You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@cassandra.apache.org by "Jonathan Ellis (JIRA)" <ji...@apache.org> on 2011/09/21 01:52:08 UTC
[jira] [Updated] (CASSANDRA-3234) LeveledCompaction has several
performance problems
[ https://issues.apache.org/jira/browse/CASSANDRA-3234?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis updated CASSANDRA-3234:
--------------------------------------
Attachment: 0002-fix-leveled-BF-size-calculation.txt
0001-optimize-single-source-case-for-MergeIterator.txt
> LeveledCompaction has several performance problems
> --------------------------------------------------
>
> Key: CASSANDRA-3234
> URL: https://issues.apache.org/jira/browse/CASSANDRA-3234
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.0.0
> Reporter: Jonathan Ellis
> Assignee: Jonathan Ellis
> Fix For: 1.0.0
>
> Attachments: 0001-optimize-single-source-case-for-MergeIterator.txt, 0002-fix-leveled-BF-size-calculation.txt
>
>
> Two main problems:
> - BF size calculation doesn't take into account LCS breaking the output apart into "bite sized" sstables, so memory use is much higher than predicted
> - ManyToMany merging is slow. At least part of this is from running the full reducer machinery against single input sources, which can be optimized away.
--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira