Kubernetes Cluster Upgrade

Overview

Kubernetes cluster upgrades ensure your cluster has the latest features, security patches, and performance improvements.

Check Current Version

View Cluster Version

Access Cluster Settings and check the current Kubernetes version:

Or via CLI:

kubectl version

Check Available Updates

View available upgrade versions:

Plan Upgrade

Before Upgrading

1. Backup Data - Export critical data
2. Test Compatibility - Verify applications work with new version
3. Review Release Notes - Check for breaking changes
4. Schedule Window - Plan for maintenance window
5. Notify Users - Inform tenant users of downtime

Upgrade Path

Check upgrade compatibility:

kubectl api-resources
kubectl convert --help

Perform Upgrade

Upgrade Approaches

• Rolling Upgrade - Gradual node updates (recommended)
• Blue-Green Upgrade - Run two clusters and switch traffic
• Canary Upgrade - Upgrade a subset first, then proceed

Upgrade Stages

1. Pre-flight Checks - Verify compatibility
2. Control Plane Upgrade - Update Kubernetes API components
3. Node Upgrade - Update compute nodes
4. Validation - Verify cluster health
5. Completion - Finalize upgrade

Step 1: Open Upgrade Action

1. In the cluster list, click the ellipsis (three-dot) menu for the cluster.
2. Click Upgrade.

Step 2: Select Target Version and Start Upgrade

1. In the New Version dropdown, select the target Kubernetes version.
2. Click Upgrade to start the process.

note

• Upgrading by +1 version is supported.
• Upgrading by +2 versions is currently under development for JupyterHub with KAI scheduler clusters.

Step 3: Monitor Upgrade Progress

1. After the process starts, status changes to Upgrading.
2. Current status shows upgrade phase details (for example, Upgrading Control Plane).
3. Wait until the cluster status returns to Running.

Step 4: Validate Cluster After Upgrade

1. Open the cluster details (click cluster name or ellipsis menu → View).
2. Open Kubectl Terminal.
3. Verify the upgraded cluster version:

kubectl version

Test Applications

Verify applications work correctly:

• Run smoke tests
• Check application logs
• Verify connectivity
• Validate data integrity

Rollback Upgrade (If Needed)

Rollback Procedure

If issues occur, rollback to previous version:

1. Navigate to Cluster Settings
2. Select Rollback Upgrade
3. Confirm rollback

Post-Rollback

After rollback:

1. Verify previous version is running
2. Investigate upgrade issue
3. Collect logs for support
4. Plan retry with different parameters

Best Practices

Planning

• Upgrade during maintenance windows
• Perform upgrades during low-traffic periods
• Coordinate with application teams
• Document upgrade decisions

Testing

• Test in non-production first
• Verify all applications
• Check data consistency
• Monitor performance

Monitoring

• Watch upgrade progress closely
• Monitor resource usage
• Check application logs
• Verify network connectivity

Troubleshooting

Common Issues

• Node takes too long to upgrade
• Pods stuck in pending state
• Network connectivity issues
• Application compatibility problems

Support

If issues occur:

1. Check cluster events:

   kubectl describe events

2. Review upgrade logs

3. Contact support with details

Next Steps

• Scale Cluster
• Manage Workloads
• Monitor Cluster Performance