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cpu utilization

 
DeafFrog
Valued Contributor

cpu utilization

Dear Gurus,

Load averages: 0.41, 0.83, 0.94
670 processes: 572 sleeping, 98 running
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 0.31 17.9% 0.0% 6.1% 76.0% 0.0% 0.0% 0.0% 0.0%
2 0.44 65.6% 0.0% 4.3% 30.1% 0.0% 0.0% 0.0% 0.0%
4 0.50 6.3% 0.0% 4.9% 88.8% 0.0% 0.0% 0.0% 0.0%
6 0.38 30.3% 0.0% 2.8% 66.9% 0.0% 0.0% 0.0% 0.0%
8 0.38 6.1% 0.0% 2.2% 91.7% 0.0% 0.0% 0.0% 0.0%
10 0.46 65.2% 0.0% 14.2% 20.7% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 0.41 32.0% 0.0% 5.7% 62.3% 0.0% 0.0% 0.0% 0.0%

System Page Size: 4Kbytes
Memory: 10907364K (6364524K) real, 22676516K (12257472K) virtual, 616268K free

CPU TTY PID USERNAME PRI NI SIZE RES STATE TIME %WCPU %CPU COMMAND
4 ? 14375 oracle 241 20 1074M 7236K run 936:33 99.40 99.22 oracleDF
0 ? 17735 oracle 232 20 1073M 6040K run 828:28 87.88 87.73 oracleDF
0 ? 6236 dfradm 152 20 831M 323M run 138:42 14.43 14.41 java

here the load average is low and idel time is high enough, yet the 2 oracle processes show 100% in %CPU time most of the time.Please let me know the possible remedies

Regards,
DeafFrog
FrogIsDeaf
5 REPLIES
Wim Rombauts
Honored Contributor

Re: cpu utilization

LOAD and CPU-time is a different thing.
LOAD is the average number of runable processes per core on your system at any time.
With only 2 very busy processes on a 6-core system, your processor cores are waiting for work. Runable processes don't get the tilme to queue-up and thus your LOAD is low.
idle time is the time that CPU's were doing nothing.
In extreme situations, LOAD and idle time may show very different things.
If you should have 6 (and only 6) very busy processes, idle time may approach 0, while your load is only 1.
If you have 6000 processes that activate themselves all together for just a microsecond, your load may go over 10, while your CPU's are next to idle.
DeafFrog
Valued Contributor

Re: cpu utilization

Hello Wim ,

Thanks for the reply .Is this a perfromance problem , whad could be the reason for these 2 process showing 100% most of the time.

Regards,
Rahul
FrogIsDeaf
Dennis Handly
Acclaimed Contributor

Re: cpu utilization

>2 oracle processes show 100% in %CPU time most of the time. Please let me know the possible remedies

Add more work on the system. Those two processes will use 100% of two CPUs. There are 4 other CPUs that make the idle time look larger.

If those Oracle processes are flopping around on all 6 CPUs, you don't see the 100% on just one, like you do for the oracleDF lines.

>Is this a performance problem, what could be the reason for these 2 process showing 100% most of the time.

Because they are doing real work? Because someone needs to add threading to the process?
Because your CPUs are too slow?
We can't tell without some detailed performance measurements with glance or Caliper on Integrity.
Jean-Luc Oudart
Honored Contributor

Re: cpu utilization

Hi

you need to check what these 2 processes are up to in oracle.
you (or your DBA) could check the sessions associated to these oracle processes and then check the activity (eg oracle trace the specific session).

Regards
Jean-Luc
fiat lux
Emil Velez
Honored Contributor

Re: cpu utilization

load average is over a 1 minute,5 min and 15 min averages.

Top updates every 5 seconds so it could show spikes on a particular CPU for a certain process.

I would look a glance and measureware numbers because sometime realtime data is not seen by top.