[slurm-users] Slurm commands for launching tasks: salloc and sbatch

[Loris Bennett]

Mike Mikailov <mmikailov at gmail.com> writes:

> Thank you Loris, for the further clarifications. The only question is
> who will wait forever in interactive mode? And how practical is it?
>
> Interactive mode is what its name implies - interactive, not queueing.

To me, "interactive" is the alternative to "batch" - queueing happens
with both.  Whether I submit an interactive job or a batch job, the job
can only start if the requested resources are available and the job has
a sufficiently high priority.

If you have enough nodes, you might be able to spare some to be
essentially idle most of the time, so that jobs sent to these nodes
will, in general, start quickly.  If you have a small cluster, this
might not be an option. 

> It would make more sense if the default setting for deadline would be set to a reasonable time not indefinite in Slurm. 

One person's "reasonable" may be another person's "ridiculously long".
A "reasonable time" may even vary for the same person depending on the
circumstances.  If you submit an interactive job before lunch, you might
be prepared to wait longer than if the building is going to close in 30
minutes and you will have to leave.  With '--deadline' you can decide
case by case.

Cheers,

Loris

> Sent from my iPhone
>
>> On Jul 5, 2023, at 1:43 AM, Loris Bennett <loris.bennett at fu-berlin.de> wrote:
>> 
>> Mike Mikailov <mmikailov at gmail.com> writes:
>> 
>>> About the last point. In the case of sbatch the jobs wait in the
>>> queue as long as it takes until the resources are available. In the
>>> case of interactive jobs
>>> (at least using Son of Grid Engine) they fail after a short time if no resources available. 
>> 
>> But you were referring to 'salloc' and not something SGE does.  The
>> default for 'salloc' is to wait indefinitely.  You can change this
>> behaviour with the option '--deadline':
>> 
>>   --deadline=<OPT>
>>           remove the job if no ending is possible before this deadline
>>           (start > (deadline - time[-min])).  Default is no deadline.
>>           Valid time formats are:
>>           HH:MM[:SS] [AM|PM]
>>           MMDD[YY] or MM/DD[/YY] or MM.DD[.YY]
>>           MM/DD[/YY]-HH:MM[:SS]
>>           YYYY-MM-DD[THH:MM[:SS]]]
>>           now[+count[seconds(default)|minutes|hours|days|weeks]]
>> 
>> [snip (36 lines)]
>>> 
>>> Queuing system  No  Yes  
>>> 
>>> I am not sure what you mean with the last point, since 'salloc' is also
>>> handled by the queueing system.  If the resources requested are
>>> currently not available, 'salloc' will wait until they are.
>> 
>> [snip (42 lines)]
>> 
>> -- 
>> Dr. Loris Bennett (Herr/Mr)
>> ZEDAT, Freie Universität Berlin
>> 
-- 
Dr. Loris Bennett (Herr/Mr)
ZEDAT, Freie Universität Berlin