[torqueusers] (no subject)

Garrick Staples garrick at usc.edu
Wed Mar 15 16:48:41 MST 2006

On Wed, Mar 15, 2006 at 09:39:52AM -0500, Efstathiadis, Efstratios alleged:
> Thanks for the reply,
> maybe I should explain a little more of what I am trying to do:
> My computing resource is a custom supercomputer (qcdoc http://www.bnl.gov/lqcd/comp/) 
> that is already partitioned: we have partitions of 2048 nodes, 1024 nodes etc.
> Each partition is unique (number of nodes, geometry, etc) and is mapped
> to toqrue queue: so jobs submitted to queue p1 will then run on machine partition
> p1. There is no sophisticated scheduling here, jobs just run one after the
> other (FIFO), only one running job per partition, and the default scheduler
> (pbs_sched) is sufficient.
> We do have though some identical small partitions (64 nodes each) that could be used
> for code debugging before allocating larger partitions. The problem is that if I put 
> all of them under one queue (debug) I loose the mapping between machine partitions
> and torque queues. If I use a separate queue for each partition (short, medium, large based
> on walltime) jobs may be queued on the, say, short queue while the other two remain idle.
> If you have any ideas on what I could map my machine partitions to (other than queues) or
> any other way to handle this, please let me know.

Wow, 12 thousand nodes?  How well does TORQUE run on that?

You should really give CRI a call on this one.  This is big. (this is
coming from the admin of a 10TF cluster too.)

Why run 1 job per partition?  Is it expected that a job should request
enough resources to fill the entire partition?

I'd throw out the idea of mapping queues to nodes and use maui/moab's
nodesets.  If you add the partition name to the node's list of
properties in TORQUE, you can do something like this in maui.cfg:

NODESETDELAY           1
NODESETLIST            part1 part2 part3...

That will make sure jobs are allocated sets of nodes that are contained
within each partition (which sounds like is your real requirement.)

> Thanks again,
> Stratos
> ________________________________
> From: torqueusers-bounces at supercluster.org on behalf of Garrick Staples
> Sent: Tue 3/14/2006 6:13 PM
> To: torqueusers at supercluster.org
> Subject: Re: [torqueusers] (no subject)
> On Tue, Mar 14, 2006 at 05:19:29PM -0500, Efstathiadis, Efstratios alleged:
> > Hi,
> >
> >
> > being new with MAUI, I can't tell if this is trivial or not:
> > I have defined in torque three queues (short, medium, long)
> > each with a resources_max.walltime of 1hr, 6hr and 12hr respectivelly,
> > and a maximum running jobs of 1 for all three queues.
> > I also have a default queue called batch.Submitted jobs get assigned to the
> > appropriate queue based on the walltime specified in the qsub command.
> > This works well with both pbs_sched and MAUI.
> FYI, routing queues have nothing to do with the scheduler, so if your
> routing works, it will work with any scheduler.
> > Now, if I submit many short jobs, one will be running (as expected) and all the
> > others will be queued, waiting for their turn to run.
> > In the mean time, the medium and the long queues may be completely idle,
> > with no jobs running or queued. How can the scheduler "move" queued
> > jobs from the short queue to the empty medium or long queues??
> > After all, a short job can also fit into the medium or long queues.
> It is doing exactly what you designed: 3 seperate queues with a max of 1
> running job per queue.
> The scheduler won't move jobs into other queues.  Its job is to
> schedule jobs within the constraints and policies that have been
> established.
> I don't know what your usage requirements are, but it sounds like queues
> are the wrong tool for the job.  You might want to look at setting
> policy in your maui config.  Or give CRI a call and get some consulting
> (they will sell you moab, and it will probably do everything you want.)
> > And another (different) question: How can I assign specific host CPUs to queues?
> > I know how to assign hosts to queues (with acl_hosts=.., keeping
> > acl_host_enable false). The reason is that I have a large IBM
> > SP machine with many CPUS and I would like to partition it.
> TORQUE doesn't support this.  My only suggestion is to partition the
> host OS; then you'd have 2 IPs, 2 pbs_moms, and 2 nodes in your server
> config.
> And of course, consider not partitioning it.  Fragmenting your cluster
> into small pieces kills overall usage by reducing scheduling
> opportunities.
> --
> Garrick Staples, Linux/HPCC Administrator
> University of Southern California

Garrick Staples, Linux/HPCC Administrator
University of Southern California
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