HBASE-24781 Clean up peer metrics when disabling peer

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/MetricsSource.java

@@ -272,10 +272,14 @@ public void incrLogReadInBytes(long readInBytes) {
 
   /** Removes all metrics about this Source. */
   public void clear() {
+    terminate();
+    singleSourceSource.clear();
+  }
+
+  public void terminate() {
     int lastQueueSize = singleSourceSource.getSizeOfLogQueue();
     globalSourceSource.decrSizeOfLogQueue(lastQueueSize);
     singleSourceSource.decrSizeOfLogQueue(lastQueueSize);
-    singleSourceSource.clear();
     globalSourceSource.decrSizeOfHFileRefsQueue(lastHFileRefsQueueSize);
     lastShippedTimeStamps.clear();
     lastHFileRefsQueueSize = 0;

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSource.java

@@ -706,10 +706,13 @@ public void terminate(String reason, Exception cause, boolean clearMetrics, bool
         }
       }
     }
-    if (clearMetrics) {
-      // Can be null in test context.
-      if (this.metrics != null) {
+
+    // Can be null in test context.
+    if (this.metrics != null) {
+      if (clearMetrics) {
         this.metrics.clear();
+      } else {
+        this.metrics.terminate();
       }
     }
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/replication/regionserver/ReplicationSourceManager.java

@@ -467,7 +467,8 @@ public void refreshSources(String peerId) throws IOException {
       ReplicationSourceInterface toRemove = this.sources.remove(peerId);
       if (toRemove != null) {
         LOG.info("Terminate replication source for " + toRemove.getPeerId());
-        toRemove.terminate(terminateMessage, null, true);
+        // Do not clear metrics
+        toRemove.terminate(terminateMessage, null, false);
       }
       src = createSource(peerId, peer);
       this.sources.put(peerId, src);

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/ReplicationSourceDummy.java

@@ -94,6 +94,8 @@ public void terminate(String reason, Exception e) {
   public void terminate(String reason, Exception e, boolean clearMetrics) {
     if (clearMetrics) {
       this.metrics.clear();
+    } else {
+      this.metrics.terminate();
     }
   }
 

hbase-server/src/test/java/org/apache/hadoop/hbase/replication/regionserver/TestReplicationSourceManager.java

@@ -572,6 +572,41 @@ public void testRemovePeerMetricsCleanup() throws Exception {
     }
   }
 
+  @Test
+  public void testDisablePeerMetricsCleanup() throws Exception {
+    final String peerId = "DummyPeer";
+    final ReplicationPeerConfig peerConfig = ReplicationPeerConfig.newBuilder()
+      .setClusterKey(utility.getZkCluster().getAddress().toString() + ":/hbase").build();
+    try {
+      MetricsReplicationSourceSource globalSource = getGlobalSource();
+      final int globalLogQueueSizeInitial = globalSource.getSizeOfLogQueue();
+      final long sizeOfLatestPath = getSizeOfLatestPath();
+      addPeerAndWait(peerId, peerConfig, true);
+      assertEquals(sizeOfLatestPath + globalLogQueueSizeInitial, globalSource.getSizeOfLogQueue());
+      ReplicationSourceInterface source = manager.getSource(peerId);
+      // Sanity check
+      assertNotNull(source);
+      final int sizeOfSingleLogQueue = source.getSourceMetrics().getSizeOfLogQueue();
+      // Enqueue log and check if metrics updated
+      source.enqueueLog(new Path("abc"));
+      assertEquals(1 + sizeOfSingleLogQueue, source.getSourceMetrics().getSizeOfLogQueue());
+      assertEquals(source.getSourceMetrics().getSizeOfLogQueue() + globalLogQueueSizeInitial,
+        globalSource.getSizeOfLogQueue());
+
+      // Refreshing the peer should decrement the global and single source metrics
+      manager.refreshSources(peerId);
+      assertEquals(globalLogQueueSizeInitial, globalSource.getSizeOfLogQueue());
+
+      source = manager.getSource(peerId);
+      assertNotNull(source);
+      assertEquals(sizeOfSingleLogQueue, source.getSourceMetrics().getSizeOfLogQueue());
+      assertEquals(source.getSourceMetrics().getSizeOfLogQueue() + globalLogQueueSizeInitial,
+        globalSource.getSizeOfLogQueue());
+    } finally {
+      removePeerAndWait(peerId);
+    }
+  }
+
   private ReplicationSourceInterface mockReplicationSource(String peerId) {
     ReplicationSourceInterface source = mock(ReplicationSourceInterface.class);
     when(source.getPeerId()).thenReturn(peerId);