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Jonathan Ellis updated CASSANDRA-4310: -------------------------------------- Affects Version/s: (was: 1.1.2) (was: 1.1.1) 1.0.0 Fix Version/s: 1.2 Assignee: Yuki Morishita Summary: Multiple independent Level Compactions in Parallel (was: Multiple independent Level Compactions in Parallel(Useful for SSD). ) > Multiple independent Level Compactions in Parallel > -------------------------------------------------- > > Key: CASSANDRA-4310 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4310 > Project: Cassandra > Issue Type: New Feature > Components: Core > Affects Versions: 1.0.0 > Reporter: sankalp kohli > Assignee: Yuki Morishita > Labels: compaction, features, leveled, performance, ssd > Fix For: 1.2 > > > Problem: If you are inserting data into cassandra and level compaction cannot > catchup, you will create lot of files in L0. > Here is a solution which will help here and also increase the performance of > level compaction. > We can do many compactions in parallel for unrelated data. > 1) For no over lapping levels. Ex: when L0 stable is compacting with L1, we > can do compactions in other levels like L2 and L3 if they are eligible. > 2) We can also do compactions with files in L1 which are not participating in > L0 compactions. > This is specially useful if you are using SSD and is not bottlenecked by IO. > I am seeing this issue in my cluster. The compactions pending are more than > 50k and the disk usage is not that much(I am using SSD). > I am doing multithreaded to true and also not throttling the IO by putting > the value as 0. > -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira