[slurm-users] job priority keeping resources from being used?

[c b]

On my low resource jobs I'm setting the time to 1 hour, and on my large
ones I'm setting time=unlimited.

Is the unlimited part the problem?  I have that setting because in my
cluster there are some machines that come in and out during the day via
reservations, and I want to keep these larger jobs from running on those
machines.





On Fri, Nov 1, 2019 at 10:56 AM Burian, John <
John.Burian at nationwidechildrens.org> wrote:

> Are you setting realistic job run times (sbatch –t <time>)?
>
>
>
> Slurm won’t backfill low priority jobs (with low resource requirements) in
> front of a high priority job (blocked waiting on high resource
> requirements) if it thinks the low priority jobs will delay the eventual
> start of the high priority job. If all jobs are submitted with the same job
> run time, then Slurm will never backfill, because as far as Slurm knows,
> the low priority jobs will take longer to finish than just waiting for the
> current running jobs to finish.
>
>
>
> John
>
>
>
>
>
> *From: *slurm-users <slurm-users-bounces at lists.schedmd.com> on behalf of
> c b <breedthoughts.www at gmail.com>
> *Reply-To: *Slurm User Community List <slurm-users at lists.schedmd.com>
> *Date: *Friday, November 1, 2019 at 10:30 AM
> *To: *"slurm-users at lists.schedmd.com" <slurm-users at lists.schedmd.com>
> *Subject: *[slurm-users] job priority keeping resources from being used?
>
>
>
> [WARNING: External Email - Use Caution]
>
>
>
> Hi,
>
>
>
> Apologies for the weird subject line...I don't know how else to describe
> what I'm seeing.
>
>
>
> Suppose my cluster has machines with 8 cores each.  I have many large high
> priority jobs that each require 6 cores, so each machine in my cluster runs
> one of each of these jobs at a time.  However, I also have lots of small
> jobs that each require one core, and these jobs have low priority so in my
> queue they are behind all my large jobs.
>
>
>
> In theory, these small jobs could slip in and run alongside the large
> jobs, but I'm not seeing that happen.  So my machines have two cores
> sitting idle when they could be doing work.  How do I configure slurm to
> run these jobs better?
>
>
>
> thanks for any help.
>
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.schedmd.com/pipermail/slurm-users/attachments/20191101/ecbd288f/attachment-0001.htm>