Added stream writer benchmark with limited CPU

.github/dependabot.yml

@@ -0,0 +1,24 @@
+version: 2
+updates:
+  - package-ecosystem: maven
+    directory: /
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 5
+    groups:
+      maven-minor-and-patch:
+        patterns:
+          - "*"
+        update-types:
+          - minor
+          - patch
+
+  - package-ecosystem: github-actions
+    directory: /
+    schedule:
+      interval: weekly
+    open-pull-requests-limit: 3
+    groups:
+      github-actions:
+        patterns:
+          - "*"

.github/pull_request_template.md

@@ -4,11 +4,13 @@
 Closes <!-- Link to an issue to close on merge. -->
 <!-- Description can be only appended not replaced. PR title should stay unchanged after creation but can be changed by user. 
   All appended comments should contain author and time.
-  Read AGENTS.md and docs/ai_review.md for review instructions.
+  Read AGENTS.md and docs/ai-review.md for review instructions.
+  Use docs/README.md to choose the authoritative documentation layer. Published website changes belong in
+  docs/clickhouse-docs/; repository integration guidance belongs in docs/integration-*.md.
   --> 
 ## Checklist
 Delete items not relevant to your PR:
 - [ ] Closes #<issue ref>
 - [ ] Unit and integration tests covering the common scenarios were added
 - [ ] A human-readable description of the changes was provided to include in CHANGELOG
-- [ ] For significant changes, documentation in https://github.com/ClickHouse/clickhouse-docs was updated with further explanations or tutorials
+- [ ] For significant changes, the authoritative source under `docs/clickhouse-docs/` was updated for publication

.github/workflows/api-compatibility.yml

@@ -0,0 +1,75 @@
+name: API compatibility
+
+on:
+  pull_request:
+    paths:
+      - "**/pom.xml"
+      - "**/src/main/java/**"
+      - "VERSION"
+      - ".github/workflows/api-compatibility.yml"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  compare-last-ga:
+    name: Compare public API with last GA
+    runs-on: ubuntu-latest
+    timeout-minutes: 20
+    steps:
+      - name: Check out repository and release tags
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Install JDKs and Maven cache
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: |
+            11
+            17
+          cache: maven
+      - name: Set up JDK toolchain
+        shell: bash
+        run: |
+          mkdir -p "$HOME/.m2"
+          cat > "$HOME/.m2/toolchains.xml" <<EOF
+          <?xml version="1.0" encoding="UTF8"?>
+          <toolchains>
+            <toolchain>
+              <type>jdk</type>
+              <provides><version>11</version></provides>
+              <configuration><jdkHome>${JAVA_HOME_11_X64}</jdkHome></configuration>
+            </toolchain>
+            <toolchain>
+              <type>jdk</type>
+              <provides><version>17</version></provides>
+              <configuration><jdkHome>${JAVA_HOME_17_X64}</jdkHome></configuration>
+            </toolchain>
+          </toolchains>
+          EOF
+      - name: Resolve last GA version
+        id: baseline
+        shell: bash
+        run: |
+          tag="$(
+            git tag --list 'v[0-9]*' --sort=-version:refname |
+              awk '/^v[0-9]+\.[0-9]+\.[0-9]+$/ { print; exit }'
+          )"
+          test -n "$tag" || {
+            echo "No vMAJOR.MINOR.PATCH GA tag was found" >&2
+            exit 1
+          }
+          echo "version=${tag#v}" >> "$GITHUB_OUTPUT"
+          echo "Comparing against $tag"
+      - name: Validate development version
+        run: python3 scripts/release/validate_version.py
+      - name: Check binary compatibility
+        run: |
+          mvn --batch-mode --no-transfer-progress \
+            -DskipTests -Dmaven.javadoc.skip=true install
+          mvn --batch-mode --no-transfer-progress \
+            --projects clickhouse-data,clickhouse-client,clickhouse-http-client,client-v2,jdbc-v2,clickhouse-jdbc,clickhouse-r2dbc \
+            -Dapi.compatibility.version="${{ steps.baseline.outputs.version }}" \
+            -Papi-compatibility japicmp:cmp

.github/workflows/build.yml

@@ -47,6 +47,10 @@ jobs:
           git fetch --no-tags --prune --progress --no-recurse-submodules --depth=1 \
             origin pull/${{ github.event.inputs.pr }}/merge:merged-pr && git checkout merged-pr
         if: github.event.inputs.pr != ''
+      - name: Validate release version metadata
+        run: |
+          python3 -m unittest discover -s scripts/release -p 'test_*.py'
+          python3 scripts/release/validate_version.py
       - name: Install JDK 8 and Maven
         uses: actions/setup-java@v4
         with:

.github/workflows/release.yml

@@ -2,88 +2,172 @@ name: Release
 
 on:
   workflow_dispatch:
+    inputs:
+      publish:
+        description: "Publish to Maven Central and create the GitHub release"
+        required: true
+        default: false
+        type: boolean
 
 env:
   CH_VERSION: "25.8"
 
 jobs:
   release:
-    name: "Build and Publish Artifact"
+    name: Verify release artifacts
     runs-on: "ubuntu-latest"
-
+    timeout-minutes: 60
+    outputs:
+      version: ${{ steps.version.outputs.version }}
     permissions:
-      contents: write
+      contents: read
 
     steps:
       - name: Check out Git repository
         uses: actions/checkout@v4
       - name: Read release version
         id: version
         shell: bash
-        run: echo "version=$(cat VERSION)" >> "$GITHUB_OUTPUT"
-      - name: Install JDK and Maven
+        run: |
+          python3 scripts/release/validate_version.py
+          echo "version=$(cat VERSION)" >> "$GITHUB_OUTPUT"
+      - name: Install JDKs and Maven cache
         uses: actions/setup-java@v4
         with:
           distribution: 'temurin'
           java-version: |
-            8
+            11
             17
           cache: 'maven'
-          server-id: central
-          server-username: MAVEN_USERNAME
-          server-password: MAVEN_PASSWORD
-          gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
-          gpg-passphrase: MAVEN_GPG_PASSPHRASE
       - name: Setup Toolchain
         shell: bash
         run: |
-          mkdir -p $HOME/.m2 \
-          && cat << EOF > $HOME/.m2/toolchains.xml
+          mkdir -p "$HOME/.m2"
+          cat > "$HOME/.m2/toolchains.xml" << EOF
           <?xml version="1.0" encoding="UTF8"?>
           <toolchains>
+            <toolchain>
+              <type>jdk</type>
+              <provides>
+                <version>11</version>
+              </provides>
+              <configuration>
+                <jdkHome>${JAVA_HOME_11_X64}</jdkHome>
+              </configuration>
+            </toolchain>
             <toolchain>
               <type>jdk</type>
               <provides>
                 <version>17</version>
               </provides>
               <configuration>
-                <jdkHome>${{ env.JAVA_HOME }}</jdkHome>
+                <jdkHome>${JAVA_HOME_17_X64}</jdkHome>
               </configuration>
             </toolchain>
           </toolchains>
           EOF
-      - name: Update Configuration
+      - name: Verify release build
+        env:
+          TEST_CLICKHOUSE_IMAGE_VERSION: ${{ env.CH_VERSION }}
         run: |
-          sed -i 's|<revision>.*</revision>|<revision>${{ steps.version.outputs.version }}</revision>|g' pom.xml
-          find . -type f -name "simplelogger.*" -exec rm -fv '{}' \;
-      - name: Release Maven package
+          mvn --batch-mode --no-transfer-progress \
+            -Drevision="${{ steps.version.outputs.version }}" \
+            -Dgpg.skip=true -DskipITs \
+            -P release clean verify
+      - name: Inventory release artifacts
+        run: |
+          python3 scripts/release/inventory_artifacts.py \
+            --version "${{ steps.version.outputs.version }}"
+      - name: Upload dry-run artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: release-${{ steps.version.outputs.version }}
+          path: release-assets/
+          if-no-files-found: error
+
+  publish:
+    name: Publish verified release
+    needs: release
+    if: ${{ inputs.publish }}
+    runs-on: ubuntu-latest
+    timeout-minutes: 45
+    environment: release
+    permissions:
+      contents: write
+    steps:
+      - name: Check out verified commit
+        uses: actions/checkout@v4
+      - name: Download verified release artifacts
+        uses: actions/download-artifact@v4
+        with:
+          name: release-${{ needs.release.outputs.version }}
+          path: release-assets
+      - name: Install JDK 11
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 11
+      - name: Configure Maven Central signing
+        uses: actions/setup-java@v4
+        with:
+          distribution: temurin
+          java-version: 17
+          cache: maven
+          server-id: central
+          server-username: MAVEN_USERNAME
+          server-password: MAVEN_PASSWORD
+          gpg-private-key: ${{ secrets.GPG_PRIVATE_KEY }}
+          gpg-passphrase: MAVEN_GPG_PASSPHRASE
+      - name: Set up JDK toolchain
+        shell: bash
+        run: |
+          mkdir -p "$HOME/.m2"
+          cat > "$HOME/.m2/toolchains.xml" << EOF
+          <?xml version="1.0" encoding="UTF8"?>
+          <toolchains>
+            <toolchain>
+              <type>jdk</type>
+              <provides><version>11</version></provides>
+              <configuration><jdkHome>${JAVA_HOME_11_X64}</jdkHome></configuration>
+            </toolchain>
+            <toolchain>
+              <type>jdk</type>
+              <provides><version>17</version></provides>
+              <configuration><jdkHome>${JAVA_HOME_17_X64}</jdkHome></configuration>
+            </toolchain>
+          </toolchains>
+          EOF
+      - name: Publish verified version to Maven Central
         env:
           MAVEN_USERNAME: ${{ secrets.SONATYPE_TOKEN_USER }}
           MAVEN_PASSWORD: ${{ secrets.SONATYPE_TOKEN }}
           MAVEN_GPG_PASSPHRASE: ${{ secrets.GPG_PASSPHRASE }}
-          TEST_CLICKHOUSE_IMAGE_VERSION: ${{ env.CH_VERSION }}
-        run: mvn -q --batch-mode -P release clean deploy
-      - name: Create Pre-release on Github
+        run: |
+          mvn --batch-mode --no-transfer-progress \
+            -Drevision="${{ needs.release.outputs.version }}" \
+            -DskipTests \
+            -P release deploy
+      - name: Create RC or GA GitHub release
+        shell: bash
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
         run: |
-          gh release create "v${{ steps.version.outputs.version }}" \
-            --prerelease \
-            --title "Release v${{ steps.version.outputs.version }}" \
-            LICENSE \
-            clickhouse-client/target/clickhouse*.jar \
-            clickhouse-data/target/clickhouse*.jar \
-            clickhouse-http-client/target/clickhouse*.jar \
-            clickhouse-jdbc/target/clickhouse*.jar \
-            clickhouse-jdbc/target/bundle/clickhouse*.jar \
-            clickhouse-r2dbc/target/clickhouse*.jar \
-            client-v2/target/client-v2*.jar \
-            jdbc-v2/target/jdbc-v2*.jar
+          version="${{ needs.release.outputs.version }}"
+          release_flags=(--generate-notes --target "$GITHUB_SHA")
+          if [[ "$version" == *-* ]]; then
+            release_flags+=(--prerelease --latest=false)
+          else
+            release_flags+=(--latest)
+          fi
+          gh release create "v${version}" \
+            --title "Release v${version}" \
+            "${release_flags[@]}" \
+            release-assets/*
   # Mirror Tableau TDVT after release (non-blocking).
   tdvt:
     name: "Tableau TDVT"
-    needs: release
-    if: ${{ needs.release.result == 'success' && startsWith(github.repository, 'ClickHouse/') }}
+    needs: publish
+    if: ${{ needs.publish.result == 'success' && startsWith(github.repository, 'ClickHouse/') }}
     runs-on: "ubuntu-latest"
     timeout-minutes: 150 # the TDVT matrix (latest/head/cloud, single-threaded) runs ~1h; allow for a queue
     steps:

.gitignore

@@ -61,6 +61,7 @@ jdbc-v2/src/main/antlr4/com/clickhouse/jdbc/internal/ClickHouseLexer.tokens
 # test configuration
 **/test/resources/test.properties
 performance/jmh-simple-results.json
+performance/results/
 *.csv
 *.sql
 *.json

AGENTS.md

@@ -40,7 +40,7 @@ Prefer targeted Maven commands over full-repo runs.
 
 Also compile examples or packaging modules (e.g. `packages/clickhouse-jdbc-all`) when a change affects examples, packaging, public APIs, or other user-facing behavior — running the touched module's tests alone isn't enough.
 
-Run benchmarks under `clickhouse-benchmark` when a change touches a performance-sensitive path (see
+Run benchmarks under `performance` when a change touches a performance-sensitive path (see
 `docs/ai-review.md`); this is optional and only worth doing when performance is actually in question.
 
 Avoid broad dependency, formatting, or unrelated cleanup churn unless required by the task.

CONTRIBUTING.md

@@ -214,11 +214,10 @@ mvn -DskipTests -Pnative clean package
 Run benchmarks when the change may affect performance:
 
 ```bash
-cd clickhouse-benchmark
-mvn clean package
+mvn -DskipTests -pl packages/clickhouse-jdbc-all -am install
+mvn -f performance/pom.xml clean package
 
-# single thread mode
-java -DdbHost=localhost -jar target/benchmarks.jar -t 1 \
-    -p client=clickhouse-jdbc -p connection=reuse \
-    -p statement=prepared -p type=default Query.selectInt8
+# list available benchmarks
+java -cp performance/target/jmh-benchmark-0.1-SNAPSHOT-jar-with-dependencies.jar \
+    org.openjdk.jmh.Main -l
 ```

README.md

@@ -90,7 +90,7 @@ Nightly Builds: https://s01.oss.sonatype.org/content/repositories/snapshots/com/
 
 ### Examples
 
-[Begin-with Usage Examples](../../tree/main/examples/client-v2)
+[Begin-with Usage Examples](examples/client-v2)
 
 [Spring Demo Service](https://github.com/ClickHouse/clickhouse-java/tree/main/examples/demo-spring-service)
 
@@ -105,7 +105,7 @@ Nightly Builds: https://s01.oss.sonatype.org/content/repositories/snapshots/com/
 
 ### Examples
 
-See [JDBC examples](../../tree/main/examples/jdbc)
+See [JDBC examples](examples/jdbc)
 
 ## R2DBC Driver