Benchmark MySQL Performance On FreeBSD And Linux

[Chris]

On 01/01/06, Michael Vince <mv at roq.com> wrote:
>
> huang leo wrote:
>
> >Hi, all:
> >
> >We had evaluated MySQL performance on FreeBSD and Linux. The result is
> >attached.
> >
> >We are longing for your feedbacks!
> >
> >
> >Best regards,
> >
> >Leo Huang
> >
> Really good work.
>
> I gave your results some thought and was thinking that maybe you should
> check to see if you reached the default 1500 threading limit  of libthr
> and maybe it needs to be increased, I set mine to 40000 like below.
> kern.threads.max_threads_per_proc=40000
> kern.threads.max_groups_per_proc=40000
>
> I was thinking it would be good to show threading usage activity with
> some kind of 1 second loop doing ps -auxwH | grep -c 'mysql' or
> something like that so we could see what limits its getting to, and so I
> can have an idea of what I can compare it to on my own servers.
>
> Just a suggestion.
>
> Regards,
> Mike


Well sorry if I am completely wrong here, but that test seems to indicate
there is a general stability problem with libpthread.  My own experience
backs up their results since on a production web server with heavy forums I
have had mysql lockups until I tinkered with the threading settings. Libthr
is the good old threading routine from the 4.x days if I am correct, so if
libpthread is indeed unstable under continous heavy load how has it become
unoticed by the developer's or has it just been tested in desktop
environments?  If libpthread is a problem is it maybe better to further
develop libthr or at least add a option in the mysql ports Makefile to allow
users to use it without tinking with libmap.conf manually.  I understand
that libpthread is mainly an advantage for SMP systems but if (a) it
introduces instability the increased performance it gives becomes irrelevant
and (b) what about UP systems what is the best threading routine for them?
libthr has that been improved in 5.x since 4.x as their results did show
libthr was better then linuxthreads when in the 4.x days linuxthreads was
considered better.

I am confused now as their is very little documentation on this, google
throws up barely anything and my main concern is stability.

Chris