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https://issues.apache.org/jira/browse/STORM-503?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Rick Kellogg updated STORM-503:
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Component/s: storm-core
> Short disruptor queue wait time leads to high CPU usage when idle
> -----------------------------------------------------------------
>
> Key: STORM-503
> URL: https://issues.apache.org/jira/browse/STORM-503
> Project: Apache Storm
> Issue Type: Bug
> Components: storm-core
> Affects Versions: 0.9.2-incubating, 0.9.1-incubating, 0.9.3
> Reporter: Milad Fatenejad
> Assignee: Xingyu Su
> Priority: Minor
> Fix For: 0.9.6
>
>
> I am fairly new to storm, but I observed some behavior which I believe may be
> unintended and wanted to report it...
> I was experimenting with using storm on a topology which had large numbers of
> threads (30) and was running on a single node for test purposes and noticed
> that even when no tuples were being processed, there was over 100% CPU
> utilization.
> I became concerned and investigated by attempting to reproduce with a very
> simple topology. I took the WordCountTopology from storm-starter and ran it
> in an Ubuntu VM. I increased the sleep time in the RandomSentenceSpout that
> feeds the topology to 10 seconds so that there was effectively no work to do.
> I then modified the topology so that there were 30 threads for each bolt and
> only one instance of the spout. When I ran the topology I noticed that there
> was again 100% CPU usage when idle even on this very simple topology. After
> extensive experimentation (netty vs. zeromq, 0.9.3, 0.9.2, 0.9.1, multiple
> JVM versions) I used yourkit and found that the high utilization was coming
> from DisruptorQueue.consumeBatchWhenAvailable where there is this code:
> final long availableSequence = _barrier.waitFor(nextSequence, 10,
> TimeUnit.MILLISECONDS);
> I increased to 100 ms and was able to reduce the CPU utilization when idle. I
> am new to storm, so I am not sure what affect modifying this number has. I Is
> this expected behavior from storm? I would like to propose modifying the code
> so that this wait is configurable if possible...
> Thank You
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