From users-return-2364-apmail-qpid-users-archive=qpid.apache.org@qpid.apache.org Wed Dec 23 13:59:20 2009 Return-Path: Delivered-To: apmail-qpid-users-archive@www.apache.org Received: (qmail 14902 invoked from network); 23 Dec 2009 13:59:20 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.3) by minotaur.apache.org with SMTP; 23 Dec 2009 13:59:20 -0000 Received: (qmail 49056 invoked by uid 500); 23 Dec 2009 13:59:20 -0000 Delivered-To: apmail-qpid-users-archive@qpid.apache.org Received: (qmail 49001 invoked by uid 500); 23 Dec 2009 13:59:19 -0000 Mailing-List: contact users-help@qpid.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: users@qpid.apache.org Delivered-To: mailing list users@qpid.apache.org Received: (qmail 48991 invoked by uid 99); 23 Dec 2009 13:59:19 -0000 Received: from athena.apache.org (HELO athena.apache.org) (140.211.11.136) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 23 Dec 2009 13:59:19 +0000 X-ASF-Spam-Status: No, hits=-6.6 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_MED X-Spam-Check-By: apache.org Received-SPF: pass (athena.apache.org: domain of aconway@redhat.com designates 209.132.183.28 as permitted sender) Received: from [209.132.183.28] (HELO mx1.redhat.com) (209.132.183.28) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 23 Dec 2009 13:59:12 +0000 Received: from int-mx05.intmail.prod.int.phx2.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.18]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id nBNDwo2a010314 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 23 Dec 2009 08:58:50 -0500 Received: from [10.11.8.221] (vpn-8-221.rdu.redhat.com [10.11.8.221]) by int-mx05.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id nBNDwnuV010722; Wed, 23 Dec 2009 08:58:50 -0500 Message-ID: <4B322235.5090009@redhat.com> Date: Wed, 23 Dec 2009 08:59:17 -0500 From: Alan Conway Organization: Red Hat User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.4pre) Gecko/20091014 Fedora/3.0-2.8.b4.fc11 Thunderbird/3.0b4 MIME-Version: 1.0 To: users@qpid.apache.org, Kim van der Riet Subject: Re: BDB Message store - rationale? References: <4B314D4E.1020405@etinternational.com> In-Reply-To: <4B314D4E.1020405@etinternational.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.67 on 10.5.11.18 On 12/22/2009 05:50 PM, Rob Springer wrote: > Hey all - we have run up against the max open files aspect of using the > message store plugin, and would rather not require our users edit > limits.conf to be able to run our software (and the fact that we'd just > be racing against the scaling up of the number of declared queues is > scary), so we were considering potential alternative solutions. > > The first question that came up was regarding the message store plugin's > use of journal files - why is such a large number (8) the default? Why > are the queues created per-queue, as opposed to a coarser-grained > implementation, etc? > > Google and mailing list searches didn't reveal a ton of rationale / > design discussions, so we figured we'd ask directly... > > Finally, if this isn't the mailing list to ask this on (is there a Red > Hat one for the message store?), could y'all direct me there? > This is the right list, all the relevant people hang out here but maybe on vacation. I believe the main reason for per-queue journal files is so the queue can be allocated a contiguous block of disk space at the outset which is used as a circular buffer, so disk heads dont have to skip around to write successive messages on the same queue. On your other questions, I'll defer to the author of the store. --------------------------------------------------------------------- Apache Qpid - AMQP Messaging Implementation Project: http://qpid.apache.org Use/Interact: mailto:users-subscribe@qpid.apache.org