[slurm-users] Slurm configuration, Weight Parameter

[Jim Prewett]

Hi Sistemas,

I could be mistaken, but I don't think there is a way to require jobs on 
the 3GB nodes to request more than 2GB!

https://slurm.schedmd.com/slurm.conf.html states this: "Note that if a job 
allocation request can not be satisfied using the nodes with the lowest 
weight, the set of nodes with the next lowest weight is added to the set 
of nodes under consideration for use (repeat as needed for higher weight 
values)."

I read that to mean "if there are only 3GB nodes available, jobs will be 
run there reguardless of the memory needed."  We had a similar request but 
were unable to find a solution (and, ultimately the particular user is 
happier to not have idle machines when there's work to be done!).

If I'm misunderstanding, I'd love to know!

HTH,
Jim

On Thu, 21 Nov 2019, Sistemas NLHPC wrote:

> Hi all,
>
> Currently we have two types of nodes, one with 3GB and another with 2GB of
> RAM, it is required that in nodes of 3 GB it is not allowed to execute
> tasks with less than 2GB, to avoid underutilization of resources.
>
> This, because we have nodes that can fulfill the condition of executing
> tasks with 2GB or less.
>
> I try in the nodes configuration with the option "Weight".I send multiples
> jobs but slurm not asigned by "Weight", it's arbitrary in the order how
> send jobs. Some configuration and logs:
>
> slurm.conf
>
> NodeName=DEFAULT RealMemory=3007 Features=3007MB Weight=500 State=idle
> Sockets=2 CoresPerSocket=1
> NodeName=devcn050
>
> NodeName=DEFAULT RealMemory=3007 Features=3007MB Weight=100 State=idle
> Sockets=2 CoresPerSocket=1
> NodeName=devcn002
>
> NodeName=DEFAULT RealMemory=2000 Features=2000MB Weight=1 State=idle
> Sockets=2 CoresPerSocket=1
> NodeName=devcn001
>
> Extra information, I see that slurm assing Weight in the node.
>
> # sinfo -N -l
>
> NODELIST   NODES PARTITION       STATE CPUS    S:C:T MEMORY TMP_DISK WEIGHT
> AVAIL_FE REASON
> devcn001       1              slims*               idle       2
> 2:1:1   2000           0                1             2000MB    none
>
> devcn002       1              slims*               idle       2
> 2:1:1   3007           0             100            3007MB    none
>
> devcn050       1              slims*               idle       2
> 2:1:1   3007           0             500            3007MB    none
>
> I test other settings, such as the TRESWeigths parameter with no results,
> for example:
>
> NodeName=devcn001 TRESWeights="CPU=2.0,Mem=2000MB"
>
> Too PriorityType=priority/multifactor plugin is also activated and
> deactivated to test, but in all these cases it does not work.
>
> Thanks in advance.
>
> Regards.
>

James E. Prewett                    Jim at Prewett.org download at hpc.unm.edu
Systems Team Leader           LoGS: http://www.hpc.unm.edu/~download/LoGS/
Designated Security Officer         OpenPGP key: pub 1024D/31816D93
HPC Systems Engineer III   UNM HPC  505.277.8210