Return-Path: Delivered-To: apmail-hadoop-common-issues-archive@minotaur.apache.org Received: (qmail 49565 invoked from network); 17 Jul 2009 01:10:34 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 17 Jul 2009 01:10:34 -0000 Received: (qmail 68079 invoked by uid 500); 17 Jul 2009 01:11:39 -0000 Delivered-To: apmail-hadoop-common-issues-archive@hadoop.apache.org Received: (qmail 68037 invoked by uid 500); 17 Jul 2009 01:11:39 -0000 Mailing-List: contact common-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: common-issues@hadoop.apache.org Delivered-To: mailing list common-issues@hadoop.apache.org Received: (qmail 68026 invoked by uid 99); 17 Jul 2009 01:11:39 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 17 Jul 2009 01:11:39 +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; Fri, 17 Jul 2009 01:11:36 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id CF5FC234C004 for ; Thu, 16 Jul 2009 18:11:14 -0700 (PDT) Message-ID: <1391540205.1247793074835.JavaMail.jira@brutus> Date: Thu, 16 Jul 2009 18:11:14 -0700 (PDT) From: "Todd Lipcon (JIRA)" To: common-issues@hadoop.apache.org Subject: [jira] Updated: (HADOOP-6148) Implement a pure Java CRC32 calculator 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/HADOOP-6148?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Todd Lipcon updated HADOOP-6148: -------------------------------- Attachment: hadoop-6148.txt Woops! Forgot to do --no-prefix on my git-diff. Same patch, just without the a/ and b/ prefixes. > Implement a pure Java CRC32 calculator > -------------------------------------- > > Key: HADOOP-6148 > URL: https://issues.apache.org/jira/browse/HADOOP-6148 > Project: Hadoop Common > Issue Type: Improvement > Components: util > Reporter: Owen O'Malley > Assignee: Todd Lipcon > Attachments: benchmarks20090714.txt, benchmarks20090715.txt, crc32-results.txt, hadoop-5598-evil.txt, hadoop-5598-hybrid.txt, hadoop-5598.txt, hadoop-5598.txt, hadoop-6148.txt, hadoop-6148.txt, hadoop-6148.txt, hdfs-297.txt, PureJavaCrc32.java, PureJavaCrc32.java, PureJavaCrc32.java, PureJavaCrc32.java, PureJavaCrc32New.java, PureJavaCrc32NewInner.java, PureJavaCrc32NewLoop.java, TestCrc32Performance.java, TestCrc32Performance.java, TestCrc32Performance.java, TestCrc32Performance.java, TestPureJavaCrc32.java > > > We've seen a reducer writing 200MB to HDFS with replication = 1 spending a long time in crc calculation. In particular, it was spending 5 seconds in crc calculation out of a total of 6 for the write. I suspect that it is the java-jni border that is causing us grief. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.