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Hadoop QA commented on HDFS-6022: --------------------------------- \\ \\ | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | pre-patch | 18m 31s | Pre-patch trunk compilation is healthy. | | {color:green}+1{color} | @author | 0m 0s | The patch does not contain any @author tags. | | {color:green}+1{color} | tests included | 0m 0s | The patch appears to include 1 new or modified test files. | | {color:green}+1{color} | javac | 7m 30s | There were no new javac warning messages. | | {color:green}+1{color} | javadoc | 9m 38s | There were no new javadoc warning messages. | | {color:green}+1{color} | release audit | 0m 22s | The applied patch does not increase the total number of release audit warnings. | | {color:red}-1{color} | checkstyle | 1m 51s | The applied patch generated 1 new checkstyle issues (total was 35, now 36). | | {color:red}-1{color} | whitespace | 0m 0s | The patch has 2 line(s) that end in whitespace. Use git apply --whitespace=fix. | | {color:green}+1{color} | install | 1m 36s | mvn install still works. | | {color:green}+1{color} | eclipse:eclipse | 0m 32s | The patch built with eclipse:eclipse. | | {color:green}+1{color} | findbugs | 4m 7s | The patch does not introduce any new Findbugs (version 3.0.0) warnings. | | {color:green}+1{color} | native | 3m 15s | Pre-build of native portion | | {color:green}+1{color} | hdfs tests | 162m 4s | Tests passed in hadoop-hdfs. | | {color:green}+1{color} | hdfs tests | 0m 16s | Tests passed in hadoop-hdfs-client. | | | | 209m 46s | | \\ \\ || Subsystem || Report/Notes || | Patch URL | http://issues.apache.org/jira/secure/attachment/12740024/HDFS-6022.002.patch | | Optional Tests | javadoc javac unit findbugs checkstyle | | git revision | trunk / 5dbc8c9 | | checkstyle | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/artifact/patchprocess/diffcheckstylehadoop-hdfs-client.txt | | whitespace | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/artifact/patchprocess/whitespace.txt | | hadoop-hdfs test log | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/artifact/patchprocess/testrun_hadoop-hdfs.txt | | hadoop-hdfs-client test log | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/artifact/patchprocess/testrun_hadoop-hdfs-client.txt | | Test Results | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/testReport/ | | Java | 1.7.0_55 | | uname | Linux asf900.gq1.ygridcore.net 3.13.0-36-lowlatency #63-Ubuntu SMP PREEMPT Wed Sep 3 21:56:12 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux | | Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/11380/console | This message was automatically generated. > Moving deadNodes from being thread local. Improving dead datanode handling in > DFSClient > ---------------------------------------------------------------------------------------- > > Key: HDFS-6022 > URL: https://issues.apache.org/jira/browse/HDFS-6022 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client > Affects Versions: 3.0.0, 0.23.9, 0.23.10, 2.2.0, 2.3.0 > Reporter: Jack Levin > Assignee: Masatake Iwasaki > Labels: patch > Attachments: HADOOP-6022.patch, HDFS-6022.002.patch > > Original Estimate: 0h > Remaining Estimate: 0h > > This patch solves an issue of deadNodes list being thread local. deadNodes > list is created by DFSClient when some problems with write/reading, or > contacting datanode exist. The problem is that deadNodes is not visible to > other DFSInputStream threads, hence every DFSInputStream ends up building its > own deadNodes. This affect performance of DFSClient to a large degree > especially when a datanode goes completely offline (there is a tcp connect > delay experienced by all DFSInputStream threads affecting performance of the > whole cluster). > This patch moves deadNodes to be global in DFSClient class so that as soon as > a single DFSInputStream thread reports a dead datanode, all other > DFSInputStream threads are informed, negating the need to create their own > independent lists (concurrent Map really). > Further, a global deadNodes health check manager thread (DeadNodeVerifier) is > created to verify all dead datanodes every 5 seconds, and remove the same > list as soon as it is up. That thread under normal conditions (deadNodes > empty) would be sleeping. If deadNodes is not empty, the thread will attempt > to open tcp connection every 5 seconds to affected datanodes. > This patch has a test (TestDFSClientDeadNodes) that is quite simple, since > the deadNodes creation is not affected by the patch, we only test datanode > removal from deadNodes by the health check manager thread. Test will create > a file in dfs minicluster, read from the same file rapidly, cause datanode to > restart, and test is the health check manager thread does the right thing, > removing the alive datanode from the global deadNodes list. -- This message was sent by Atlassian JIRA (v6.3.4#6332)