[slurm-users] Can job submit plugin detect "--exclusive" ?

[Christopher Benjamin Coffey]

Hello!

The job_submit plugin doesn't appear to have a way to detect whether a user requested "--exclusive". Can someone confirm this? Going through the code: src/plugins/job_submit/lua/job_submit_lua.c I don't see anything related. Potentially "shared" could be possible in some way. But trials using this do not seem to be fruitful so far.

If a user requests --exclusive, I'd like to append "--exclude=<nodes>" on to their job request to keep them off of certain nodes. For instance, we have our gpu nodes in a default partition with a high priority so that jobs don't land on them until last. And this is the same for our highmem nodes. Normally this works fine, but if someone asks for "--exclusive" this will land on these nodes quite often unfortunately.

Any ideas? Of course, I could take these nodes out of the partition, yet I'd like to see if something like this would be possible.

Thanks! :)

Best,
Chris

--
Christopher Coffey
High-Performance Computing
Northern Arizona University
928-523-1167

[Greg Wickham]

Hi Chris,

 

You mentioned “But trials using this do not seem to be fruitful so far.” . . why?

 

In our job_submit.lua there is:

    if job_desc.shared == 0 then

      slurm.user_msg("exclusive access is not permitted with GPU jobs.")

      slurm.user_msg("Remove '--exclusive' from your job submission script")

      return ESLURM_NOT_SUPPORTED

    end

 

and testing:

$ srun --exclusive --time 00:10:00 --gres gpu:1 --pty /bin/bash -i 

srun: error: exclusive access is not permitted with GPU jobs.

srun: error: Remove '--exclusive' from your job submission script

srun: error: Unable to allocate resources: Requested operation is presently disabled

 

In slurm.h the job_descriptor struct has:

        uint16_t shared;        /* 2 if the job can only share nodes with other

                                 *   jobs owned by that user,

                                 * 1 if job can share nodes with other jobs,

                                 * 0 if job needs exclusive access to the node,

                                 * or NO_VAL to accept the system default.

                                 * SHARED_FORCE to eliminate user control. */

 

If there’s a case where using “.shared” isn’t working please let us know.

 

   -Greg

[Christopher Benjamin Coffey]

Hi Greg,

Thank you! The key was to use integer boolean instead of true/false. It seems this is inconsistent for job_desc elements as some use true/false. Have a great one!

Best,
Chris

--
Christopher Coffey
High-Performance Computing
Northern Arizona University
928-523-1167

[Renfro, Michael]

For later reference, [1] should be the (current) authoritative source on data types for the job_desc values: some strings, some numbers, some booleans.

 

[1] https://github.com/SchedMD/slurm/blob/4c21239d420962246e1ac951eda90476283e7af0/src/plugins/job_submit/lua/job_submit_lua.c#L450

 

From: slurm-users <slurm-use...@lists.schedmd.com> on behalf of Christopher Benjamin Coffey <Chris....@nau.edu>
Date: Tuesday, February 22, 2022 at 11:02 AM
To: Slurm User Community List <slurm...@lists.schedmd.com>
Subject: Re: [slurm-users] Can job submit plugin detect "--exclusive" ?

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[Christopher Benjamin Coffey]

Yup, go to the source code for the specifics lol! Thanks :)

Best,
Chris

--
Christopher Coffey
High-Performance Computing
Northern Arizona University
928-523-1167