Hm. Anyone run into some strange threading issues with MySQL on FreeBSD? Long-running queries eventually tie up mySQLd even though no resources appear to have been exhausted. Perhaps there is some locking or threading difference with MySQL/Freebsd as opposed to MySQL/Linux which I didn't experience this problem.

- wil

Try running `mysqladmin proc` to see what's happening, or running `SHOW PROCESSLIST` from the SQL monitor (may not show you all depending on your access though).

Cheers,

Alex
--
Gossamer Threads Inc.

Well on doing some more research, Alex, it seems that FreeBSD is not the best platform to run MySQL as it does indeed have some issus. Apparently FreeBSD won't use SMP for threads until v5 (a year from now). Only after this will things start to get better for MySQL on FreeBSD.

And another quote from an IRC conversation with a few developers unearthed:

"..linux vs. freebsd issue for mysql came up at the silicon valley mongers talk given by a guy from yahoo. they're a freebsd shop, except for some of their mysql servers.."

But I couldn't find any more information on this. By the time I came back to the screen, the user had left, but I've sent an email asking for the text of this PM meeting.

I'll keep you informed.

- wil

Aha. I've managed to track it down.

It was a talk given by Jeremy Zawodny from Yahoo! Finance (which uses MySQL as it's backend). He gave a talk to Silicon Valley PM and in that talk he mentioned why they moved from FreeBSD to Linux to run their MySQL operations.

The talk can be found here: http://jeremy.zawodny.com/mysql/sv.pm/index.html

And the relevent slides are:

http://jeremy.zawodny.com/.../sv.pm/mgp00012.html
http://jeremy.zawodny.com/.../sv.pm/mgp00013.html

Cheers

- wil

Recent experiments on a some dual-cpu FreeBSD boxes and a custom built MySQL using the LinuxThreads package have yielded some impressive results. I'm hoping to publish something about this in the next few weeks. Probably not until after OSCON, though.
--
Jeremy Zawodny <Jeremy@Zawodny.com>
Perl, Web, MySQL, Linux Magazine, Yahoo!
http://jeremy.zawodny.com/

What versions of FreeBSD and MySQL were you using? I keep finding this as a problem on old versions of FreeBSD, but can't find anything on it not working correctly in the latest version. Even the slides you referenced said "(now fixed in 4.3)".

Sean

Yes, this was an old machine that has since been 'upgraded' to Debian. Sorry, I can't remember the actual version of the dist. but it was over 2 years old that's for sure.

- wil

Jeremy has recently posted an update on this topic at his blog, if anyone is interested:

http://jeremy.zawodny.com/...s/000203.html#000203

- wil