SLURM_NTASKS is only unset when no task count flags are handed to salloc (no
--ntasks, --ntasks-per-node, etc.). Can't you then assume if it's not present
in the environment you've got a single task allocated to you? So in your
generic starter script instead of using SLURM_NTASKS itself, use an expansion
with a default value of 1:
${SLURM_NTASKS:-1}
> On Jul 11, 2018, at 9:39 AM, Alexander Grund <alexander.gr...@tu-dresden.de>
> wrote:
>
> Hi Peter,
>
> thanks for the information, you are right: SLURM_NTASKS is not set if "-n" is
> not passed to salloc.
>
> I am kinda relying on what happens after I call "srun ./binary" especially
> how many instances will be started. scontrol shows this information, so I
> could parse this. But is there any better way?
> The script in question is a generic starter (wrapper) and should work no
> matter what the user passed to salloc. It should just be able to know, how
> many processes would be started by srun. How can I do that?
>
> Alex
>
>
> Am 11.07.2018 um 15:12 schrieb Peter Kjellström:
>> On Wed, 11 Jul 2018 14:10:51 +0200
>> Alexander Grund <alexander.gr...@tu-dresden.de> wrote:
>>
>> > Hi all,
>> >
>> > is it expected/intended that the env variable SLURM_NTASKS is not
>> > defined after salloc? It only gets defined after the an srun command.
>> > The number of tasks appear in `scontrol -d show job <jobid>` though.
>> > So is it a bug in our installation or expected?
>>
>> my salloc sets SLURM_NTASKS (if you pass -n, otherwise not). This is
>> similar to how sbatch works.
>>
>> Tested on 17.11.7
>>
>> /Peter
>>
>> --
>> Sent from my Android device with K-9 Mail. Please excuse my brevity.
>
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> Alexander Grund
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