Return-Path: Delivered-To: apmail-db-derby-dev-archive@www.apache.org Received: (qmail 43569 invoked from network); 28 Aug 2007 13:57:55 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 28 Aug 2007 13:57:55 -0000 Received: (qmail 95639 invoked by uid 500); 28 Aug 2007 13:57:50 -0000 Delivered-To: apmail-db-derby-dev-archive@db.apache.org Received: (qmail 95427 invoked by uid 500); 28 Aug 2007 13:57:50 -0000 Mailing-List: contact derby-dev-help@db.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: Delivered-To: mailing list derby-dev@db.apache.org Received: (qmail 95417 invoked by uid 99); 28 Aug 2007 13:57:50 -0000 Received: from nike.apache.org (HELO nike.apache.org) (192.87.106.230) by apache.org (qpsmtpd/0.29) with ESMTP; Tue, 28 Aug 2007 06:57:49 -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; Tue, 28 Aug 2007 13:58:47 +0000 Received: from brutus (localhost [127.0.0.1]) by brutus.apache.org (Postfix) with ESMTP id 7BD41714208 for ; Tue, 28 Aug 2007 06:57:31 -0700 (PDT) Message-ID: <14059404.1188309451504.JavaMail.jira@brutus> Date: Tue, 28 Aug 2007 06:57:31 -0700 (PDT) From: "Knut Anders Hatlen (JIRA)" To: derby-dev@db.apache.org Subject: [jira] Assigned: (DERBY-2911) Implement a buffer manager using java.util.concurrent classes In-Reply-To: <19242816.1183715524465.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/DERBY-2911?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Knut Anders Hatlen reassigned DERBY-2911: ----------------------------------------- Assignee: Knut Anders Hatlen > Implement a buffer manager using java.util.concurrent classes > ------------------------------------------------------------- > > Key: DERBY-2911 > URL: https://issues.apache.org/jira/browse/DERBY-2911 > Project: Derby > Issue Type: Improvement > Components: Performance, Services > Affects Versions: 10.4.0.0 > Reporter: Knut Anders Hatlen > Assignee: Knut Anders Hatlen > Priority: Minor > > There are indications that the buffer manager is a bottleneck for some types of multi-user load. For instance, Anders Morken wrote this in a comment on DERBY-1704: "With a separate table and index for each thread (to remove latch contention and lock waits from the equation) we (...) found that org.apache.derby.impl.services.cache.Clock.find()/release() caused about 5 times more contention than the synchronization in LockSet.lockObject() and LockSet.unlock(). That might be an indicator of where to apply the next push". > It would be interesting to see the scalability and performance of a buffer manager which exploits the concurrency utilities added in Java SE 5. -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.