[jira] [Commented] (HELIX-96) ZkBaseDataAccessor.get() hangs during Zookeeper failure

["kishore gopalakrishna (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/HELIX-96?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13661504#comment-13661504 ] 

kishore gopalakrishna commented on HELIX-96:
--------------------------------------------

 677: // we give the event thread some time to update the status to 'Disconnected'
 678: Thread.yield();
 679: waitUntilConnected();

678 is just allowing the event thread to update its satus to disconnected.
679 basically means it will wait indefinitely until its connected again. 

Ideally waitUntilConnected() should probably be  waitUntilConnected(connectionTimeout, TimeUnit).

Let me think some more, if its the right to so

                
> ZkBaseDataAccessor.get() hangs during Zookeeper failure
> -------------------------------------------------------
>
>                 Key: HELIX-96
>                 URL: https://issues.apache.org/jira/browse/HELIX-96
>             Project: Apache Helix
>          Issue Type: Bug
>          Components: helix-core
>    Affects Versions: 0.6.0-incubating
>            Reporter: Ming Fang
>            Assignee: Shi Lu
>
> During our failure testing with Zookeeper running in standalone mode, we sometimes see our application hanging in the callstack below...
>    java.lang.Thread.State: TIMED_WAITING (parking)
> 	at sun.misc.Unsafe.park(Native Method)
> 	- parking to wait for  <0x187c1f10> (a java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject)
> 	at java.util.concurrent.locks.LockSupport.parkUntil(LockSupport.java:237)
> 	at java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.awaitUntil(AbstractQueuedSynchronizer.java:2072)
> 	at org.I0Itec.zkclient.ZkClient.waitForKeeperState(ZkClient.java:636)
> 	at org.I0Itec.zkclient.ZkClient.waitUntilConnected(ZkClient.java:619)
> 	at org.I0Itec.zkclient.ZkClient.waitUntilConnected(ZkClient.java:615)
> 	at org.I0Itec.zkclient.ZkClient.retryUntilConnected(ZkClient.java:679)
> 	at org.apache.helix.manager.zk.ZkClient.readData(ZkClient.java:254)
> 	at org.I0Itec.zkclient.ZkClient.readData(ZkClient.java:761)
> 	at org.apache.helix.manager.zk.ZkBaseDataAccessor.get(ZkBaseDataAccessor.java:315)
> 	at org.apache.helix.manager.zk.ZkCacheBaseDataAccessor.get(ZkCacheBaseDataAccessor.java:461)
> The comment in ZKClient.java line 677 seems to say that eventually it would get a Disconnected event and then throw an exception, but we waited for many minutes.
> Also we were able to resume by simply restarting Zookeeper.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira