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Vijay commented on CASSANDRA-3623: ---------------------------------- constant performance => not a lot of difference from 95th percentile and Average. Before patch there was a huge swing between those. Data is shown above. Plz note i am not selling this patch ;) I am trying to find a better performance for our use case which needs compression... I am completely open for other options. > use MMapedBuffer in CompressedSegmentedFile.getSegment > ------------------------------------------------------ > > Key: CASSANDRA-3623 > URL: https://issues.apache.org/jira/browse/CASSANDRA-3623 > Project: Cassandra > Issue Type: Improvement > Components: Core > Affects Versions: 1.1 > Reporter: Vijay > Assignee: Vijay > Labels: compression > Fix For: 1.1 > > Attachments: 0001-MMaped-Compression-segmented-file-v2.patch, > 0001-MMaped-Compression-segmented-file.patch, > 0002-tests-for-MMaped-Compression-segmented-file-v2.patch > > > CompressedSegmentedFile.getSegment seem to open a new file and doesnt seem to > use the MMap and hence a higher CPU on the nodes and higher latencies on > reads. > This ticket is to implement the TODO mentioned in CompressedRandomAccessReader > // TODO refactor this to separate concept of "buffer to avoid lots of read() > syscalls" and "compression buffer" > but i think a separate class for the Buffer will be better. -- 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