Platforms

Cron in Kubernetes

Kubernetes CronJobs create Jobs on a schedule. The schedule field uses cron syntax and the controller manages job creation.

CronJob YAML example

apiVersion: batch/v1
kind: CronJob
metadata:
  name: nightly-report
spec:
  schedule: "0 2 * * *"
  concurrencyPolicy: Forbid
  startingDeadlineSeconds: 300
  successfulJobsHistoryLimit: 3
  failedJobsHistoryLimit: 1
  jobTemplate:
    spec:
      template:
        spec:
          restartPolicy: OnFailure
          containers:
            - name: report
              image: example/report:latest

Important fields

schedule defines when Jobs are created.
concurrencyPolicy controls overlapping runs.
successfulJobsHistoryLimit controls retained successful Jobs.
failedJobsHistoryLimit controls retained failed Jobs.
startingDeadlineSeconds allows late starts within a deadline.

Common mistakes

Leaving concurrencyPolicy unset for non-idempotent jobs.
Keeping too many old Jobs.
Forgetting cluster timezone and controller behavior.

FAQ

Does Kubernetes CronJob use Linux cron syntax?

It uses a cron-like 5-field schedule for the schedule property.

How do I avoid overlapping Kubernetes CronJobs?

Set concurrencyPolicy to Forbid for jobs that should not overlap.

Related learning pages

Cron Best Practices

Production cron best practices for logging, timezones, retries, monitoring, paths, and avoiding overlapping jobs.

Cron in Linux

Learn Linux crontab basics including crontab -e, crontab -l, environment variables, logs, and safe command examples.