mysql 5 debian cpuload mysqld over 100%

[gozer]

Hi,

Im running mysql 5.0.32-Debian_7etch1-log Debian etch distribution

On a Dell poweredge with 4gb ram and 2 x dual xeon 3.0 ghz cpu s what i lately have is that mysqld shoots out to 150% 200% in top.

Is this a bug of mysql that it goes over 100% ?

top - 10:13:15 up 1 day, 10:49, 2 users, load average: 0.21, 0.26, 0.27
Tasks: 78 total, 1 running, 77 sleeping, 0 stopped, 0 zombie
Cpu(s): 0.2%us, 0.2%sy, 0.0%ni, 60.7%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 3897492k total, 3736200k used, 161292k free, 132312k buffers
Swap: 1502036k total, 32k used, 1502004k free, 1549644k cached

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
2576 mysql 15 0 1977m 1.8g 5996 S 1 150.3 676:54.63 mysqld

[erkules]

Hi gozer,

top is saying your CPUs are idle 60% of the time.
2 x dual mean 400% CPU. So 150%-200% mean up to 50% of CPU-Time.

Anyway have a look into “show processlist”. Have a look into iostat or vmstat to see if IO is your bottleneck.

[gozer]

isnt 2 cpus then 200% instead of 400% ?

Tnx for your reply.

[gozer]

ah ok ) from the stats i posted does it look like a high IO?

[gozer]

Is there a way to view cached querys ?

I was monitoring with mytop and everytime i see a certain query passingby then the cpu load hits 130/200%

[erkules]

turn on your log-slow-queries in your my.cnf there is a good chance to see the query.

If your CPU rises with a query QueryCache is not used.
Have you got the query?
What is "iostat -c " … saying while the query ist in progress?

It looks like an SQL-Problem:-)