[ https://issues.apache.org/jira/browse/HADOOP-1652?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12548389 ]
Hadoop QA commented on HADOOP-1652: ----------------------------------- -1 overall. Here are the results of testing the latest attachment http://issues.apache.org/jira/secure/attachment/12370962/balancer5.patch against trunk revision r601038. @author +1. The patch does not contain any @author tags. javadoc +1. The javadoc tool did not generate any warning messages. javac +1. The applied patch does not generate any new compiler warnings. findbugs -1. The patch appears to introduce 9 new Findbugs warnings. core tests +1. The patch passed core unit tests. contrib tests -1. The patch failed contrib unit tests. Test results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1259/testReport/ Findbugs warnings: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1259/artifact/trunk/build/test/findbugs/newPatchFindbugsWarnings.html Checkstyle results: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1259/artifact/trunk/build/test/checkstyle-errors.html Console output: http://lucene.zones.apache.org:8080/hudson/job/Hadoop-Patch/1259/console This message is automatically generated. > Rebalance data blocks when new data nodes added or data nodes become full > ------------------------------------------------------------------------- > > Key: HADOOP-1652 > URL: https://issues.apache.org/jira/browse/HADOOP-1652 > Project: Hadoop > Issue Type: New Feature > Components: dfs > Affects Versions: 0.13.0 > Reporter: Hairong Kuang > Assignee: Hairong Kuang > Fix For: 0.16.0 > > Attachments: balancer.patch, balancer1.patch, balancer2.patch, > balancer3.patch, balancer4.patch, balancer5.patch, BalancerAdminGuide.pdf, > BalancerAdminGuide1.pdf, BalancerUserGuide2.pdf, RebalanceDesign4.pdf, > RebalanceDesign5.pdf, RebalanceDesign6.pdf > > > When a new data node joins hdfs cluster, it does not hold much data. So any > map task assigned to the machine most likely does not read local data, thus > increasing the use of network bandwidth. On the other hand, when some data > nodes become full, new data blocks are placed on only non-full data nodes, > thus reducing their read parallelism. > This jira aims to find an approach to redistribute data blocks when imbalance > occurs in the cluster. An solution should meet the following requirements: > 1. It maintains data availablility guranteens in the sense that rebalancing > does not reduce the number of replicas that a block has or the number of > racks that the block resides. > 2. An adminstrator should be able to invoke and interrupt rebalancing from a > command line. > 3. Rebalancing should be throttled so that rebalancing does not cause a > namenode to be too busy to serve any incoming request or saturate the network. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.