[ https://issues.apache.org/jira/browse/CASSANDRA-1470?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12969794#action_12969794 ]
Pavel Yaskevich commented on CASSANDRA-1470: -------------------------------------------- Test using -S 2048 on writes byte[] | Direct I/O (this shows elapsed_time) ----------------------------- write | 33 | 73 ----------------------------- read | 90 | 89 ----------------------------- read | 39 | 58 ----------------------------- write | 35 | 74 ----------------------------- read | 132 | 56 ----------------------------- Speaks for itself :) > 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.