Subject: Re: [kris@obsecurity.org: Progress on scaling of FreeBSD
	on 8 CPU systems]
From: Scott Marlowe <smarlowe@g2switchworks.com>
To: Alvaro Herrera <alvherre@commandprompt.com>
Cc: "Jim C. Nasby" <decibel@decibel.org>, pgsql-performance@postgresql.org
In-Reply-To: <20070302150129.GF4885@alvh.no-ip.org>
References: <20070227182621.GE29041@decibel.org>
	<20070302150129.GF4885@alvh.no-ip.org>
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Date: Fri, 02 Mar 2007 10:35:01 -0600

On Fri, 2007-03-02 at 09:01, Alvaro Herrera wrote:
> > From: Kris Kennaway <kris@obsecurity.org>
> 
> > We have recently made significant progress on optimizing for MySQL
> > running on an 8-core amd64 system. The graph of results may be found
> > here:
> > 
> >   http://www.freebsd.org/~kris/scaling/scaling.png
> > 
> > This shows the graph of MySQL transactions/second performed by a
> > multi-threaded client workload against a local MySQL database with
> > varying numbers of client threads, with identically configured FreeBSD
> > and Linux systems on the same machine.
> 
> Interesting -- the MySQL/Linux graph is very similar to the graphs from
> the .nl magazine posted last year.  I think this suggests that the
> "MySQL deficiency" was rather a performance bug in Linux, not in MySQL
> itself ...

I rather think it's a combination of how MySQL does things and Linux not
being optimized to handle that situation.

It may well be that the fixes to BSD have simply moved the point at
which performance dives off quickly from 50 connections to 300 or
something.

I'd really like to see freebsd tested on the 32 thread Sun CPU that had
such horrible performance with linux, and with many more threads to see
if there's still a cliff there somewhere, and to see where postgresql's
cliff would be as well.  After all, the most interesting part of
performance graphs are the ones you see when the system is heading into
overload.