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Hadoop QA commented on HBASE-5898: ---------------------------------- {color:red}-1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12553057/5898-v3.txt against trunk revision . {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 3 new or modified tests. {color:green}+1 hadoop2.0{color}. The patch compiles against the hadoop 2.0 profile. {color:red}-1 javadoc{color}. The javadoc tool appears to have generated 87 warning messages. {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:red}-1 findbugs{color}. The patch appears to introduce 17 new Findbugs (version 1.3.9) warnings. {color:green}+1 release audit{color}. The applied patch does not increase the total number of release audit warnings. {color:red}-1 core tests{color}. The patch failed these unit tests: org.apache.hadoop.hbase.client.TestFromClientSide org.apache.hadoop.hbase.client.TestFromClientSideWithCoprocessor Test results: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//testReport/ Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-hadoop2-compat.html Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-examples.html Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-server.html Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-hadoop1-compat.html Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-common.html Findbugs warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//artifact/trunk/patchprocess/newPatchFindbugsWarningshbase-hadoop-compat.html Console output: https://builds.apache.org/job/PreCommit-HBASE-Build/3308//console This message is automatically generated. > Consider double-checked locking for block cache lock > ---------------------------------------------------- > > Key: HBASE-5898 > URL: https://issues.apache.org/jira/browse/HBASE-5898 > Project: HBase > Issue Type: Improvement > Components: Performance > Affects Versions: 0.94.1 > Reporter: Todd Lipcon > Assignee: Todd Lipcon > Priority: Critical > Fix For: 0.94.3, 0.96.0 > > Attachments: 5898-TestBlocksRead.txt, 5898-v2.txt, 5898-v3.txt, > HBASE-5898-0.patch, HBASE-5898-1.patch, HBASE-5898-1.patch, hbase-5898.txt > > > Running a workload with a high query rate against a dataset that fits in > cache, I saw a lot of CPU being used in IdLock.getLockEntry, being called by > HFileReaderV2.readBlock. Even though it was all cache hits, it was wasting a > lot of CPU doing lock management here. I wrote a quick patch to switch to a > double-checked locking and it improved throughput substantially for this > workload. -- 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