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https://issues.apache.org/jira/browse/CASSANDRA-8150?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14227361#comment-14227361
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Oleg Anastasyev edited comment on CASSANDRA-8150 at 11/27/14 7:58 AM:
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Let me add 2 -cents- GC options from our production clusters, which i believe
could be useful for all:
-XX:+ParallelRefProcEnabled
-XX:+CMSParallelInitialMarkEnabled
to improve CMS parallelization
I'd also propose add -XX:+DisableExplicitGC , b/c java RMI runtime invokes a
System.gc every hour or increasing sun.rmi.dgc.server.gcInterval to infinity.
We found, that on Sun JVMs 7 and 8 CMSWait durations are not governed by CMS
when GC is initiated by System.gc and this was the reason for most long rescan
phase pauses.
was (Author: m0nstermind):
Let me add 2 -cents- GC options from our production clusters, which i believe
could be useful for all:
-XX:+CMSScavengeBeforeRemark
to reduce rescan phase even of CMSWait exceeded
-XX:+ParallelRefProcEnabled
-XX:+CMSParallelInitialMarkEnabled
to improve CMS parallelization
-XX:CMSMaxAbortablePrecleanTime=20000
I'd also propose add -XX:+DisableExplicitGC , b/c java RMI runtime invokes a
System.gc every hour or increasing sun.rmi.dgc.server.gcInterval to infinity.
We found, that on Sun JVMs 7 and 8 CMSWait durations are not governed by CMS
when GC is initiated by System.gc and this was the reason for most long rescan
phase pauses.
> Revaluate Default JVM tuning parameters
> ---------------------------------------
>
> Key: CASSANDRA-8150
> URL: https://issues.apache.org/jira/browse/CASSANDRA-8150
> Project: Cassandra
> Issue Type: Improvement
> Components: Config
> Reporter: Matt Stump
> Assignee: Brandon Williams
> Attachments: upload.png
>
>
> It's been found that the old twitter recommendations of 100m per core up to
> 800m is harmful and should no longer be used.
> Instead the formula used should be 1/3 or 1/4 max heap with a max of 2G. 1/3
> or 1/4 is debatable and I'm open to suggestions. If I were to hazard a guess
> 1/3 is probably better for releases greater than 2.1.
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