Re: High CPU usage

shiva wrote:
>
> > Which oracle processes exactly are using more cpu than they used to?
> Each client connection used to consume about 0.01% CPU before and
> there were about 80 connections. Now each connection is consuming about
> 0.25% CPU and there are about 1000 connections. We definately see more
> connections then we saw before. (PGA was set to 256MB before and now is
> set to 2GB)

In your original post, you were comparing cpu utitlization between 2 systems. Now you add that the old system was supporting 80 connections and the new one 1000 connections.

Is that a significant difference that makes comparing cpu utilization a fairly senseless exercise?

Good tuned oracle systems are cpu bound. They have to be limited by something ... cpu is the resource it takes to perform work.

Are these 1000 connections performing real work on a regular basis?

What kind of wait events is your system exhibiting?

Are users complaining about system performance or is it within acceptable norms?

What would the customers and end users pick if they could select 3 or 5 things they would like to run faster?

Those are the kinds of questions I would be concentrating on if I were you.

You could submit questions about what you noticed with the kernel utilization to oracle and/or sun in a service request.

I would recommend you obtain and read Cary Millsap's book "Optimizing Oracle Performance".

>
> > What happens to the cpu utilization if you temporarily turn off RAC (
> > run on one node of the cluster ONLY with cluster_database set to false
> > for the instance you are running )?
> We haven't done this yet. Thanks for quick response.

I don't think this is an area to go into now based on your note that the number of connections is so different between the 2 systems. Received on Wed Oct 11 2006 - 15:50:44 CDT