Operating System - Tru64 Unix
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Safe usage of 'max_proc_per_user'

Russ Park
Frequent Advisor

Safe usage of 'max_proc_per_user'

I have a system that is being pounded with oracle queries and at times has a load at or near 12. I'm getting 'max_proc_per_user' exceeded messages, but I'm concerned that allowing more processes will continue to overload the 2 1gig CPUs I have in my ES-45 box with 4GB RAM.

Any thoughts?
Ralf Puchner
Honored Contributor

Re: Safe usage of 'max_proc_per_user'

maybe there is a tuning mismatch on your system. be sure you have configured the database and the system as described in the oracle tuning guide.

There are dependencies within the max_proc_per_user parameters. But maybe there is another problem leading to the increased processes. Please verify if tcp timeout is an issue here leading to processes in WAIT state.
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Michael Schulte zur Sur
Honored Contributor

Re: Safe usage of 'max_proc_per_user'


I know, it makes you feel uneasy to see the machine at it's limit, however 'max_proc_per_user' exceeded messages are worse bacause you never know, when they hit. I would first of all check if oracle is running with good performance. We have a 4cpu/4gb 4100 and only after I tuned indexes and oracle configuration, the machine is now running smoothly.

Johan Brusche
Honored Contributor

Re: Safe usage of 'max_proc_per_user'

The limit that is hit here is a per-user limit NOT a system limit.
So what user is this logged against ? Do all your clients connect with the same username ?
Can't you give different usergroups another collective username against which they could authenticate ?

If you increase max_proc_per_user, you should also check max_threads_per user. By default it's 4 times max_proc_per_user and it should at least be larger than max_proc_per_user. (See man sys_attrs_proc)

Probably the dependencies Ralf was thinking about are those that come with maxusers, which in turn influences taskmax, threadmax and min_free_vnodes, but nowadays maxusers is selfconfiguring at boot-time based on the available physical memory.