pkuwm commented on a change in pull request #1066:
URL: https://github.com/apache/helix/pull/1066#discussion_r437786008



##########
File path: 
helix-core/src/main/java/org/apache/helix/controller/stages/MessageDispatchStage.java
##########
@@ -78,7 +78,13 @@ protected void processEvent(ClusterEvent event, 
MessageOutput messageOutput) thr
         batchMessage(dataAccessor.keyBuilder(), messagesToSend, resourceMap, 
liveInstanceMap,
             manager.getProperties());
 
-    List<Message> messagesSent = sendMessages(dataAccessor, outputMessages);
+    String expectedSession = 
event.getAttribute(AttributeName.CONTROLLER_LEADER_SESSION.name());
+    // An early check for expected leader session. If the sessions don't 
match, it means the
+    // controller lost leadership, then messages should not be sent. This 
potentially avoid
+    // double masters for a single partition.
+    List<Message> messagesSent = manager.getSessionId().equals(expectedSession)

Review comment:
       I've updated it to stop the pipeline at this point: thrown 
StageException.




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
[email protected]



---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to