[ https://issues.apache.org/jira/browse/HBASE-4714?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
stack updated HBASE-4714: ------------------------- Resolution: Fixed Hadoop Flags: Reviewed Status: Resolved (was: Patch Available) Committed trunk and 0.92 branch. Commit on trunk took two attempts because I committed more than just patch so backed it all out. Thanks for review J-D > Don't ship w/ icms enabled by default > ------------------------------------- > > Key: HBASE-4714 > URL: https://issues.apache.org/jira/browse/HBASE-4714 > Project: HBase > Issue Type: Task > Reporter: stack > Assignee: stack > Fix For: 0.92.0 > > Attachments: icms-v2.txt, icms.txt > > > "Incremental CMS (iCMS) was written for a specific use case - 1 or 2 hardware > threads where concurrent activity by CMS would look like a STW (if > only 1 hardware thread) or a high tax on the cpu cycles (2 hardware > threads). It has a higher overhead and also is less efficient in terms > of identifying garbage. The latter is because iCMS spreads out the > concurrent work so that objects that it has identified as live earlier > may actually be dead when the dead objects are swept up. It's > worth testing with regular CMS instead of iCMS." > From recent hotspot mailing list message. > Rare is the case where we run on systems of 1 or 2 hardware threads (other > than fellows laptops and there the above likely doesn't matter). -- 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