Re: [Condor-users] uniform distribution of processes on physical nodes

[Dan Bradley <dan@xxxxxxxxxxxx>]

Matt Hope wrote:

> On Thu, Jul 3, 2008 at 4:45 PM, Ian Chesal <ICHESAL@xxxxxxxxxx> wrote:
>  
>
> > > What's the best way to achieve an uniform distribution of
> > > processes on the physical nodes, so that, in the previous
> > > example, each physical node run two processes?
> > >      
> > ##  The NEGOTIATOR_POST_JOB_RANK expression chooses between
> > ##  resources that are equally preferred by the job.
> > ##  The following example expression steers jobs toward
> > ##  faster machines and tends to fill a cluster of multi-processors
> > ##  breadth-first instead of depth-first.  In this example,
> > ##  the expression is chosen to have no effect when preemption
> > ##  would take place, allowing control to pass on to
> > ##  PREEMPTION_RANK.
> > ##
> > ##  Break ties by looking for machines that have Idle longer than others
> > ##  and use them first. Also try and use faster machines before slower
> > ##  machines and assign jobs to separate machines before we start
> > putting
> > ##  two jobs on a machine.
> > NEGOTIATOR_POST_JOB_RANK = (((Activity =?= 'Owner') * (State =?=
> > 'Idle')) * 1000000000) + ((Activity =?= 'Unclaimed') * 100000000) +
> > (KFlops * 0.001) - (VirtualMachineID * 10)
> >
> > If you just want breadth-first filling:
> >
> > NEGOTIATOR_POST_JOB_RANK = (RemoteOwner =?= UNDEFINED) *
> > VirtualMachineID
> >
> > That'll fill the higher VMs first.
> >    
>
> Incidentally on the version we are running (6.8.8) this did not have
> the desired effect (I had assumed it was working and was rather
> shocked to discover it wasn't and we were wasting a lot of through
> put).
>  

What aspect of this policy was not working as expected?  The preference 
for idle machines?  Or the uniform distribution across machines?

One thing to keep in mind about NEGOTIATOR_POST_JOB_RANK is that it may 
be overruled by NEGOTIATOR_PRE_JOB_RANK or the rank specified by the 
job.  Only if those expressions leave more than one match tied for top 
place does the post job rank come into play.

--Dan