Kubernetes CronJobs: Complete Scheduling Guide

Introduction

Kubernetes CronJobs create Jobs on a cron schedule. They are ideal for recurring tasks like database backups, report generation, or cleanup jobs.

CronJob Spec Basics

apiVersion: batch/v1 kind: CronJob metadata: name: report-generator spec: schedule: "0 2 * * *" jobTemplate: spec: template: spec: containers: - name: report image: myrepo/report:latest args: ["/app/generate-report.sh"] restartPolicy: OnFailure

Concurrency & History Policies

• concurrencyPolicy: Allow | Forbid | Replace
• successfulJobsHistoryLimit & failedJobsHistoryLimit
• Set resource requests/limits to avoid cluster overload

Timezones & DST

Kubernetes relies on node time settings. Prefer UTC schedules for predictability. Use the Timezone Converter to preview runs in different regions.

Retries & Backoff

Configure backoffLimit on Jobs and add retry logic within your workload for transient failures.

Best Practices

• Use Forbid or Replace to avoid overlapping jobs
• Log to stdout/stderr for centralized collection
• Tag images immutably and pin versions
• Add readiness checks to pre-validate dependencies