CKA Cluster Architecture, Installation, and Configuration 3

Question 1

When upgrading a cluster with kubeadm, what is the correct order of operations?

Accepted Answer

Upgrade control plane first, then workers

Answer

You must upgrade the control plane components first with kubeadm upgrade apply, then upgrade each worker node individually.

Question 2

Which command drains a node and marks it as unschedulable before maintenance?

Accepted Answer

kubectl drain

Answer

kubectl drain evicts all pods from a node and marks it unschedulable, making it safe for maintenance.

Question 3

In a high-availability control plane, how does the kube-scheduler ensure only one instance is active at a time?

Accepted Answer

Leader election using a lease object

Answer

The kube-scheduler uses leader election via a Lease API object in the kube-system namespace so only one scheduler instance is active.

Question 4

What does the kubelet use to authenticate to the kube-apiserver in a kubeadm cluster?

Accepted Answer

A client TLS certificate in /var/lib/kubelet/pki

Answer

The kubelet uses a client certificate (in /var/lib/kubelet/pki/kubelet-client-current.pem) generated during node bootstrapping to authenticate to the API server.

Question 5

Which ConfigMap in the kube-system namespace stores the kubeadm cluster configuration?

Accepted Answer

kubeadm-config

Answer

kubeadm stores its ClusterConfiguration in the kubeadm-config ConfigMap in the kube-system namespace.

(CKA) Certified Kubernetes Administrator Practice Test

(CKA) Certified Kubernetes Administrator Practice Test

CKA Cluster Architecture, Installation, and Configuration 3