[ https://issues.apache.org/jira/browse/HDFS-6840?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14139797#comment-14139797 ]
Hadoop QA commented on HDFS-6840: --------------------------------- {color:red}-1 overall{color}. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12669817/hdfs-6840.003.patch against trunk revision eb92cc6. {color:green}+1 @author{color}. The patch does not contain any @author tags. {color:green}+1 tests included{color}. The patch appears to include 2 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 2.0.3) 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 in hadoop-common-project/hadoop-common hadoop-hdfs-project/hadoop-hdfs: org.apache.hadoop.hdfs.TestEncryptionZonesWithKMS org.apache.hadoop.hdfs.web.TestWebHdfsFileSystemContract org.apache.hadoop.hdfs.server.namenode.ha.TestPipelinesFailover {color:green}+1 contrib tests{color}. The patch passed contrib unit tests. Test results: https://builds.apache.org/job/PreCommit-HDFS-Build/8090//testReport/ Console output: https://builds.apache.org/job/PreCommit-HDFS-Build/8090//console This message is automatically generated. > Clients are always sent to the same datanode when read is off rack > ------------------------------------------------------------------ > > Key: HDFS-6840 > URL: https://issues.apache.org/jira/browse/HDFS-6840 > Project: Hadoop HDFS > Issue Type: Bug > Affects Versions: 2.5.0 > Reporter: Jason Lowe > Assignee: Andrew Wang > Priority: Critical > Attachments: hdfs-6840.001.patch, hdfs-6840.002.patch, > hdfs-6840.003.patch > > > After HDFS-6268 the sorting order of block locations is deterministic for a > given block and locality level (e.g.: local, rack. off-rack), so off-rack > clients all see the same datanode for the same block. This leads to very > poor behavior in distributed cache localization and other scenarios where > many clients all want the same block data at approximately the same time. > The one datanode is crushed by the load while the other replicas only handle > local and rack-local requests. -- This message was sent by Atlassian JIRA (v6.3.4#6332)