Limit CPU usage / Cores on AIX process?

Question

We have two processes running on an AIX machine, one is Oracle the other is Business Objects. BO takes nearly 100% CPU cycles when running and Oracle is unable to process at an acceptable speed obviously. BO has not given us an application specific solution to keep it from using all of the resources.

Is their any method in AIX to limit the BO process to a certain CPU cycle % or number of cores? Moving BO off of this machine is not an option at present. Any advise is greatly appreciated.

Answer 1

Here I've found a pretty extensive explanation about process priority and control on AIX. According to it, you can get the top N performing processes by typing the following:

ps -elf | egrep -v "STIME|$LOGNAME" | sort +<N> -r | head -n 15

Then, when you know which processes are killing the system (in your case you already know that..), you can use 2 commands:

nice - Let you prioritize how the kernel schedules its processing. For example, the following command will add 10 to the default of 20 and create the new nice value of 30, with the priority of 70.:

# nice -n 10 thisjob

renice - Allows you to prioritize a process again that is already running. For example, the following command will cause process 1683 to have a nice value of 30:

# renice -n 10 -p 1683

That should be enough but you can find more detailed explanation in the above mentioned link.

Answer 2

Application WPAR's provide process isolation,

http://www.ibm.com/developerworks/aix/library/au-wpar61aix/

Depending on your hardware you might find micro-partitioning an option, or System WPAR's.

Micro-partitioning allows you to allocate less than a single CPU to different OS instances but still allow them to flex, and System WPAR's offer a similar feature but internally within an OS image.

Both have their place but bring different challenges.

Or, you can as others have suggested, use priorities to give Oracle a boost.