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Workflow queue

To support workflows on the Perlmutter system, we offer a workflow scrontab queue for users to submit lightweight tasks which coordinate computational work.

Getting access to the workflow queue

To request access to the Perlmutter workflow queue, please fill out the Workflow Queue Request Form at the NERSC help desk.

To help us decide if your use case is appropriate for the workflow queue, you will be required to enter:

Project name:
Statement of purpose:
Estimated memory usage:
Estimated CPU usage:
Estimated data usage:
Estimated I/O:
Frequency / length of process:
Need external resources (yes/no):

Example workflow scrontab script

Scripts must include traditional Slurm flags like -q, -A, and -t. Below is an an example workflow scrontab script with a walltime of 30 days that will run once every hour. Note the #SCRON --open-mode=append line, which instructs Slurm to append any new output to the output file:

#SCRON -q workflow
#SCRON -A <account>
#SCRON -t 30-00:00:00
#SCRON -o output-%j.out
#SCRON --open-mode=append
0 */1 * * * <full_path_to_your_script>

Scrontab times are in UTC

Currently, scrontab times on Perlmutter are in UTC.

Workflow queue details

Jobs in the workflow queue may request a walltime of up to 90 days and up to one quarter of the resources (CPU and/or memory) of a Perlmutter login node.

Known issues

If an scrontab job is cancelled for any reason (e.g., by the user or ahead of an upcoming maintenance), the user must manually reenable the job by editing their scrontab file with scrontab -e and removing comment characters which were inserted by Slurm upon job cancellation.