diff --git a/example-setup/Dockerfile b/example-setup/Dockerfile
index 167b9f5..fea2ac9 100644
--- a/example-setup/Dockerfile
+++ b/example-setup/Dockerfile
@@ -1,4 +1,4 @@
-FROM gerritcodereview/gerrit:3.5.4-almalinux8
+FROM gerritcodereview/gerrit:3.6.3-almalinux8
 
 USER root
 
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/FetchOne.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/FetchOne.java
index d8da65e..eb543a0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/FetchOne.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/FetchOne.java
@@ -328,7 +328,6 @@
     } catch (NotSupportedException e) {
       stateLog.error("Cannot replicate from " + uri, e, getStatesAsArray());
     } catch (TransportException e) {
-      Throwable cause = e.getCause();
       if (e instanceof LockFailureException) {
         lockRetryCount++;
         // The LockFailureException message contains both URI and reason
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueue.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueue.java
index 380ac8e..f5b27ee 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueue.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueue.java
@@ -156,11 +156,7 @@
           event.getRefName(),
           event.getOldObjectId(),
           event.getNewObjectId());
-      fire(
-          event.getProjectName(),
-          ObjectId.fromString(event.getNewObjectId()),
-          event.getRefName(),
-          event.isDelete());
+      fire(ReferenceUpdatedEvent.from(event));
     }
   }
 
@@ -189,34 +185,39 @@
     return !refsFilter.match(refName);
   }
 
-  private void fire(String projectName, ObjectId objectId, String refName, boolean isDelete) {
+  private void fire(ReferenceUpdatedEvent event) {
     ReplicationState state = new ReplicationState(new GitUpdateProcessing(dispatcher.get()));
-    fire(Project.nameKey(projectName), objectId, refName, isDelete, state);
+    fire(event, state);
     state.markAllFetchTasksScheduled();
   }
 
-  private void fire(
-      Project.NameKey project,
-      ObjectId objectId,
-      String refName,
-      boolean isDelete,
-      ReplicationState state) {
+  private void fire(ReferenceUpdatedEvent event, ReplicationState state) {
     if (!running) {
       stateLog.warn(
           "Replication plugin did not finish startup before event, event replication is postponed",
           state);
-      beforeStartupEventsQueue.add(
-          ReferenceUpdatedEvent.create(project.get(), refName, objectId, isDelete));
+      beforeStartupEventsQueue.add(event);
       return;
     }
     ForkJoinPool fetchCallsPool = null;
     try {
-      fetchCallsPool = new ForkJoinPool(sources.get().getAll().size());
+      List<Source> allSources = sources.get().getAll();
+      int numSources = allSources.size();
+      if (numSources == 0) {
+        repLog.debug("No replication sources configured -> skipping fetch");
+        return;
+      }
+      fetchCallsPool = new ForkJoinPool(numSources);
 
       final Consumer<Source> callFunction =
-          callFunction(project, objectId, refName, isDelete, state);
+          callFunction(
+              Project.nameKey(event.projectName()),
+              event.objectId(),
+              event.refName(),
+              event.isDelete(),
+              state);
       fetchCallsPool
-          .submit(() -> sources.get().getAll().parallelStream().forEach(callFunction))
+          .submit(() -> allSources.parallelStream().forEach(callFunction))
           .get(fetchCallsTimeout, TimeUnit.MILLISECONDS);
     } catch (InterruptedException | ExecutionException | TimeoutException e) {
       stateLog.error(
@@ -491,7 +492,7 @@
       String eventKey = String.format("%s:%s", event.projectName(), event.refName());
       if (!eventsReplayed.contains(eventKey)) {
         repLog.info("Firing pending task {}", event);
-        fire(event.projectName(), event.objectId(), event.refName(), event.isDelete());
+        fire(event);
         eventsReplayed.add(eventKey);
       }
     }
@@ -517,6 +518,14 @@
           projectName, refName, objectId, isDelete);
     }
 
+    static ReferenceUpdatedEvent from(GitReferenceUpdatedListener.Event event) {
+      return ReferenceUpdatedEvent.create(
+          event.getProjectName(),
+          event.getRefName(),
+          ObjectId.fromString(event.getNewObjectId()),
+          event.isDelete());
+    }
+
     public abstract String projectName();
 
     public abstract String refName();
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommand.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommand.java
index d86287a..fd62910 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommand.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommand.java
@@ -36,7 +36,6 @@
 import com.googlesource.gerrit.plugins.replication.pull.ReplicationState;
 import com.googlesource.gerrit.plugins.replication.pull.Source;
 import com.googlesource.gerrit.plugins.replication.pull.SourcesCollection;
-import com.googlesource.gerrit.plugins.replication.pull.fetch.ApplyObject;
 import com.googlesource.gerrit.plugins.replication.pull.fetch.RefUpdateState;
 import java.io.IOException;
 import java.util.Optional;
@@ -49,7 +48,6 @@
   private static final FluentLogger logger = FluentLogger.forEnclosingClass();
 
   private final PullReplicationStateLogger fetchStateLog;
-  private final ApplyObject applyObject;
   private final DynamicItem<EventDispatcher> eventDispatcher;
   private final ProjectCache projectCache;
   private final SourcesCollection sourcesCollection;
@@ -61,13 +59,11 @@
       PullReplicationStateLogger fetchStateLog,
       ProjectCache projectCache,
       SourcesCollection sourcesCollection,
-      ApplyObject applyObject,
       PermissionBackend permissionBackend,
       DynamicItem<EventDispatcher> eventDispatcher,
       LocalGitRepositoryManagerProvider gitManagerProvider) {
     this.fetchStateLog = fetchStateLog;
     this.projectCache = projectCache;
-    this.applyObject = applyObject;
     this.eventDispatcher = eventDispatcher;
     this.sourcesCollection = sourcesCollection;
     this.permissionBackend = permissionBackend;
diff --git a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/fetch/CGitFetchValidator.java b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/fetch/CGitFetchValidator.java
index 9a10898..434c0f0 100644
--- a/src/main/java/com/googlesource/gerrit/plugins/replication/pull/fetch/CGitFetchValidator.java
+++ b/src/main/java/com/googlesource/gerrit/plugins/replication/pull/fetch/CGitFetchValidator.java
@@ -35,7 +35,7 @@
 
   @Override
   public Void visit(AssistedInjectBinding<? extends FetchFactory> binding) {
-    TypeLiteral<CGitFetch> nativeGitFetchType = new TypeLiteral<CGitFetch>() {};
+    TypeLiteral<CGitFetch> nativeGitFetchType = new TypeLiteral<>() {};
     for (AssistedMethod method : binding.getAssistedMethods()) {
       if (method.getImplementationType().equals(nativeGitFetchType)) {
         String[] command = new String[] {"git", "--version"};
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/FetchGitUpdateProcessingTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/FetchGitUpdateProcessingTest.java
index 68044b4..5a26054 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/FetchGitUpdateProcessingTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/FetchGitUpdateProcessingTest.java
@@ -47,8 +47,7 @@
   }
 
   @Test
-  public void headRefReplicatedInGitUpdateProcessing()
-      throws URISyntaxException, PermissionBackendException {
+  public void headRefReplicatedInGitUpdateProcessing() throws PermissionBackendException {
     FetchRefReplicatedEvent expectedEvent =
         new FetchRefReplicatedEvent(
             "someProject",
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/PullReplicationIT.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/PullReplicationIT.java
index f3c62c5..86b22b2 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/PullReplicationIT.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/PullReplicationIT.java
@@ -336,7 +336,6 @@
     BranchInput input = new BranchInput();
     input.revision = master;
     gApi.projects().name(testProjectName).branch(newBranch).create(input);
-    String branchRevision = gApi.projects().name(testProjectName).branch(newBranch).get().revision;
 
     ReplicationQueue pullReplicationQueue =
         plugin.getSysInjector().getInstance(ReplicationQueue.class);
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueueTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueueTest.java
index 0743cb9..927aec2 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueueTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/ReplicationQueueTest.java
@@ -45,7 +45,6 @@
 import com.googlesource.gerrit.plugins.replication.ReplicationConfig;
 import com.googlesource.gerrit.plugins.replication.ReplicationFileBasedConfig;
 import com.googlesource.gerrit.plugins.replication.pull.api.data.RevisionData;
-import com.googlesource.gerrit.plugins.replication.pull.api.exception.RefUpdateException;
 import com.googlesource.gerrit.plugins.replication.pull.client.FetchApiClient;
 import com.googlesource.gerrit.plugins.replication.pull.client.FetchRestApiClient;
 import com.googlesource.gerrit.plugins.replication.pull.client.HttpResult;
@@ -206,7 +205,7 @@
 
   @Test
   public void shouldFallbackToCallFetchWhenIOException()
-      throws ClientProtocolException, IOException, LargeObjectException, RefUpdateException {
+      throws ClientProtocolException, IOException, LargeObjectException {
     Event event = new TestEvent("refs/changes/01/1/meta");
     objectUnderTest.start();
 
@@ -219,7 +218,7 @@
 
   @Test
   public void shouldFallbackToCallFetchWhenLargeRef()
-      throws ClientProtocolException, IOException, LargeObjectException, RefUpdateException {
+      throws ClientProtocolException, IOException, LargeObjectException {
     Event event = new TestEvent("refs/changes/01/1/1");
     objectUnderTest.start();
 
@@ -307,7 +306,7 @@
   }
 
   @Test
-  public void shouldCallDeleteWhenReplicateProjectDeletionsTrue() throws IOException {
+  public void shouldCallDeleteWhenReplicateProjectDeletionsTrue() {
     when(source.wouldDeleteProject(any())).thenReturn(true);
 
     String projectName = "testProject";
@@ -323,7 +322,7 @@
   }
 
   @Test
-  public void shouldNotCallDeleteWhenProjectNotToDelete() throws IOException {
+  public void shouldNotCallDeleteWhenProjectNotToDelete() {
     when(source.wouldDeleteProject(any())).thenReturn(false);
 
     FakeProjectDeletedEvent event = new FakeProjectDeletedEvent("testProject");
@@ -335,7 +334,7 @@
   }
 
   @Test
-  public void shouldScheduleUpdateHeadWhenWouldFetchProject() throws IOException {
+  public void shouldScheduleUpdateHeadWhenWouldFetchProject() {
     when(source.wouldFetchProject(any())).thenReturn(true);
 
     String projectName = "aProject";
@@ -351,7 +350,7 @@
   }
 
   @Test
-  public void shouldNotScheduleUpdateHeadWhenNotWouldFetchProject() throws IOException {
+  public void shouldNotScheduleUpdateHeadWhenNotWouldFetchProject() {
     when(source.wouldFetchProject(any())).thenReturn(false);
 
     String projectName = "aProject";
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ActionITBase.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ActionITBase.java
index 20c1fea..e638653 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ActionITBase.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ActionITBase.java
@@ -163,7 +163,7 @@
   }
 
   public ResponseHandler<Object> assertHttpResponseCode(int responseCode) {
-    return new ResponseHandler<Object>() {
+    return new ResponseHandler<>() {
 
       @Override
       public Object handleResponse(HttpResponse response)
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ApplyObjectCommandTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ApplyObjectCommandTest.java
index 9b5ef46..4c188df 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ApplyObjectCommandTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/ApplyObjectCommandTest.java
@@ -64,7 +64,6 @@
 
   private String sampleCommitObjectId = "9f8d52853089a3cf00c02ff7bd0817bd4353a95a";
   private String sampleTreeObjectId = "4b825dc642cb6eb9a060e54bf8d69288fbee4904";
-  private String sampleBlobObjectId = "b5d7bcf1d1c5b0f0726d10a16c8315f06f900bfb";
 
   @Mock private PullReplicationStateLogger fetchStateLog;
   @Mock private ApplyObject applyObject;
diff --git a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommandTest.java b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommandTest.java
index 2adf72f..efa931f 100644
--- a/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommandTest.java
+++ b/src/test/java/com/googlesource/gerrit/plugins/replication/pull/api/DeleteRefCommandTest.java
@@ -102,7 +102,6 @@
             fetchStateLog,
             projectCache,
             sourceCollection,
-            applyObject,
             permissionBackend,
             eventDispatcherDataItem,
             new LocalGitRepositoryManagerProvider(gitManager));