topic Re: High CPU usage. in Operating System - HP-UX

High CPU usage.

John Tyler — Thu, 07 Nov 2002 20:33:14 GMT

K580/2CPU/1Gig RAM running 11.0, patched with june 2002 bundle.

This is a new install running sybase Direct Connect.

I see very high CPU usage.
%usr %sys %wio %idle
15:25:48 30 69 0 0
15:25:50 33 67 0 0
15:25:52 35 64 0 0
15:25:54 33 67 0 0
15:25:56 37 63 0 0

And sar -q gives
runq-sz %runocc
15:32:37 1.2 100 0.0 0
15:32:39 1.0 100 0.0 0
15:32:41 1.2 100 0.0 0
15:32:43 2.3 75 0.0 0
15:32:45 1.0 100 0.0 0
15:32:47 2.0 50 0.0 0
15:32:49 1.7 75 0.0 0

This is causing problems. I don't have glance on this box to get a clearer picture.

Any thoughts?
TIA

Re: High CPU usage.

John Tyler — Thu, 07 Nov 2002 20:38:41 GMT

I forgot to mention that the sybase engines are the "top" users of CPU. I don't see much of memory being utilized or any swapping.

Re: High CPU usage.

John Palmer — Thu, 07 Nov 2002 21:05:23 GMT

It certainly looks as though you have a couple of processes that are CPU bound.

I'm afraid that I don't know anything about Sybase - but I wouldn't heve thought it was normal behaviour?

I'd recommend installing the evaluation version of glance from the Apps CD.

Regards,
John

Re: High CPU usage.

Dan Herington — Fri, 08 Nov 2002 14:54:10 GMT

Hi John,

I am not a database guru, but I have heard that Sybase uses busy-waits. Which means that is chews up CPU while it is waiting for work to do. I mention this only because this could indeed be normal behavior.

Dan

Re: High CPU usage.

Martin Johnson — Fri, 08 Nov 2002 16:25:16 GMT

You should talk to Sybase about tuning. The sybase processes do a lot of polling to determine what work needs to be done. This uses a lot of CPU resources. As more work is found, less polling is done. When there is less work, more polling is done. The result is Sybase uses large amounts of CPU. This is fine, if nothing else is running on the system, but on a normal timesharing system, it makes Sybase a pig. You need to do some tuning.

HTH
Marty

Re: High CPU usage.

fg_1 — Fri, 08 Nov 2002 16:30:25 GMT

Hi there

Sybase is very much like any other rdbms product, it will usually grab as much cpu as it can. Oracle does the same thing, so does informix.

As others have suggested here, download or load from application cd #1 the trial version of glance plus/pak for series 800 machines. At least you will get to use the product for 60days and then you might be able to get HP to give you an extension on it. During that time you should try to convince management that this is a worthwhile product to buy as it does present lots of nice metrics to report on, can be used also to make lots of nice reports for mgmt.

Gl 2u

Re: High CPU usage.

Dan Herington — Fri, 08 Nov 2002 17:08:28 GMT

Since this forum is about our resource and workload management products, I will offer some insights into how those can be used to help with this.

If this database is the only thing running on this system, the fact that it is chewing CPU looking for something to do probably isn't an issue. If you have other workloads on the system, you can use our PRM and/or WLM products to control how much CPU is wasted by Sybase and ensure that the other workloads get the cycles they need as well. If you want more details on those products, let me know.

Dan