hfutatzhanghb commented on code in PR #5330:
URL: https://github.com/apache/hadoop/pull/5330#discussion_r1095415826


##########
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BPOfferService.java:
##########
@@ -679,16 +679,19 @@ boolean processCommandFromActor(DatanodeCommand cmd,
       actor.reRegister();
       return false;
     }
+    boolean isActiveActor;
     writeLock();
     try {
-      if (actor == bpServiceToActive) {
-        return processCommandFromActive(cmd, actor);
-      } else {
-        return processCommandFromStandby(cmd, actor);
-      }
+      isActiveActor = actor == bpServiceToActive;
     } finally {
       writeUnlock();
     }
+
+    if (actor == bpServiceToActive) {
+      return processCommandFromActive(cmd, actor);
+    } else {
+      return processCommandFromStandby(cmd, actor);
+    }

Review Comment:
   Hi, @virajjasani . thanks for your careful review.  Surely, before 
[HDFS-6788](https://issues.apache.org/jira/browse/HDFS-6788), this part was 
covered by synchronized lock.
   but in method `processCommandFromActive` and `processCommandFromStandby`,  
it just use the parameter actor to print log info. The lock here is just trying 
to decide actor is whether bpServiceToActive or not and determine to execute 
either processCommandFromActive or processCommandFromStandby.  
   
   when occurs switchover between active namenode and standby namenode,  the 
datanodes would be set to stale status, in stale status, we are not allowed to 
delete blocks directly, we put those blocks into postponedMisreplicatedBlocks.  
So, even we execute the DatanodeCommand from the previous active namenode(now 
standby), it is okay.



-- 
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.

To unsubscribe, e-mail: [email protected]

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