Return-Path: Delivered-To: apmail-hadoop-mapreduce-issues-archive@minotaur.apache.org Received: (qmail 87912 invoked from network); 18 May 2010 22:09:04 -0000 Received: from unknown (HELO mail.apache.org) (140.211.11.3) by 140.211.11.9 with SMTP; 18 May 2010 22:09:04 -0000 Received: (qmail 14362 invoked by uid 500); 18 May 2010 22:09:04 -0000 Delivered-To: apmail-hadoop-mapreduce-issues-archive@hadoop.apache.org Received: (qmail 14335 invoked by uid 500); 18 May 2010 22:09:04 -0000 Mailing-List: contact mapreduce-issues-help@hadoop.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: mapreduce-issues@hadoop.apache.org Delivered-To: mailing list mapreduce-issues@hadoop.apache.org Received: (qmail 14327 invoked by uid 99); 18 May 2010 22:09:04 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 18 May 2010 22:09:04 +0000 X-ASF-Spam-Status: No, hits=-1441.0 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; Tue, 18 May 2010 22:09:03 +0000 Received: from thor (localhost [127.0.0.1]) by thor.apache.org (8.13.8+Sun/8.13.8) with ESMTP id o4IM8hQh009463 for ; Tue, 18 May 2010 22:08:43 GMT Message-ID: <3045770.115331274220523809.JavaMail.jira@thor> Date: Tue, 18 May 2010 18:08:43 -0400 (EDT) From: "dhruba borthakur (JIRA)" To: mapreduce-issues@hadoop.apache.org Subject: [jira] Created: (MAPREDUCE-1797) The JobTracker lock can be a reader/writer lock MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 The JobTracker lock can be a reader/writer lock ----------------------------------------------- Key: MAPREDUCE-1797 URL: https://issues.apache.org/jira/browse/MAPREDUCE-1797 Project: Hadoop Map/Reduce Issue Type: Improvement Components: jobtracker Reporter: dhruba borthakur The Jobtracker has a global lock and a per-job JobInProgress lock. The aim for the JobInprogress lock is to support the ability to lock a single job's metadata without blocking out the entire JobTracker. However, many code paths acquire the JobTracker lock and then acquire the JobInProgress lock while keeping the JobTracker lock. This somewhat defeats the benefit of having a per-job lock. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.