Return-Path: Delivered-To: apmail-lucene-java-dev-archive@www.apache.org Received: (qmail 59375 invoked from network); 16 Aug 2007 15:13:55 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 16 Aug 2007 15:13:55 -0000 Received: (qmail 71733 invoked by uid 500); 16 Aug 2007 15:13:49 -0000 Delivered-To: apmail-lucene-java-dev-archive@lucene.apache.org Received: (qmail 71672 invoked by uid 500); 16 Aug 2007 15:13:49 -0000 Mailing-List: contact java-dev-help@lucene.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: java-dev@lucene.apache.org Delivered-To: mailing list java-dev@lucene.apache.org Received: (qmail 71661 invoked by uid 99); 16 Aug 2007 15:13:49 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 16 Aug 2007 08:13:49 -0700 X-ASF-Spam-Status: No, hits=-100.0 required=10.0 tests=ALL_TRUSTED X-Spam-Check-By: apache.org Received: from [140.211.11.4] (HELO brutus.apache.org) (140.211.11.4) by apache.org (qpsmtpd/0.29) with ESMTP; Thu, 16 Aug 2007 15:13:51 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 1E22D7141F0 for ; Thu, 16 Aug 2007 08:13:31 -0700 (PDT) Message-ID: <3942555.1187277211118.JavaMail.jira@brutus> Date: Thu, 16 Aug 2007 08:13:31 -0700 (PDT) From: "Yonik Seeley (JIRA)" To: java-dev@lucene.apache.org Subject: [jira] Commented: (LUCENE-845) If you "flush by RAM usage" then IndexWriter may over-merge In-Reply-To: <19098386.1174594592143.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/LUCENE-845?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#action_12520271 ] Yonik Seeley commented on LUCENE-845: ------------------------------------- Is there a change in filedescriptor use if you don't use setRamBufferSizeMB? > If you "flush by RAM usage" then IndexWriter may over-merge > ----------------------------------------------------------- > > Key: LUCENE-845 > URL: https://issues.apache.org/jira/browse/LUCENE-845 > Project: Lucene - Java > Issue Type: Bug > Components: Index > Affects Versions: 2.1 > Reporter: Michael McCandless > Assignee: Michael McCandless > Priority: Minor > Attachments: LUCENE-845.patch > > > I think a good way to maximize performance of Lucene's indexing for a > given amount of RAM is to flush (writer.flush()) the added documents > whenever the RAM usage (writer.ramSizeInBytes()) has crossed the max > RAM you can afford. > But, this can confuse the merge policy and cause over-merging, unless > you set maxBufferedDocs properly. > This is because the merge policy looks at the current maxBufferedDocs > to figure out which segments are level 0 (first flushed) or level 1 > (merged from level 0 segments). > I'm not sure how to fix this. Maybe we can look at net size (bytes) > of a segment and "infer" level from this? Still we would have to be > resilient to the application suddenly increasing the RAM allowed. > The good news is to workaround this bug I think you just need to > ensure that your maxBufferedDocs is less than mergeFactor * > typical-number-of-docs-flushed. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online. --------------------------------------------------------------------- To unsubscribe, e-mail: java-dev-unsubscribe@lucene.apache.org For additional commands, e-mail: java-dev-help@lucene.apache.org