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https://issues.apache.org/jira/browse/CASSANDRA-13508?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16018140#comment-16018140
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Blake Eggleston commented on CASSANDRA-13508:
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I agree, LCS is probably the better choice, which is the default in trunk. I
think being able to tune the paxos table might not be a bad idea, given how
heavily it can be used in some systems, but it also has some risks. First,
supporting it won't be straightforward. System table schemas are hardcoded (see
{{SystemKeyspace}}), so just allowing alter table statements against them isn't
enough. Any changes you make will be lost after a node restart. Storing system
table schemas as regular tables is also a non-starter. Any user configurable
system properties are something that would have to be configured in
cassandra.yaml or something, which for non-replicated tables, isn't terrible
(and not the same thing as the schema.xml file used ca 0.6 this will remind
people of). [~iamaleksey], do you have any thoughts on this?
> 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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