workload.md

Workload

A workload is an application that will run to completion. It can be composed by one or multiple Pods that, loosely or tightly coupled, that, as a whole, complete a task. A workload is the unit of admission in Kueue.

The prototypical workload can be represented with a Kubernetes batch/v1.Job. For this reason, we sometimes use the word job to refer to any workload, and Job when we refer specifically to the Kubernetes API.

However, Kueue does not directly manipulate Job objects. Instead, Kueue manages Workload objects that represent the resource requirements of an arbitrary workload. Kueue automatically creates a Workload for each Job object and syncs the decisions and statuses.

The manifest for a Workload looks like the following:

apiVersion: kueue.x-k8s.io/v1alpha1
kind: Workload
metadata:
  name: sample-job
  namespace: default
spec:
  queueName: user-queue
  podSets:
  - count: 3
    name: main
    spec:
      containers:
      - image: gcr.io/k8s-staging-perf-tests/sleep:latest
        imagePullPolicy: Always
        name: container
        resources:
          requests:
            cpu: "1"
            memory: 200Mi
      restartPolicy: Never

Queue name

To indicate in which LocalQueue you want your Workload to be enqueued, set the name of the LocalQueue in the .spec.queueName field.

Pod sets

A Workload might be composed of multiple Pods with different pod specs.

Each item of the .spec.pods list represents a set of homogeneous Pods and has the following fields:

• spec describes the pods using a v1/core.PodSpec.
• count is the number of pods that use the same spec.
• name is a human-readable identifier for the pod set. You can use the role of the Pods in the workload, like driver, worker, parameter-server, etc.

Priority

Workloads have a priority that influences the order in which they are admitted by a ClusterQueue. You can see the priority of the Workload in the field .spec.priority.

For a batch/v1.Job, Kueue sets the priority of the Workload based on the pod priority of the Job's pod template.

Custom workloads

As described previously, Kueue has built-in support for workloads created with the Job API. But any custom workload API can integrate with Kueue by creating a corresponding Workload object for it.

What's next

• Learn how to run jobs.