But won't that first process be able to use 100% of a core? What if
enough users do this such that every core is at 100% utilization? Or,
what if the application is MPI + OpenMP? In that case, that one process
on the login node could spawn multiple threads that use the remaining
cores on the login node.
Prentice
On 4/26/21 2:01 AM, Marcus Wagner wrote:
Hi,
we also have a wrapper script, together with a number of "MPI-Backends".
If mpiexec is called on the login nodes, only the first process is
started on the login node, the rest runs on the MPI backends.
Best
Marcus
Am 25.04.2021 um 09:46 schrieb Patrick Begou:
Hi,
I also saw a cluster setup where mpirun or mpiexec commands were
replaced by a shell script just saying "please use srun or sbatch...".
Patrick
Le 24/04/2021 à 10:03, Ole Holm Nielsen a écrit :
On 24-04-2021 04:37, Cristóbal Navarro wrote:
Hi Community,
I have a set of users still not so familiar with slurm, and yesterday
they bypassed srun/sbatch and just ran their CPU program directly on
the head/login node thinking it would still run on the compute node.
I am aware that I will need to teach them some basic usage, but in
the meanwhile, how have you solved this type of user-behavior
problem? Is there a preffered way to restrict the master/login
resources, or actions, to the regular users ?
We restrict user limits in /etc/security/limits.conf so users can't
run very long or very big tasks on the login nodes:
# Normal user limits
* hard cpu 20
* hard rss 50000000
* hard data 50000000
* soft stack 40000000
* hard stack 50000000
* hard nproc 250
/Ole
