Job Queueing and Submission

Introduction

ALCF's Graphcore POD64 system uses Slurm for job submission and queueing. Below are some of the important commands for using Slurm. For more information refer to Slurm Documentation.

NOTE: Jobs that require IPUs will fail unless launched with srun or sbatch. NOTE: There is a single Slurm scheduler for the Graphcore POD64.

SRun

The Slurm command srun can be used to run individual Python scripts (or other programs) in parallel with other scripts on a cluster managed by Slurm. An example of srun usage is shown below. Use the --ipus= option to specify the number of IPUs required for the run.

Example:

srun --ipus=1 python mnist_poptorch.py

SBatch

Alternatively, these jobs can be submitted to the Slurm workload manager through a batch script by using the sbatch command. To do this, create a bash script (submit-mnist-poptorch-job.sh here as an example) with the commands that you want to execute.

#!/bin/sh

python mnist_poptorch.py

Then pass the bash script as an input to the sbatch command as shown below, requesting the number of IPUs required:

sbatch --ipus=1 --output=mnist-poptorch-output.log submit-mnist-poptorch-job.sh

SQueue

The squeue command provides information about jobs located in the Slurm scheduling queue.

$ squeue
             JOBID PARTITION     NAME     USER ST       TIME  NODES NODELIST(REASON)
              2572       p64 Graphcor username  R       1:12      1 gc-poplar-02

SInfo

SInfo is used to view partition and node information for a system running Slurm.

$ sinfo
PARTITION AVAIL  TIMELIMIT  NODES  STATE NODELIST
p64*         up   infinite      3   idle gc-poplar-[02-04]

For more information, see SInfo.

SCancel

SCancel is used to signal or cancel jobs, job arrays, or job steps.

scancel job_id