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:
User: Email: 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
-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.
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.