[ https://issues.apache.org/jira/browse/HDFS-10335?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Tsz Wo Nicholas Sze updated HDFS-10335: --------------------------------------- Hadoop Flags: Reviewed +1 patch looks good. > Mover$Processor#chooseTarget() always chooses the first matching target > storage group > ------------------------------------------------------------------------------------- > > Key: HDFS-10335 > URL: https://issues.apache.org/jira/browse/HDFS-10335 > Project: Hadoop HDFS > Issue Type: Bug > Components: balancer & mover > Affects Versions: 2.8.0 > Reporter: Mingliang Liu > Assignee: Mingliang Liu > Priority: Critical > Attachments: HDFS-10335.000.patch > > > Currently the > {{org.apache.hadoop.hdfs.server.mover.Mover$Processor#chooseTarget()}} always > chooses the first matching target datanode from the candidate list. This may > make the mover schedule a lot of task to a few of the datanodes (first > several datanodes of the candidate list). The overall performance will suffer > significantly from this because of the saturated network/disk usage. > Specially, if the {{dfs.datanode.balance.max.concurrent.moves}} is set, the > scheduled move task will be queued on a few of the storage group, regardless > of other available storage groups. We need an algorithm which can distribute > the move tasks approximately even across all the candidate target storage > groups. > Thanks [~szetszwo] for offline discussion. -- This message was sent by Atlassian JIRA (v6.3.4#6332)