Return-Path: X-Original-To: apmail-hadoop-mapreduce-dev-archive@minotaur.apache.org Delivered-To: apmail-hadoop-mapreduce-dev-archive@minotaur.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id EBD434D2D for ; Fri, 1 Jul 2011 08:31:12 +0000 (UTC) Received: (qmail 46955 invoked by uid 500); 1 Jul 2011 08:31:10 -0000 Delivered-To: apmail-hadoop-mapreduce-dev-archive@hadoop.apache.org Received: (qmail 45335 invoked by uid 500); 1 Jul 2011 08:30:57 -0000 Mailing-List: contact mapreduce-dev-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: mapreduce-dev@hadoop.apache.org Delivered-To: mailing list mapreduce-dev@hadoop.apache.org Received: (qmail 45304 invoked by uid 99); 1 Jul 2011 08:30:51 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 01 Jul 2011 08:30:51 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=5.0 tests=ALL_TRUSTED,T_RP_MATCHES_RCVD X-Spam-Check-By: apache.org Received: from [140.211.11.116] (HELO hel.zones.apache.org) (140.211.11.116) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 01 Jul 2011 08:30:49 +0000 Received: from hel.zones.apache.org (hel.zones.apache.org [140.211.11.116]) by hel.zones.apache.org (Postfix) with ESMTP id 9279143D253 for ; Fri, 1 Jul 2011 08:30:29 +0000 (UTC) Date: Fri, 1 Jul 2011 08:30:29 +0000 (UTC) From: "Evert Lammerts (JIRA)" To: mapreduce-dev@hadoop.apache.org Message-ID: <1080614838.8121.1309509029596.JavaMail.tomcat@hel.zones.apache.org> Subject: [jira] [Created] (MAPREDUCE-2636) Scheduling over disks horizontally MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 Scheduling over disks horizontally ---------------------------------- Key: MAPREDUCE-2636 URL: https://issues.apache.org/jira/browse/MAPREDUCE-2636 Project: Hadoop Map/Reduce Issue Type: Improvement Components: job submission Reporter: Evert Lammerts Priority: Minor Based on this message: http://mail-archives.apache.org/mod_mbox/hadoop-hdfs-user/201106.mbox/browser The JT schedules tasks on nodes based on metadata it gets from the NN. The namenode does not know on which disk a block resides. It might happen that on a node running 4 tasks, all read from the same disk. This can affect performance. An optimization might be to schedule horizontally over disks instead of nodes. Any ideas? -- This message is automatically generated by JIRA. For more information on JIRA, see: http://www.atlassian.com/software/jira