What are Workloads?

A workload is an application running on the cluster. This application can be a single component or multiple components that work together, all running inside a set of pods. A Pod in Kubernetes is the smallest deployable unit and represents a group of one or more containers that share storage, network, and specifications on how to run them.

Pods have a defined lifecycle in Kubernetes. For example, once a pod is running in your cluster, if a critical fault occurs on the node where that pod is running, all the pods on that node will fail. Kubernetes treats such a failure as final, meaning it will not try to recover the failed pods on the faulty node. Instead, you would need to create new pods to replace the failed ones, even if the node becomes healthy again later.

However, managing each Pod individually can be complex and time-consuming. To make this easier, Kubernetes provides workload resources that manage sets of pods on your behalf. These resources configure controllers, which are responsible for ensuring that the correct number of the correct type of pods are always running, based on the state you have specified.

For example, a Deployment is a type of workload resource that manages a set of identical pods. If one of these pods fails or the node it’s running on fails, the Deployment controller will automatically create a new pod to replace the failed one, ensuring that the desired number of pods is always running.

Kubernetes provides several built-in workload resources:

• Deployment and Replica set
• Statefulset
• Daemonset
• Job and CronJob

In this article, we will focus on the Job/Cron Job workload.

Kubernetes Jobs and CronJobs are essential tools for managing workloads within your Kubernetes cluster. Jobs enable you to execute one-time tasks, while CronJobs automates repetitive tasks based on a defined schedule. This comprehensive guide will walk you through creating and configuring both Jobs and CronJobs, empowering you to streamline your Kubernetes workflows.