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CRC Forcing Jobs to Run in Sequence via SLURM
Occasionally it might be necessary for your jobs to run in a particular sequence. This document will describe how to force a submitted job to wait on the completion of another job before it executes.
Use --dependency=afterok feature
In order to get a job to wait (block) and not run until another job has completed successfully, you must use the SLURM parameter --dependency. For example, once you submit your first job you will receive a jobID number. You can now use this jobID on subsequent sbatch commands to force your jobs to run in sequence by specifying the option --dependency=afterok:jobID as follows:
Your job script must be the last parameter i.e. sbatch myJobScript.slurm --dependency=afterok:JobID does not work. Order matters.
Using this option, the second job will be put in a 'Dependency' state until the first job completes successfully. Submitting multiple jobs in an automated fashion will require some scripting (i.e. bash, tcsh, perl) to run the sbatch command in a loop while trapping the jobID of each job into a variable. This variable can then be used to represent the jobID in subsequent calls to sbatch. The technical details of a script like this are beyond the scope of this document.
It is possible to submit what are called "singleton" jobs defined as:
This job can begin execution after any previously launched jobs sharing the same job name and user have terminated.