apache · ctubbsii · Feb 28, 2026 · Feb 27, 2026
diff --git a/.github/workflows/maven-full-its.yaml b/.github/workflows/maven-full-its.yaml
@@ -19,7 +19,6 @@
 
 # This workflow will build a Java project with Maven
 # See also:
-#   https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
 #   https://docs.github.com/en/actions/reference/events-that-trigger-workflows#manual-events
 #   https://docs.github.com/en/actions/reference/context-and-expression-syntax-for-github-actions#fromjson
 
@@ -45,14 +44,14 @@ jobs:
   fastbuild:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         ref: ${{ github.event.inputs.buildRef }}
-    - name: Set up JDK 17
-      uses: actions/setup-java@v4
+    - name: Set up JDK 21
+      uses: actions/setup-java@v5
       with:
         distribution: temurin
-        java-version: 17
+        java-version: 21
         cache: 'maven'
     - name: Show the first log message
       run: git log -n1
@@ -68,7 +67,7 @@ jobs:
       matrix: ${{ steps.set-matrix.outputs.CUSTOM_MATRIX }}
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         ref: ${{ github.event.inputs.buildRef }}
     - id: set-matrix
@@ -82,14 +81,14 @@ jobs:
       fail-fast: false
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         ref: ${{ github.event.inputs.buildRef }}
-    - name: Set up JDK 17
-      uses: actions/setup-java@v4
+    - name: Set up JDK 21
+      uses: actions/setup-java@v5
       with:
         distribution: temurin
-        java-version: 17
+        java-version: 21
         cache: 'maven'
     - name: Override DNS to fix IP address for hostname
       run: |
@@ -113,21 +112,21 @@ jobs:
         MAVEN_OPTS: -Djansi.force=true
     - name: Upload unit test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: surefire-reports-${{ matrix.profile.name }}
         path: ./**/target/surefire-reports/
         if-no-files-found: ignore
     - name: Upload integration test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: failsafe-reports-${{ matrix.profile.name }}
         path: ./**/target/failsafe-reports/
         if-no-files-found: ignore
     - name: Upload mini test logs
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: mini-tests-logs-${{ matrix.profile.name }}
         path: ./**/target/**/mini-tests/**/logs/

diff --git a/.github/workflows/maven-on-demand.yaml b/.github/workflows/maven-on-demand.yaml
@@ -18,9 +18,6 @@
 #
 
 # This workflow will build a Java project with Maven
-# See also:
-#   https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
-#   https://docs.github.com/en/actions/reference/events-that-trigger-workflows#manual-events
 
 name: Manual Build
 
@@ -62,14 +59,14 @@ jobs:
     name: mvn (triggered by ${{ github.event.sender.login }})
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
       with:
         ref: ${{ github.event.inputs.buildRef }}
-    - name: Set up JDK 17
-      uses: actions/setup-java@v4
+    - name: Set up JDK 21
+      uses: actions/setup-java@v5
       with:
         distribution: temurin
-        java-version: 17
+        java-version: 21
         cache: 'maven'
     - name: Show the first log message
       run: git log -n1
@@ -95,21 +92,21 @@ jobs:
         MAVEN_OPTS: -Djansi.force=true
     - name: Upload unit test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: surefire-reports
         path: ./**/target/surefire-reports/
         if-no-files-found: ignore
     - name: Upload integration test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: failsafe-reports
         path: ./**/target/failsafe-reports/
         if-no-files-found: ignore
     - name: Upload mini test logs
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: mini-tests-logs
         path: ./**/target/**/mini-tests/**/logs/

diff --git a/.github/workflows/maven.yaml b/.github/workflows/maven.yaml
@@ -18,8 +18,6 @@
 #
 
 # This workflow will build a Java project with Maven
-# See also:
-#   https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
 
 name: QA
 
@@ -37,12 +35,12 @@ jobs:
   fastbuild:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
-    - name: Set up JDK 17
-      uses: actions/setup-java@v4
+    - uses: actions/checkout@v6
+    - name: Set up JDK 21
+      uses: actions/setup-java@v5
       with:
         distribution: temurin
-        java-version: 17
+        java-version: 21
         cache: 'maven'
     - name: Show the first log message
       run: git log -n1
@@ -65,16 +63,16 @@ jobs:
     strategy:
       matrix:
         profile:
-          - {name: 'unit-tests',    javaver: 17, args: 'verify -PskipQA -DskipTests=false'}
-          - {name: 'qa-checks',     javaver: 17, args: 'verify javadoc:jar -Psec-bugs -DskipTests -Dspotbugs.timeout=3600000'}
-          - {name: 'compat',        javaver: 17, args: 'package -DskipTests -Dversion.hadoop=3.0.3 -Dversion.zookeeper=3.5.10'}
-          - {name: 'errorprone',    javaver: 17, args: 'verify -Derrorprone -PskipQA'}
+          - {name: 'unit-tests',    javaver: 21, args: 'verify -PskipQA -DskipTests=false'}
+          - {name: 'qa-checks',     javaver: 21, args: 'verify javadoc:jar -Psec-bugs -DskipTests -Dspotbugs.timeout=3600000'}
+          - {name: 'compat',        javaver: 21, args: 'package -DskipTests -Dversion.hadoop=3.0.3 -Dversion.zookeeper=3.5.10'}
+          - {name: 'errorprone',    javaver: 21, args: 'verify -Derrorprone -PskipQA'}
       fail-fast: false
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up JDK ${{ matrix.profile.javaver }}
-      uses: actions/setup-java@v4
+      uses: actions/setup-java@v5
       with:
         distribution: temurin
         java-version: ${{ matrix.profile.javaver }}
@@ -101,21 +99,21 @@ jobs:
         MAVEN_OPTS: -Djansi.force=true
     - name: Upload unit test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: surefire-reports-${{ matrix.profile.name }}
         path: ./**/target/surefire-reports/
         if-no-files-found: ignore
     - name: Upload integration test results
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: failsafe-reports-${{ matrix.profile.name }}
         path: ./**/target/failsafe-reports/
         if-no-files-found: ignore
     - name: Upload mini test logs
       if: ${{ failure() }}
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: mini-tests-logs-${{ matrix.profile.name }}
         path: ./**/target/**/mini-tests/**/logs/

diff --git a/.github/workflows/scripts.yaml b/.github/workflows/scripts.yaml
@@ -18,8 +18,6 @@
 #
 
 # This workflow will build a Java project with Maven
-# See also:
-#   https://help.github.com/actions/language-and-framework-guides/building-and-testing-java-with-maven
 
 name: ScriptQA
 

diff --git a/core/pom.xml b/core/pom.xml
@@ -42,11 +42,6 @@
       <groupId>com.github.ben-manes.caffeine</groupId>
       <artifactId>caffeine</artifactId>
     </dependency>
-    <dependency>
-      <groupId>com.google.auto.service</groupId>
-      <artifactId>auto-service</artifactId>
-      <optional>true</optional>
-    </dependency>
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>

diff --git a/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooSession.java b/core/src/main/java/org/apache/accumulo/core/fate/zookeeper/ZooSession.java
@@ -110,7 +110,7 @@ public void process(WatchedEvent event) {
    */
   static ZooKeeper connect(String host, int timeout, String scheme, byte[] auth, Watcher watcher) {
     final int TIME_BETWEEN_CONNECT_CHECKS_MS = 100;
-    int connectTimeWait = Math.min(10_000, timeout);
+    long connectTimeWait = Math.min(10_000, timeout);
     boolean tryAgain = true;
     long sleepTime = 100;
     ZooKeeper zooKeeper = null;

diff --git a/core/src/main/java/org/apache/accumulo/core/security/Authorizations.java b/core/src/main/java/org/apache/accumulo/core/security/Authorizations.java
@@ -43,11 +43,9 @@
 public class Authorizations implements Iterable<byte[]>, Serializable, AuthorizationContainer {
 
   private static final long serialVersionUID = 1L;
-  private static final Set<ByteSequence> EMPTY_AUTH_SET = Collections.emptySet();
-  private static final List<byte[]> EMPTY_AUTH_LIST = Collections.emptyList();
 
-  private final Set<ByteSequence> auths;
-  private final List<byte[]> authsList; // sorted order
+  private final HashSet<ByteSequence> auths; // type must be serializable
+  private final ArrayList<byte[]> authsList; // sorted order; type must be serializable
 
   /**
    * An empty set of authorizations.
@@ -103,21 +101,12 @@ private void checkAuths() {
     }
   }
 
-  private static Set<ByteSequence> createInternalSet(int size) {
-    if (size < 1) {
-      return EMPTY_AUTH_SET;
-    } else {
-      return new HashSet<>(size);
-    }
+  private static HashSet<ByteSequence> createInternalSet(int size) {
+    return new HashSet<>(size);
   }
 
-  private static List<byte[]> createInternalList(int size) {
-    if (size < 1) {
-      return EMPTY_AUTH_LIST;
-    } else {
-      return new ArrayList<>(size);
-    }
-
+  private static ArrayList<byte[]> createInternalList(int size) {
+    return new ArrayList<>(size);
   }
 
   /**
@@ -195,8 +184,8 @@ public Authorizations(byte[] authorizations) {
         this.authsList = createInternalList(parts.length);
         setAuthorizations(parts);
       } else {
-        this.auths = EMPTY_AUTH_SET;
-        this.authsList = EMPTY_AUTH_LIST;
+        this.auths = createInternalSet(0);
+        this.authsList = createInternalList(0);
       }
     }
   }
@@ -207,8 +196,8 @@ public Authorizations(byte[] authorizations) {
    * @see #Authorizations(String...)
    */
   public Authorizations() {
-    this.auths = EMPTY_AUTH_SET;
-    this.authsList = EMPTY_AUTH_LIST;
+    this.auths = createInternalSet(0);
+    this.authsList = createInternalList(0);
   }
 
   /**

diff --git a/core/src/test/java/org/apache/accumulo/core/spi/balancer/GroupBalancerTest.java b/core/src/test/java/org/apache/accumulo/core/spi/balancer/GroupBalancerTest.java
@@ -166,20 +166,20 @@ void checkBalance() {
 
       Map<String,Integer> expectedCounts = new HashMap<>();
 
-      int totalExtra = 0;
+      long totalExtra = 0;
       for (String group : groupCounts.keySet()) {
         long groupCount = groupCounts.get(group);
         totalExtra += groupCount % tservers.size();
         expectedCounts.put(group, (int) (groupCount / tservers.size()));
       }
 
       // The number of extra tablets from all groups that each tserver must have.
-      int expectedExtra = totalExtra / tservers.size();
-      int maxExtraGroups = expectedExtra + ((totalExtra % tservers.size() > 0) ? 1 : 0);
+      long expectedExtra = totalExtra / tservers.size();
+      long maxExtraGroups = expectedExtra + ((totalExtra % tservers.size() > 0) ? 1 : 0);
 
       for (Entry<TabletServerId,MapCounter<String>> entry : tserverGroupCounts.entrySet()) {
         MapCounter<String> tgc = entry.getValue();
-        int tserverExtra = 0;
+        long tserverExtra = 0;
         for (String group : groupCounts.keySet()) {
           assertTrue(tgc.get(group) >= expectedCounts.get(group));
           assertTrue(tgc.get(group) <= expectedCounts.get(group) + 1,

diff --git a/minicluster/pom.xml b/minicluster/pom.xml
@@ -34,11 +34,6 @@
       <groupId>com.beust</groupId>
       <artifactId>jcommander</artifactId>
     </dependency>
-    <dependency>
-      <groupId>com.google.auto.service</groupId>
-      <artifactId>auto-service</artifactId>
-      <optional>true</optional>
-    </dependency>
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>