Return-Path: Delivered-To: apmail-hadoop-hdfs-issues-archive@minotaur.apache.org Received: (qmail 19804 invoked from network); 8 Oct 2009 13:29:04 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 8 Oct 2009 13:29:04 -0000 Received: (qmail 98765 invoked by uid 500); 8 Oct 2009 13:29:04 -0000 Delivered-To: apmail-hadoop-hdfs-issues-archive@hadoop.apache.org Received: (qmail 98703 invoked by uid 500); 8 Oct 2009 13:29:04 -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 98693 invoked by uid 99); 8 Oct 2009 13:29:04 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 08 Oct 2009 13:29:04 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=10.0 tests=ALL_TRUSTED 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; Thu, 08 Oct 2009 13:28:52 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 6C81C234C1EF for ; Thu, 8 Oct 2009 06:28:31 -0700 (PDT) Message-ID: <793046448.1255008511443.JavaMail.jira@brutus> Date: Thu, 8 Oct 2009 06:28:31 -0700 (PDT) From: "Hudson (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 X-Virus-Checked: Checked by ClamAV on apache.org [ https://issues.apache.org/jira/browse/HDFS-503?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12763493#action_12763493 ] Hudson commented on HDFS-503: ----------------------------- Integrated in Hadoop-Hdfs-trunk #106 (See [http://hudson.zones.apache.org/hudson/job/Hadoop-Hdfs-trunk/106/]) > 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: 0.22.0 > > 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.