Return-Path: X-Original-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 7A51718BD5 for ; Wed, 27 Apr 2016 02:14:13 +0000 (UTC) Received: (qmail 98122 invoked by uid 500); 27 Apr 2016 02:14:13 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 98065 invoked by uid 500); 27 Apr 2016 02:14:13 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 98052 invoked by uid 99); 27 Apr 2016 02:14:13 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 27 Apr 2016 02:14:13 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id CAE942C1F54 for ; Wed, 27 Apr 2016 02:14:12 +0000 (UTC) Date: Wed, 27 Apr 2016 02:14:12 +0000 (UTC) From: "Mingliang Liu (JIRA)" To: hdfs-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Work started] (HDFS-10335) Mover$Processor#chooseTarget() always chooses the first matching target storage group MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/HDFS-10335?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Work on HDFS-10335 started by Mingliang Liu. -------------------------------------------- > Mover$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 > > 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)