KCNA Practice Test 27 — 15 Questions

Question 1

A pod has resource requests of 512Mi memory and 500m CPU, and limits of 1Gi memory and 1 CPU. The node has 4Gi memory and 2 CPU cores. If the pod tries to use 700m CPU, what will happen?

Accepted Answer

The pod will be allowed to use 700m CPU. The pod's CPU request is 500m, and its CPU limit is 1 CPU (1000m). When the pod attempts to use 700m CPU, it is below the limit of 1000m, so it is allowed to burst up to that amount. Kubernetes uses the CPU request for scheduling and the limit for throttling; since 700m is within the limit, no throttling occurs. The pod is not evicted or terminated because it has not exceeded its memory limit or violated any resource constraints.

Answer

The pod will be throttled to 500m CPU

Answer

The pod will be evicted from the node

Answer

The pod will be terminated for exceeding the limit

Question 2

A development team wants to deploy a serverless function that scales to zero when not in use. Which CNCF project or platform is BEST suited for this requirement?

Accepted Answer

Knative. Knative is a Kubernetes-based platform to build, deploy, and manage serverless workloads that can scale to zero. AWS Lambda is a proprietary offering, not CNCF. OpenFaaS and Kubeless are also serverless frameworks but Knative is the most prominent CNCF serverless project.

Answer

Kubeless

Answer

AWS Lambda

Answer

OpenFaaS

Question 3

What is the purpose of a readiness probe in a Kubernetes pod?

Accepted Answer

To signal that the pod is ready to accept traffic. A readiness probe in Kubernetes determines whether a container inside a pod is ready to start accepting traffic. If the probe fails, the pod is removed from the Service's endpoints, ensuring that only healthy pods receive requests. This is distinct from liveness probes, which check if the container is alive and should be restarted.

Answer

To determine if the pod should be terminated

Answer

To check if the pod is alive and restart it if not

Answer

To measure CPU usage of the container

Question 4

Which command would you use to view the logs of a container named 'web' in a pod named 'frontend' running in the 'production' namespace?

Accepted Answer

kubectl logs frontend -c web -n production. The `kubectl logs` command requires the pod name as the first positional argument, and the `-c` flag specifies the container name when a pod has multiple containers. The `-n` flag sets the namespace. The correct syntax is `kubectl logs -c -n `, which matches option B exactly.

Answer

kubectl logs -c web frontend --namespace production

Answer

kubectl logs frontend -n production container web

Answer

kubectl logs frontend web --namespace production

Question 5

A team uses Flux to manage GitOps. Which Flux component is responsible for reconciling the cluster state with the desired state defined in a Git repository?

Accepted Answer

Kustomize Controller. In Flux, the Kustomize Controller (option A) is responsible for reconciling the cluster state with the desired state defined in a Git repository. It applies Kubernetes manifests, including Kustomize overlays, to the cluster to ensure the actual state matches the desired state. The Source Controller (option B) fetches source artifacts from Git or other sources, but does not perform reconciliation. The Helm Controller (option C) manages Helm releases, and the Notification Controller (option D) handles event notifications. Therefore, the correct answer is the Kustomize Controller.

Answer

Source Controller

Answer

Helm Controller

Answer

Notification Controller

Question 6

Which TWO of the following are core principles of cloud native architecture according to the CNCF?

Accepted Answer

Microservices architecture. Options B and C are correct. Microservices architecture and dynamic orchestration are core principles of cloud native architecture according to the CNCF. Option A (static scaling) is not a core principle; cloud native emphasizes dynamic scaling. Option D (manual infrastructure management) contradicts the principle of automation. Option E (monolithic deployment) is antithetical to the microservices principle. Thus, the correct answers are B and C.

Answer

Static scaling based on predefined thresholds

Answer

Manual infrastructure management

Answer

Monolithic deployment

Question 7

Which TWO of the following statements about Kubernetes namespaces are true?

Accepted Answer

Deleting a namespace will delete all objects in it. Deleting a namespace triggers cascading deletion of all objects within it. Option D is correct because resource quotas can be applied per namespace to limit aggregate resource consumption. Option E is not entirely accurate: namespaces provide logical isolation, but dividing cluster resources among multiple users requires additional mechanisms like RBAC and resource quotas. Without those, namespaces alone do not enforce resource division.

Answer

Services in different namespaces cannot communicate with each other

Answer

Every Kubernetes object must be created in a namespace

Answer

Namespaces provide a way to divide cluster resources between multiple users

Question 8

A Deployment has a strategy of RollingUpdate with maxSurge=1 and maxUnavailable=0. The Deployment manages 3 replicas. The image is updated. What happens during the update?

Accepted Answer

One new Pod is created, and once it is ready, one old Pod is terminated. This repeats until all Pods are updated.. The RollingUpdate strategy with maxSurge=1 and maxUnavailable=0 ensures that during the update, exactly one new Pod is created above the desired replica count (surge of 1) while keeping all existing Pods running (maxUnavailable=0). Once the new Pod reaches the Ready state, one old Pod is terminated, maintaining the desired 3 replicas throughout the process. This cycle repeats until all Pods are updated, guaranteeing zero downtime.

Answer

All 3 new Pods are created, and then the old ones are terminated all at once

Answer

All 3 old Pods are terminated simultaneously before new ones start

Answer

The update fails because maxUnavailable cannot be 0

Question 9

Which two of the following are benefits of using Kubernetes for container orchestration? (Select TWO.)

Accepted Answer

Self-healing: automatically restarts failed containers. Kubernetes provides self-healing capabilities through controllers like ReplicaSets and Deployments, which monitor pod health via liveness probes. If a container fails or becomes unresponsive, the controller automatically terminates the unhealthy pod and creates a replacement to maintain the desired replica count, ensuring application resilience without manual intervention.

Answer

Integrated continuous integration pipeline

Answer

Automatic code compilation

Answer

Built-in database management

Question 10

Which THREE of the following are valid types of Kubernetes Services? (Select THREE)

Accepted Answer

LoadBalancer. (LoadBalancer) is correct because it exposes the Service externally using a cloud provider's load balancer, which automatically routes external traffic to the NodePort and ClusterIP Services. This is one of the four standard Kubernetes Service types defined in the core API.

Answer

InternalIP

Answer

ExternalName

Question 11

Which TWO of the following are features of ArgoCD that support GitOps principles?

Accepted Answer

Health status visualization of applications. ArgoCD supports GitOps by automatically syncing the cluster to the desired state defined in Git (option D) and providing health status visualization (option B) to monitor applications. Option A is incorrect because ArgoCD does not manage secrets automatically; it relies on external tools like SealedSecrets or external secret operators. Option C is incorrect because ArgoCD does not have a built-in template engine; it delegates manifest generation to tools like Kustomize or Helm. Option E is incorrect because while ArgoCD can be configured for self-healing, it is not a standalone feature; self-healing is a behavior that results from the automated sync (option D) and is not a separate feature listed in the core capabilities.

Answer

Automatic secret management

Answer

Built-in template engine for generating manifests

Answer

Self-healing by reverting manual changes

Question 12

Which THREE are examples of DORA metrics used to measure DevOps performance? (Choose 3)

Accepted Answer

Deployment Frequency. DORA metrics include Deployment Frequency, Lead Time for Changes, Mean Time to Restore (MTTR), and Change Failure Rate. Options A, D, and E are the three correct ones. Option B (Number of developers per team) is not a DORA metric. Option C (Code coverage percentage) is a software quality metric, not a DORA metric.

Answer

Number of developers per team

Answer

Code coverage percentage

Question 13

A team is deploying a microservice application on Kubernetes. They want to ensure that during rolling updates, the new version of the service receives traffic only after the readiness probe succeeds. However, they observe that the old pods are terminated before the new pods are ready, causing a brief downtime. Which configuration change should they make to the Deployment to prevent this?

Accepted Answer

Set spec.strategy.rollingUpdate.maxSurge=1 and maxUnavailable=0. Setting spec.strategy.rollingUpdate.maxSurge=1 and maxUnavailable=0 ensures that during a rolling update, new pods are created before old pods are terminated. This prevents downtime by maintaining the desired number of available pods at all times. Option B is incorrect because maxSurge=0 prevents creating new pods before terminating old ones, which can cause downtime if old pods are removed before new ones are ready. Option A is incorrect because minReadySeconds controls how long a pod must be ready before being considered available, not the order of creation/termination. Option C is incorrect because a liveness probe is for restarting unhealthy pods, not for controlling rollout behavior.

Answer

Set spec.strategy.rollingUpdate.minReadySeconds to 0

Answer

Set spec.strategy.rollingUpdate.maxSurge=0 and maxUnavailable=1

Answer

Add a liveness probe to the container spec

Question 14

Which TWO statements are true about cloud-native architecture?

Accepted Answer

Infrastructure is treated as immutable. Immutable infrastructure (e.g., replacing servers rather than patching) ensures consistency and reduces configuration drift, a key cloud-native principle. Option D is correct because microservices in cloud-native architectures are designed to be independently scalable, allowing efficient resource use. Option A is wrong because cloud-native applications typically use microservices, not monolithic architectures. Option C is wrong because cloud-native environments favor automated scaling (horizontal pod autoscaling, etc.) over manual scaling. Option E is wrong because stateful components introduce complexity and are generally avoided unless necessary; stateless components are preferred for scalability and resilience.

Answer

Applications are typically monolithic for simplicity

Answer

Manual scaling is the default approach

Answer

Stateful components are preferred for performance

Question 15

Which TWO of the following are valid Kubernetes resource types that can be used to store configuration data or secrets?

Accepted Answer

Secret. ConfigMaps and Secrets are the only dedicated Kubernetes resource types for storing configuration data and secrets, respectively. ConfigMaps store non-sensitive data as key-value pairs, while Secrets store sensitive data (base64-encoded). Other options like Volume, PersistentVolumeClaim, and ServiceAccount are not designed for this purpose.

Answer

Volume

Answer

PersistentVolumeClaim

Answer

ServiceAccount