From common-dev-return-74387-apmail-hadoop-common-dev-archive=hadoop.apache.org@hadoop.apache.org Thu Oct 14 17:06:57 2010 Return-Path: Delivered-To: apmail-hadoop-common-dev-archive@www.apache.org Received: (qmail 95134 invoked from network); 14 Oct 2010 17:06:56 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 14 Oct 2010 17:06:56 -0000 Received: (qmail 58769 invoked by uid 500); 14 Oct 2010 17:06:55 -0000 Delivered-To: apmail-hadoop-common-dev-archive@hadoop.apache.org Received: (qmail 58705 invoked by uid 500); 14 Oct 2010 17:06:55 -0000 Mailing-List: contact common-dev-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: common-dev@hadoop.apache.org Delivered-To: mailing list common-dev@hadoop.apache.org Received: (qmail 58697 invoked by uid 99); 14 Oct 2010 17:06:54 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 14 Oct 2010 17:06:54 +0000 X-ASF-Spam-Status: No, hits=2.2 required=10.0 tests=FREEMAIL_FROM,HTML_MESSAGE,RCVD_IN_DNSWL_NONE,SPF_PASS,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: apache.org Received-SPF: pass (nike.apache.org: domain of airbots@gmail.com designates 209.85.161.48 as permitted sender) Received: from [209.85.161.48] (HELO mail-fx0-f48.google.com) (209.85.161.48) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 14 Oct 2010 17:06:47 +0000 Received: by fxm13 with SMTP id 13so2176369fxm.35 for ; Thu, 14 Oct 2010 10:06:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:date:message-id :subject:from:to:content-type; bh=H+XmACGvsLomSxbHWlD9gYCsd+eTIctSprXMsZ0TBgk=; b=MnHNb7at+avhpUrei9BxkrFMbyNBjhUi9qMs8ifjIidsxx+iXVibyJLBVcjrq03spD ne9jPk/+CaEx+jOvvO5m3E2oqb5MsKpK4cPtPHYAwCY5qAfySg/imccXWZUmdI44KG6W knpwMcjww40vfwFj7xkn0smAuCTFyyoCCNsw0= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:date:message-id:subject:from:to:content-type; b=f38AdisU/CfbSRDrDZAxg2Hh8JXsVhYtKYDhtHQjHp5P0fyiW/rTa92bQCOuCrUcOT 5OAOUlWKxp7Qt+JT0FGZsGfO6Tz8odkAo6jnyTBsN5CFJECsTr3lYvbgQyD8pH7+5CFz Scouh1NUqJ/nrBHie3Tp4C+jeqzWOF2eW0eMc= MIME-Version: 1.0 Received: by 10.216.10.5 with SMTP id 5mr10207709weu.81.1287075986681; Thu, 14 Oct 2010 10:06:26 -0700 (PDT) Received: by 10.216.85.79 with HTTP; Thu, 14 Oct 2010 10:06:26 -0700 (PDT) Date: Thu, 14 Oct 2010 12:06:26 -0500 Message-ID: Subject: Hadoop's deafult FIFO scheduler From: He Chen To: common-dev@hadoop.apache.org Content-Type: multipart/alternative; boundary=001636498f31fc31bc049296baea X-Virus-Checked: Checked by ClamAV on apache.org --001636498f31fc31bc049296baea Content-Type: text/plain; charset=ISO-8859-1 Hi all I am testing the performance of my Hadoop clsuters with Hadoop Default FIFO schedular. But I find a interesting phenomina. When I submit a series of jobs, some job will be executed earlier even they are submitted late. All jobs are request same amount of blocks. For example: job 1 submit at time 0 job 2 submit at time 1 job 3 submit at time 2 job 4 submit at time 3 job 4 's queue time is smaller than job3's queue time. This disobey the FIFO principle. Any one can give a hint? Thanks Chen --001636498f31fc31bc049296baea--