Summary: In this blog post, we will discuss the best practices for upgrading your cloud cluster to newer versions. Upgrading your cluster to the latest version is crucial for maintaining a functioning workload and reducing downtime. We will cover major, minor, and patch upgrades, before you upgrade considerations, and the step-by-step process for applying upgrades.

Major, Minor, and Patch Upgrades:
The Kubernetes community releases new major/minor versions every three to four months, and the IBM Cloud Kubernetes Service closely follows this schedule. These upgrades introduce new features, operation changes, and may deprecate or stabilize existing features. Patch updates, which include community patches, security patches, and component updates, are released by IBM Cloud on a bi-weekly basis.

Before You Upgrade:
Before you begin the upgrade process, it is important to analyze and understand the changes included in the release. This will help you determine if you need to adjust your setup, such as changing scripts that rely on deprecated or unsupported features in the new version.

Applying Upgrades:
When applying version upgrades, it is important to take a step-by-step approach to prevent downtime for your services. Start with your development environment, followed by your QA clusters. If there are no issues, you can then upgrade your production environment. The upgrade process involves upgrading the cluster master and worker nodes.

1. Upgrade the cluster master in your development environment by running the specified command. You can track the progress with another command.
2. Next, upgrade the worker nodes in your development environment. Refer to the previous blog post mentioned in this article for guidance on worker node upgrades.
3. Test your services after upgrading the cluster master and worker nodes in your development cluster. Address any issues before proceeding to the next step.
4. Repeat steps 1 through 3 for your QA cluster or any other pre-production clusters.
5. Finally, upgrade your production clusters after completing the upgrades and testing in the pre-production clusters.

Wrap-up:
Keeping your clusters up to date with the latest Kubernetes version is crucial for a healthy workload. By following the best practices and testing your services at each step, you can prevent issues and downtime when upgrading your production clusters. Stay tuned for the next blog in this series, which will cover migrating workers to a new OS version.

FAQ:

1. How often are major/minor versions of Kubernetes released?
– The Kubernetes community releases new major/minor versions every three to four months.

2. What are patch updates?
– Patch updates are released by IBM Cloud on a bi-weekly basis and include community patches, security patches, and component updates.

3. How can I track the progress of upgrading the cluster master?
– You can use the command “ibmcloud ks cluster get –cluster ” to track the progress. Look for the “Master → Version” field in the output.

4. Should I test my services after upgrading the cluster master and worker nodes in the development cluster?
– Yes, it is important to test your services after every upgrade step to identify and address any issues before proceeding.

5. When should I upgrade my production clusters?
– Upgrade your production clusters after completing the upgrades and testing in the pre-production clusters.

Sources:
– IBM Cloud Kubernetes Service: https://cloud.ibm.com/docs/containers?topic=containers-cs_versions&interface=ui#release_lifecycle
– Kubernetes Community: https://kubernetes.io/releases/