[torqueusers] Curious question
knielson at adaptivecomputing.com
Tue Mar 30 08:40:28 MDT 2010
Glen Beane wrote:
> On Tue, Mar 30, 2010 at 10:07 AM, Glen Beane <glen.beane at gmail.com
> <mailto:glen.beane at gmail.com>> wrote:
> On Tue, Mar 30, 2010 at 9:55 AM, Charles Johnson
> <charles.johnson at accre.vanderbilt.edu
> <mailto:charles.johnson at accre.vanderbilt.edu>> wrote:
> About the nodes file ... I have always been under the
> impression that
> the nodes file gives an ordering to nodes selected for jobs, i.e.,
> nodes at the top of the list are considered before nodes at the
> bottom. We are currently in a down time for refreshing
> hardware, and
> the whole cluster is quiescent. As a test of hardware we
> submitted a
> single job suitable for any one of several hundred nodes at
> the top of
> the nodes file. The job ran on a node roughly halfway down the
> file. Again, there were no other jobs on the cluster.
> I am curious as to why? Any ideas?
> We are using torque 2.4.5 and moab 5.3.6
> This is really a Moab question since Moab selects the node that
> the job will run on, it has nothing to do with the order of the
> nodes in the TORQUE node file. I think the default for Moab might
> be "last fit", so as it scans the available nodes it will select
> the last one it finds that satisfies the requirements for the
> job. There is a "first fit" and "best fit" option if I remember
> With the fifo scheduler, then yes, I think the job would run on
> the first available node in the node list.
> actually, I was thinking of LASTAVAILABLE, not "last fit", so the
> definition would be different than what I stated. This is the correct
> definition: "This algorithm is a best fit in time algorithm that
> minimizes the impact of reservation based node-time fragmentation." I
> think this might be the default, but I don't remember for sure.
> torqueusers mailing list
> torqueusers at supercluster.org
If you were to run TORQUE without a scheduler and started the job
manually TORQUE will choose the last node in the nodes file to run on.
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