From owner-freebsd-questions@FreeBSD.ORG Fri Aug 29 08:00:26 2008 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 315551065670 for ; Fri, 29 Aug 2008 08:00:26 +0000 (UTC) (envelope-from pprocacci@datapipe.com) Received: from fmailhost04.isp.att.net (fmailhost04.isp.att.net [204.127.217.104]) by mx1.freebsd.org (Postfix) with ESMTP id 1FF638FC1F for ; Fri, 29 Aug 2008 08:00:26 +0000 (UTC) (envelope-from pprocacci@datapipe.com) Received: from [10.5.21.122] (adsl-241-169-57.bna.bellsouth.net[74.241.169.57]) by isp.att.net (frfwmhc04) with ESMTP id <20080829080025H0400990cee>; Fri, 29 Aug 2008 08:00:25 +0000 X-Originating-IP: [74.241.169.57] Message-ID: <48B7AC89.70502@datapipe.com> Date: Fri, 29 Aug 2008 03:00:09 -0500 From: "Paul A. Procacci" User-Agent: Thunderbird 2.0.0.16 (Windows/20080708) MIME-Version: 1.0 To: Kris Kennaway References: <48B7A67F.8050204@datapipe.com> <48B7AAA9.8000706@FreeBSD.org> In-Reply-To: <48B7AAA9.8000706@FreeBSD.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: FreeBSD Subject: Re: General Mysql Performance Question X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Aug 2008 08:00:26 -0000 Kris Kennaway wrote: > Paul A. Procacci wrote: >> My question is in reference to the 1st and 2nd graphs on this page. >> While testing the performance of the databases given in this graph, >> the one thing that sticks out is that when Mysql uses the myisam >> engine with the ULE schedular, performance drops quite considerably >> regardless of mysql version. The clearly shows ULE to perform worst >> at higher work loads than 4BSD, at least in this one example. >> >> Now, I read that lockmgr code is still a work in progress, but I'm >> unsure if that applies specifically to this specific problem that I'm >> providing. What I'm hoping for quite frankly is a "yes, this is >> because...." type of response. >> >> This isn't a problem per se, but rather a curiosity type of question. > > myisam has huge lock contention, so probably ULE is more efficiently > scheduling the processes and increasing contention yet further, > leading to a net drop of performance. That kind of thing is fairly > common when you have a workload with high contention; if you improve > performance at one bottleneck the performance at a later bottleneck > can get worse. Performance will still be better on other workloads, or > when further work improves the other bottlenecks. > > Kris > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org" Kris, Thanks for your prompt response. I was aware that myisam had pretty huge lock contention, but didn't think ULE, because it's doing it's job better, is actually making things worse. I appreciate your insight. ~Paul