mysql - cpu user usage>90.0%

[Piotr Kirklewski]

Hi there
About two hours ago it started:

cpu user usage>90.0%

If I reboot the

process /etc/init.f/mysqld/reboot

Then its fine for 5 mins.

How can I check what exactly is mysql doing ?

Cheers

[Philip Gunter · Accepted solution]

Hi Nagileon,

you should have a look at mytop. That should help you locate where the perf issue is with mysql.

http://jeremy.zawodny.com/mysql/mytop/

Cheers,
Philip.

[Steven E. Protter]

Shalom,

90% CPU use is not a serious problem on a Linux or Unix system.

I would suggest the sar utility to measure performance and see if its cpu, i/o or whatnot.

SEP

[Piotr Kirklewski]

Monit is set to send a message if the user cpu usage is > 90% but in the reality its obout 99.9%.
I don't like it.

How can I limit cpu usage for this user ?

Cheers

[Stuart Browne]

mysqladmin processlist

This will list the queries that are currently running in mysql.

Hopefully, there'll be an easy to see operation occuring which you can track back.

if that's not it, ensure that the slow query log is on, and see if there's a re-occuring query which is chomping the machine.