[ https://issues.apache.org/jira/browse/CASSANDRA-3610?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Jonathan Ellis reopened CASSANDRA-3610: --------------------------------------- We still do a lot of int and long CRC updates in the commitlog though. Seems like that would be a better fit for the pure java implementation, which still does better for <= 64 bytes. > Checksum improvement for CompressedRandomAccessReader > ----------------------------------------------------- > > Key: CASSANDRA-3610 > URL: https://issues.apache.org/jira/browse/CASSANDRA-3610 > Project: Cassandra > Issue Type: Improvement > Components: Core > Affects Versions: 1.1.0 > Environment: JVM > Reporter: Vijay > Assignee: Vijay > Priority: Minor > Fix For: 1.1.1 > > Attachments: 0001-use-pure-java-CRC32-v2.patch, > 0001-use-pure-java-CRC32-v3.patch, 0001-use-pure-java-CRC32.patch, > TestCrc32Performance.java, TestCrc32Performance.java, crc32Test.xlsx > > > When compression is on, Currently we see checksum taking up about 40% of the > CPU more than snappy library. > Looks like hadoop solved it by implementing their own checksum, we can either > use it or implement something like that. > http://images.slidesharecdn.com/1toddlipconyanpeichen-cloudera-hadoopandperformance-final-111110132228-phpapp01-slide-15-768.jpg?1321043717 > in our test env it provided 50% improvement over native implementation which > uses jni to call the OS. -- 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