Tsz Wo Nicholas Sze created HDFS-8826: -----------------------------------------
Summary: Balancer may not move blocks efficiently in some cases Key: HDFS-8826 URL: https://issues.apache.org/jira/browse/HDFS-8826 Project: Hadoop HDFS Issue Type: Sub-task Components: balancer & mover Reporter: Tsz Wo Nicholas Sze Assignee: Tsz Wo Nicholas Sze Balancer is inefficient in the following case: || Datanode || Utilization || Rack || | D1 | 95% | A | | D2 | 30% | B | | D3, D4, D5 | 0% | B | The average utilization is 25% so that D2 is within 10% threshold. However, Balancer currently will first move blocks from D2 to D3, D4 and D5 since they are under the same rack. Then, it will move blocks from D1. -- This message was sent by Atlassian JIRA (v6.3.4#6332)