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https://issues.apache.org/jira/browse/CASSANDRA-13943?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16202520#comment-16202520
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Marcus Eriksson commented on CASSANDRA-13943:
---------------------------------------------
Yeah getting the lock is clearly a problem
My thinking was that we should try if we see a big improvement when lowering
the throughput, and thus finishing fewer compactions where we grab the write
lock to replace sstables
You might also want to try the patch in CASSANDRA-13948
> Infinite compaction of L0 SSTables in JBOD
> ------------------------------------------
>
> Key: CASSANDRA-13943
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13943
> Project: Cassandra
> Issue Type: Bug
> Components: Compaction
> Environment: Cassandra 3.11.0 / Centos 6
> Reporter: Dan Kinder
> Assignee: Marcus Eriksson
> Attachments: cassandra-jstack-2017-10-12-infinite-sstable-adding.txt,
> cassandra-jstack-2017-10-12.txt, cassandra.yaml, debug.log,
> debug.log-with-commit-d8f3f2780, debug.log.1.zip, debug.log.zip, jvm.options
>
>
> I recently upgraded from 2.2.6 to 3.11.0.
> I am seeing Cassandra loop infinitely compacting the same data over and over.
> Attaching logs.
> It is compacting two tables, one on /srv/disk10, the other on /srv/disk1. It
> does create new SSTables but immediately recompacts again. Note that I am not
> inserting anything at the moment, there is no flushing happening on this
> table (Memtable switch count has not changed).
> My theory is that it somehow thinks those should be compaction candidates.
> But they shouldn't be, they are on different disks and I ran nodetool
> relocatesstables as well as nodetool compact. So, it tries to compact them
> together, but the compaction results in the exact same 2 SSTables on the 2
> disks, because the keys are split by data disk.
> This is pretty serious, because all our nodes right now are consuming CPU
> doing this for multiple tables, it seems.
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