7 +574,7 @@ lfc_write(RelFileNode rnode, ForkNumber forkNum, BlockNumber blkno,
 	{
 		lfc_desc = BasicOpenFile(lfc_path, O_RDWR|O_CREAT);
 		if (lfc_desc < 0) {
-			elog(LOG, "Failed to open file cache %s: %m", lfc_path);
+			elog(WARNING, "Failed to open file cache %s: %m, disabling file cache", lfc_path);
 			lfc_size_limit = 0; /* disable file cache */
 		}
 	}
@@ -583,7 +583,7 @@ lfc_write(RelFileNode rnode, ForkNumber forkNum, BlockNumber blkno,
 		rc = pwrite(lfc_desc, buffer, BLCKSZ, ((off_t)entry->offset*BLOCKS_PER_CHUNK + chunk_offs)*BLCKSZ);
 		if (rc != BLCKSZ)
 		{
-			elog(INFO, "Failed to write file cache: %m");
+			elog(WARNING, "Failed to write file cache: %m, disabling file cache");
 			lfc_size_limit = 0; /* disable file cache */
 		}
 	}

pgxn/neon/libpqwalproposer.c

@@ -292,7 +292,7 @@ walprop_async_read(WalProposerConn *conn, char **buf, int *amount)
 	/*
 	 * The docs for PQgetCopyData list the return values as: 0 if the copy is
 	 * still in progress, but no "complete row" is available -1 if the copy is
-	 * done -2 if an error occured (> 0) if it was successful; that value is
+	 * done -2 if an error occurred (> 0) if it was successful; that value is
 	 * the amount transferred.
 	 *
 	 * The protocol we use between walproposer and safekeeper means that we
@@ -353,7 +353,7 @@ walprop_async_write(WalProposerConn *conn, void const *buf, size_t size)
 	/*
 	 * The docs for PQputcopyData list the return values as: 1 if the data was
 	 * queued, 0 if it was not queued because of full buffers, or -1 if an
-	 * error occured
+	 * error occurred
 	 */
 	result = PQputCopyData(conn->pg_conn, buf, size);
 

pgxn/neon/neon.c

@@ -35,8 +35,11 @@ _PG_init(void)
 {
 	pg_init_libpagestore();
 	pg_init_walproposer();
+
 	InitControlPlaneConnector();
 
+	pg_init_extension_server();
+
         // Important: This must happen after other parts of the extension
         // are loaded, otherwise any settings to GUCs that were set before
         // the extension was loaded will be removed.

pgxn/neon/neon.h

@@ -21,6 +21,8 @@ extern char *neon_tenant;
 extern void pg_init_libpagestore(void);
 extern void pg_init_walproposer(void);
 
+extern void pg_init_extension_server(void);
+
 /*
  * Returns true if we shouldn't do REDO on that block in record indicated by
  * block_id; false otherwise.

pgxn/neon/walproposer.c

@@ -788,7 +788,7 @@ ReconnectSafekeepers(void)
 
 /*
  * Performs the logic for advancing the state machine of the specified safekeeper,
- * given that a certain set of events has occured.
+ * given that a certain set of events has occurred.
  */
 static void
 AdvancePollState(Safekeeper *sk, uint32 events)

pgxn/neon/walproposer.h

@@ -23,7 +23,7 @@
 									 * message header */
 
 /*
- * In the spirit of WL_SOCKET_READABLE and others, this corresponds to no events having occured,
+ * In the spirit of WL_SOCKET_READABLE and others, this corresponds to no events having occurred,
  * because all WL_* events are given flags equal to some (1 << i), starting from i = 0
  */
 #define WL_NO_EVENTS 0
@@ -317,7 +317,7 @@ typedef struct AppendResponse
 	/* this is a criterion for walproposer --sync mode exit */
 	XLogRecPtr	commitLsn;
 	HotStandbyFeedback hs;
-	/* Feedback recieved from pageserver includes standby_status_update fields */
+	/* Feedback received from pageserver includes standby_status_update fields */
 	/* and custom neon feedback. */
 	/* This part of the message is extensible. */
 	PageserverFeedback rf;

pgxn/neon/walproposer_utils.c

@@ -37,68 +37,14 @@ static XLogSegNo walpropSegNo = 0;
 
 /* START cloned file-local variables and functions from walsender.c */
 
-/*
- * xlogreader used for replication.  Note that a WAL sender doing physical
- * replication does not need xlogreader to read WAL, but it needs one to
- * keep a state of its work.
- */
-static XLogReaderState *xlogreader = NULL;
-
-/*
- * These variables keep track of the state of the timeline we're currently
- * sending. sendTimeLine identifies the timeline. If sendTimeLineIsHistoric,
- * the timeline is not the latest timeline on this server, and the server's
- * history forked off from that timeline at sendTimeLineValidUpto.
- */
-static TimeLineID sendTimeLine = 0;
-static TimeLineID sendTimeLineNextTLI = 0;
-static bool sendTimeLineIsHistoric = false;
-static XLogRecPtr sendTimeLineValidUpto = InvalidXLogRecPtr;
-
-/*
- * Timestamp of last ProcessRepliesIfAny() that saw a reply from the
- * standby. Set to 0 if wal_sender_timeout doesn't need to be active.
- */
-static TimestampTz last_reply_timestamp = 0;
-
-/* Have we sent a heartbeat message asking for reply, since last reply? */
-static bool waiting_for_ping_response = false;
-
-static bool streamingDoneSending;
-static bool streamingDoneReceiving;
-
-/* Are we there yet? */
-static bool WalSndCaughtUp = false;
-
-/* Flags set by signal handlers for later service in main loop */
-static volatile sig_atomic_t got_STOPPING = false;
-
 /*
  * How far have we sent WAL already? This is also advertised in
  * MyWalSnd->sentPtr.  (Actually, this is the next WAL location to send.)
  */
 static XLogRecPtr sentPtr = InvalidXLogRecPtr;
 
-/*
- * This is set while we are streaming. When not set
- * PROCSIG_WALSND_INIT_STOPPING signal will be handled like SIGTERM. When set,
- * the main loop is responsible for checking got_STOPPING and terminating when
- * it's set (after streaming any remaining WAL).
- */
-static volatile sig_atomic_t replication_active = false;
-
-typedef void (*WalSndSendDataCallback) (void);
-static void WalSndLoop(WalSndSendDataCallback send_data);
-static void XLogSendPhysical(void);
-#if PG_VERSION_NUM >= 150000
-static XLogRecPtr GetStandbyFlushRecPtr(TimeLineID *tli);
-#else
-static XLogRecPtr GetStandbyFlushRecPtr(void);
-#endif
-
-static void WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
-							  TimeLineID *tli_p);
-
+static void WalSndLoop(void);
+static void XLogBroadcastWalProposer(void);
 /* END cloned file-level variables and functions from walsender.c */
 
 int
@@ -506,7 +452,7 @@ XLogWalPropClose(XLogRecPtr recptr)
 /* START of cloned functions from walsender.c */
 
 /*
- * Handle START_REPLICATION command.
+ * Subscribe for new WAL and stream it in the loop to safekeepers.
  *
  * At the moment, this never returns, but an ereport(ERROR) will take us back
  * to the main loop.
@@ -524,18 +470,6 @@ StartProposerReplication(StartReplicationCmd *cmd)
 				 errmsg("IDENTIFY_SYSTEM has not been run before START_REPLICATION")));
 #endif
 
-	/* create xlogreader for physical replication */
-	xlogreader =
-		XLogReaderAllocate(wal_segment_size, NULL,
-						   XL_ROUTINE(.segment_open = WalSndSegmentOpen,
-									  .segment_close = wal_segment_close),
-						   NULL);
-
-	if (!xlogreader)
-		ereport(ERROR,
-				(errcode(ERRCODE_OUT_OF_MEMORY),
-				 errmsg("out of memory")));
-
 	/*
 	 * We assume here that we're logging enough information in the WAL for
 	 * log-shipping, since this is checked in PostmasterMain().
@@ -569,341 +503,61 @@ StartProposerReplication(StartReplicationCmd *cmd)
 	 * we keep this code around to lighten the load for when we need it.
 	 */
 #if PG_VERSION_NUM >= 150000
-	if (am_cascading_walsender)
-	{
-		/* this also updates ThisTimeLineID */
-		FlushPtr = GetStandbyFlushRecPtr(&currTLI);
-	}
-	else
-		FlushPtr = GetFlushRecPtr(&currTLI);
+	FlushPtr = GetFlushRecPtr(&currTLI);
 #else
-	if (am_cascading_walsender)
-	{
-		/* this also updates ThisTimeLineID */
-		FlushPtr = GetStandbyFlushRecPtr();
-	}
-	else
-		FlushPtr = GetFlushRecPtr();
-
+	FlushPtr = GetFlushRecPtr();
 	currTLI = ThisTimeLineID;
 #endif
 
+	/*
+	 * When we first start replication the standby will be behind the
+	 * primary. For some applications, for example synchronous
+	 * replication, it is important to have a clear state for this initial
+	 * catchup mode, so we can trigger actions when we change streaming
+	 * state later. We may stay in this state for a long time, which is
+	 * exactly why we want to be able to monitor whether or not we are
+	 * still here.
+	 */
+	WalSndSetState(WALSNDSTATE_CATCHUP);
 
-	if (cmd->timeline != 0)
+	/*
+	 * Don't allow a request to stream from a future point in WAL that
+	 * hasn't been flushed to disk in this server yet.
+	 */
+	if (FlushPtr < cmd->startpoint)
 	{
-		XLogRecPtr	switchpoint;
-
-		sendTimeLine = cmd->timeline;
-		if (sendTimeLine == currTLI)
-		{
-			sendTimeLineIsHistoric = false;
-			sendTimeLineValidUpto = InvalidXLogRecPtr;
-		}
-		else
-		{
-			List	   *timeLineHistory;
-
-			sendTimeLineIsHistoric = true;
-
-			/*
-			 * Check that the timeline the client requested exists, and the
-			 * requested start location is on that timeline.
-			 */
-			timeLineHistory = readTimeLineHistory(currTLI);
-			switchpoint = tliSwitchPoint(cmd->timeline, timeLineHistory,
-										 &sendTimeLineNextTLI);
-			list_free_deep(timeLineHistory);
-
-			/*
-			 * Found the requested timeline in the history. Check that
-			 * requested startpoint is on that timeline in our history.
-			 *
-			 * This is quite loose on purpose. We only check that we didn't
-			 * fork off the requested timeline before the switchpoint. We
-			 * don't check that we switched *to* it before the requested
-			 * starting point. This is because the client can legitimately
-			 * request to start replication from the beginning of the WAL
-			 * segment that contains switchpoint, but on the new timeline, so
-			 * that it doesn't end up with a partial segment. If you ask for
-			 * too old a starting point, you'll get an error later when we
-			 * fail to find the requested WAL segment in pg_wal.
-			 *
-			 * XXX: we could be more strict here and only allow a startpoint
-			 * that's older than the switchpoint, if it's still in the same
-			 * WAL segment.
-			 */
-			if (!XLogRecPtrIsInvalid(switchpoint) &&
-				switchpoint < cmd->startpoint)
-			{
-				ereport(ERROR,
-						(errmsg("requested starting point %X/%X on timeline %u is not in this server's history",
-								LSN_FORMAT_ARGS(cmd->startpoint),
-								cmd->timeline),
-						 errdetail("This server's history forked from timeline %u at %X/%X.",
-								   cmd->timeline,
-								   LSN_FORMAT_ARGS(switchpoint))));
-			}
-			sendTimeLineValidUpto = switchpoint;
-		}
-	}
-	else
-	{
-		sendTimeLine = currTLI;
-		sendTimeLineValidUpto = InvalidXLogRecPtr;
-		sendTimeLineIsHistoric = false;
+		ereport(ERROR,
+				(errmsg("requested starting point %X/%X is ahead of the WAL flush position of this server %X/%X",
+						LSN_FORMAT_ARGS(cmd->startpoint),
+						LSN_FORMAT_ARGS(FlushPtr))));
 	}
 
-	streamingDoneSending = streamingDoneReceiving = false;
+	/* Start streaming from the requested point */
+	sentPtr = cmd->startpoint;
 
-	/* If there is nothing to stream, don't even enter COPY mode */
-	if (!sendTimeLineIsHistoric || cmd->startpoint < sendTimeLineValidUpto)
-	{
-		/*
-		 * When we first start replication the standby will be behind the
-		 * primary. For some applications, for example synchronous
-		 * replication, it is important to have a clear state for this initial
-		 * catchup mode, so we can trigger actions when we change streaming
-		 * state later. We may stay in this state for a long time, which is
-		 * exactly why we want to be able to monitor whether or not we are
-		 * still here.
-		 */
-		WalSndSetState(WALSNDSTATE_CATCHUP);
+	/* Initialize shared memory status, too */
+	SpinLockAcquire(&MyWalSnd->mutex);
+	MyWalSnd->sentPtr = sentPtr;
+	SpinLockRelease(&MyWalSnd->mutex);
 
-		/*
-		 * Don't allow a request to stream from a future point in WAL that
-		 * hasn't been flushed to disk in this server yet.
-		 */
-		if (FlushPtr < cmd->startpoint)
-		{
-			ereport(ERROR,
-					(errmsg("requested starting point %X/%X is ahead of the WAL flush position of this server %X/%X",
-							LSN_FORMAT_ARGS(cmd->startpoint),
-							LSN_FORMAT_ARGS(FlushPtr))));
-		}
+	SyncRepInitConfig();
 
-		/* Start streaming from the requested point */
-		sentPtr = cmd->startpoint;
+	/* Infinite send loop, never returns */
+	WalSndLoop();
 
-		/* Initialize shared memory status, too */
-		SpinLockAcquire(&MyWalSnd->mutex);
-		MyWalSnd->sentPtr = sentPtr;
-		SpinLockRelease(&MyWalSnd->mutex);
-
-		SyncRepInitConfig();
-
-		/* Main loop of walsender */
-		replication_active = true;
-
-		WalSndLoop(XLogSendPhysical);
-
-		replication_active = false;
-		if (got_STOPPING)
-			proc_exit(0);
-		WalSndSetState(WALSNDSTATE_STARTUP);
-
-		Assert(streamingDoneSending && streamingDoneReceiving);
-	}
+	WalSndSetState(WALSNDSTATE_STARTUP);
 
 	if (cmd->slotname)
 		ReplicationSlotRelease();
-
-	/*
-	 * Copy is finished now. Send a single-row result set indicating the next
-	 * timeline.
-	 */
-	if (sendTimeLineIsHistoric)
-	{
-		char		startpos_str[8 + 1 + 8 + 1];
-		DestReceiver *dest;
-		TupOutputState *tstate;
-		TupleDesc	tupdesc;
-		Datum		values[2];
-		bool		nulls[2];
-
-		snprintf(startpos_str, sizeof(startpos_str), "%X/%X",
-				 LSN_FORMAT_ARGS(sendTimeLineValidUpto));
-
-		dest = CreateDestReceiver(DestRemoteSimple);
-		MemSet(nulls, false, sizeof(nulls));
-
-		/*
-		 * Need a tuple descriptor representing two columns. int8 may seem
-		 * like a surprising data type for this, but in theory int4 would not
-		 * be wide enough for this, as TimeLineID is unsigned.
-		 */
-		tupdesc = CreateTemplateTupleDesc(2);
-		TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 1, "next_tli",
-								  INT8OID, -1, 0);
-		TupleDescInitBuiltinEntry(tupdesc, (AttrNumber) 2, "next_tli_startpos",
-								  TEXTOID, -1, 0);
-
-		/* prepare for projection of tuple */
-		tstate = begin_tup_output_tupdesc(dest, tupdesc, &TTSOpsVirtual);
-
-		values[0] = Int64GetDatum((int64) sendTimeLineNextTLI);
-		values[1] = CStringGetTextDatum(startpos_str);
-
-		/* send it to dest */
-		do_tup_output(tstate, values, nulls);
-
-		end_tup_output(tstate);
-	}
-
-	/* Send CommandComplete message */
-	EndReplicationCommand("START_STREAMING");
 }
 
-#if PG_VERSION_NUM >= 150000
-static XLogRecPtr
-GetStandbyFlushRecPtr(TimeLineID *tli)
-{
-	XLogRecPtr	replayPtr;
-	TimeLineID	replayTLI;
-	XLogRecPtr	receivePtr;
-	TimeLineID	receiveTLI;
-	XLogRecPtr	result;
-
-	/*
-	 * We can safely send what's already been replayed. Also, if walreceiver
-	 * is streaming WAL from the same timeline, we can send anything that it
-	 * has streamed, but hasn't been replayed yet.
-	 */
-
-	receivePtr = GetWalRcvFlushRecPtr(NULL, &receiveTLI);
-	replayPtr = GetXLogReplayRecPtr(&replayTLI);
-
-	*tli = replayTLI;
-
-	result = replayPtr;
-	if (receiveTLI == replayTLI && receivePtr > replayPtr)
-		result = receivePtr;
-
-	return result;
-}
-#else
 /*
- * Returns the latest point in WAL that has been safely flushed to disk, and
- * can be sent to the standby. This should only be called when in recovery,
- * ie. we're streaming to a cascaded standby.
- *
- * As a side-effect, ThisTimeLineID is updated to the TLI of the last
- * replayed WAL record.
+ * Main loop that waits for LSN updates and calls the walproposer.
+ * Synchronous replication sets latch in WalSndWakeup at walsender.c
  */
-static XLogRecPtr
-GetStandbyFlushRecPtr(void)
-{
-	XLogRecPtr	replayPtr;
-	TimeLineID	replayTLI;
-	XLogRecPtr	receivePtr;
-	TimeLineID	receiveTLI;
-	XLogRecPtr	result;
-
-	/*
-	 * We can safely send what's already been replayed. Also, if walreceiver
-	 * is streaming WAL from the same timeline, we can send anything that it
-	 * has streamed, but hasn't been replayed yet.
-	 */
-
-	receivePtr = GetWalRcvFlushRecPtr(NULL, &receiveTLI);
-	replayPtr = GetXLogReplayRecPtr(&replayTLI);
-
-	ThisTimeLineID = replayTLI;
-
-	result = replayPtr;
-	if (receiveTLI == ThisTimeLineID && receivePtr > replayPtr)
-		result = receivePtr;
-
-	return result;
-}
-#endif
-
-
-
-/* XLogReaderRoutine->segment_open callback */
 static void
-WalSndSegmentOpen(XLogReaderState *state, XLogSegNo nextSegNo,
-				  TimeLineID *tli_p)
+WalSndLoop(void)
 {
-	char		path[MAXPGPATH];
-
-	/*-------
-	 * When reading from a historic timeline, and there is a timeline switch
-	 * within this segment, read from the WAL segment belonging to the new
-	 * timeline.
-	 *
-	 * For example, imagine that this server is currently on timeline 5, and
-	 * we're streaming timeline 4. The switch from timeline 4 to 5 happened at
-	 * 0/13002088. In pg_wal, we have these files:
-	 *
-	 * ...
-	 * 000000040000000000000012
-	 * 000000040000000000000013
-	 * 000000050000000000000013
-	 * 000000050000000000000014
-	 * ...
-	 *
-	 * In this situation, when requested to send the WAL from segment 0x13, on
-	 * timeline 4, we read the WAL from file 000000050000000000000013. Archive
-	 * recovery prefers files from newer timelines, so if the segment was
-	 * restored from the archive on this server, the file belonging to the old
-	 * timeline, 000000040000000000000013, might not exist. Their contents are
-	 * equal up to the switchpoint, because at a timeline switch, the used
-	 * portion of the old segment is copied to the new file.  -------
-	 */
-	*tli_p = sendTimeLine;
-	if (sendTimeLineIsHistoric)
-	{
-		XLogSegNo	endSegNo;
-
-		XLByteToSeg(sendTimeLineValidUpto, endSegNo, state->segcxt.ws_segsize);
-		if (nextSegNo == endSegNo)
-			*tli_p = sendTimeLineNextTLI;
-	}
-
-	XLogFilePath(path, *tli_p, nextSegNo, state->segcxt.ws_segsize);
-	state->seg.ws_file = BasicOpenFile(path, O_RDONLY | PG_BINARY);
-	if (state->seg.ws_file >= 0)
-		return;
-
-	/*
-	 * If the file is not found, assume it's because the standby asked for a
-	 * too old WAL segment that has already been removed or recycled.
-	 */
-	if (errno == ENOENT)
-	{
-		char		xlogfname[MAXFNAMELEN];
-		int			save_errno = errno;
-
-		XLogFileName(xlogfname, *tli_p, nextSegNo, wal_segment_size);
-		errno = save_errno;
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("requested WAL segment %s has already been removed",
-						xlogfname)));
-	}
-	else
-		ereport(ERROR,
-				(errcode_for_file_access(),
-				 errmsg("could not open file \"%s\": %m",
-						path)));
-}
-
-
-/* Main loop of walsender process that streams the WAL over Copy messages. */
-static void
-WalSndLoop(WalSndSendDataCallback send_data)
-{
-	/*
-	 * Initialize the last reply timestamp. That enables timeout processing
-	 * from hereon.
-	 */
-	last_reply_timestamp = GetCurrentTimestamp();
-	waiting_for_ping_response = false;
-
-	/*
-	 * Loop until we reach the end of this timeline or the client requests to
-	 * stop streaming.
-	 */
 	for (;;)
 	{
 		/* Clear any already-pending wakeups */
@@ -911,153 +565,41 @@ WalSndLoop(WalSndSendDataCallback send_data)
 
 		CHECK_FOR_INTERRUPTS();
 
-		/* Process any requests or signals received recently */
-		if (ConfigReloadPending)
-		{
-			ConfigReloadPending = false;
-			ProcessConfigFile(PGC_SIGHUP);
-			SyncRepInitConfig();
-		}
+		XLogBroadcastWalProposer();
 
-		/* always true */
-		if (am_wal_proposer)
-		{
-			send_data();
-			if (WalSndCaughtUp)
-			{
-				if (MyWalSnd->state == WALSNDSTATE_CATCHUP)
-					WalSndSetState(WALSNDSTATE_STREAMING);
-				WalProposerPoll();
-				WalSndCaughtUp = false;
-			}
-			continue;
-		}
+		if (MyWalSnd->state == WALSNDSTATE_CATCHUP)
+			WalSndSetState(WALSNDSTATE_STREAMING);
+		WalProposerPoll();
 	}
 }
 
 /*
- * Send out the WAL in its normal physical/stored form.
- *
- * Read up to MAX_SEND_SIZE bytes of WAL that's been flushed to disk,
- * but not yet sent to the client, and buffer it in the libpq output
- * buffer.
- *
- * If there is no unsent WAL remaining, WalSndCaughtUp is set to true,
- * otherwise WalSndCaughtUp is set to false.
+ * Notify walproposer about the new WAL position.
  */
 static void
-XLogSendPhysical(void)
+XLogBroadcastWalProposer(void)
 {
-	XLogRecPtr	SendRqstPtr;
 	XLogRecPtr	startptr;
 	XLogRecPtr	endptr;
-	Size		nbytes PG_USED_FOR_ASSERTS_ONLY;
-	TimeLineID	currTLI;
 
-	/* If requested switch the WAL sender to the stopping state. */
-	if (got_STOPPING)
-		WalSndSetState(WALSNDSTATE_STOPPING);
+	/* Start from the last sent position */
+	startptr = sentPtr;
 
-	if (streamingDoneSending)
-	{
-		WalSndCaughtUp = true;
-		return;
-	}
-
-	/* Figure out how far we can safely send the WAL. */
-	if (sendTimeLineIsHistoric)
-	{
-		/*
-		 * Streaming an old timeline that's in this server's history, but is
-		 * not the one we're currently inserting or replaying. It can be
-		 * streamed up to the point where we switched off that timeline.
-		 */
-		SendRqstPtr = sendTimeLineValidUpto;
-	}
-	else if (am_cascading_walsender)
-	{
-		/*
-		 * Streaming the latest timeline on a standby.
-		 *
-		 * Attempt to send all WAL that has already been replayed, so that we
-		 * know it's valid. If we're receiving WAL through streaming
-		 * replication, it's also OK to send any WAL that has been received
-		 * but not replayed.
-		 *
-		 * The timeline we're recovering from can change, or we can be
-		 * promoted. In either case, the current timeline becomes historic. We
-		 * need to detect that so that we don't try to stream past the point
-		 * where we switched to another timeline. We check for promotion or
-		 * timeline switch after calculating FlushPtr, to avoid a race
-		 * condition: if the timeline becomes historic just after we checked
-		 * that it was still current, it's still be OK to stream it up to the
-		 * FlushPtr that was calculated before it became historic.
-		 */
-		bool		becameHistoric = false;
+	/*
+	 * Streaming the current timeline on a primary.
+	 *
+	 * Attempt to send all data that's already been written out and
+	 * fsync'd to disk.  We cannot go further than what's been written out
+	 * given the current implementation of WALRead().  And in any case
+	 * it's unsafe to send WAL that is not securely down to disk on the
+	 * primary: if the primary subsequently crashes and restarts, standbys
+	 * must not have applied any WAL that got lost on the primary.
+	 */
 #if PG_VERSION_NUM >= 150000
-		SendRqstPtr = GetStandbyFlushRecPtr(&currTLI);
+	endptr = GetFlushRecPtr(NULL);
 #else
-		SendRqstPtr = GetStandbyFlushRecPtr();
-		currTLI = ThisTimeLineID;
+	endptr = GetFlushRecPtr();
 #endif
-		if (!RecoveryInProgress())
-		{
-			/*
-			 * We have been promoted. RecoveryInProgress() updated
-			 * ThisTimeLineID to the new current timeline.
-			 */
-			am_cascading_walsender = false;
-			becameHistoric = true;
-		}
-		else
-		{
-			/*
-			 * Still a cascading standby. But is the timeline we're sending
-			 * still the one recovery is recovering from? currTLI was updated
-			 * by the GetStandbyFlushRecPtr() call above.
-			 */
-			if (sendTimeLine != currTLI)
-				becameHistoric = true;
-		}
-
-		if (becameHistoric)
-		{
-			/*
-			 * The timeline we were sending has become historic. Read the
-			 * timeline history file of the new timeline to see where exactly
-			 * we forked off from the timeline we were sending.
-			 */
-			List	   *history;
-
-			history = readTimeLineHistory(currTLI);
-			sendTimeLineValidUpto = tliSwitchPoint(sendTimeLine, history, &sendTimeLineNextTLI);
-
-			Assert(sendTimeLine < sendTimeLineNextTLI);
-			list_free_deep(history);
-
-			sendTimeLineIsHistoric = true;
-
-			SendRqstPtr = sendTimeLineValidUpto;
-		}
-	}
-	else
-	{
-		/*
-		 * Streaming the current timeline on a primary.
-		 *
-		 * Attempt to send all data that's already been written out and
-		 * fsync'd to disk.  We cannot go further than what's been written out
-		 * given the current implementation of WALRead().  And in any case
-		 * it's unsafe to send WAL that is not securely down to disk on the
-		 * primary: if the primary subsequently crashes and restarts, standbys
-		 * must not have applied any WAL that got lost on the primary.
-		 */
-#if PG_VERSION_NUM >= 150000
-		SendRqstPtr = GetFlushRecPtr(NULL);
-#else
-		SendRqstPtr = GetFlushRecPtr();
-#endif
-	}
 
 	/*
 	 * Record the current system time as an approximation of the time at which
@@ -1083,91 +625,14 @@ XLogSendPhysical(void)
 	 * that arbitrary LSN is eventually reported as written, flushed and
 	 * applied, so that it can measure the elapsed time.
 	 */
-	LagTrackerWrite(SendRqstPtr, GetCurrentTimestamp());
-
-	/*
-	 * If this is a historic timeline and we've reached the point where we
-	 * forked to the next timeline, stop streaming.
-	 *
-	 * Note: We might already have sent WAL > sendTimeLineValidUpto. The
-	 * startup process will normally replay all WAL that has been received
-	 * from the primary, before promoting, but if the WAL streaming is
-	 * terminated at a WAL page boundary, the valid portion of the timeline
-	 * might end in the middle of a WAL record. We might've already sent the
-	 * first half of that partial WAL record to the cascading standby, so that
-	 * sentPtr > sendTimeLineValidUpto. That's OK; the cascading standby can't
-	 * replay the partial WAL record either, so it can still follow our
-	 * timeline switch.
-	 */
-	if (sendTimeLineIsHistoric && sendTimeLineValidUpto <= sentPtr)
-	{
-		/* close the current file. */
-		if (xlogreader->seg.ws_file >= 0)
-			wal_segment_close(xlogreader);
-
-		/* Send CopyDone */
-		pq_putmessage_noblock('c', NULL, 0);
-		streamingDoneSending = true;
-
-		WalSndCaughtUp = true;
-
-		elog(DEBUG1, "walsender reached end of timeline at %X/%X (sent up to %X/%X)",
-			 LSN_FORMAT_ARGS(sendTimeLineValidUpto),
-			 LSN_FORMAT_ARGS(sentPtr));
-		return;
-	}
+	LagTrackerWrite(endptr, GetCurrentTimestamp());
 
 	/* Do we have any work to do? */
-	Assert(sentPtr <= SendRqstPtr);
-	if (SendRqstPtr <= sentPtr)
-	{
-		WalSndCaughtUp = true;
+	Assert(startptr <= endptr);
+	if (endptr <= startptr)
 		return;
-	}
 
-	/*
-	 * Figure out how much to send in one message. If there's no more than
-	 * MAX_SEND_SIZE bytes to send, send everything. Otherwise send
-	 * MAX_SEND_SIZE bytes, but round back to logfile or page boundary.
-	 *
-	 * The rounding is not only for performance reasons. Walreceiver relies on
-	 * the fact that we never split a WAL record across two messages. Since a
-	 * long WAL record is split at page boundary into continuation records,
-	 * page boundary is always a safe cut-off point. We also assume that
-	 * SendRqstPtr never points to the middle of a WAL record.
-	 */
-	startptr = sentPtr;
-	endptr = startptr;
-	endptr += MAX_SEND_SIZE;
-
-	/* if we went beyond SendRqstPtr, back off */
-	if (SendRqstPtr <= endptr)
-	{
-		endptr = SendRqstPtr;
-		if (sendTimeLineIsHistoric)
-			WalSndCaughtUp = false;
-		else
-			WalSndCaughtUp = true;
-	}
-	else
-	{
-		/* round down to page boundary. */
-		endptr -= (endptr % XLOG_BLCKSZ);
-		WalSndCaughtUp = false;
-	}
-
-	nbytes = endptr - startptr;
-	Assert(nbytes <= MAX_SEND_SIZE);
-
-	/* always true */
-	if (am_wal_proposer)
-	{
-		WalProposerBroadcast(startptr, endptr);
-	}
-	else
-	{
-		/* code removed for brevity */
-	}
+	WalProposerBroadcast(startptr, endptr);
 	sentPtr = endptr;
 
 	/* Update shared memory status */

poetry.lock

@@ -740,13 +740,13 @@ typing-extensions = ">=4.1.0"
 
 [[package]]
 name = "certifi"
-version = "2022.12.7"
+version = "2023.7.22"
 description = "Python package for providing Mozilla's CA Bundle."
 optional = false
 python-versions = ">=3.6"
 files = [
-    {file = "certifi-2022.12.7-py3-none-any.whl", hash = "sha256:4ad3232f5e926d6718ec31cfc1fcadfde020920e278684144551c91769c7bc18"},
-    {file = "certifi-2022.12.7.tar.gz", hash = "sha256:35824b4c3a97115964b408844d64aa14db1cc518f6562e8d7261699d1350a9e3"},
+    {file = "certifi-2023.7.22-py3-none-any.whl", hash = "sha256:92d6037539857d8206b8f6ae472e8b77db8058fec5937a1ef3f54304089edbb9"},
+    {file = "certifi-2023.7.22.tar.gz", hash = "sha256:539cc1d13202e33ca466e88b2807e29f4c13049d6d87031a3c110744495cb082"},
 ]
 
 [[package]]
@@ -887,34 +887,34 @@ files = [
 
 [[package]]
 name = "cryptography"
-version = "41.0.2"
+version = "41.0.3"
 description = "cryptography is a package which provides cryptographic recipes and primitives to Python developers."
 optional = false
 python-versions = ">=3.7"
 files = [
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-    {file = "cryptography-41.0.2-cp37-abi3-macosx_10_12_x86_64.whl", hash = "sha256:079347de771f9282fbfe0e0236c716686950c19dee1b76240ab09ce1624d76d7"},
-    {file = "cryptography-41.0.2-cp37-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:439c3cc4c0d42fa999b83ded80a9a1fb54d53c58d6e59234cfe97f241e6c781d"},
-    {file = "cryptography-41.0.2-cp37-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:f14ad275364c8b4e525d018f6716537ae7b6d369c094805cae45300847e0894f"},
-    {file = "cryptography-41.0.2-cp37-abi3-manylinux_2_28_aarch64.whl", hash = "sha256:84609ade00a6ec59a89729e87a503c6e36af98ddcd566d5f3be52e29ba993182"},
-    {file = "cryptography-41.0.2-cp37-abi3-manylinux_2_28_x86_64.whl", hash = "sha256:49c3222bb8f8e800aead2e376cbef687bc9e3cb9b58b29a261210456a7783d83"},
-    {file = "cryptography-41.0.2-cp37-abi3-musllinux_1_1_aarch64.whl", hash = "sha256:d73f419a56d74fef257955f51b18d046f3506270a5fd2ac5febbfa259d6c0fa5"},
-    {file = "cryptography-41.0.2-cp37-abi3-musllinux_1_1_x86_64.whl", hash = "sha256:2a034bf7d9ca894720f2ec1d8b7b5832d7e363571828037f9e0c4f18c1b58a58"},
-    {file = "cryptography-41.0.2-cp37-abi3-win32.whl", hash = "sha256:d124682c7a23c9764e54ca9ab5b308b14b18eba02722b8659fb238546de83a76"},
-    {file = "cryptography-41.0.2-cp37-abi3-win_amd64.whl", hash = "sha256:9c3fe6534d59d071ee82081ca3d71eed3210f76ebd0361798c74abc2bcf347d4"},
-    {file = "cryptography-41.0.2-pp310-pypy310_pp73-macosx_10_12_x86_64.whl", hash = "sha256:a719399b99377b218dac6cf547b6ec54e6ef20207b6165126a280b0ce97e0d2a"},
-    {file = "cryptography-41.0.2-pp310-pypy310_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:182be4171f9332b6741ee818ec27daff9fb00349f706629f5cbf417bd50e66fd"},
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-    {file = "cryptography-41.0.2-pp310-pypy310_pp73-win_amd64.whl", hash = "sha256:f0dc40e6f7aa37af01aba07277d3d64d5a03dc66d682097541ec4da03cc140ee"},
-    {file = "cryptography-41.0.2-pp38-pypy38_pp73-macosx_10_12_x86_64.whl", hash = "sha256:674b669d5daa64206c38e507808aae49904c988fa0a71c935e7006a3e1e83831"},
-    {file = "cryptography-41.0.2-pp38-pypy38_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:7af244b012711a26196450d34f483357e42aeddb04128885d95a69bd8b14b69b"},
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-    {file = "cryptography-41.0.2-pp38-pypy38_pp73-win_amd64.whl", hash = "sha256:192255f539d7a89f2102d07d7375b1e0a81f7478925b3bc2e0549ebf739dae0e"},
-    {file = "cryptography-41.0.2-pp39-pypy39_pp73-macosx_10_12_x86_64.whl", hash = "sha256:f772610fe364372de33d76edcd313636a25684edb94cee53fd790195f5989d14"},
-    {file = "cryptography-41.0.2-pp39-pypy39_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:b332cba64d99a70c1e0836902720887fb4529ea49ea7f5462cf6640e095e11d2"},
-    {file = "cryptography-41.0.2-pp39-pypy39_pp73-manylinux_2_28_x86_64.whl", hash = "sha256:9a6673c1828db6270b76b22cc696f40cde9043eb90373da5c2f8f2158957f42f"},
-    {file = "cryptography-41.0.2-pp39-pypy39_pp73-win_amd64.whl", hash = "sha256:342f3767e25876751e14f8459ad85e77e660537ca0a066e10e75df9c9e9099f0"},
-    {file = "cryptography-41.0.2.tar.gz", hash = "sha256:7d230bf856164de164ecb615ccc14c7fc6de6906ddd5b491f3af90d3514c925c"},
+    {file = "cryptography-41.0.3-cp37-abi3-macosx_10_12_universal2.whl", hash = "sha256:652627a055cb52a84f8c448185922241dd5217443ca194d5739b44612c5e6507"},
+    {file = "cryptography-41.0.3-cp37-abi3-macosx_10_12_x86_64.whl", hash = "sha256:8f09daa483aedea50d249ef98ed500569841d6498aa9c9f4b0531b9964658922"},
+    {file = "cryptography-41.0.3-cp37-abi3-manylinux_2_17_aarch64.manylinux2014_aarch64.whl", hash = "sha256:4fd871184321100fb400d759ad0cddddf284c4b696568204d281c902fc7b0d81"},
+    {file = "cryptography-41.0.3-cp37-abi3-manylinux_2_17_x86_64.manylinux2014_x86_64.whl", hash = "sha256:84537453d57f55a50a5b6835622ee405816999a7113267739a1b4581f83535bd"},
+    {file = "cryptography-41.0.3-cp37-abi3-manylinux_2_28_aarch64.whl", hash = "sha256:3fb248989b6363906827284cd20cca63bb1a757e0a2864d4c1682a985e3dca47"},
+    {file = "cryptography-41.0.3-cp37-abi3-manylinux_2_28_x86_64.whl", hash = "sha256:42cb413e01a5d36da9929baa9d70ca90d90b969269e5a12d39c1e0d475010116"},
+    {file = "cryptography-41.0.3-cp37-abi3-musllinux_1_1_aarch64.whl", hash = "sha256:aeb57c421b34af8f9fe830e1955bf493a86a7996cc1338fe41b30047d16e962c"},
+    {file = "cryptography-41.0.3-cp37-abi3-musllinux_1_1_x86_64.whl", hash = "sha256:6af1c6387c531cd364b72c28daa29232162010d952ceb7e5ca8e2827526aceae"},
+    {file = "cryptography-41.0.3-cp37-abi3-win32.whl", hash = "sha256:0d09fb5356f975974dbcb595ad2d178305e5050656affb7890a1583f5e02a306"},
+    {file = "cryptography-41.0.3-cp37-abi3-win_amd64.whl", hash = "sha256:a983e441a00a9d57a4d7c91b3116a37ae602907a7618b882c8013b5762e80574"},
+    {file = "cryptography-41.0.3-pp310-pypy310_pp73-macosx_10_12_x86_64.whl", hash = "sha256:5259cb659aa43005eb55a0e4ff2c825ca111a0da1814202c64d28a985d33b087"},
+    {file = "cryptography-41.0.3-pp310-pypy310_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:67e120e9a577c64fe1f611e53b30b3e69744e5910ff3b6e97e935aeb96005858"},
+    {file = "cryptography-41.0.3-pp310-pypy310_pp73-manylinux_2_28_x86_64.whl", hash = "sha256:7efe8041897fe7a50863e51b77789b657a133c75c3b094e51b5e4b5cec7bf906"},
+    {file = "cryptography-41.0.3-pp310-pypy310_pp73-win_amd64.whl", hash = "sha256:ce785cf81a7bdade534297ef9e490ddff800d956625020ab2ec2780a556c313e"},
+    {file = "cryptography-41.0.3-pp38-pypy38_pp73-macosx_10_12_x86_64.whl", hash = "sha256:57a51b89f954f216a81c9d057bf1a24e2f36e764a1ca9a501a6964eb4a6800dd"},
+    {file = "cryptography-41.0.3-pp38-pypy38_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:4c2f0d35703d61002a2bbdcf15548ebb701cfdd83cdc12471d2bae80878a4207"},
+    {file = "cryptography-41.0.3-pp38-pypy38_pp73-manylinux_2_28_x86_64.whl", hash = "sha256:23c2d778cf829f7d0ae180600b17e9fceea3c2ef8b31a99e3c694cbbf3a24b84"},
+    {file = "cryptography-41.0.3-pp38-pypy38_pp73-win_amd64.whl", hash = "sha256:95dd7f261bb76948b52a5330ba5202b91a26fbac13ad0e9fc8a3ac04752058c7"},
+    {file = "cryptography-41.0.3-pp39-pypy39_pp73-macosx_10_12_x86_64.whl", hash = "sha256:41d7aa7cdfded09b3d73a47f429c298e80796c8e825ddfadc84c8a7f12df212d"},
+    {file = "cryptography-41.0.3-pp39-pypy39_pp73-manylinux_2_28_aarch64.whl", hash = "sha256:d0d651aa754ef58d75cec6edfbd21259d93810b73f6ec246436a21b7841908de"},
+    {file = "cryptography-41.0.3-pp39-pypy39_pp73-manylinux_2_28_x86_64.whl", hash = "sha256:ab8de0d091acbf778f74286f4989cf3d1528336af1b59f3e5d2ebca8b5fe49e1"},
+    {file = "cryptography-41.0.3-pp39-pypy39_pp73-win_amd64.whl", hash = "sha256:a74fbcdb2a0d46fe00504f571a2a540532f4c188e6ccf26f1f178480117b33c4"},
+    {file = "cryptography-41.0.3.tar.gz", hash = "sha256:6d192741113ef5e30d89dcb5b956ef4e1578f304708701b8b73d38e3e1461f34"},
 ]
 
 [package.dependencies]

proxy/src/auth/backend.rs

@@ -53,6 +53,12 @@ pub enum BackendType<'a, T> {
     Postgres(Cow<'a, console::provider::mock::Api>, T),
     /// Authentication via a web browser.
     Link(Cow<'a, url::ApiUrl>),
+    /// Test backend.
+    Test(&'a dyn TestBackend),
+}
+
+pub trait TestBackend: Send + Sync + 'static {
+    fn wake_compute(&self) -> Result<CachedNodeInfo, console::errors::WakeComputeError>;
 }
 
 impl std::fmt::Display for BackendType<'_, ()> {
@@ -62,6 +68,7 @@ impl std::fmt::Display for BackendType<'_, ()> {
             Console(endpoint, _) => fmt.debug_tuple("Console").field(&endpoint.url()).finish(),
             Postgres(endpoint, _) => fmt.debug_tuple("Postgres").field(&endpoint.url()).finish(),
             Link(url) => fmt.debug_tuple("Link").field(&url.as_str()).finish(),
+            Test(_) => fmt.debug_tuple("Test").finish(),
         }
     }
 }
@@ -75,6 +82,7 @@ impl<T> BackendType<'_, T> {
             Console(c, x) => Console(Cow::Borrowed(c), x),
             Postgres(c, x) => Postgres(Cow::Borrowed(c), x),
             Link(c) => Link(Cow::Borrowed(c)),
+            Test(x) => Test(*x),
         }
     }
 }
@@ -89,6 +97,7 @@ impl<'a, T> BackendType<'a, T> {
             Console(c, x) => Console(c, f(x)),
             Postgres(c, x) => Postgres(c, f(x)),
             Link(c) => Link(c),
+            Test(x) => Test(x),
         }
     }
 }
@@ -102,6 +111,7 @@ impl<'a, T, E> BackendType<'a, Result<T, E>> {
             Console(c, x) => x.map(|x| Console(c, x)),
             Postgres(c, x) => x.map(|x| Postgres(c, x)),
             Link(c) => Ok(Link(c)),
+            Test(x) => Ok(Test(x)),
         }
     }
 }
@@ -147,6 +157,7 @@ impl BackendType<'_, ClientCredentials<'_>> {
             Console(_, creds) => creds.project.clone(),
             Postgres(_, creds) => creds.project.clone(),
             Link(_) => Some("link".to_owned()),
+            Test(_) => Some("test".to_owned()),
         }
     }
     /// Authenticate the client via the requested backend, possibly using credentials.
@@ -188,6 +199,9 @@ impl BackendType<'_, ClientCredentials<'_>> {
                     .await?
                     .map(CachedNodeInfo::new_uncached)
             }
+            Test(_) => {
+                unreachable!("this function should never be called in the test backend")
+            }
         };
 
         info!("user successfully authenticated");
@@ -206,6 +220,7 @@ impl BackendType<'_, ClientCredentials<'_>> {
             Console(api, creds) => api.wake_compute(extra, creds).map_ok(Some).await,
             Postgres(api, creds) => api.wake_compute(extra, creds).map_ok(Some).await,
             Link(_) => Ok(None),
+            Test(x) => x.wake_compute().map(Some),
         }
     }
 }

proxy/src/auth/backend/classic.rs

@@ -1,13 +1,16 @@
+use std::ops::ControlFlow;
+
 use super::AuthSuccess;
 use crate::{
     auth::{self, AuthFlow, ClientCredentials},
     compute,
     console::{self, AuthInfo, CachedNodeInfo, ConsoleReqExtra},
+    proxy::{handle_try_wake, retry_after},
     sasl, scram,
     stream::PqStream,
 };
 use tokio::io::{AsyncRead, AsyncWrite};
-use tracing::info;
+use tracing::{error, info, warn};
 
 pub(super) async fn authenticate(
     api: &impl console::Api,
@@ -48,7 +51,25 @@ pub(super) async fn authenticate(
         }
     };
 
-    let mut node = api.wake_compute(extra, creds).await?;
+    info!("compute node's state has likely changed; requesting a wake-up");
+    let mut num_retries = 0;
+    let mut node = loop {
+        let wake_res = api.wake_compute(extra, creds).await;
+        match handle_try_wake(wake_res, num_retries) {
+            Err(e) => {
+                error!(error = ?e, num_retries, retriable = false, "couldn't wake compute node");
+                return Err(e.into());
+            }
+            Ok(ControlFlow::Continue(e)) => {
+                warn!(error = ?e, num_retries, retriable = true, "couldn't wake compute node");
+            }
+            Ok(ControlFlow::Break(n)) => break n,
+        }
+
+        let wait_duration = retry_after(num_retries);
+        num_retries += 1;
+        tokio::time::sleep(wait_duration).await;
+    };
     if let Some(keys) = scram_keys {
         use tokio_postgres::config::AuthKeys;
         node.config.auth_keys(AuthKeys::ScramSha256(keys));

proxy/src/auth/credentials.rs

@@ -48,6 +48,14 @@ impl ClientCredentials<'_> {
 }
 
 impl<'a> ClientCredentials<'a> {
+    #[cfg(test)]
+    pub fn new_noop() -> Self {
+        ClientCredentials {
+            user: "",
+            project: None,
+        }
+    }
+
     pub fn parse(
         params: &'a StartupMessageParams,
         sni: Option<&str>,

proxy/src/compute.rs

@@ -230,7 +230,8 @@ pub struct PostgresConnection {
 }
 
 impl ConnCfg {
-    async fn do_connect(
+    /// Connect to a corresponding compute node.
+    pub async fn connect(
         &self,
         allow_self_signed_compute: bool,
         timeout: Duration,
@@ -270,20 +271,6 @@ impl ConnCfg {
 
         Ok(connection)
     }
-
-    /// Connect to a corresponding compute node.
-    pub async fn connect(
-        &self,
-        allow_self_signed_compute: bool,
-        timeout: Duration,
-    ) -> Result<PostgresConnection, ConnectionError> {
-        self.do_connect(allow_self_signed_compute, timeout)
-            .inspect_err(|err| {
-                // Immediately log the error we have at our disposal.
-                error!("couldn't connect to compute node: {err}");
-            })
-            .await
-    }
 }
 
 /// Retrieve `options` from a startup message, dropping all proxy-secific flags.

proxy/src/console/provider.rs

@@ -14,6 +14,7 @@ pub mod errors {
     use crate::{
         error::{io_error, UserFacingError},
         http,
+        proxy::ShouldRetry,
     };
     use thiserror::Error;
 
@@ -72,6 +73,24 @@ pub mod errors {
         }
     }
 
+    impl ShouldRetry for ApiError {
+        fn could_retry(&self) -> bool {
+            match self {
+                // retry some transport errors
+                Self::Transport(io) => io.could_retry(),
+                // retry some temporary failures because the compute was in a bad state
+                // (bad request can be returned when the endpoint was in transition)
+                Self::Console {
+                    status: http::StatusCode::BAD_REQUEST | http::StatusCode::LOCKED,
+                    ..
+                } => true,
+                // retry server errors
+                Self::Console { status, .. } if status.is_server_error() => true,
+                _ => false,
+            }
+        }
+    }
+
     impl From<reqwest::Error> for ApiError {
         fn from(e: reqwest::Error) -> Self {
             io_error(e).into()

proxy/src/console/provider/neon.rs

@@ -8,6 +8,7 @@ use super::{
 use crate::{auth::ClientCredentials, compute, http, scram};
 use async_trait::async_trait;
 use futures::TryFutureExt;
+use tokio::time::Instant;
 use tokio_postgres::config::SslMode;
 use tracing::{error, info, info_span, warn, Instrument};
 
@@ -47,7 +48,9 @@ impl Api {
                 .build()?;
 
             info!(url = request.url().as_str(), "sending http request");
+            let start = Instant::now();
             let response = self.endpoint.execute(request).await?;
+            info!(duration = ?start.elapsed(), "received http response");
             let body = match parse_body::<GetRoleSecret>(response).await {
                 Ok(body) => body,
                 // Error 404 is special: it's ok not to have a secret.
@@ -88,7 +91,9 @@ impl Api {
                 .build()?;
 
             info!(url = request.url().as_str(), "sending http request");
+            let start = Instant::now();
             let response = self.endpoint.execute(request).await?;
+            info!(duration = ?start.elapsed(), "received http response");
             let body = parse_body::<WakeCompute>(response).await?;
 
             // Unfortunately, ownership won't let us use `Option::ok_or` here.

proxy/src/http.rs

@@ -7,11 +7,14 @@ pub mod server;
 pub mod sql_over_http;
 pub mod websocket;
 
-use std::time::Duration;
+use std::{sync::Arc, time::Duration};
 
+use futures::FutureExt;
 pub use reqwest::{Request, Response, StatusCode};
 pub use reqwest_middleware::{ClientWithMiddleware, Error};
 pub use reqwest_retry::{policies::ExponentialBackoff, RetryTransientMiddleware};
+use tokio::time::Instant;
+use tracing::trace;
 
 use crate::url::ApiUrl;
 use reqwest_middleware::RequestBuilder;
@@ -20,13 +23,21 @@ use reqwest_middleware::RequestBuilder;
 /// because it takes care of observability (OpenTelemetry).
 /// We deliberately don't want to replace this with a public static.
 pub fn new_client() -> ClientWithMiddleware {
-    reqwest_middleware::ClientBuilder::new(reqwest::Client::new())
+    let client = reqwest::ClientBuilder::new()
+        .dns_resolver(Arc::new(GaiResolver::default()))
+        .connection_verbose(true)
+        .build()
+        .expect("Failed to create http client");
+
+    reqwest_middleware::ClientBuilder::new(client)
         .with(reqwest_tracing::TracingMiddleware::default())
         .build()
 }
 
 pub fn new_client_with_timeout(default_timout: Duration) -> ClientWithMiddleware {
     let timeout_client = reqwest::ClientBuilder::new()
+        .dns_resolver(Arc::new(GaiResolver::default()))
+        .connection_verbose(true)
         .timeout(default_timout)
         .build()
         .expect("Failed to create http client with timeout");
@@ -39,6 +50,10 @@ pub fn new_client_with_timeout(default_timout: Duration) -> ClientWithMiddleware
         // As per docs, "This middleware always errors when given requests with streaming bodies".
         // That's all right because we only use this client to send `serde_json::RawValue`, which
         // is not a stream.
+        //
+        // ex-maintainer note:
+        // this limitation can be fixed if streaming is necessary.
+        // retries will still not be performed, but it wont error immediately
         .with(RetryTransientMiddleware::new_with_policy(retry_policy))
         .build()
 }
@@ -81,6 +96,37 @@ impl Endpoint {
     }
 }
 
+/// https://docs.rs/reqwest/0.11.18/src/reqwest/dns/gai.rs.html
+use hyper::{
+    client::connect::dns::{GaiResolver as HyperGaiResolver, Name},
+    service::Service,
+};
+use reqwest::dns::{Addrs, Resolve, Resolving};
+#[derive(Debug)]
+pub struct GaiResolver(HyperGaiResolver);
+
+impl Default for GaiResolver {
+    fn default() -> Self {
+        Self(HyperGaiResolver::new())
+    }
+}
+
+impl Resolve for GaiResolver {
+    fn resolve(&self, name: Name) -> Resolving {
+        let this = &mut self.0.clone();
+        let start = Instant::now();
+        Box::pin(
+            Service::<Name>::call(this, name.clone()).map(move |result| {
+                let resolve_duration = start.elapsed();
+                trace!(duration = ?resolve_duration, addr = %name, "resolve host complete");
+                result
+                    .map(|addrs| -> Addrs { Box::new(addrs) })
+                    .map_err(|err| -> Box<dyn std::error::Error + Send + Sync> { Box::new(err) })
+            }),
+        )
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

proxy/src/http/sql_over_http.rs

@@ -1,7 +1,9 @@
 use std::sync::Arc;
 
+use anyhow::bail;
 use futures::pin_mut;
 use futures::StreamExt;
+use hashbrown::HashMap;
 use hyper::body::HttpBody;
 use hyper::http::HeaderName;
 use hyper::http::HeaderValue;
@@ -11,6 +13,8 @@ use serde_json::Map;
 use serde_json::Value;
 use tokio_postgres::types::Kind;
 use tokio_postgres::types::Type;
+use tokio_postgres::GenericClient;
+use tokio_postgres::IsolationLevel;
 use tokio_postgres::Row;
 use url::Url;
 
@@ -23,12 +27,25 @@ struct QueryData {
     params: Vec<serde_json::Value>,
 }
 
-pub const MAX_RESPONSE_SIZE: usize = 1024 * 1024; // 1 MB
+#[derive(serde::Deserialize)]
+struct BatchQueryData {
+    queries: Vec<QueryData>,
+}
+
+#[derive(serde::Deserialize)]
+#[serde(untagged)]
+enum Payload {
+    Single(QueryData),
+    Batch(BatchQueryData),
+}
+
+pub const MAX_RESPONSE_SIZE: usize = 10 * 1024 * 1024; // 10 MB
 const MAX_REQUEST_SIZE: u64 = 1024 * 1024; // 1 MB
 
 static RAW_TEXT_OUTPUT: HeaderName = HeaderName::from_static("neon-raw-text-output");
 static ARRAY_MODE: HeaderName = HeaderName::from_static("neon-array-mode");
-static ALLOW_POOL: HeaderName = HeaderName::from_static("neon-pool-opt-in");
+static TXN_ISOLATION_LEVEL: HeaderName = HeaderName::from_static("neon-batch-isolation-level");
+static TXN_READ_ONLY: HeaderName = HeaderName::from_static("neon-batch-read-only");
 
 static HEADER_VALUE_TRUE: HeaderValue = HeaderValue::from_static("true");
 
@@ -162,7 +179,7 @@ pub async fn handle(
     request: Request<Body>,
     sni_hostname: Option<String>,
     conn_pool: Arc<GlobalConnPool>,
-) -> anyhow::Result<Value> {
+) -> anyhow::Result<(Value, HashMap<HeaderName, HeaderValue>)> {
     //
     // Determine the destination and connection params
     //
@@ -175,7 +192,24 @@ pub async fn handle(
     let array_mode = headers.get(&ARRAY_MODE) == Some(&HEADER_VALUE_TRUE);
 
     // Allow connection pooling only if explicitly requested
-    let allow_pool = headers.get(&ALLOW_POOL) == Some(&HEADER_VALUE_TRUE);
+    let allow_pool = false;
+
+    // isolation level and read only
+
+    let txn_isolation_level_raw = headers.get(&TXN_ISOLATION_LEVEL).cloned();
+    let txn_isolation_level = match txn_isolation_level_raw {
+        Some(ref x) => Some(match x.as_bytes() {
+            b"Serializable" => IsolationLevel::Serializable,
+            b"ReadUncommitted" => IsolationLevel::ReadUncommitted,
+            b"ReadCommitted" => IsolationLevel::ReadCommitted,
+            b"RepeatableRead" => IsolationLevel::RepeatableRead,
+            _ => bail!("invalid isolation level"),
+        }),
+        None => None,
+    };
+
+    let txn_read_only_raw = headers.get(&TXN_READ_ONLY).cloned();
+    let txn_read_only = txn_read_only_raw.as_ref() == Some(&HEADER_VALUE_TRUE);
 
     let request_content_length = match request.body().size_hint().upper() {
         Some(v) => v,
@@ -184,7 +218,7 @@ pub async fn handle(
 
     if request_content_length > MAX_REQUEST_SIZE {
         return Err(anyhow::anyhow!(
-            "request is too large (max {MAX_REQUEST_SIZE} bytes)"
+            "request is too large (max is {MAX_REQUEST_SIZE} bytes)"
         ));
     }
 
@@ -192,28 +226,85 @@ pub async fn handle(
     // Read the query and query params from the request body
     //
     let body = hyper::body::to_bytes(request.into_body()).await?;
-    let QueryData { query, params } = serde_json::from_slice(&body)?;
-    let query_params = json_to_pg_text(params)?;
+    let payload: Payload = serde_json::from_slice(&body)?;
+
+    let mut client = conn_pool.get(&conn_info, !allow_pool).await?;
 
     //
     // Now execute the query and return the result
     //
-    let client = conn_pool.get(&conn_info, !allow_pool).await?;
+    let result = match payload {
+        Payload::Single(query) => query_to_json(&client, query, raw_output, array_mode)
+            .await
+            .map(|x| (x, HashMap::default())),
+        Payload::Batch(batch_query) => {
+            let mut results = Vec::new();
+            let mut builder = client.build_transaction();
+            if let Some(isolation_level) = txn_isolation_level {
+                builder = builder.isolation_level(isolation_level);
+            }
+            if txn_read_only {
+                builder = builder.read_only(true);
+            }
+            let transaction = builder.start().await?;
+            for query in batch_query.queries {
+                let result = query_to_json(&transaction, query, raw_output, array_mode).await;
+                match result {
+                    Ok(r) => results.push(r),
+                    Err(e) => {
+                        transaction.rollback().await?;
+                        return Err(e);
+                    }
+                }
+            }
+            transaction.commit().await?;
+            let mut headers = HashMap::default();
+            headers.insert(
+                TXN_READ_ONLY.clone(),
+                HeaderValue::try_from(txn_read_only.to_string())?,
+            );
+            if let Some(txn_isolation_level_raw) = txn_isolation_level_raw {
+                headers.insert(TXN_ISOLATION_LEVEL.clone(), txn_isolation_level_raw);
+            }
+            Ok((json!({ "results": results }), headers))
+        }
+    };
 
-    let row_stream = client.query_raw_txt(query, query_params).await?;
+    if allow_pool {
+        // return connection to the pool
+        tokio::task::spawn(async move {
+            let _ = conn_pool.put(&conn_info, client).await;
+        });
+    }
+
+    result
+}
+
+async fn query_to_json<T: GenericClient>(
+    client: &T,
+    data: QueryData,
+    raw_output: bool,
+    array_mode: bool,
+) -> anyhow::Result<Value> {
+    let query_params = json_to_pg_text(data.params)?;
+    let row_stream = client
+        .query_raw_txt::<String, _>(data.query, query_params)
+        .await?;
 
     // Manually drain the stream into a vector to leave row_stream hanging
     // around to get a command tag. Also check that the response is not too
     // big.
     pin_mut!(row_stream);
     let mut rows: Vec<tokio_postgres::Row> = Vec::new();
-    let mut curret_size = 0;
+    let mut current_size = 0;
     while let Some(row) = row_stream.next().await {
         let row = row?;
-        curret_size += row.body_len();
+        current_size += row.body_len();
         rows.push(row);
-        if curret_size > MAX_RESPONSE_SIZE {
-            return Err(anyhow::anyhow!("response too large"));
+        if current_size > MAX_RESPONSE_SIZE {
+            return Err(anyhow::anyhow!(
+                "response is too large (max is {MAX_RESPONSE_SIZE} bytes)"
+            ));
         }
     }
 
@@ -256,13 +347,6 @@ pub async fn handle(
         .map(|row| pg_text_row_to_json(row, raw_output, array_mode))
         .collect::<Result<Vec<_>, _>>()?;
 
-    if allow_pool {
-        // return connection to the pool
-        tokio::task::spawn(async move {
-            let _ = conn_pool.put(&conn_info, client).await;
-        });
-    }
-
     // resulting JSON format is based on the format of node-postgres result
     Ok(json!({
         "command": command_tag_name,

proxy/src/http/websocket.rs

@@ -6,6 +6,7 @@ use crate::{
 };
 use bytes::{Buf, Bytes};
 use futures::{Sink, Stream, StreamExt};
+use hashbrown::HashMap;
 use hyper::{
     server::{
         accept,
@@ -181,15 +182,21 @@ async fn ws_handler(
 
     // Check if the request is a websocket upgrade request.
     if hyper_tungstenite::is_upgrade_request(&request) {
+        info!(session_id = ?session_id, "performing websocket upgrade");
+
         let (response, websocket) = hyper_tungstenite::upgrade(&mut request, None)
             .map_err(|e| ApiError::BadRequest(e.into()))?;
 
-        tokio::spawn(async move {
-            if let Err(e) = serve_websocket(websocket, config, &cancel_map, session_id, host).await
-            {
-                error!("error in websocket connection: {e:?}");
+        tokio::spawn(
+            async move {
+                if let Err(e) =
+                    serve_websocket(websocket, config, &cancel_map, session_id, host).await
+                {
+                    error!(session_id = ?session_id, "error in websocket connection: {e:#}");
+                }
             }
-        });
+            .in_current_span(),
+        );
 
         // Return the response so the spawned future can continue.
         Ok(response)
@@ -203,7 +210,7 @@ async fn ws_handler(
             Ok(_) => StatusCode::OK,
             Err(_) => StatusCode::BAD_REQUEST,
         };
-        let json = match result {
+        let (json, headers) = match result {
             Ok(r) => r,
             Err(e) => {
                 let message = format!("{:?}", e);
@@ -214,7 +221,14 @@ async fn ws_handler(
                     },
                     None => Value::Null,
                 };
-                json!({ "message": message, "code": code })
+                error!(
+                    ?code,
+                    "sql-over-http per-client task finished with an error: {e:#}"
+                );
+                (
+                    json!({ "message": message, "code": code }),
+                    HashMap::default(),
+                )
             }
         };
         json_response(status_code, json).map(|mut r| {
@@ -222,6 +236,9 @@ async fn ws_handler(
                 "Access-Control-Allow-Origin",
                 hyper::http::HeaderValue::from_static("*"),
             );
+            for (k, v) in headers {
+                r.headers_mut().insert(k, v);
+            }
             r
         })
     } else if request.uri().path() == "/sql" && request.method() == Method::OPTIONS {

proxy/src/metrics.rs

@@ -11,7 +11,6 @@ const PROXY_IO_BYTES_PER_CLIENT: &str = "proxy_io_bytes_per_client";
 
 const DEFAULT_HTTP_REPORTING_TIMEOUT: Duration = Duration::from_secs(60);
 
-///
 /// Key that uniquely identifies the object, this metric describes.
 /// Currently, endpoint_id is enough, but this may change later,
 /// so keep it in a named struct.
@@ -19,8 +18,7 @@ const DEFAULT_HTTP_REPORTING_TIMEOUT: Duration = Duration::from_secs(60);
 /// Both the proxy and the ingestion endpoint will live in the same region (or cell)
 /// so while the project-id is unique across regions the whole pipeline will work correctly
 /// because we enrich the event with project_id in the control-plane endpoint.
-///
-#[derive(Eq, Hash, PartialEq, Serialize, Debug)]
+#[derive(Eq, Hash, PartialEq, Serialize, Debug, Clone)]
 pub struct Ids {
     pub endpoint_id: String,
     pub branch_id: String,
@@ -149,7 +147,7 @@ async fn collect_metrics_iteration(
                     stop_time: *curr_time,
                 },
                 metric: PROXY_IO_BYTES_PER_CLIENT,
-                idempotency_key: idempotency_key(hostname.to_owned()),
+                idempotency_key: idempotency_key(hostname),
                 value,
                 extra: Ids {
                     endpoint_id: curr_key.endpoint_id.clone(),
@@ -167,12 +165,11 @@ async fn collect_metrics_iteration(
     // Send metrics.
     // Split into chunks of 1000 metrics to avoid exceeding the max request size
     for chunk in metrics_to_send.chunks(CHUNK_SIZE) {
-        let chunk_json = serde_json::value::to_raw_value(&EventChunk { events: chunk })
-            .expect("ProxyConsumptionMetric should not fail serialization");
-
         let res = client
             .post(metric_collection_endpoint.clone())
-            .json(&chunk_json)
+            .json(&EventChunk {
+                events: chunk.into(),
+            })
             .send()
             .await;