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https://issues.apache.org/jira/browse/CASSANDRA-13508?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16746698#comment-16746698
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Blake Eggleston commented on CASSANDRA-13508:
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Keyspace level lwts would be cool, but I think they've always been more of a
pony than a feature anyone was seriously considering implementing. Implicitly
expanding paxos granularity from table/primary_key into keyspace/primary_key
isn't a good idea imo, since you can introduce cross table contention that
users don't necessarily need or want. Also, assuming keyspace lwts does become
a thing, splitting system.paxos up per table wouldn't necessarily preclude
them.
> Make system.paxos table compaction strategy configurable
> --------------------------------------------------------
>
> Key: CASSANDRA-13508
> URL: https://issues.apache.org/jira/browse/CASSANDRA-13508
> Project: Cassandra
> Issue Type: Improvement
> Components: Legacy/Coordination
> Reporter: Jay Zhuang
> Assignee: Jay Zhuang
> Priority: Major
> Labels: LWT, core, paxos
> Fix For: 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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