Re: MySQL benchmarks

Miguel Mendez wrote:

> Hi all,
> 
> Someone has posted a link to a newsforge article on the NetBSD lists
> that benchmarks MySQL performance on several systems, you can see it at:
> 
> http://software.newsforge.com/article.pl?sid=04/12/27/1243207&from=rss
> 
> I don't know how much Linux-specific code there is in MySQL because,
> honestly, I always try to avoid it and go with PostgreSQL, but perhaps
> somebody with more MySQL-fu can fill in the blanks and confirm that the
> better performance seen on Linux systems is due to how the software is
> designed and not so much related to FreeBSD per se.
> 
> Cheers,

There has long been speculation that Linux cuts corners on these tests
by ignoring things like fsync.  One thing that I've been meaning to do
for a while is to ktrace some of the mysql benchmarks and see what
exactly is going on, then compare that to a similar ktrace run under
Linux.  If it turns out that there are lots of synchronization calls
(i.e. fsync-like calls), try stubbing them out in FreeBSD and see if it
brings you any closer to the linux scores.

An easier but also informative test would be to remount the database
filesystem as async-noatime-nosoftupdates and see how it compares.