[jira] [Commented] (CASSANDRA-4387) Multiple RPC threads waiting on a single thread

["Jonathan Ellis (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/CASSANDRA-4387?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13402686#comment-13402686 ] 

Jonathan Ellis commented on CASSANDRA-4387:
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Odd.  Sounds like a problem with SynchronousQueue internals to me.  Only thing I could suggest trying is replacing it (in AbstractCassandraDaemon) with the java7 TransferQueue, which is supposed to be significantly more performant.

http://docs.oracle.com/javase/7/docs/api/java/util/concurrent/TransferQueue.html


                
> Multiple RPC threads waiting on a single thread
> -----------------------------------------------
>
>                 Key: CASSANDRA-4387
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-4387
>             Project: Cassandra
>          Issue Type: Bug
>    Affects Versions: 1.0.7
>         Environment: sun java 6.24
>            Reporter: Jason Harvey
>            Priority: Minor
>         Attachments: output.log
>
>
> I'm investigating a load spike issue on our cluster. A thread dump that I collected during a spike shows a peculiar symptom. There are 162 RPC threads all parked waiting on a single java.util.concurrent.SynchronousQueue$TransferStack thread. Brandon took a peek and recommended I create a ticket for investigation.
> Full thread dump attached. The thread which is being waited on is 0x00000006ac1aba60.

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