[torqueusers] limit number of processes in a queue

Joshua Bernstein jbernstein at penguincomputing.com
Tue Jan 20 12:57:01 MST 2009

Tony Schreiner wrote:
> I want to set up a queue that is limited in the number of processors it 
> uses.
> I've so far set it up to use a class of machines  mem64 in my nodes 
> file, and there are 10 of these nodes, and they are all 8 core (with 
> np=8 in nodes).
> I would like my queue to use not more than 32 processors. I thought 
> resources_max.nodect=32 might do it (or resources_max.nodect=4) , but I 
> can submit more than 32 and they all run immediately.
> Here is the full pbs parameter list for the queue:
> et queue bigmemhigh queue_type = Execution
> set queue bigmemhigh Priority = 80
> set queue bigmemhigh resources_max.nodect = 4
> set queue bigmemhigh resources_max.walltime = 24:00:00
> set queue bigmemhigh resources_default.neednodes = mem64
> set queue bigmemhigh resources_default.nodect = 1
> set queue bigmemhigh keep_completed = 86400
> set queue bigmemhigh enabled = True
> set queue bigmemhigh started = True
> I've got another queue called bigmem to  uses the mem64 nodes but is not 
> limited
> set queue bigmem queue_type = Execution
> set queue bigmem Priority = 50
> set queue bigmem resources_default.neednodes = mem64
> set queue bigmem resources_default.nodect = 1
> set queue bigmem resources_default.walltime = 168:00:00
> set queue bigmem keep_completed = 86400
> set queue bigmem enabled = True
> set queue bigmem started = True
> what's the proper way for me to limit the processors?
> I'm running the maui scheduler if that is pertinent.

If your jobs are all serial you might try something like:

qmgr -c "set queue bighighmem max_running=32"

This will prevent more then 32 jobs from running at a single time. If you codes 
are parallel though this may not be what you want.

The nodect parameter is just a setting as to how many nodes maximum a single job 
can use. I do believe though that it basically maps to physical processes, so 
with your setting I *think* you couldn't run with more then a processors.

I think to get what you're looking for you may need to create a CLASS inside of 
Maui and configure MAUI to limit the total utilized cores.

-Joshua Bernstein
Software Engineer
Penguin Computing

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