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https://issues.apache.org/jira/browse/CASSANDRA-13508?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16016611#comment-16016611
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Jay Zhuang commented on CASSANDRA-13508:
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Hi [~jjirsa], what do you think about this?
Paxos table could be very large. In our case, it's actually even larger than
one user table. As all the CAS write data are stored in Paxos table with
gc_grace TTL. If we have several tables using CAS write, the paxos table is
very large. Tuning the compaction would be useful.
This patch is giving the customer the option to change or configure the
compaction strategy. Let me know if you have any suggestion.
> Make system.paxos table compaction strategy configurable
> --------------------------------------------------------
>
> Key: CASSANDRA-13508
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13508
> Project: Cassandra
> Issue Type: Improvement
> Reporter: Jay Zhuang
> Assignee: Jay Zhuang
> Fix For: 4.0, 4.x
>
> Attachments: test11.png, test2.png
>
>
> The default compaction strategy for {{system.paxos}} table is LCS for
> performance reason: CASSANDRA-7753. But for CAS heavily used cluster, the
> system is busy with {{system.paxos}} compaction.
> As the data in {{paxos}} table are TTL'ed, TWCS might be a better fit. In our
> test, it significantly reduced the number of compaction without impacting the
> latency too much:
> !test11.png!
> The time window for TWCS is set to 2 minutes for the test.
> Here is the p99 latency impact:
> !test2.png!
> the yellow one is LCS, the purple one is TWCS. Average p99 has about 10%
> increase.
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