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Jeff Jirsa commented on CASSANDRA-13508: ---------------------------------------- Also cc [~kohlisankalp] and [~bdeggleston] - both of whom have spent quite a bit of time thinking about paxos. I think LCS is better than TWCS, for read performance (if we have to go to disk), so I'm glad you've wont-fixed that. Tuning compaction (or compression, more likely, as dropping compression chunk size can be really helpful for read performance) may be useful, but I suspect your patch allows the altering of more than just properties - would also let users edit schema structure, which we should definitely prevent. > 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. -- This message was sent by Atlassian JIRA (v6.3.15#6346) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org