On Tue, Jul 06, 2004 at 02:29:16PM -0400, Charles Sprickman wrote: > On Tue, 6 Jul 2004, Jeremy Zawodny wrote: > > > Do you have a summary of the poor performance somewhere? Or at least > > a sense of where you think the bottleneck is? > > The best I can tell you is that mysql + moderate qmail load on the > same box causes problems. I don't know if this is a scheduler issue > with FreeBSD, or just qmail telling me that I should be using > Postfix.
Interesting. Do you find the mysqld process using alot of CPU? > Out of the blue mysql will start logging stuff like this in the slow query > log: > > # administrator command: Ping; > # [EMAIL PROTECTED]: squirrelmail[squirrelmail] @ localhost [] > # Query_time: 47 Lock_time: 0 Rows_sent: 0 Rows_examined: 0 > # administrator command: Ping; > # [EMAIL PROTECTED]: vpopmail[vpopmail] @ localhost [] > # Query_time: 48 Lock_time: 0 Rows_sent: 0 Rows_examined: 0 > > Load is moderate, but not so bad that any other services on here are > affected in any perceptible way. Without looking at the box, I can hazard a few guesses. I suspect you're seeing one of two things (or both). I suspect that qmail, like some mail servers, makes heavy use of syncrous disk writes. And it's probably competing with MySQL for precious disk I/O resources. (Are they sharing a disk?) What's iostat look like? If you're not using LinuxThreads, you'll find that MySQL on FreeBSD behaves very poorly in high I/O situations. FreeBSD's userspace, self-scheduling threads just suck for database applications. There's no way around that. Jeremy -- Jeremy D. Zawodny | Perl, Web, MySQL, Linux Magazine, Yahoo! <[EMAIL PROTECTED]> | http://jeremy.zawodny.com/ [book] High Performance MySQL -- http://highperformancemysql.com/ -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
