Return-Path: Delivered-To: apmail-hadoop-core-dev-archive@www.apache.org Received: (qmail 9366 invoked from network); 18 Mar 2008 15:39:23 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 18 Mar 2008 15:39:23 -0000 Received: (qmail 62677 invoked by uid 500); 18 Mar 2008 15:39:15 -0000 Delivered-To: apmail-hadoop-core-dev-archive@hadoop.apache.org Received: (qmail 62624 invoked by uid 500); 18 Mar 2008 15:39:15 -0000 Mailing-List: contact core-dev-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: core-dev@hadoop.apache.org Delivered-To: mailing list core-dev@hadoop.apache.org Received: (qmail 62603 invoked by uid 99); 18 Mar 2008 15:39:14 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Mar 2008 08:39:14 -0700 X-ASF-Spam-Status: No, hits=-1998.8 required=10.0 tests=ALL_TRUSTED,FS_REPLICA X-Spam-Check-By: apache.org Received: from [140.211.11.140] (HELO brutus.apache.org) (140.211.11.140) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 Mar 2008 15:38:32 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id B673C234C0B5 for ; Tue, 18 Mar 2008 08:37:25 -0700 (PDT) Message-ID: <301874047.1205854645746.JavaMail.jira@brutus> Date: Tue, 18 Mar 2008 08:37:25 -0700 (PDT) From: "Hudson (JIRA)" To: core-dev@hadoop.apache.org Subject: [jira] Commented: (HADOOP-2559) DFS should place one replica per rack MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Virus-Checked: Checked by ClamAV on apache.org [ https://issues.apache.org/jira/browse/HADOOP-2559?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12579894#action_12579894 ] Hudson commented on HADOOP-2559: -------------------------------- Integrated in Hadoop-trunk #432 (See [http://hudson.zones.apache.org/hudson/job/Hadoop-trunk/432/]) > DFS should place one replica per rack > ------------------------------------- > > Key: HADOOP-2559 > URL: https://issues.apache.org/jira/browse/HADOOP-2559 > Project: Hadoop Core > Issue Type: Improvement > Components: dfs > Reporter: Runping Qi > Assignee: lohit vijayarenu > Fix For: 0.17.0 > > Attachments: HADOOP-2559-1-2.patch, HADOOP-2559-1-3.patch, HADOOP-2559-1-4.patch, HADOOP-2559-1.patch, HADOOP-2559-1.patch, HADOOP-2559-2.patch, Patch1_Block_Report.png.jpg, Patch1_Rack_Node_Mapping.jpg, Patch2 Block Report.jpg, Patch2_Rack_Node_Mapping.jpg, Trunk_Block_Report.png, Trunk_Rack_Node_Mapping.jpg > > > Currently, when writing out a block, dfs will place one copy to a local data node, one copy to a rack local node > and another one to a remote node. This leads to a number of undesired properties: > 1. The block will be rack-local to two tacks instead of three, reducing the advantage of rack locality based scheduling by 1/3. > 2. The Blocks of a file (especiallya large file) are unevenly distributed over the nodes: One third will be on the local node, and two thirds on the nodes on the same rack. This may make some nodes full much faster than others, > increasing the need of rebalancing. Furthermore, this also make some nodes become "hot spots" if those big > files are popular and accessed by many applications. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.