Re: Looking for help with high volume MySQL

On Friday, 17 Aug 2007 1:50:08
John Klos <[email protected]> wrote:

> Is SMP efficient enough with NetBSD that a single 4, 6, or 8
> processor system would be as capable or perhaps more capable than,
> say, 2, 3, or 4 separate dual processor systems?

I do not know the answer to this question, however netbsd-4 and
-current branches are known to have better SMP support than the
netbsd-3 stable branch.  With netbsd-3 threads, number crunching
applications in userspace should probably do fine but I do not have
experience with it.

Although some of that information may now be outdated here are links
that might be of interest:

http://bulk.fefe.de/scalability/
http://www.linux.com/articles/41348?tid=3D72&tid=3D29
http://www.linux.com/articles/41347?tid=3D152&tid=3D72&tid=3D29
http://mail-index.netbsd.org/tech-perform/2005/01/12/0000.html
http://www.feyrer.de/NetBSD/gmcgarry/

> Why, on an amd64 system with 4 gigs of memory and MySQL ulimited
> as such:

>          ulimit -n 4096         ulimit -d 1572864         ulimit
> -n 600         ulimit -s 32768
> do I sometimes get out of memory errors from MySQL? The total size
> of MySQL seems to grow to about 1 gig, but never any larger, and
> I've had to lower memory usage in my.cnf.

> Why is my.cnf in /usr/local/ and not in /usr/local/etc/?

You might need to also setup a special login class, or to change the
settings for the default user class.  See the login.conf(5) manual
page for more information.

As for /usr/local, it's not the default path netbsd uses (pkgsrc by
default uses /usr/pkg/ yet this is configurable).  If you built mysql
yourself without pkgsrc it's probably necessary to configure the
scripts prior to building to chose the configuration file location,
./configure --help might show other options than only --prefix for
this...

> Does anyone have recommendations for setting up an arbitrary
> number of replication slaves easily? Experience and suggestions?
> What's the best way to benchmark two machines against each other?
> AMD or Intel?

Hopefully someone with large scale mysql setup experience can answer
this :)

Good luck,
--=20
Matthew Mondor