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Hadoop QA commented on HDFS-13157: ---------------------------------- | (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} patch {color} | {color:red} 0m 5s{color} | {color:red} https://github.com/apache/hadoop/pull/1391 does not apply to trunk. Rebase required? Wrong Branch? See https://wiki.apache.org/hadoop/HowToContribute for help. {color} | \\ \\ || Subsystem || Report/Notes || | GITHUB PR | https://github.com/apache/hadoop/pull/1391 | | JIRA Issue | HDFS-13157 | | Console output | https://ci-hadoop.apache.org/job/hadoop-multibranch/job/PR-1391/3/console | | versions | git=2.17.1 | | Powered by | Apache Yetus 0.12.0 https://yetus.apache.org | This message was automatically generated. > Do Not Remove Blocks Sequentially During Decommission > ------------------------------------------------------ > > Key: HDFS-13157 > URL: https://issues.apache.org/jira/browse/HDFS-13157 > Project: Hadoop HDFS > Issue Type: Improvement > Components: datanode, namenode > Affects Versions: 3.0.0 > Reporter: David Mollitor > Assignee: David Mollitor > Priority: Major > Attachments: HDFS-13157.1.patch > > > From what I understand of [DataNode > decommissioning|https://github.com/apache/hadoop/blob/42a1c98597e6dba2e371510a6b2b6b1fb94e4090/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeAdminManager.java] > it appears that all the blocks are scheduled for removal _in order._. I'm > not 100% sure what the ordering is exactly, but I think it loops through each > data volume and schedules each block to be replicated elsewhere. The net > affect is that during a decommission, all of the DataNode transfer threads > slam on a single volume until it is cleaned out. At which point, they all > slam on the next volume, etc. > Please randomize the block list so that there is a more even distribution > across all volumes when decommissioning a node. -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org