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Hadoop QA commented on HBASE-13082: ----------------------------------- {color:green}+1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12774054/HBASE-13082_17.patch against master branch at commit 0bae444b34b6be3a28b5ccc036afb5add23818c6. ATTACHMENT ID: 12774054 {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 46 new or modified tests. {color:green}+1 hadoop versions{color}. The patch compiles with all supported hadoop versions (2.4.0 2.4.1 2.5.0 2.5.1 2.5.2 2.6.0 2.6.1 2.7.0 2.7.1) {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:green}+1 protoc{color}. The applied patch does not increase the total number of protoc compiler warnings. {color:green}+1 javadoc{color}. The javadoc tool did not generate any warning messages. {color:green}+1 checkstyle{color}. The applied patch does not increase the total number of checkstyle errors {color:green}+1 findbugs{color}. The patch does not introduce any new Findbugs (version 2.0.3) warnings. {color:green}+1 release audit{color}. The applied patch does not increase the total number of release audit warnings. {color:green}+1 lineLengths{color}. The patch does not introduce lines longer than 100 {color:green}+1 site{color}. The mvn post-site goal succeeds with this patch. {color:green}+1 core tests{color}. The patch passed unit tests in . Test results: https://builds.apache.org/job/PreCommit-HBASE-Build/16651//testReport/ Release Findbugs (version 2.0.3) warnings: https://builds.apache.org/job/PreCommit-HBASE-Build/16651//artifact/patchprocess/newFindbugsWarnings.html Checkstyle Errors: https://builds.apache.org/job/PreCommit-HBASE-Build/16651//artifact/patchprocess/checkstyle-aggregate.html Console output: https://builds.apache.org/job/PreCommit-HBASE-Build/16651//console This message is automatically generated. > Coarsen StoreScanner locks to RegionScanner > ------------------------------------------- > > Key: HBASE-13082 > URL: https://issues.apache.org/jira/browse/HBASE-13082 > Project: HBase > Issue Type: Bug > Reporter: Lars Hofhansl > Assignee: ramkrishna.s.vasudevan > Attachments: 13082-test.txt, 13082-v2.txt, 13082-v3.txt, > 13082-v4.txt, 13082.txt, 13082.txt, HBASE-13082.pdf, HBASE-13082_1.pdf, > HBASE-13082_12.patch, HBASE-13082_13.patch, HBASE-13082_14.patch, > HBASE-13082_15.patch, HBASE-13082_16.patch, HBASE-13082_17.patch, > HBASE-13082_1_WIP.patch, HBASE-13082_2.pdf, HBASE-13082_2_WIP.patch, > HBASE-13082_3.patch, HBASE-13082_4.patch, HBASE-13082_9.patch, > HBASE-13082_9.patch, HBASE-13082_withoutpatch.jpg, HBASE-13082_withpatch.jpg, > LockVsSynchronized.java, gc.png, gc.png, gc.png, hits.png, next.png, next.png > > > Continuing where HBASE-10015 left of. > We can avoid locking (and memory fencing) inside StoreScanner by deferring to > the lock already held by the RegionScanner. > In tests this shows quite a scan improvement and reduced CPU (the fences make > the cores wait for memory fetches). > There are some drawbacks too: > * All calls to RegionScanner need to be remain synchronized > * Implementors of coprocessors need to be diligent in following the locking > contract. For example Phoenix does not lock RegionScanner.nextRaw() and > required in the documentation (not picking on Phoenix, this one is my fault > as I told them it's OK) > * possible starving of flushes and compaction with heavy read load. > RegionScanner operations would keep getting the locks and the > flushes/compactions would not be able finalize the set of files. > I'll have a patch soon. -- This message was sent by Atlassian JIRA (v6.3.4#6332)