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Hadoop QA commented on HDFS-10335: ---------------------------------- | (x) *{color:red}-1 overall{color}* | \\ \\ || Vote || Subsystem || Runtime || Comment || | {color:blue}0{color} | {color:blue} reexec {color} | {color:blue} 0m 0s {color} | {color:blue} Docker mode activated. {color} | | {color:red}-1{color} | {color:red} docker {color} | {color:red} 0m 3s {color} | {color:red} Docker failed to build yetus/hadoop:7b1c37a. {color} | \\ \\ || Subsystem || Report/Notes || | JIRA Patch URL | https://issues.apache.org/jira/secure/attachment/12800935/HDFS-10335.000.patch | | JIRA Issue | HDFS-10335 | | Console output | https://builds.apache.org/job/PreCommit-HDFS-Build/15309/console | | Powered by | Apache Yetus 0.2.0 http://yetus.apache.org | This message was automatically generated. > 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)