[ https://issues.apache.org/jira/browse/HADOOP-1652?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Hairong Kuang updated HADOOP-1652: ---------------------------------- Attachment: balancer8.patch The patch has a minor change to make the junit test to run faster. > 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, balancer6.patch, > balancer7.patch, balancer8.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.