[slurm-users] How to deal with user running stuff in frontend node?

[Loris Bennett]

Hi Manuel,

Manuel Rodríguez Pascual <manuel.rodriguez.pascual at gmail.com> writes:

> Hi all, 
>
> Although this is not strictly related to Slurm, maybe you can
> recommend me some actions to deal with a particular user.
>
> On our small cluster, currently there are no limits to run
> applications in the frontend. This is sometimes really useful for some
> users, for example to have scripts monitoring the execution of jobs
> and taking decisions depending on the partial results.
>
> However, we have this user that keeps abusing this system: when the
> job queue is long and there is a significant time wait, he sometimes
> runs his jobs on the frontend, resulting on a CPU load of 100% and
> some delays on using it for the things it is supposed to serve (user
> login, monitoring and so).
>
> Have you faced the same issue? Is there any solution? I am thinking
> about using ulimit to limit the execution time of this jobs in the
> frontend to 5 minutes or so. This however does not look so elegant as
> other users can perform the sabe abuse on the future, and he should
> also be able to run low cpu-consuming jobs for a longer
> period. However I am not an experienced sysadmin so I am completely
> open to suggestions or different ways of facing this issue.
>
> Any thoughts?
>
> cheers, 
>
> Manuel

You can use cgroups to limit users, but you have modify the
configuration when new users are set up.  We have also had problems
automating the restart of the two daemons affected, so it is not that
elegant a solution.  However it works for us as we only set up a few new
users a week.

Cheers,

Loris

-- 
Dr. Loris Bennett (Mr.)
ZEDAT, Freie Universität Berlin         Email loris.bennett at fu-berlin.de