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https://issues.apache.org/jira/browse/DIRMINA-678?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12683685#action_12683685
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Serge Baranov commented on DIRMINA-678:
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I've got patches from Sun fixing this issue for JDK 1.6.0_12 and JDK 1.7.0 b50.
According to them, the fix will go into 6u15 or 6u16. Servers are running for
more than 10 hours with no problems after applying the patch.
Unfortunately, it's for testers only and I'm not allowed to share it, so please
don't ask.
The root case of the problem is related to this bug:
http://bugs.sun.com/view_bug.do?bug_id=6693490 .
Quoting JDK developer:
"In summary, the bug we have in the epoll
Selector relates to a timing issue between select and close that results
in the preclose file descriptor getting registered with the epoll
facility. The preclose file descriptor is connected to a socketpair
where the other end is closed so the end that is registered in epoll is
always pollable (and so causes the spin)."
> NioProcessor 100% CPU usage on Linux (epoll selector bug)
> ---------------------------------------------------------
>
> Key: DIRMINA-678
> URL: https://issues.apache.org/jira/browse/DIRMINA-678
> Project: MINA
> Issue Type: Bug
> Components: Core
> Affects Versions: 2.0.0-M4
> Environment: CentOS 5.x, 32/64-bit, 32/64-bit Sun JDK 1.6.0_12, also
> _11/_10/_09 and Sun JDK 1.7.0 b50, Kernel 2.6.18-92.1.22.el5 and also older
> versions,
> Reporter: Serge Baranov
> Fix For: 2.0.0
>
> Attachments: snap973.png, snap974.png
>
>
> It's the same bug as described at http://jira.codehaus.org/browse/JETTY-937 ,
> but affecting MINA in the very similar way.
> NioProcessor threads start to eat 100% resources per CPU. After 10-30 minutes
> of running depending on the load (sometimes after several hours) one of the
> NioProcessor starts to consume all the available CPU resources probably
> spinning in the epoll select loop. Later, more threads can be affected by the
> same issue, thus 100% loading all the available CPU cores.
> Sample trace:
> NioProcessor-10 [RUNNABLE] CPU time: 5:15
> sun.nio.ch.EPollArrayWrapper.epollWait(long, int, long, int)
> sun.nio.ch.EPollArrayWrapper.poll(long)
> sun.nio.ch.EPollSelectorImpl.doSelect(long)
> sun.nio.ch.SelectorImpl.lockAndDoSelect(long)
> sun.nio.ch.SelectorImpl.select(long)
> org.apache.mina.transport.socket.nio.NioProcessor.select(long)
> org.apache.mina.core.polling.AbstractPollingIoProcessor$Processor.run()
> org.apache.mina.util.NamePreservingRunnable.run()
> java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor$Worker)
> java.util.concurrent.ThreadPoolExecutor$Worker.run()
> java.lang.Thread.run()
> It seems to affect any NIO based Java server applications running in the
> specified environment.
> Some projects provide workarounds for similar JDK bugs, probably MINA can
> also think about a workaround.
> As far as I know, there are at least 3 users who experience this issue with
> Jetty and all of them are running CentOS (some distribution default setting
> is a trigger?). As for MINA, I'm not aware of similar reports yet.
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