Which component stores the cluster state in Kubernetes?

Which component stores the cluster state in Kubernetes?

• A. kube-apiserver
• B. kubelet
• C. etcd
• D. docker

Answer: (C)

etcd is the distributed key-value store that acts as the source of truth for the entire cluster. The API server writes and reads all Kubernetes objects and their state to etcd, so etcd holds the persistent cluster state. Other components like the kubelet run on individual nodes and talk to the API server to reconcile workloads; they don’t store the cluster’s state themselves. The container runtime (Docker) is just the on-node execution engine and likewise doesn’t hold the cluster’s state. Because etcd is designed to be highly available and strongly consistent, it is the correct place to store the cluster’s state.

etcd is the distributed key-value store that acts as the source of truth for the entire cluster. The API server writes and reads all Kubernetes objects and their state to etcd, so etcd holds the persistent cluster state. Other components like the kubelet run on individual nodes and talk to the API server to reconcile workloads; they don’t store the cluster’s state themselves. The container runtime (Docker) is just the on-node execution engine and likewise doesn’t hold the cluster’s state. Because etcd is designed to be highly available and strongly consistent, it is the correct place to store the cluster’s state.