On Thu, Jan 03, 2008 at 10:52:39PM +0100, Kris Kennaway wrote: > Gergely CZUCZY wrote: > > >>* Compare to my config file here: > >> > >>http://people.freebsd.org/~kris/scaling/my.cnf > >> > >>The default mysql config has very poor performance for innodb (you need at > >>least innodb_thread_concurrency = 0 to disable some mysql brain-death). > >>Maybe tuning is required for myisam also. > >> > >>* Also make sure you are using identical config settings on the two systems. > >http://phoemix.harmless.hu/mysql/ verify yourself. Only the paths are > >updated, but the main parameters are just the same. > > You are not in fact using the same config parameters as I am. When I use > your config file I see a large performance loss when I run locally even with > innodb. So, the updated config is here: http://phoemix.harmless.hu/mysql/my.cnf.kris
I've migrated the values from your config. And the plot is here: http://phoemix.harmless.hu/mysql/rw-kris.png I"ve also plotted a current production system, which crashes around 96 threads in the test, or so. That's a Linux-2.6.12 and MySQL 5.0.22, so it should be quite unoptimized compared to any recent version of anything. As it seems, you were right. These adjustments made a very slight performance boost, around 5%. But it's still lagging behind. Again, this is MyISAM, not innodb. The "tc4" and "tc16" strings mean the thread_concurrency is either set to 4 or 16. Your config had 16, but I've googled for it, and some resources suggested setting that to CPUs*2, and that's 4 in my case. I've updated the MySQL version on FreeBSD to 5.0.51, and will try to get this version on linux also, and do a comparision with that one, too. Sincerely, Gergely Czuczy mailto: [EMAIL PROTECTED] -- Weenies test. Geniuses solve problems that arise.
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