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KCNA · Question #166

A CronJob is scheduled to run by a user every one hour. What happens in the cluster when it's time for this CronJob to run?

The correct answer is D. CronJob controller component creates a Job. Then the Job controller creates a Pod and waits. When a CronJob is scheduled to run, the CronJob controller creates a Job object, which the Job controller then uses to create and manage the necessary Pods.

Submitted by ngozi_ng· May 4, 2026Kubernetes Fundamentals

Question

A CronJob is scheduled to run by a user every one hour. What happens in the cluster when it's time for this CronJob to run?

Options

  • AKubelet watches API Server for CronJob objects. When it's time for a Job to run, it runs the Pod
  • BKube-scheduler watches API Server for CronJob objects, and this is why it's called kube-
  • CCronJob controller component creates a Pod and waits until it finishes to run.
  • DCronJob controller component creates a Job. Then the Job controller creates a Pod and waits

How the community answered

(60 responses)
  • A
    2% (1)
  • B
    2% (1)
  • C
    5% (3)
  • D
    92% (55)

Why each option

When a CronJob is scheduled to run, the CronJob controller creates a Job object, which the Job controller then uses to create and manage the necessary Pods.

AKubelet watches API Server for CronJob objects. When it's time for a Job to run, it runs the Pod

Kubelet is responsible for running containers on a node based on Pod specifications, not for watching CronJob objects or directly creating Pods from them.

BKube-scheduler watches API Server for CronJob objects, and this is why it's called kube-

Kube-scheduler watches for newly created Pods that have no assigned node and selects a node for them; it does not watch for CronJob objects.

CCronJob controller component creates a Pod and waits until it finishes to run.

The CronJob controller creates a Job, not directly a Pod; the Job controller then manages the Pod lifecycle for that specific job.

DCronJob controller component creates a Job. Then the Job controller creates a Pod and waitsCorrect

When it's time for a CronJob to run, the CronJob controller component detects this schedule and creates a new Job object. Subsequently, the Job controller takes this newly created Job and is responsible for creating one or more Pods to execute the defined task, monitoring their completion, and ensuring the job finishes successfully.

Concept tested: Kubernetes CronJob lifecycle

Source: https://kubernetes.io/docs/concepts/workloads/controllers/cron-jobs/

Topics

#CronJob#Kubernetes Controllers#Job Resource#Workload Management

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