[slurm-users] License management and invoking scontrol in the prolog

[Davide DelVento]

Thanks again, Brian, indeed that grep returns many hits, but none of
them includes lua, i.e.

 strings `which slurmctld ` | grep -i job_submit | grep -i lua

returns nothing. So I should use the C rather than the more convenient
lua interface, unless I recompile or am I missing something?

On Thu, Sep 1, 2022 at 12:30 PM Brian Andrus <toomuchit at gmail.com> wrote:
>
> I would be surprised if it were compiled without the support. However,
> you could check and run something like:
>
> strings /sbin/slurmctld | grep job_submit
>
> (or where ever your slurmctld binary is). There should be quite a few
> lines with that in it.
>
> Brian Andrus
>
> On 9/1/2022 10:54 AM, Davide DelVento wrote:
> > Thanks Brian for the suggestion, which I am now exploring.
> >
> > The documentation is a bit cryptic for me, but exploring a few things
> > and checking https://funinit.wordpress.com/2018/06/07/how-to-use-job_submit_lua-with-slurm/
> > I suspect my slurm install (provided by cluster vendor) was not
> > compiled with the lua plugin installed. Do you know how to verify if
> > that is the case or if it's something else? I don't see a way to show
> > if the plugin is actually being "seen" by slurm, and I suspect it's
> > not.
> >
> > Does anyone else have other suggestions or comment on either the
> > plugin or the prolog workaround?
> >
> > Thanks!
> >
> >
> > On Tue, Aug 30, 2022 at 3:01 PM Brian Andrus <toomuchit at gmail.com> wrote:
> >> Not sure if you can do all the things you intend, but the job_submit
> >> script is precisely where you want to check submission options.
> >>
> >> https://slurm.schedmd.com/job_submit_plugins.html
> >>
> >> Brian Andrus
> >>
> >> On 8/30/2022 12:58 PM, Davide DelVento wrote:
> >>> Hi,
> >>>
> >>> I would like to soft-enforce license utilization only when the -L is
> >>> set. My idea: check in the prolog if the license was requested and
> >>> only if it were, set the environmental variables needed for the
> >>> license.
> >>>
> >>> I looked at all environmental variables set by slurm and did not find
> >>> any related to the license as I was hoping.
> >>>
> >>> As a workaround, I could check
> >>>
> >>> scontrol show job $SLURM_JOB_ID | grep License
> >>>
> >>> and that would work, but (as discussed in other messages in this list)
> >>> the documentation at https://slurm.schedmd.com/prolog_epilog.html say
> >>>
> >>>> Prolog and Epilog scripts should be designed to be as short as possible
> >>>> and should not call Slurm commands (e.g. squeue, scontrol, sacctmgr,
> >>>> etc). [...] Slurm commands in these scripts can potentially lead to performance
> >>>> issues and should not be used.
> >>> This is a bit of a concern, since the prolog would be invoked for
> >>> every job on the cluster, and it's a prolog (rather than the epilogue
> >>> like discussed in earlier messages).
> >>>
> >>> So two questions:
> >>>
> >>> 1) is there a better workaround to check in the prolog if the current
> >>> job requested a license and/or
> >>> 2) would this kind of use of scontrol be okay or is indeed a concern
> >>>
> >>> Thanks!
> >>>
>