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https://issues.apache.org/jira/browse/HADOOP-12855?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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John Zhuge updated HADOOP-12855:
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Attachment: HADOOP-12855-001.patch
Patch 001:
* Start a pause monitor thread only when no such thread is running in JVM
* Stop the thread when stopping the last instance of JvmPauseMonitor
* Pass TestMiniDFSCluster and TestMiniYarnCluster unit tests. Only see 1 line
of log message “Starting JVM pause monitor" per minicluster session.
> Add option to disable JVMPauseMonitor across services
> -----------------------------------------------------
>
> Key: HADOOP-12855
> URL: https://issues.apache.org/jira/browse/HADOOP-12855
> Project: Hadoop Common
> Issue Type: Improvement
> Components: performance
> Affects Versions: 2.8.0
> Environment: JVMs with miniHDFS and miniYarn clusters
> Reporter: Steve Loughran
> Assignee: John Zhuge
> Attachments: HADOOP-12855-001.patch
>
>
> Now that the YARN and HDFS services automatically start a JVM pause monitor,
> if you start up the mini HDFS and YARN clusters, with history server, you are
> spinning off 5 + threads, all looking for JVM pauses, all printing things out
> when it happens.
> We do not need these monitors in minicluster testing; they merely add load
> and noise to tests.
> Rather than retrofit new options everywhere, how about having a
> "jvm.pause.monitor.enabled" flag (default true), which, when set, starts off
> the monitor thread.
> That way, the existing code is unchanged, there is always a JVM pause monitor
> for the various services —it just isn't spinning up threads.
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