Return-Path: X-Original-To: apmail-hadoop-mapreduce-issues-archive@minotaur.apache.org Delivered-To: apmail-hadoop-mapreduce-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 DBB5BE6A2 for ; Fri, 21 Dec 2012 18:45:14 +0000 (UTC) Received: (qmail 35022 invoked by uid 500); 21 Dec 2012 18:45:14 -0000 Delivered-To: apmail-hadoop-mapreduce-issues-archive@hadoop.apache.org Received: (qmail 34975 invoked by uid 500); 21 Dec 2012 18:45:14 -0000 Mailing-List: contact mapreduce-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: mapreduce-issues@hadoop.apache.org Delivered-To: mailing list mapreduce-issues@hadoop.apache.org Received: (qmail 34925 invoked by uid 99); 21 Dec 2012 18:45:14 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 21 Dec 2012 18:45:14 +0000 Date: Fri, 21 Dec 2012 18:45:14 +0000 (UTC) From: "Mariappan Asokan (JIRA)" To: mapreduce-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (MAPREDUCE-4842) Shuffle race can hang reducer 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/MAPREDUCE-4842?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13538290#comment-13538290 ] Mariappan Asokan commented on MAPREDUCE-4842: --------------------------------------------- Hi Jason, It was a pleasure working with all of you. I know this race condition is very hard to reproduce let alone debug. You did an excellent job. All your feedback and challenges encouraged me to find the best possible solution. -- Asokan > Shuffle race can hang reducer > ----------------------------- > > Key: MAPREDUCE-4842 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-4842 > Project: Hadoop Map/Reduce > Issue Type: Bug > Components: mrv2 > Affects Versions: 2.0.2-alpha, 0.23.5 > Reporter: Jason Lowe > Assignee: Mariappan Asokan > Priority: Blocker > Fix For: 2.0.3-alpha, 0.23.6 > > Attachments: MAPREDUCE-4842-2.patch, mapreduce-4842.patch, mapreduce-4842.patch, mapreduce-4842.patch, mapreduce-4842.patch, mapreduce-4842.patch, mapreduce-4842.patch, MAPREDUCE-4842.patch, MAPREDUCE-4842.patch, MAPREDUCE-4842.patch, MAPREDUCE-4842.patch > > > Saw an instance where the shuffle caused multiple reducers in a job to hang. It looked similar to the problem described in MAPREDUCE-3721, where the fetchers were all being told to WAIT by the MergeManager but no merge was taking place. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira