High Availability

Amazon EKS runs and scales the Kubernetes control plane across multiple AWS Availability Zones to ensure high availability. Amazon EKS automatically scales control plane instances based on load, detects and replaces unhealthy control plane instances, and automatically patches the control plane.

The EKS cluster consists of EC2 instances deployed in multiple availability zones within the region. Each instance has replicas of the services and nodes which exist across all the EC2 instances.

Each zone or instance has an active pod listening to other instances. In case of a failure of any instance, the active pod ensures seamless functioning of the application by activating the nodes from any other working cluster.

Note: EKS clusters are deployed within specific regions and each region has multiple availability zones. Example - Region : us-east-1 and the respective zones : us-east-1a, us-east-1b, us-east-1c.