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 2013/06/14 06:20:20 UTC
[jira] [Assigned] (CASSANDRA-5342) ancestors are not cleared in
SSTableMetadata after compactions are done and old SSTables are removed
[ https://issues.apache.org/jira/browse/CASSANDRA-5342?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis reassigned CASSANDRA-5342:
-----------------------------------------
Assignee: Marcus Eriksson
> ancestors are not cleared in SSTableMetadata after compactions are done and old SSTables are removed
> ----------------------------------------------------------------------------------------------------
>
> Key: CASSANDRA-5342
> URL: https://issues.apache.org/jira/browse/CASSANDRA-5342
> Project: Cassandra
> Issue Type: Bug
> Components: Core
> Affects Versions: 1.1.3
> Reporter: Wei Zhu
> Assignee: Marcus Eriksson
> Fix For: 1.2.6
>
> Attachments: Screen Shot 2013-03-13 at 12.05.08 PM.png
>
>
> We are using LCS and have total of 38000 SSTables for one CF. During LCS, there could be over a thousand SSTable involved. All those SSTable IDs are stored in ancestors field of SSTableMetatdata for the new table. In our case, it consumes more than 1G of heap memory for those field. Put it in perspective, the ancestors consume 2 - 3 times more memory than bloomfilter (fp = 0.1 by default) in LCS.
> We should remove those ancestors from SSTableMetadata after the compaction is finished and the old SSTable is removed. It might be a big deal for Sized Compaction since there are small number of SSTable involved. But it consumes a lot of memory for LCS.
> At least, we shouldn't load those ancestors to the memory during startup if the files are removed.
> I would love to contribute and provide patch. Please let me know how to start.
--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira