[ https://issues.apache.org/jira/browse/CASSANDRA-5342?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Wei Zhu updated CASSANDRA-5342: ------------------------------- Attachment: Screen Shot 2013-03-13 at 12.05.08 PM.png > 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: 1.1.10, 1.2.2 > Reporter: Wei Zhu > 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