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https://issues.apache.org/jira/browse/CASSANDRA-1181?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12882612#action_12882612
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Jonathan Ellis commented on CASSANDRA-1181:
-------------------------------------------
to enable, add to cassandra.in.sh:
-XX:+UseThreadPriorities \
-XX:ThreadPriorityPolicy=42 \
-Dcassandra.compaction_priority=1 \
(TPP=42 is a workaround to allow us to *lower* thread priority without root
privileges, explained at
http://tech.stolsvik.com/2010/01/linux-java-thread-priorities-workaround.html)
> kinder gentler compaction
> -------------------------
>
> Key: CASSANDRA-1181
> URL: https://issues.apache.org/jira/browse/CASSANDRA-1181
> Project: Cassandra
> Issue Type: Task
> Reporter: Jonathan Ellis
> Assignee: Jonathan Ellis
> Fix For: 0.7
>
> Attachments: CompactionManager.java
>
>
> I suggested this in a ML thread but it seems that nobody actually tried it.
> I think it's worth following up on:
> You could try setting the compaction thread to a lower priority. You could
> add a thread priority to NamedThreadPool, and pass that up from
> CompactionExecutor constructor. According to
> http://www.javamex.com/tutorials/threads/priority_what.shtml you have to run
> as root and add a JVM option to get this to work.
> In particular, Brandon saw stress.py read latencies spike to 100ms during
> [anti]compaction on a 2 core machine. I'd like to see if this can mitigate
> that.
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