Return-Path: X-Original-To: apmail-hadoop-common-user-archive@www.apache.org Delivered-To: apmail-hadoop-common-user-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id D0D0697DC for ; Fri, 11 May 2012 17:48:08 +0000 (UTC) Received: (qmail 48660 invoked by uid 500); 11 May 2012 17:48:05 -0000 Delivered-To: apmail-hadoop-common-user-archive@hadoop.apache.org Received: (qmail 48590 invoked by uid 500); 11 May 2012 17:48:05 -0000 Mailing-List: contact common-user-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: common-user@hadoop.apache.org Delivered-To: mailing list common-user@hadoop.apache.org Received: (qmail 48582 invoked by uid 99); 11 May 2012 17:48:05 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 May 2012 17:48:05 +0000 X-ASF-Spam-Status: No, hits=-0.7 required=5.0 tests=RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of lleung@ddn.com designates 74.62.46.229 as permitted sender) Received: from [74.62.46.229] (HELO mail.datadirectnet.com) (74.62.46.229) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 11 May 2012 17:47:57 +0000 Received: from MAILBOXCLUSTER.datadirect.datadirectnet.com ([10.8.16.28]) by dermtp01.datadirect.datadirectnet.com ([10.8.16.38]) with mapi; Fri, 11 May 2012 10:48:32 -0700 From: Leo Leung To: "common-user@hadoop.apache.org" Date: Fri, 11 May 2012 10:48:32 -0700 Subject: RE: Question on MapReduce Thread-Topic: Question on MapReduce Thread-Index: Ac0vlmaHWHcuVFyWSOaFrumDhXBFQQABuYyA Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Nope, you must tune the config on that specific super node to have more M/R= slots (this is for 1.0.x) This does not mean the JobTracker will be eager to stuff that super node wi= th all the M/R jobs at hand. It still goes through the scheduler, Capacity Scheduler is most likely wha= t you have. (check your config) IMO, If the data locality is not going to be there, your cluster is going t= o suffer from Network I/O. -----Original Message----- From: Satheesh Kumar [mailto:nkseam@gmail.com]=20 Sent: Friday, May 11, 2012 9:51 AM To: common-user@hadoop.apache.org Subject: Question on MapReduce Hi, I am a newbie on Hadoop and have a quick question on optimal compute vs. storage resources for MapReduce. If I have a multiprocessor node with 4 processors, will Hadoop schedule hig= her number of Map or Reduce tasks on the system than on a uni-processor sys= tem? In other words, does Hadoop detect denser systems and schedule denser = tasks on multiprocessor systems? If yes, will that imply that it makes sense to attach higher capacity stora= ge to store more number of blocks on systems with dense compute? Any insights will be very useful. Thanks, Satheesh