Homo-Adminus Blog - Latest Comments in Found an Ideal I/O Scheduler for my MySQL boxes

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Илья — Wed, 08 Oct 2008 07:11:30 -0000

Спасибо!очнь интересная статья!

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Marcelb — Fri, 15 Aug 2008 09:28:20 -0000

Link to the conference:
http://video.google.com/vid...

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Scoundrel — Mon, 21 Jul 2008 19:19:12 -0000

2Yordan: There were 8 separate threads in our "database load generation tool" (sphinx indexer) + some number of requests is being done from the site directly.

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Yordan — Mon, 21 Jul 2008 03:52:28 -0000

what is the number of threads in mysqld?

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Scoundrel — Sun, 20 Jul 2008 14:55:08 -0000

2.6.18-53.el5

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Kostas Georgiou — Sun, 20 Jul 2008 13:47:07 -0000

Well there isn't much that the I/O schedulers can do if your access pattern is quite random beyond maybe giving you better average latencies .

Running cfq with slice_idle=0 might be a good idea btw, keeping the disks idle for up to slice_idle (8ms by default) isn't probably the best option for a db workload.

It would be interesting to get some plots/movies from seekwatcher also, I find that it gives you a nice insight on your workload and how each scheduler is affecting it.

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Yordan — Sun, 20 Jul 2008 13:43:52 -0000

Kernel version?

Re: Found an Ideal I/O Scheduler for my MySQL boxes

Me — Sun, 20 Jul 2008 10:35:35 -0000

echo 1 > /proc/sys/vm/drop_caches

Re: Found an Ideal I/O Scheduler for my MySQL boxes

koticka — Sun, 20 Jul 2008 07:34:29 -0000

Result is predictable, this situation (raid controller) described in many documents about linux io scheduler. Scheduler (any) works only for hdd without any raid controllers.