Re: Benchmark MySQL Performance On FreeBSD And Linux

Chris wrote:

On 01/01/06, Michael Vince <mv@xxxxxxx> 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.

Personally I was surprised by this statement that libpthread wasn't working for his test, for me it does benchmark a tad slower but I have always seen libpthread as the most stable threading library.

libthr doesn't work very well at all under amd64 in Java benchmarks (Java will core in a few minutes of usage) while pthread is much more reliable.

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

Chris


I believe the best thing to do is always just benchmark and use whats best for you, there is no guarantee with this stuff.

BTW I did a few super smack tests and saw that the thread numbers doesn't appear to reach thread numbers above 1500 but I only tested with smaller client numbers.

Mike




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