How to deploy a multi-availability zone Kubernetes cluster for High Availability

Deploying a multi-availability zone (AZ) Kubernetes cluster is crucial for ensuring high availability, particularly in the event of an AZ outage, as it allows services to continue functioning without interruption. Many cloud providers default to setting up Kubernetes clusters in a single AZ, which poses risks if that AZ fails, causing the entire cluster and its services to go offline. To achieve high availability, clusters should be distributed across multiple AZs, requiring additional setup and potentially higher costs, yet offering significant benefits for critical services. Tools like Amazon Elastic Kubernetes Service (EKS) and kubeadm facilitate the creation of such clusters by distributing control planes and worker nodes across various AZs, and employing methods like topology spread constraints can ensure applications remain operational across different zones. Gremlin provides a platform to simulate AZ failures and validate the redundancy of clusters, emphasizing the importance of making not only Kubernetes clusters but also related resources like load balancers AZ-redundant to prevent service disruptions.