CKA Practice Test 7 — 10 Questions

Question 1

You have a StatefulSet with 5 pods, each requiring a unique stable network identity. The StatefulSet is scaled down from 5 to 3. Which pods will be terminated?

Accepted Answer

Pods with the highest ordinals (4 and 3). When a StatefulSet is scaled down, Kubernetes terminates pods in reverse order of their ordinal indices, starting from the highest. For a StatefulSet with 5 pods (ordinals 0-4) scaled to 3, pods with ordinals 4 and 3 are terminated first, ensuring that the remaining pods (0, 1, 2) maintain their stable network identities and storage.

Answer

Random pods

Answer

Pods with the lowest ordinals (0 and 1)

Answer

Pods with the highest resource usage

Question 2

A DevOps team is deploying a stateful application that requires persistent storage with ReadWriteMany access mode across multiple pods running on different nodes in a Kubernetes cluster. Which storage solution should they choose to meet this requirement?

Accepted Answer

Configure a PersistentVolume backed by NFS and a PersistentVolumeClaim with accessModes: ReadWriteMany. NFS supports ReadWriteMany (RWX) access mode, allowing multiple pods across different nodes to read and write to the same persistent storage simultaneously. A PersistentVolume backed by NFS, combined with a PersistentVolumeClaim specifying accessModes: ReadWriteMany, meets the requirement for a stateful application needing shared storage across nodes.

Answer

Use an emptyDir volume and share it among pods via a service

Answer

Create a local PersistentVolume on each node and use nodeSelector to pin pods

Answer

Use a hostPath volume mounted in each pod with the same path on each node

Question 3

A node is NotReady. You ssh into the node and run 'systemctl status kubelet'. It shows 'Active: inactive (dead)'. What is the most appropriate next step?

Accepted Answer

systemctl start kubelet. Starting the kubelet service with systemctl start kubelet is the correct action. Investigating logs may be needed if it fails to start.

Answer

journalctl -u kubelet

Answer

kubectl delete node <node-name>

Answer

systemctl restart docker

Question 4

A Deployment's pod is stuck in Pending state. 'kubectl describe pod' shows Events: '0/4 nodes are available: 1 node(s) had taint {node-role.kubernetes.io/control-plane: }, that the pod didn't tolerate, 3 Insufficient memory'. What is the likely fix?

Accepted Answer

Increase the memory limit of the pod or add more worker nodes. The error '3 Insufficient memory' indicates that three worker nodes lack the required memory to schedule the pod. Increasing the pod's memory limit (if it's set too high) or adding more worker nodes directly addresses the resource shortage. The control-plane node's taint is irrelevant because the pod is not trying to schedule there; the issue is insufficient memory on the available worker nodes.

Answer

Remove the taint from the control-plane node

Answer

Add a toleration for the control-plane taint to the pod spec

Answer

Set nodeSelector to schedule on control-plane nodes

Question 5

A user creates a PersistentVolumeClaim with a storage class 'ssd' that does not exist in the cluster. What will happen when the PVC is created?

Accepted Answer

The PVC will remain in Pending state.. When a PersistentVolumeClaim (PVC) references a StorageClass that does not exist in the cluster, the PVC cannot be dynamically provisioned because the provisioner associated with that StorageClass is missing. Without a matching StorageClass, the system cannot create a new PersistentVolume (PV) for the PVC, and since no existing PV matches the claim (or the PVC is set to use dynamic provisioning), the PVC will remain in a Pending state indefinitely until the StorageClass is created or the PVC is deleted.

Answer

The PVC will be deleted automatically after a timeout.

Answer

The PVC will be automatically bound to any available PV.

Answer

The cluster will create the storage class automatically.

Question 6

A developer deployed a Pod that is stuck in Pending state. The cluster has one worker node with taint 'node.kubernetes.io/disk-pressure:NoSchedule'. The Pod does not specify any tolerations. What is the most likely cause?

Accepted Answer

The node has a taint that the Pod does not tolerate.. A Pod stuck in Pending state indicates the scheduler cannot find a suitable node. The cluster has a worker node with the taint 'node.kubernetes.io/disk-pressure:NoSchedule', and the Pod has no tolerations. Since taints with effect NoSchedule prevent scheduling of Pods that do not tolerate them, the Pod cannot be placed on that node, leaving it in Pending.

Answer

The Pod was evicted due to resource pressure.

Answer

The Pod requests more CPU than available on the node.

Answer

The scheduler failed to communicate with the API server.

Question 7

Which command retrieves the rollout history of a Deployment named 'web'?

Accepted Answer

kubectl rollout history deployment web. The `kubectl rollout history deployment web` command retrieves the revision history of the specified Deployment, showing each revision number and, with the `--revision` flag, the details of a specific revision. This is the standard Kubernetes command for viewing rollout history, as defined in the kubectl reference.

Answer

kubectl describe deployment web

Answer

kubectl get events --field-selector involvedObject.name=web

Answer

kubectl rollout status deployment web

Question 8

A StatefulSet named 'mysql' is deployed with 3 replicas. A developer reports that the pod 'mysql-0' is failing due to persistent volume issues. After fixing the underlying storage, they want to recreate 'mysql-0' while preserving its stable network identity. What is the correct approach?

Accepted Answer

Delete the pod 'mysql-0' using kubectl delete pod mysql-0, and let the StatefulSet controller recreate it. StatefulSet pods are managed by a controller that automatically recreates a pod with the same identity (name, hostname, and stable network identity) when it is deleted. Deleting the pod 'mysql-0' triggers the StatefulSet controller to create a new pod with the same ordinal index and persistent storage binding, preserving its stable network identity.

Answer

Delete the StatefulSet and recreate it with the same configuration

Answer

Use kubectl replace --force on the StatefulSet to recreate the pod

Answer

Scale the StatefulSet down to 0 replicas, then scale back up to 3

Question 9

A HorizontalPodAutoscaler (HPA) is configured for a Deployment with targetCPUUtilizationPercentage: 80. The current CPU utilization is 90%. The deployment has minReplicas: 3 and maxReplicas: 10. What will the HPA do?

Accepted Answer

It increases the number of replicas.. The HPA increases the number of replicas because the current CPU utilization (90%) exceeds the target of 80%. The HPA calculates the desired replica count using the formula: desiredReplicas = ceil[currentReplicas * (currentMetricValue / targetMetricValue)], which yields ceil[3 * (90/80)] = ceil[3.375] = 4 replicas. This scales the deployment up to reduce per-pod CPU load, staying within the configured minReplicas (3) and maxReplicas (10).

Answer

It does nothing because the utilization is within the acceptable range.

Answer

It adds a new node to the cluster.

Answer

It decreases the number of replicas to reduce CPU usage.

Question 10

A pod 'my-pod' in the 'default' namespace cannot resolve the service 'db-service' in the 'production' namespace. Which DNS name should be used to reach the service from 'my-pod'?

Accepted Answer

db-service.production.svc.cluster.local. Kubernetes DNS resolves services across namespaces using the fully qualified domain name (FQDN) format `..svc.cluster.local`. Since 'my-pod' is in the 'default' namespace and 'db-service' is in the 'production' namespace, the short name 'db-service' will not resolve; the FQDN must include the namespace and the cluster domain suffix to reach the service.

Answer

db-service

Answer

db-service.production.pod.cluster.local

Answer

production.db-service.svc.cluster.local