CKA Practice Test 34 — 15 Questions

Question 1

A Deployment named 'app' has 3 replicas. The rolling update strategy is set with maxSurge=1 and maxUnavailable=1. During an update, a new ReplicaSet is created. How many pods will be in terminating state at the moment when the new ReplicaSet has 2 pods ready?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

1. With maxSurge=1 and maxUnavailable=1, the Deployment controller ensures that during a rolling update, the total number of pods across old and new ReplicaSets does not exceed desiredReplicas + maxSurge (3+1=4). When the new ReplicaSet has 2 pods ready, the controller will begin terminating old pods to bring the total down. At that exact moment, exactly 1 old pod will be in Terminating state, as the controller scales down the old ReplicaSet by 1 to maintain the surge limit.

Answer

3

Answer

0

Answer

2

Question 2

You are managing a Kubernetes cluster with three worker nodes. A deployment named 'frontend' is configured with 3 replicas. After a node failure, you notice that only 2 pods are running, and the third pod is stuck in 'Pending' state. The remaining nodes have sufficient CPU and memory. You check the deployment events and find no errors. You also verify that the PersistentVolumeClaims (PVCs) used by the deployment are bound. What is the most likely reason the third pod is not scheduled?

Accepted Answer

The pod has a nodeSelector that only matches the failed node.. A nodeSelector that exclusively matches the failed node would prevent the scheduler from placing the pod on any other node, even if those nodes have sufficient resources. Since the failed node is unavailable, the pod remains in 'Pending' state indefinitely, as no other node satisfies the constraint.

Answer

The ReplicaSet controller is not creating a new pod because the deployment's progressDeadlineSeconds has expired.

Answer

The PersistentVolumeClaims are using 'WaitForFirstConsumer' binding mode and the pod is pending because the volume is not yet bound.

Answer

The kube-scheduler is down or misconfigured.

Question 3

A CronJob is configured to run every hour. You notice that the job did not run at the scheduled time. What is the most likely reason?

Accepted Answer

The concurrency policy is set to 'Forbid' and a previous job was still running. When a CronJob's concurrency policy is set to 'Forbid', it prevents a new job from starting if the previous job is still running. If the previous job took longer than the scheduled interval (e.g., more than one hour), the next scheduled run will be skipped, causing the job not to run at the expected time. This is a common scenario where a long-running job overlaps with the next scheduled time, and the 'Forbid' policy enforces that only one job instance runs at a time.

Answer

The concurrency policy is set to 'Allow'

Answer

The previous job run succeeded and the CronJob is configured to not rerun after success

Answer

The concurrency policy is set to 'Replace'

Question 4

A system administrator needs to install a Kubernetes cluster using kubeadm. The control plane node must be initialized with a specific Pod network CIDR of 10.244.0.0/16 for Flannel. Which command should be used?

Accepted Answer

kubeadm init --pod-network-cidr 10.244.0.0/16. `kubeadm init` uses the `--pod-network-cidr` flag to specify the CIDR range for Pod IP addresses, which is required by Flannel and other CNI plugins to allocate subnets to nodes. The 10.244.0.0/16 range is the default Pod network CIDR for Flannel, ensuring proper network configuration without conflicts.

Answer

kubeadm init --service-cidr 10.244.0.0/16

Answer

kubeadm init --network-cidr 10.244.0.0/16

Answer

kubeadm init --apiserver-advertise-address 10.244.0.0

Question 5

Which of the following YAML snippets correctly defines a Kubernetes Deployment with 3 replicas and a rolling update strategy?

Accepted Answer

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deploy
spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1
      maxSurge: 1. It uses the stable `apps/v1` API version, specifies 3 replicas, and defines a `RollingUpdate` strategy with both `maxUnavailable` and `maxSurge` set to 1. This ensures that during an update, at most one Pod is unavailable and at most one extra Pod is created, maintaining application availability.

Answer

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: my-deploy
spec:
  replicas: 3
  strategy:
    type: RollingUpdate

Answer

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deploy
spec:
  replicas: 3
  strategy:
    type: RollingUpdate
    rollingUpdate:
  maxUnavailable: 1
  maxSurge: 1

Answer

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deploy
spec:
  replicas: 3
  strategy:
    type: OnDelete

Question 6

A cluster administrator wants to expand an existing PersistentVolumeClaim (PVC) that is bound to a PersistentVolume (PV) with reclaim policy Delete and storage class 'fast'. The PV was dynamically provisioned. Which condition is required for the PVC expansion to succeed?

Accepted Answer

The StorageClass 'fast' must have allowVolumeExpansion: true.. For PVC expansion to succeed with a dynamically provisioned PV, the StorageClass must have the `allowVolumeExpansion: true` field set. This field explicitly enables volume expansion for all PVCs using that StorageClass. Without it, the PVC expansion request will be rejected even if other conditions are met.

Answer

The PV must be in Released state.

Answer

The reclaim policy must be changed to Retain before expansion.

Answer

The PVC must be using access mode ReadWriteOnce.

Question 7

Which TWO components are part of the Kubernetes control plane? (Select two.)

Accepted Answer

etcd. etcd is a distributed key-value store that serves as the primary datastore for the Kubernetes cluster, storing all cluster state and configuration data. The kube-controller-manager runs controller processes that regulate the state of the cluster, such as the node controller, replication controller, and endpoints controller. Both are core control plane components that run on the master node(s).

Answer

kubelet

Answer

kube-proxy

Answer

container runtime

Question 8

A cluster administrator is configuring a Pod to use a PersistentVolumeClaim (PVC) that is dynamically provisioned using a StorageClass with volumeBindingMode: WaitForFirstConsumer. The PVC is created before the Pod. When the Pod is created, which node will the PV be provisioned on?

Accepted Answer

The node where the Pod is scheduled.. When a StorageClass uses volumeBindingMode: WaitForFirstConsumer, the PersistentVolume (PV) is not provisioned until a Pod that uses the PersistentVolumeClaim (PVC) is scheduled. The PV is then provisioned on the exact node where the Pod is scheduled, ensuring that the volume is created in the same zone or topology as the Pod. This avoids unnecessary cross-zone data transfer and ensures the PV is available locally to the Pod's node.

Answer

The PV is provisioned immediately on the node specified in the StorageClass's allowedTopologies.

Answer

Any node in the cluster that has sufficient resources for the PV.

Answer

The control plane node.

Question 9

You run 'kubectl get nodes' and one node shows 'NotReady'. You SSH into the node and run 'systemctl status kubelet'. The output shows 'active (running)'. What should you check NEXT?

Accepted Answer

Check the kubelet logs with 'journalctl -u kubelet' for errors. Since the kubelet is running but the node is NotReady, the issue is likely that the kubelet cannot communicate with the API server or has encountered an error during its operation. Checking the kubelet logs with 'journalctl -u kubelet' is the next logical step to identify specific errors, such as certificate issues, network connectivity problems, or pod lifecycle failures, which would not be visible from the service status alone.

Answer

Check if the kubelet is registered with the API server using 'kubectl get cs'

Answer

Restart the kubelet service

Answer

Check if the node has sufficient disk space

Question 10

Which of the following commands will list all PersistentVolumeClaims in a cluster?

Accepted Answer

kubectl get pvc. `kubectl get pvc` is the correct command to list PersistentVolumeClaims using the official short name. Option A lists PersistentVolumes (`pv`). Option C (`claims`) and Option D (`persistent-volume-claims` with hyphens) are invalid resource names and will result in an error.

Answer

kubectl get pv

Answer

kubectl get claims

Answer

kubectl get persistent-volume-claims

Question 11

A node has a taint 'gpu=true:NoSchedule'. A pod has a toleration 'key: gpu, operator: Exists, effect: NoSchedule'. Will the pod be scheduled on the node?

Accepted Answer

Yes, because the toleration matches the taint. A toleration with `operator: Exists` and no `value` field matches any taint that has the specified key (`gpu`) and effect (`NoSchedule`), regardless of the taint's value. The taint `gpu=true:NoSchedule` has the key `gpu` and effect `NoSchedule`, so the toleration matches it perfectly, allowing the pod to be scheduled on the node. Tolerations do not require a value when using the `Exists` operator, as it checks only for the key and effect.

Answer

Yes, only if the pod has a nodeSelector for gpu

Answer

No, because the toleration does not specify a value

Answer

No, because the node also has other taints

Question 12

A StatefulSet named 'web' uses volumeClaimTemplates to create a PVC named 'data' with storage class 'ssd'. The StatefulSet has 3 replicas. After scaling down to 2 replicas, what happens to the PVC of the third pod (web-2)?

Accepted Answer

The PVC remains and must be manually deleted if not needed. When a StatefulSet is scaled down, the associated pods are terminated, but the PVCs created via volumeClaimTemplates are not automatically deleted. This is by design to prevent accidental data loss, as the PVCs may contain stateful data that should persist even if the pod is removed. Therefore, the PVC for web-2 remains in the cluster and must be manually deleted if it is no longer needed.

Answer

The PVC is detached but not deleted

Answer

The PVC's reclaim policy determines its fate

Answer

The PVC is automatically deleted along with the pod

Question 13

Which TWO of the following are valid reclaim policies for a PersistentVolume? (Select TWO)

Accepted Answer

Retain. A is correct because the Retain reclaim policy is one of the two valid policies for PersistentVolumes in Kubernetes. When a PersistentVolume is released from its claim, the Retain policy leaves the volume and its data intact, requiring manual administrator intervention to reclaim the storage. This is defined in the PersistentVolume spec under the `persistentVolumeReclaimPolicy` field.

Answer

Recycle

Answer

Preserve

Answer