Scheduled Upgrades in Thalassa Cloud Kubernetes

Thalassa Cloud Kubernetes provides automated scheduled upgrades to keep your clusters up-to-date with the latest security patches and features. By configuring maintenance windows, you can control when upgrades are applied to your clusters while ensuring minimal disruption to your workloads.

Overview

Scheduled upgrades allow you to automatically update your Kubernetes clusters to newer versions within predefined maintenance windows. The platform will automatically schedule upgrades once a new version becomes available, ensuring your clusters remain secure and up-to-date.

How It Works

Maintenance Windows

Maintenance windows define when upgrades can be performed on your cluster. You can configure:

• Maintenance Day: Choose which day of the week maintenance can occur
• Maintenance Time: Specify the time of day (in UTC) when maintenance can start
• Upgrade Strategy: Select how aggressive you want upgrades to be

Upgrade Process

During a scheduled upgrade, the following occurs:

1. Control Plane Upgrade: The Kubernetes control plane is upgraded to the target version
2. Node Pool Updates: Any node pools with auto-upgrades enabled are automatically patched to the target version
3. Rolling Updates: Updates are applied using rolling update strategies to minimize downtime

Configuration

Setting Up Maintenance Windows

To configure maintenance windows for your cluster:

1. Navigate to your Kubernetes cluster in the Thalassa Cloud Console
2. Go to the Maintenance tab
3. Configure the following settings:

Upgrade Strategy Options

• None: Disable automatic upgrades (manual upgrades only)
• Stable: Upgrade to stable releases only (recommended for production)
• Latest: Upgrade to the latest available version (may include pre-release versions)

Maintenance Window Settings

• Day of Week: Select which day maintenance can occur (e.g., Sunday)
• Time (UTC): Specify the time when maintenance can start (e.g., 02:00 UTC)
• Duration: Maintenance windows typically last 2-4 hours depending on cluster size

Viewing Maintenance Information

You can view upcoming maintenance events and current maintenance window configurations:

Upcoming Maintenance Notifications

The platform provides clear visibility into upcoming maintenance events:

Notifications

Email Notifications

You will receive email notifications for scheduled maintenance events:

• Scheduled Maintenance: Notification when maintenance is scheduled (sent to organization owners)
• Maintenance Start: Notification when maintenance begins
• Maintenance Complete: Notification when maintenance is finished
• Maintenance Issues: Notification if any issues occur during maintenance

Console Notifications

The Thalassa Cloud Console also displays maintenance information:

• Upcoming maintenance events in the cluster overview
• Current maintenance status in real-time
• Historical maintenance logs

Best Practices

Production Clusters

• Use the Stable upgrade strategy for production environments
• Schedule maintenance during low-traffic periods
• Test upgrades in non-production environments first
• Monitor applications during and after maintenance

Development Clusters

• Consider using the Latest strategy for development clusters
• Schedule maintenance during business hours for easier monitoring

Node Pool Configuration

• Enable auto-upgrades for node pools that can tolerate brief interruptions
• Use multiple node pools to ensure high availability during upgrades

Troubleshooting

Common Issues

Upgrade Failures

• Check cluster health before maintenance windows
• Ensure sufficient resources are available
• Review logs for specific error messages

Node Pool Issues

• Verify node pool configurations are compatible with target Kubernetes version
• Check for any custom configurations that might conflict with upgrades

Application Disruptions

• Ensure applications are designed for rolling updates
• Use proper health checks and readiness probes
• Consider using multiple replicas for critical applications

Manual Upgrades

If you prefer manual control over upgrades:

1. Set the upgrade strategy to None
2. Monitor for new Kubernetes versions
3. Manually trigger upgrades when ready
4. Test upgrades in staging environments first

Manual upgrades give you complete control but require more operational overhead.

Version Compatibility

Before upgrading, ensure:

• Your applications are compatible with the target Kubernetes version
• Any custom controllers or operators support the new version
• Storage classes and persistent volumes are compatible
• Network policies and security configurations remain valid

For detailed compatibility information, refer to the Kubernetes release notes and Thalassa Cloud Kubernetes release notes.