PBS Scheduler

Ivan Oleynik oleynik at chuma.cas.usf.edu
Sun Sep 29 21:04:37 EDT 2002


Joseph,

Thanks very much for your reply. I made the following changes to
xinted.conf file:

instances 200 (original value - 60)
cps 50 30 (original values 25 30 )

First run of my test went well with no problem reported from pbs
scheduler. But during the second run the same problem has appeared:
pbs_scheduler went down.

Do you think that the above parameters are not large enough to keep the
nfs traffic from 36 processors simultaneously writing 300 Mb per
processor?

Ivan 

------------------------------------------------------------------------

On 27 Sep 2002, Joseph Landman wrote:

> On Fri, 2002-09-27 at 07:27, Ivan Oleynik wrote:
> > Hi,
> > 
> > I have a problem with PBS scheduler: every time when I run IO intensive
> > series of jobs it goes down. As a result, the whole pbs queue with other
> > jobs become suspended.
> > 
> > I could not see any useful info in sched_logs and server_logs files except
> > of noninformative messages:
> > 
> > 0001;PBS_Server;Svr;PBS_Server;Connection refused (111) in contact_sched,Could not contact Scheduler
> 
> This is actually quite informative.  What I have experienced in the past
> with PBS and heavy NFS loads is that the cluster head node runs out of
> tcp/udp slots as specified in the /etc/inetd.conf or /etc/xinetd.conf
> files.  Depending upon which one you use, you will need to bump those
> limits up a bit. 
> 
> > For this particular test I run a bunch of mpich jobs requesting just 1
> > processor per job, and the number of the submitted jobs was 6 times the
> > number of available nodes. Each job does intensive IO via NFS running over
> > Myrinet (writing files ~ 300 Mb each).
> 
> [...]
> 
> -- 
> Joseph Landman, Ph.D
> Scalable Informatics LLC
> email: landman at scalableinformatics.com
>   web: http://scalableinformatics.com
> phone: +1 734 612 4615
> 
> 
------------------------------------------------------------------------
Ivan I. Oleynik                       E-mail : oleynik at chuma.cas.usf.edu
Department of Physics
University of South Florida
4202 East Fowler Avenue                  Tel : (813) 974-8186
Tampa, Florida 33620-5700                Fax : (813) 974-5813
------------------------------------------------------------------------

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