topic Re: PRM utilization in Operating System - HP-UX

PRM utilization

ITSD-ACCS — Mon, 17 Jun 2002 08:39:11 GMT

Hi !

I have the prm configured to 30% for oracle user group, however when I "top", I found some process under oracle users has used up 98% in certain time. Does that mean it take 98% of 30% given ? Or it took 98% for one of the CPU ?

However do I know if 30% is enough ?

Re: PRM utilization

T G Manikandan — Mon, 17 Jun 2002 09:36:32 GMT

Process Resource Manager has a functionality like
The resources are used by the groups even more than what it is entitled,but when ever there is a need for resource it starts cutting the resource from the group where you had a percentage.
now eg.
Group A is given a CPU % of 40% and Group B is 60%.
So when the CPU is not fully used Group A can also use 70 and group B 15%.
The situation comes when your CPU utilization is now 100%.Now PRM acts so that group1 will not use more than 40% and Group B will not use more than 60%.

The figure which I have attached from the PRM manual will explain you in detail.

Also check the manual for a detailed explanation
http://docs.hp.com/hpux/onlinedocs/B8733-90001/B8733-90001.html

Thanks
G Manikandan

Re: PRM utilization

Jim Carter — Mon, 17 Jun 2002 11:53:21 GMT

A very simple answer is that PRM only throttles when the TOTAL USAGE reachs 100%. If you aren't at 100% then there are still available resources, so why put limits on any process or process group?

Re: PRM utilization

Martin Johnson — Mon, 17 Jun 2002 13:05:56 GMT

30% is the average of all the processes in the group. Which means the processes can get much less than 30% if all the processes within a group are competing for CPU resources.

Marty