Return-Path: X-Original-To: apmail-hbase-issues-archive@www.apache.org Delivered-To: apmail-hbase-issues-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 607F39ED0 for ; Tue, 6 Mar 2012 22:02:22 +0000 (UTC) Received: (qmail 43569 invoked by uid 500); 6 Mar 2012 22:02:22 -0000 Delivered-To: apmail-hbase-issues-archive@hbase.apache.org Received: (qmail 43450 invoked by uid 500); 6 Mar 2012 22:02:21 -0000 Mailing-List: contact issues-help@hbase.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Delivered-To: mailing list issues@hbase.apache.org Received: (qmail 43437 invoked by uid 99); 6 Mar 2012 22:02:21 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 06 Mar 2012 22:02:21 +0000 X-ASF-Spam-Status: No, hits=-2000.0 required=5.0 tests=ALL_TRUSTED,T_RP_MATCHES_RCVD X-Spam-Check-By: apache.org Received: from [140.211.11.116] (HELO hel.zones.apache.org) (140.211.11.116) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 06 Mar 2012 22:02:20 +0000 Received: from hel.zones.apache.org (hel.zones.apache.org [140.211.11.116]) by hel.zones.apache.org (Postfix) with ESMTP id 8EE05BEB0 for ; Tue, 6 Mar 2012 22:02:00 +0000 (UTC) Date: Tue, 6 Mar 2012 22:02:00 +0000 (UTC) From: "stack (Commented) (JIRA)" To: issues@hbase.apache.org Message-ID: <102137366.29840.1331071320587.JavaMail.tomcat@hel.zones.apache.org> In-Reply-To: <155647929.29704.1324361611230.JavaMail.tomcat@hel.zones.apache.org> Subject: [jira] [Commented] (HBASE-5074) support checksums in HBase block cache 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/HBASE-5074?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13223705#comment-13223705 ] stack commented on HBASE-5074: ------------------------------ @Dhruba Try resubmitting your patch too. We regularly see three of these mr tests fail. Fixed in hadoop 1.0.2 apparently. > support checksums in HBase block cache > -------------------------------------- > > Key: HBASE-5074 > URL: https://issues.apache.org/jira/browse/HBASE-5074 > Project: HBase > Issue Type: Improvement > Components: regionserver > Reporter: dhruba borthakur > Assignee: dhruba borthakur > Fix For: 0.94.0 > > Attachments: D1521.1.patch, D1521.1.patch, D1521.10.patch, D1521.10.patch, D1521.10.patch, D1521.10.patch, D1521.10.patch, D1521.11.patch, D1521.11.patch, D1521.12.patch, D1521.12.patch, D1521.13.patch, D1521.13.patch, D1521.2.patch, D1521.2.patch, D1521.3.patch, D1521.3.patch, D1521.4.patch, D1521.4.patch, D1521.5.patch, D1521.5.patch, D1521.6.patch, D1521.6.patch, D1521.7.patch, D1521.7.patch, D1521.8.patch, D1521.8.patch, D1521.9.patch, D1521.9.patch > > > The current implementation of HDFS stores the data in one block file and the metadata(checksum) in another block file. This means that every read into the HBase block cache actually consumes two disk iops, one to the datafile and one to the checksum file. This is a major problem for scaling HBase, because HBase is usually bottlenecked on the number of random disk iops that the storage-hardware offers. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa For more information on JIRA, see: http://www.atlassian.com/software/jira