[gridengine users] "Packing" jobs on nodes

[Dave Love]

James Gladden <gladden at chem.washington.edu> writes:

> I have no such explicit resource quota configuration (as describe below) 
> on my systems, yet no host slot over-subscription occurs.  I just tried 
> the experiment on an 8 slot node with two queues assigned.  When I 
> submit jobs to the specific queue instances associated with that 
> execution host, the first 8 jobs I submit get dispatched to the node 
> while the remainder (from either of the two queues) wait in the "qw" state.
>
> The only thing I have done to facilitate this behavior is to set the 
> value of the consumable "slots" resource for each execution host to 8 
> (which happens to be the number of cores on each execution host).  
> Presumably if I had wanted to allow over-subscription, or utilize 
> hyper-threading, I could set the value to something larger.
>
> My conclusion is that enforcing the "slots" resource limit on hosts is 
> the default behavior for SGE.  Has anyone actually observed different 
> behavior?

Yes, with overlapping, non-mutually-suspended queue definitions.

I don't understand `default behaviour' as there's no default slots host
resource, and no necessary relationship between slots ans processors.
On the other hand, the rqs for num_proc exactly expresses what I
understand by not over-subscribing hosts.

-- 
Excuse the typping -- I have a broken wrist