4.4. Managing workloads with the JobSet Operator

Procedure

1. Create a new project by running the following command:

   $ oc new-project <my_namespace>

2. Create a file named jobset.yaml:

   apiVersion: jobset.x-k8s.io/v1alpha2
   kind: JobSet
   metadata:
     name: pytorch
   spec:
     replicatedJobs:
     - name: workers
       template:
         spec:
           parallelism: 3
           completions: 3
           backoffLimit: 0
           template:
             spec:
               imagePullSecrets:
                 - name: my-registry-secret
               initContainers:
                 - name: prepare
                   image: docker.io/alpine/git:v2.52.0
                   args: ['clone', 'https://github.com/pytorch/examples']
                   volumeMounts:
                     - name: workdir
                       mountPath: /git
               containers:
                 - name: pytorch
                   image: docker.io/pytorch/pytorch:2.10.0-cuda13.0-cudnn9-runtime
                   resources:
                     limits:
                       nvidia.com/gpu: "1"
                     requests:
                       nvidia.com/gpu: "1"
                   ports:
                   - containerPort: 4321
                   env:
                   - name: MASTER_ADDR
                     value: "pytorch-workers-0-0.pytorch"
                   - name: MASTER_PORT
                     value: "4321"
                   - name: RANK
                     valueFrom:
                       fieldRef:
                         fieldPath: metadata.annotations['batch.kubernetes.io/job-completion-index']
                   - name: PYTHONUNBUFFERED
                     value: "0"
                   command:
                   - /bin/sh
                   - -c
                   - |
                     cd examples/distributed/ddp-tutorial-series
                     torchrun --nproc_per_node=1 --nnodes=3 --rdzv_id=100 --rdzv_backend=c10d --rdzv_endpoint=$MASTER_ADDR:$MASTER_PORT multinode.py 1000 100
                   volumeMounts:
                     - name: workdir
                       mountPath: /workspace
               volumes:
                 - name: workdir
                   emptyDir: {}

   where:

   spec.replicatedJobs.template.spec.parallelism

   Specifies the number of pods running at the same time.

   spec.replicatedJobs.template.spec.completions

   Specifies the total number of pods that must finish successfully for the job to be marked complete.

3. Apply the JobSet configuration by running the following command:

   $ oc apply -f jobset.yaml