Return-Path: Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: (qmail 52563 invoked from network); 7 Jun 2010 08:50:31 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 7 Jun 2010 08:50:31 -0000 Received: (qmail 4969 invoked by uid 500); 7 Jun 2010 08:50:31 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 4876 invoked by uid 500); 7 Jun 2010 08:50:30 -0000 Mailing-List: contact hdfs-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: hdfs-issues@hadoop.apache.org Delivered-To: mailing list hdfs-issues@hadoop.apache.org Received: (qmail 4867 invoked by uid 99); 7 Jun 2010 08:50:29 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 07 Jun 2010 08:50:29 +0000 X-ASF-Spam-Status: No, hits=-1502.3 required=10.0 tests=ALL_TRUSTED,AWL X-Spam-Check-By: apache.org Received: from [140.211.11.22] (HELO thor.apache.org) (140.211.11.22) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 07 Jun 2010 08:50:28 +0000 Received: from thor (localhost [127.0.0.1]) by thor.apache.org (8.13.8+Sun/8.13.8) with ESMTP id o578o8Tg010193 for ; Mon, 7 Jun 2010 08:50:08 GMT Message-ID: <25882683.213351275900608178.JavaMail.jira@thor> Date: Mon, 7 Jun 2010 04:50:08 -0400 (EDT) From: "shravankumar (JIRA)" To: hdfs-issues@hadoop.apache.org Subject: [jira] Commented: (HDFS-503) Implement erasure coding as a layer on HDFS In-Reply-To: <242063006.1248420974911.JavaMail.jira@brutus> 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/HDFS-503?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12876178#action_12876178 ] shravankumar commented on HDFS-503: ----------------------------------- Thank you sir. > Implement erasure coding as a layer on HDFS > ------------------------------------------- > > Key: HDFS-503 > URL: https://issues.apache.org/jira/browse/HDFS-503 > Project: Hadoop HDFS > Issue Type: New Feature > Components: contrib/raid > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Fix For: 0.21.0 > > Attachments: raid1.txt, raid2.txt > > > The goal of this JIRA is to discuss how the cost of raw storage for a HDFS file system can be reduced. Keeping three copies of the same data is very costly, especially when the size of storage is huge. One idea is to reduce the replication factor and do erasure coding of a set of blocks so that the over probability of failure of a block remains the same as before. > Many forms of error-correcting codes are available, see http://en.wikipedia.org/wiki/Erasure_code. Also, recent research from CMU has described DiskReduce https://opencirrus.org/system/files/Gibson-OpenCirrus-June9-09.ppt. > My opinion is to discuss implementation strategies that are not part of base HDFS, but is a layer on top of HDFS. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.