which session is consuming CPU

awdba · #1 (**permalink**) 12-10-03, 03:59

Hi,
We are using IDS 7.31 opn AIX 4.3.3.
It happens that we are having a bad performance ... and when we use the system tools (monitor) we see that the oninit process(es) are consuming a lot of CPU.
The question is : HOW CAN WE FIND OUT WHICH INFORMIX SESSION IS RESPONSIBLE FOR THIS CPU USAGE.

best regards,
Erwin.

gurey · #2 (**permalink**) 12-11-03, 11:24

Quote:

Originally posted by awdba
Hi,
We are using IDS 7.31 opn AIX 4.3.3.
It happens that we are having a bad performance ... and when we use the system tools (monitor) we see that the oninit process(es) are consuming a lot of CPU.
The question is : HOW CAN WE FIND OUT WHICH INFORMIX SESSION IS RESPONSIBLE FOR THIS CPU USAGE.

best regards,
Erwin.

Hi,

The oninit process always consume CPU, because are virtual processor, then operating system penalty this process.
This is normal.
Please read Administrator's Guide documents.
One question: Run you update statistics, with frequency ?

Gustavo.

awdba · #3 (**permalink**) 12-11-03, 11:43

Hi,

I know it is normal that the oninitprocesses are using CPU, but when the processes are using 25 % of the CPU in normal conditions, and then suddenly 65 % of the CPU , there is a problem.
I suppose the oninit processes are using more cpu at this time because either one of the user threads is using abnormally much cpu, or some internal informix process is using it. That is what I want to find out : try to link the abnormally high CPU usage with a program (for instance a recently modified 4GL program).

About the update statistics : it is scheduled on a regular basis.

best regards,
Erwin.

gurey · #4 (**permalink**) 12-12-03, 08:56

Quote:

Originally posted by awdba
Hi,

I know it is normal that the oninitprocesses are using CPU, but when the processes are using 25 % of the CPU in normal conditions, and then suddenly 65 % of the CPU , there is a problem.
I suppose the oninit processes are using more cpu at this time because either one of the user threads is using abnormally much cpu, or some internal informix process is using it. That is what I want to find out : try to link the abnormally high CPU usage with a program (for instance a recently modified 4GL program).

About the update statistics : it is scheduled on a regular basis.

best regards,
Erwin.

Hi Erwin,

The it fear performance it is very extensive, one must verify since various points, the layout of disks, the times of answer of the sql, times of answer of the network and the load of processes in a the server.
One question: That the users say ?

Gustavo.

awdba · #5 (**permalink**) 12-12-03, 09:30

Hi Gustavo,

you are right about performance being a very difficult topic ...
at this moment everything is OK for the users

I just wanted to know how to find out which informix session is responsible for the cpu-consommation of the oninit process; then by killing the responsible session the system load falls back to normal.

best regards,
Erwin.

sundialsvcs · #6 (**permalink**) 12-12-03, 10:41

Don't be worried so much about CPU consumption. If the CPU is lucky enough to be 100% busy, 100% of the time, that's probably a good thing.

Instead, look for what the various tasks are waiting on: what is delaying them, such as:

I/O devices
Memory availability
Other processes or resources (e.g. query-engine availability; locks

The CPU is always the fastest resource there is, and unless you are ding mongo-heavy scientific computing, it will never be what you are waiting on. Therefore, high CPU utilization is a sign of health, not sickness. It means that the computer has work to do; that it is using its time productively.