4.5. CronJobs

Overview

The CronJobs page manages every CronJob held on the MCM control plane in one place. A CronJob is the workload that creates and runs a Job periodically according to a cron schedule.

What it is for:

• Managing multi-cluster CronJobs together
• Running work automatically on a schedule
• Tracking the Job creation history and status
• Checking the PropagationPolicy and OverridePolicy

Where CronJobs are used:

• Regular backups (a database backup every midnight)
• Periodic report generation (a report every Monday)
• Cache cleanup (deleting old cache entries hourly)
• System health checks (a health check every 5 minutes)
• Log rotation and cleanup

How the Screen Is Laid Out

The CronJobs page shows the CronJob list as a table.

The Elements at the Top of the Page

Element	Description
Namespace filter	Shows only the CronJobs of a particular namespace
Refresh button	Refreshes the CronJob list
Create button	Opens the dialog for creating a new CronJob
Search box	Searches by CronJob name

Table Columns

Column	Description	Sortable
Name	The CronJob name	✅
Namespace	The namespace the CronJob belongs to	✅
Schedule	The cron expression and its description ("*/5 * * * *" -- every 5 minutes, for example)	✅
Status	Active / Suspended	✅
Image	The container image name	✅
Last Schedule	When a Job last ran	✅
Age	The time since the CronJob was created	✅
Actions	The edit and delete buttons	-

How Status Is Shown

Status	Description	How it is shown
Active	The CronJob is running normally on its schedule	A green badge
Suspended	The CronJob's runs are suspended	A yellow badge

How the Schedule Is Shown

The Schedule column shows the cron expression together with a human-readable description:

• */5 * * * * → "every 5 minutes"
• 0 0 * * * → "every day at midnight"
• 0 0 * * 0 → "every Sunday at midnight"

CronJob Detail

Clicking a CronJob row opens the detail panel.

The Detail Panel Header

Element	Description
CronJob name	The name of the chosen CronJob
Namespace	The namespace the CronJob belongs to
Schedule	The cron expression (*/5 * * * *, for example)
Status	Ready / Suspended

The Action Buttons

Button	What it does
Refresh	Refreshes the CronJob information
Edit	Opens the YAML edit mode
Delete	Deletes the CronJob

The Tabs

The Overview Tab

Shows the CronJob's basic information, schedule, and status.

Basic information:

Item	Description
Name	The CronJob name
Namespace	The namespace the CronJob belongs to
Status	Ready / Suspended
Age	The time since creation
Created	When the CronJob was created

Schedule Info:

Item	Description
Schedule	The cron expression (*/5 * * * *, for example)
Schedule Description	The human-readable description of the schedule (every 5 minutes, for example)
Suspended	Yes / No
Concurrency Policy	Allow / Forbid / Replace
Starting Deadline (s)	How long a Job creation may be delayed

CronJob Status:

Item	Description
Last Schedule Time	When a Job was last scheduled
Last Successful Time	When a Job last succeeded
Active Jobs	The number of Jobs running now

History Limits:

Item	Description
Successful Jobs History	How many successful Jobs to keep (default: 3)
Failed Jobs History	How many failed Jobs to keep (default: 1)

Container images:

Shows the container images defined on the CronJob.

The Multi-Cluster Policies Tab

Shows the multi-cluster policies that apply to the CronJob.

PropagationPolicy:

Column	Description
Name	The PropagationPolicy name
Namespace	The namespace the policy belongs to
Scope	Namespace-scoped policies / cluster-scoped policies
Target Clusters	The list of target clusters

OverridePolicy:

Shown where there are per-cluster custom settings.

The Labels Tab

Shows the list of Kubernetes labels applied to the CronJob.

The Annotations Tab

Shows the list of annotations applied to the CronJob.

The Pods Tab

Shows the pods of the Jobs created by that CronJob.

Note: a CronJob creates a Job on schedule, and the Job creates the pods. When no Job is running now, no pods are shown.

Column	Description
Name	The pod name
Cluster	The cluster the pod is running on
Status	The pod state (Running / Pending / Succeeded / Failed)
Node	The node the pod is scheduled on
Restarts	The pod restart count
Age	The time since the pod was created
Actions	The view and delete buttons

The Events Tab

Shows the Kubernetes events related to the CronJob.

Creating a CronJob

Creates a new CronJob on the MCM control plane.

Fields

Field	Required	Description
Name	✅	The CronJob name
Namespace	✅	The namespace to deploy into
Container image	✅	The container image URL
Schedule	✅	The cron expression (*/5 * * * *, for example)
Command	-	The container command
Concurrency Policy	-	Allow / Forbid / Replace (default: Allow)
Starting Deadline	-	How long a Job creation may be delayed, in seconds
Successful Jobs History	-	How many successful Jobs to keep (default: 3)
Failed Jobs History	-	How many failed Jobs to keep (default: 1)

Editing the YAML

The "Edit YAML" tab lets you write the CronJob definition directly.

CronJob Operations

Editing a CronJob

1. Choose the CronJob
2. Press the "Edit" button in the detail panel
3. Change the CronJob definition in the YAML editor
4. Press the "Save" button

Suspending and Resuming a CronJob

A CronJob's runs can be suspended for a while and started again.

1. Choose the CronJob and press "Edit"
2. Change spec.suspend in the YAML:
   • true: suspended
   • false: resumed
3. Press the "Save" button

Deleting a CronJob

⚠️ Caution: deleting a CronJob deletes every Job and pod that belongs to it.

1. Choose the CronJob to delete
2. Press the "Delete" button in the detail panel
3. Type the CronJob name in the confirmation dialog
4. Press the "Delete" button

Worked Examples

Scenario 1: Creating a Regular Backup CronJob

1. Press the "Create" button
2. Enter the CronJob details:
   • Name: daily-backup
   • Namespace: production
   • Container image: my-registry/backup:v1.0
   • Schedule: 0 2 * * * (2 am every day)
   • Command: ["/backup.sh", "--full"]
3. Press the "Create" button
4. Name the target clusters with a PropagationPolicy
5. Confirm the Job is created on the Events tab

Scenario 2: Checking a CronJob's Schedule

1. Click the CronJob you want to check in the list
2. Check the schedule on the Overview tab:
   • The schedule expression
   • The schedule description (in human-readable form)
   • When it is next due to run
3. Check the last run in CronJob Status

Scenario 3: Checking the History of Failed Jobs

1. Choose the CronJob and open the Overview tab
2. Check the History Limits section:
   • Successful Jobs History: how many successful Jobs are kept
   • Failed Jobs History: how many failed Jobs are kept
3. Check the failure events on the Events tab
4. Check the failed pod's logs on the Pods tab

Scenario 4: Suspending a CronJob

1. Choose the CronJob to suspend
2. Press the "Edit" button
3. Set spec.suspend: true in the YAML
4. Press "Save"
5. Confirm the status changes to "Suspended"
6. Confirm no new Job is created

Scenario 5: Running a CronJob Across Clusters

1. Create the CronJob and apply a PropagationPolicy
2. Check the "Multi-Cluster Policies" tab in the detail panel
3. Confirm the CronJob has been shared out to the target clusters
4. Monitor the Jobs being created on schedule on each cluster
5. Check how the pods are running per cluster on the Pods tab

Related Concepts

CronJob against Job

Trait	CronJob	Job
How it runs	On a periodic schedule	Once
Trigger	Automatically, on the cron schedule	Runs as soon as it is created
Job creation	Creates a new Job each schedule	A single Job created directly
Where it is used	Regular backups, reports	Migrations, batch processing
Management	Creates and deletes Jobs automatically	Created and deleted by hand

The Cron Expression

A cron expression is made up of five fields:

Common examples:

Expression	Description
*/5 * * * *	Every 5 minutes
0 * * * *	On the hour, every hour
0 0 * * *	Every day at midnight
0 2 * * *	Every day at 2 am
0 0 * * 0	Every Sunday at midnight
0 0 1 * *	The 1st of every month, at midnight
0 0 1 1 *	1 January every year, at midnight

The Concurrency Policy

Policy	Description
Allow	Allows a new Job even if the previous one has not finished (the default)
Forbid	Skips creating a new Job while the previous one is running
Replace	Cancels the previous Job and replaces it with the new one

The Starting Deadline

• How late a Job may start after its scheduled time
• Past that, the Job creation is skipped
• It affects how a backlog of Jobs is handled after cluster downtime

For example startingDeadlineSeconds: 200

• A Job may be created only within 200 seconds of the scheduled time
• After 200 seconds that scheduled run is skipped

History Limits

• successfulJobsHistoryLimit: how many successful Jobs to keep (default: 3)
• failedJobsHistoryLimit: how many failed Jobs to keep (default: 1)

Beyond these limits, the oldest Jobs are deleted automatically.

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Next Steps

• ConfigMaps -- managing multi-cluster ConfigMaps
• Jobs -- managing multi-cluster Jobs
• Propagation Policies -- configuring a PropagationPolicy

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