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Hudson commented on HBASE-4714: ------------------------------- Integrated in HBase-TRUNK #2396 (See [https://builds.apache.org/job/HBase-TRUNK/2396/]) HBASE-4714 Don't ship w/ icms enabled by default; REDO HBASE-4714 Don't ship w/ icms enabled by default; REVERT -- I overcommitted by mistake HBASE-4714 Don't ship w/ icms enabled by default stack : Files : * /hbase/trunk/CHANGES.txt * /hbase/trunk/conf/hbase-env.sh * /hbase/trunk/src/docbkx/performance.xml stack : Files : * /hbase/trunk/CHANGES.txt * /hbase/trunk/conf/hbase-env.sh * /hbase/trunk/src/docbkx/performance.xml * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/HConstants.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/master/handler/CreateTableHandler.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/HMerge.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/Merge.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegionInfo.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestFSTableDescriptors.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestFSUtils.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestMergeTable.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestMergeTool.java stack : Files : * /hbase/trunk/CHANGES.txt * /hbase/trunk/conf/hbase-env.sh * /hbase/trunk/src/docbkx/performance.xml * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/HConstants.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/master/MasterFileSystem.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/master/handler/CreateTableHandler.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/FSTableDescriptors.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/FSUtils.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/HMerge.java * /hbase/trunk/src/main/java/org/apache/hadoop/hbase/util/Merge.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/master/TestMasterFailover.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/regionserver/TestHRegionInfo.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestFSTableDescriptors.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestFSUtils.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestMergeTable.java * /hbase/trunk/src/test/java/org/apache/hadoop/hbase/util/TestMergeTool.java > 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