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Hadoop QA commented on HDFS-6268: --------------------------------- {color:green}+1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12648051/hdfs-6268-5.patch 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 4 new or modified test files. {color:green}+1 javac{color}. The applied patch does not increase the total number of javac compiler warnings. {color:green}+1 javadoc{color}. There were no new javadoc warning messages. {color:green}+1 eclipse:eclipse{color}. The patch built with eclipse:eclipse. {color:green}+1 findbugs{color}. The patch does not introduce any 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:green}+1 core tests{color}. The patch passed unit tests in hadoop-common-project/hadoop-common hadoop-hdfs-project/hadoop-hdfs. {color:green}+1 contrib tests{color}. The patch passed contrib unit tests. Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/7029//testReport/ Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/7029//console This message is automatically generated. > Better sorting in NetworkTopology#pseudoSortByDistance when no local node is > found > ---------------------------------------------------------------------------------- > > Key: HDFS-6268 > URL: https://issues.apache.org/jira/browse/HDFS-6268 > Project: Hadoop HDFS > Issue Type: Improvement > Affects Versions: 2.4.0 > Reporter: Andrew Wang > Assignee: Andrew Wang > Priority: Minor > Attachments: hdfs-6268-1.patch, hdfs-6268-2.patch, hdfs-6268-3.patch, > hdfs-6268-4.patch, hdfs-6268-5.patch > > > In NetworkTopology#pseudoSortByDistance, if no local node is found, it will > always place the first rack local node in the list in front. > This became an issue when a dataset was loaded from a single datanode. This > datanode ended up being the first replica for all the blocks in the dataset. > When running an Impala query, the non-local reads when reading past a block > boundary were all hitting this node, meaning massive load skew. -- This message was sent by Atlassian JIRA (v6.2#6252)