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policies_loginnodes

Login-Nodes

Calculations are to be submitted as jobs. This means jobs are not to be run on login-nodes. Processes run directly on these nodes should be limited to tasks such as editing, data transfer and management, data analysis, compiling codes and debugging, as long as it is not resource intensive (memory, cpu, network and/or i/o). Any resource intensive work must be run on the compute nodes through the batch system.

Please do not impair the work of other users by cluttering login-nodes.

Therefore: Any process that is consuming extensive resources on a login-node may be killed, especially when it begins to impact other users on that node. If a process is creating significant problems on the system, the process will be killed immediately and the user will be contacted via email.

SLURM-commands are resource intensive, if not on login nodes, they are the user interaction tool with the scheduling system. Please avoid placing them in loops, like

for i in `seq ...`; do
  sbatch ... cmd $i
done

This could be replaced by a job array.

Something like watch squeue to act upon a job status is causing strain on the scheduler1). If it is about checking a job status for subsequent work, this could be implemented using job dependencies.

Also, the scheduler needs time to work: The default time between watch cycles is below the update frequency of the scheduler.

Interactive work, e.g. to test code can be executed in interactive jobs.

Repeated abuse of login-nodes may result in notification of your group administrator and potentially locking your account.

There are always better solutions, do not hesitate asking us.

1)
particularly, if invoked by numerous users
policies_loginnodes.txt · Last modified: 2019/04/10 21:09 by meesters