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 8A001185B6 for ; Thu, 25 Feb 2016 23:34:18 +0000 (UTC) Received: (qmail 71348 invoked by uid 500); 25 Feb 2016 23:34:18 -0000 Delivered-To: apmail-hadoop-mapreduce-issues-archive@hadoop.apache.org Received: (qmail 71255 invoked by uid 500); 25 Feb 2016 23:34:18 -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 71227 invoked by uid 99); 25 Feb 2016 23:34:18 -0000 Received: from arcas.apache.org (HELO arcas) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 25 Feb 2016 23:34:18 +0000 Received: from arcas.apache.org (localhost [127.0.0.1]) by arcas (Postfix) with ESMTP id 110A32C14F8 for ; Thu, 25 Feb 2016 23:34:18 +0000 (UTC) Date: Thu, 25 Feb 2016 23:34:18 +0000 (UTC) From: "Ray Chiang (JIRA)" To: mapreduce-issues@hadoop.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Commented] (MAPREDUCE-6622) Add capability to set JHS job cache to a task-based limit 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-6622?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15168112#comment-15168112 ] Ray Chiang commented on MAPREDUCE-6622: --------------------------------------- RE: Failing unit test MAPREDUCE-6625 has been filed for testCLI#testGetJob() > Add capability to set JHS job cache to a task-based limit > --------------------------------------------------------- > > Key: MAPREDUCE-6622 > URL: https://issues.apache.org/jira/browse/MAPREDUCE-6622 > Project: Hadoop Map/Reduce > Issue Type: Improvement > Components: jobhistoryserver > Affects Versions: 2.7.2 > Reporter: Ray Chiang > Assignee: Ray Chiang > Labels: supportability > Attachments: MAPREDUCE-6622.001.patch, MAPREDUCE-6622.002.patch, MAPREDUCE-6622.003.patch, MAPREDUCE-6622.004.patch, MAPREDUCE-6622.005.patch, MAPREDUCE-6622.006.patch, MAPREDUCE-6622.007.patch, MAPREDUCE-6622.008.patch, MAPREDUCE-6622.009.patch, MAPREDUCE-6622.010.patch > > > When setting the property mapreduce.jobhistory.loadedjobs.cache.size the jobs can be of varying size. This is generally not a problem when the jobs sizes are uniform or small, but when the job sizes can be very large (say greater than 250k tasks), then the JHS heap size can grow tremendously. > In cases, where multiple jobs are very large, then the JHS can lock up and spend all its time in GC. However, since the cache is holding on to all the jobs, not much heap space can be freed up. > By setting a property that sets a cap on the number of tasks allowed in the cache and since the total number of tasks loaded is directly proportional to the amount of heap used, this should help prevent the JHS from locking up. -- This message was sent by Atlassian JIRA (v6.3.4#6332)