Return-Path: Delivered-To: apmail-hadoop-core-dev-archive@www.apache.org Received: (qmail 51713 invoked from network); 3 Mar 2009 04:03:23 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 3 Mar 2009 04:03:23 -0000 Received: (qmail 46899 invoked by uid 500); 3 Mar 2009 04:03:17 -0000 Delivered-To: apmail-hadoop-core-dev-archive@hadoop.apache.org Received: (qmail 46888 invoked by uid 500); 3 Mar 2009 04:03:17 -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 46877 invoked by uid 99); 3 Mar 2009 04:03:17 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Mon, 02 Mar 2009 20:03:17 -0800 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; Tue, 03 Mar 2009 04:03:16 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 2F9CD234C4AE for ; Mon, 2 Mar 2009 20:02:56 -0800 (PST) Message-ID: <2039535911.1236052976191.JavaMail.jira@brutus> Date: Mon, 2 Mar 2009 20:02:56 -0800 (PST) From: "Amar Kamat (JIRA)" To: core-dev@hadoop.apache.org Subject: [jira] Resolved: (HADOOP-5377) Inefficient jobtracker history file layout In-Reply-To: <1133093312.1236013616316.JavaMail.jira@brutus> 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-5377?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Amar Kamat resolved HADOOP-5377. -------------------------------- Resolution: Duplicate Nick, HADOOP-4670 is opened to address the same. > Inefficient jobtracker history file layout > ------------------------------------------ > > Key: HADOOP-5377 > URL: https://issues.apache.org/jira/browse/HADOOP-5377 > Project: Hadoop Core > Issue Type: Bug > Components: mapred > Environment: This is at least a problem on 0.15. > Reporter: Nick Rettinghouse > > Storing too many files in a single directory slows things down tremendously and in this case, makes the grid just a bit more difficult to manage. On our jobtrackers, even with a 45 day purge cycle, we see hundreds of thousands of files in logs/hadoop/history. The following is an example: > pchdm01.ypost.re1: logs/hadoop/history - 1,176,927 files! > This is the time(1) output of the `ls | wc -l` > real 0m56.042s > user 0m28.702s > sys 0m1.794s > Note that this was the second time I ran this filecount. The first run took more than 4 minutes of real time. > =========================================== > My recommended solution is that the Hadoop team store these files in the following structure: > history/2008/08/19 > history/2008/08/20 > history/2008/08/21 > Using this structure gives us 2 important things: consistently good performance and the ability to easily delete or archive old files. > If we expect a Hadoop cluster to process hundreds of thousands of jobs per day, then we may want to break it down by > hour like this: > history/2008/08/19/00 > history/2008/08/19/01 > ... > history/2008/08/19/22 > history/2008/08/19/23 -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.