Amazon EKS architecture

The control plane positions at least two API server instances and three etcd instances across three AWS Availability Zones within an AWS Region.

Amazon EKS actively monitors and adjusts control plane instances to maintain peak performance.

If a control plane instance falters, Amazon EKS quickly replaces it, using different Availability Zone if needed.

By running clusters across multiple Availability Zones, a reliable API server endpoint availability Service Level Agreement (SLA) is achieved.

EKS Auto Mode extends AWS management beyond the control plane to include the data plane, automating cluster infrastructure management. It integrates core Kubernetes capabilities as built-in components, including compute autoscaling, networking, load balancing, DNS, storage, and GPU support. EKS Auto Mode dynamically manages nodes based on workload demands, using immutable AMIs with enhanced security features. It automates updates and upgrades while respecting Pod Disruption Budgets, and includes managed components that would otherwise require add-on management. This option is ideal for users who want to leverage AWS expertise for day-to-day operations, minimize operational overhead, and focus on application development rather than infrastructure management.

Fargate is a serverless compute engine for containers that eliminates the need to manage the underlying instances. With Fargate, you specify your application’s resource needs, and AWS automatically provisions, scales, and maintains the infrastructure. This option is ideal for users who prioritize ease-of-use and want to concentrate on application development and deployment rather than managing infrastructure.

Karpenter is a flexible, high-performance Kubernetes cluster autoscaler that helps improve application availability and cluster efficiency. Karpenter launches right-sized compute resources in response to changing application load. This option can provision just-in-time compute resources that meet the requirements of your workload.

Managed node groups are a blend of automation and customization for managing a collection of Amazon EC2 instances within an Amazon EKS cluster. AWS takes care of tasks like patching, updating, and scaling nodes, easing operational aspects. In parallel, custom kubelet arguments are supported, opening up possibilities for advanced CPU and memory management policies. Moreover, they enhance security via AWS Identity and Access Management (IAM) roles for service accounts, while curbing the need for separate permissions per cluster.

Self-managed nodes offer full control over your Amazon EC2 instances within an Amazon EKS cluster. You are in charge of managing, scaling, and maintaining the nodes, giving you total control over the underlying infrastructure. This option is suitable for users who need granular control and customization of their nodes and are ready to invest time in managing and maintaining their infrastructure.

With Amazon EKS Hybrid Nodes, you can use your on-premises and edge infrastructure as nodes in Amazon EKS clusters. Amazon EKS Hybrid Nodes unifies Kubernetes management across environments and offloads Kubernetes control plane management to AWS for your on-premises and edge applications.