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Oleg Anastasyev commented on CASSANDRA-1470: -------------------------------------------- Guys, may be I misunderstand something, but are we trying to make compaction writes faster ? This is background data maintenance process, and I think it is not very much important how fast is it. I think most important about it is how much it makes normal (read) requests serving slower, keeping valuable resources, especially memory, busy. Did we measured the impact of compaction on read requests of direct IO writes compaction vs old normal writes compaction ? > use direct io for compaction > ---------------------------- > > Key: CASSANDRA-1470 > URL: https://issues.apache.org/jira/browse/CASSANDRA-1470 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Jonathan Ellis > Assignee: Pavel Yaskevich > Fix For: 0.7.1 > > Attachments: 1470-v2.txt, 1470.txt, CASSANDRA-1470-for-0.6.patch, > CASSANDRA-1470-v10-for-0.7.patch, CASSANDRA-1470-v11-for-0.7.patch, > CASSANDRA-1470-v12-0.7.patch, CASSANDRA-1470-v2.patch, > CASSANDRA-1470-v3-0.7-with-LastErrorException-support.patch, > CASSANDRA-1470-v4-for-0.7.patch, CASSANDRA-1470-v5-for-0.7.patch, > CASSANDRA-1470-v6-for-0.7.patch, CASSANDRA-1470-v7-for-0.7.patch, > CASSANDRA-1470-v8-for-0.7.patch, CASSANDRA-1470-v9-for-0.7.patch, > CASSANDRA-1470.patch, > use.DirectIORandomAccessFile.for.commitlog.against.1022235.patch > > > When compaction scans through a group of sstables, it forces the data in the > os buffer cache being used for hot reads, which can have a dramatic negative > effect on performance. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.