[
https://issues.apache.org/jira/browse/YARN-2946?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14254376#comment-14254376
]
Jian He commented on YARN-2946:
-------------------------------
[~rohithsharma], I had a quick look at the patch. one comment is:
In each store/update method, instead of doing this:
{code}
if (isFencedState()) {
LOG.info("State store is in Fenced state. Can't remove RM Delegation "
+ "Token Master key.");
return;
}
this.stateMachine.doTransition(RMStateStoreEventType.UPDATE_AMRM_TOKEN,
new RMStateStoreAMRMTokenEvent(amrmTokenSecretManagerState, isUpdate,
RMStateStoreEventType.UPDATE_AMRM_TOKEN));
{code}
we can do this
{code}
handleStoreEvent(RMStateStoreEvent event)
{code}
> DeadLocks in RMStateStore<->ZKRMStateStore
> ------------------------------------------
>
> Key: YARN-2946
> URL: https://issues.apache.org/jira/browse/YARN-2946
> Project: Hadoop YARN
> Issue Type: Bug
> Components: resourcemanager
> Affects Versions: 2.7.0
> Reporter: Rohith
> Assignee: Rohith
> Priority: Blocker
> Attachments: 0001-YARN-2946.patch, 0001-YARN-2946.patch,
> 0002-YARN-2946.patch, RM_BeforeFix_Deadlock_cycle_1.png,
> RM_BeforeFix_Deadlock_cycle_2.png, TestYARN2946.java
>
>
> Found one deadlock in ZKRMStateStore.
> # Initial stage zkClient is null because of zk disconnected event.
> # When ZKRMstatestore#runWithCheck() wait(zkSessionTimeout) for zkClient to
> re establish zookeeper connection either via synconnected or expired event,
> it is highly possible that any other thred can obtain lock on
> {{ZKRMStateStore.this}} from state machine transition events. This cause
> Deadlock in ZKRMStateStore.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
