From owner-freebsd-database Wed Jan 10 20:56:16 2001 Delivered-To: freebsd-database@freebsd.org Received: from misery.sdf.com (misery.sdf.com [204.244.213.49]) by hub.freebsd.org (Postfix) with ESMTP id 6B7AB37B401 for ; Wed, 10 Jan 2001 20:55:55 -0800 (PST) Received: from tom (helo=localhost) by misery.sdf.com with local-esmtp (Exim 2.12 #1) id 14GZ4E-0007T4-00; Wed, 10 Jan 2001 20:10:26 -0800 Date: Wed, 10 Jan 2001 20:10:23 -0800 (PST) From: Tom Samplonius To: David Miller Cc: Lauri Laupmaa , database@freebsd.org Subject: Re: mysql (smp) performance In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-database@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Wed, 10 Jan 2001, David Miller wrote: > On Wed, 10 Jan 2001, Tom Samplonius wrote: > > > On Wed, 10 Jan 2001, Lauri Laupmaa wrote: > > > > ... > > > It seems that on SMP mysql doesn't scale well. (currently testing on > > > dual 833 PIII and running on couple older dual systems) > > > > Because there is no such thing as SMP mysql. It is a single process, > > and can only run on a single processor at a time. > > My understanding is that it's single process but multithreaded. When I > asked a very similar question on a mysql list a year ago I was told that > on linux it ran much better on multiple cpu's. You can however compile mysql with linuxthreads. BTW, the linuxthreads is a full FreeBSD port of the linuxthreads package, which provides pseudo-process threads. These threads are scheduled as processes and you will see a performance improvement with SMP. Linux threads are rather heavy weight, so this solution has not been included as the standard thread package. Standard FreeBSD theads are now (as 4.2-stable) solid and reliable. Reliability has been inconsistant. I have a 3.5-STABLE system using mysql and the native threads on a 2 GB database. No problems. Standard FreeBSD threads have less overhead that threads on Linux, or Linux-like threads on FreeBSD. > --- David Tom To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-database" in the body of the message