Control Plane and Nodes: Control Plane

We already said a Kubernetes cluster is one or more control plane nodes and worker nodes.

Control plane nodes have to be Linux, but workers can be Linux or Windows.

Almost all cloud-native apps are Linux and will run on Linux worker nodes. However, we’ll need one or more worker nodes running Windows if we have cloud-native Windows apps. Fortunately, a single Kubernetes cluster can have a mix of Linux and Windows worker nodes, and Kubernetes is intelligent enough to schedule apps to the correct nodes.

The control plane

The control plane is a collection of system services that implement the brains of Kubernetes. It exposes the API, schedules tasks, implements self-healing, manages scaling operations, and more.

The simplest setups run a single control plane node and are best suited for labs and testing. However, as previously mentioned, we should run three or five control plane nodes in production environments and spread them across availability zones for high availability.