Return-Path: X-Original-To: apmail-lucene-dev-archive@www.apache.org Delivered-To: apmail-lucene-dev-archive@www.apache.org Received: from mail.apache.org (hermes.apache.org [140.211.11.3]) by minotaur.apache.org (Postfix) with SMTP id 381D5E142 for ; Fri, 1 Feb 2013 11:23:16 +0000 (UTC) Received: (qmail 10270 invoked by uid 500); 1 Feb 2013 11:23:13 -0000 Delivered-To: apmail-lucene-dev-archive@lucene.apache.org Received: (qmail 9950 invoked by uid 500); 1 Feb 2013 11:23:13 -0000 Mailing-List: contact dev-help@lucene.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: dev@lucene.apache.org Delivered-To: mailing list dev@lucene.apache.org Received: (qmail 9923 invoked by uid 99); 1 Feb 2013 11:23:13 -0000 Received: from arcas.apache.org (HELO arcas.apache.org) (140.211.11.28) by apache.org (qpsmtpd/0.29) with ESMTP; Fri, 01 Feb 2013 11:23:13 +0000 Date: Fri, 1 Feb 2013 11:23:13 +0000 (UTC) From: "Uwe Schindler (JIRA)" To: dev@lucene.apache.org Message-ID: In-Reply-To: References: Subject: [jira] [Updated] (LUCENE-4740) Weak references cause extreme GC churn MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-JIRA-FingerPrint: 30527f35849b9dde25b450d4833f0394 [ https://issues.apache.org/jira/browse/LUCENE-4740?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Uwe Schindler updated LUCENE-4740: ---------------------------------- Attachment: LUCENE-4740.patch Better patch using the getter method instead stupid MMapDirectory.this.useUnmap. > Weak references cause extreme GC churn > -------------------------------------- > > Key: LUCENE-4740 > URL: https://issues.apache.org/jira/browse/LUCENE-4740 > Project: Lucene - Core > Issue Type: Bug > Components: core/store > Affects Versions: 3.6.1 > Environment: Linux debian squeeze 64 bit, Oracle JDK 6, 32 GB RAM, 16 cores > Reporter: Kristofer Karlsson > Priority: Critical > Attachments: LUCENE-4740.patch, LUCENE-4740.patch > > > We are running a set of independent search machines, running our custom software using lucene as a search library. We recently upgraded from lucene 3.0.3 to 3.6.1 and noticed a severe degradation of performance. > After doing some heap dump digging, it turns out the process is stalling because it's spending so much time in GC. We noticed about 212 million WeakReference, originating from WeakIdentityMap, originating from MMapIndexInput. > Our problem completely went away after removing the clones weakhashmap from MMapIndexInput, and as a side-effect, disabling support for explictly unmapping the mmapped data. -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org For additional commands, e-mail: dev-help@lucene.apache.org