Node Types

Broadly speaking, there are two types of machines in a production Kubernetes cluster:

• Control Plane
• Worker Nodes

The control plane is responsible for managing the cluster. It's where the API server, scheduler, and controller manager live. The control plane used to be called "master nodes", but that term is deprecated now.

When you hear the word "node" used in isolation it's usually referring to worker nodes. In fact, because I'm using GKE for Boot.dev, when I run:

kubectl get nodes

I get back:

NAME                                       STATUS   ROLES    AGE     VERSION
gk3-kube-prod-nap-1cmjprlt-92e1dc91-jmi8   Ready    <none>   5d21h   v1.25.12-gke.500
gk3-kube-prod-nap-1cmjprlt-dfe4d6de-cq0k   Ready    <none>   5d21h   v1.25.12-gke.500

These are my worker nodes. They're the machines that are actually running my containers. The control plane is fully managed by GKE, so I don't have to worry about it. That's usually fine because as the load on my cluster increases, I'm mostly concerned with scaling out my worker nodes and making sure they're healthy. The control plane is fairly static.