[ https://issues.apache.org/jira/browse/CASSANDRA-4937?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Sylvain Lebresne updated CASSANDRA-4937: ---------------------------------------- Fix Version/s: (was: 1.2.2) 1.2.3 > CRAR improvements (object cache + CompressionMetadata chunk offset storage > moved off-heap). > ------------------------------------------------------------------------------------------- > > Key: CASSANDRA-4937 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4937 > Project: Cassandra > Issue Type: Improvement > Reporter: Pavel Yaskevich > Assignee: Pavel Yaskevich > Labels: core > Fix For: 1.2.3 > > Attachments: 4937-v3.txt, CASSANDRA-4937.patch, > CASSANDRA-4937-trunk.patch > > > After good amount of testing on one of the clusters it was found that in > order to improve read latency we need to minimize allocation rate that > compression involves, that minimizes GC (as well as heap usage) and > substantially decreases latency on read heavy workloads. > I have also discovered that RAR skip cache harms performance in situation > when reads are done in parallel with compaction working with relatively big > SSTable files (few GB and more). The attached patch removes possibility to > skip cache from compressed files (I can also add changes to RAR to remove > skip cache functionality as a separate patch). -- 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