KCNA Practice Test 1 — 30 Questions

Question 1

A cloud-native application experiences intermittent failures when calling an external API. The team implements a pattern that allows the application to temporarily stop calling the failing API and serve stale data or a fallback response. Which resiliency pattern does this describe?

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

Accepted Answer

Circuit Breaker pattern. The circuit breaker pattern prevents repeated calls to a failing service, allowing the system to degrade gracefully.

Answer

Retry pattern

Answer

Bulkhead pattern

Answer

Timeout pattern

Question 2

Drag and drop the steps to troubleshoot a Pod stuck in CrashLoopBackOff into the correct order.

Accepted Answer

1. Use kubectl describe pod to check events, 2. Use kubectl logs to see application errors, 3. Check resource constraints (CPU/memory limits), 4. Verify image name and command in the pod spec, 5. Fix the issue and redeploy.. Start with describe for events, then logs for errors, check resources, verify image/command, then fix and redeploy.

Answer

1. Use kubectl logs to see application errors, 2. Use kubectl describe pod to check events, 3. Verify image name and command in the pod spec, 4. Check resource constraints (CPU/memory limits), 5. Fix the issue and redeploy.

Answer

1. Check resource constraints (CPU/memory limits), 2. Use kubectl describe pod to check events, 3. Use kubectl logs to see application errors, 4. Verify image name and command in the pod spec, 5. Fix the issue and redeploy.

Answer

1. Fix the issue and redeploy, 2. Use kubectl describe pod to check events, 3. Use kubectl logs to see application errors, 4. Check resource constraints (CPU/memory limits), 5. Verify image name and command in the pod spec.

Question 3

Which TWO of the following are characteristics of immutable infrastructure? (Select two.)

Accepted Answer

Servers are never modified after they are deployed. Immutable infrastructure means that once a server or container is deployed, it is never modified in place. If a change is needed, a new image is built and deployed, and the old instance is destroyed. This ensures consistency and eliminates configuration drift, which is a core principle of immutable deployments in Kubernetes and cloud-native environments.

Answer

Containers are used exclusively

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Infrastructure is version-controlled and tested

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Configuration updates are applied directly to running servers

Question 4

A developer wants to deploy a stateless web application that should scale to 5 replicas. Each replica must be identical and should be automatically replaced if it fails. Which Kubernetes resource should be used?

Accepted Answer

Deployment. A Deployment is the correct resource because it manages a ReplicaSet to ensure the desired number of identical, stateless pod replicas (5) are running. It provides declarative updates, self-healing (automatic replacement of failed pods), and scaling capabilities, which directly match the requirement for a stateless web application.

Answer

StatefulSet

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DaemonSet

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ReplicationController

Question 5

Drag and drop the steps to create a Kubernetes Namespace and deploy an application into it into the correct order.

Accepted Answer

Create the namespace using 'kubectl create namespace my-namespace', then deploy the application using 'kubectl apply -f deployment.yaml -n my-namespace', then verify the deployment using 'kubectl get pods -n my-namespace'.. First create namespace, then deploy resources specifying that namespace, and verify.

Answer

Deploy the application using 'kubectl apply -f deployment.yaml' without specifying a namespace, then create the namespace using 'kubectl create namespace my-namespace', then verify using 'kubectl get pods'.

Answer

Verify the deployment using 'kubectl get pods', then create the namespace using 'kubectl create namespace my-namespace', then deploy the application using 'kubectl apply -f deployment.yaml -n my-namespace'.

Answer

Create the namespace using 'kubectl create namespace my-namespace', then verify using 'kubectl get pods -n my-namespace', then deploy the application using 'kubectl apply -f deployment.yaml -n my-namespace'.

Question 6

Which TWO of the following are valid ways to assign a pod to a specific node?

Accepted Answer

nodeSelector. `nodeSelector` is a simple, built-in field in the Pod spec that matches the pod to nodes with specific labels. When you add a `nodeSelector` with a key-value pair, the scheduler only places the pod on nodes that have that exact label. This is the most straightforward way to constrain a pod to a subset of nodes.

Answer

affinity: nodeAntiAffinity

Answer

tolerations

Answer

podSelector

Question 7

What is the primary role of the OpenTelemetry Collector?

Accepted Answer

To receive, process, and export telemetry data. The OpenTelemetry Collector receives, processes, and exports telemetry data to various backends.

Answer

To replace Prometheus for metric collection

Answer

To store traces and metrics long-term

Answer

To generate traces for applications

Question 8

Which two of the following are true about ConfigMaps? (Select TWO.)

Accepted Answer

ConfigMaps are namespace-scoped. ConfigMaps are namespace-scoped objects (B) and can be mounted as volumes or exposed as environment variables (D).

Answer

ConfigMaps are automatically encrypted at rest

Answer

ConfigMaps can hold binary data

Answer

ConfigMaps are used to store sensitive configuration data

Question 9

Which TWO of the following are key characteristics of cloud-native applications? (Select two.)

Accepted Answer

Microservices architecture. Cloud-native applications are designed as microservices and use containers for deployment, enabling scalability and resilience.

Answer

Monolithic architecture

Answer

Manual scaling

Answer

Long-lived virtual machines

Question 10

In serverless computing, what is the primary characteristic of Function-as-a-Service (FaaS)?

Accepted Answer

Auto-scaling to zero. FaaS enables functions to scale automatically from zero based on demand, often event-driven.

Answer

Stateful execution

Answer

Always running instances

Answer

Manual scaling

Question 11

Which TWO of the following are CNCF graduated projects? (Select 2)

Accepted Answer

Prometheus. Prometheus and Envoy are both CNCF graduated projects. CoreDNS is also graduated, but the question asks for two; Fluentd and Helm are both graduated as well, but the correct answers here are Prometheus and Envoy.

Answer

Kyverno

Answer

Knative

Answer

ArgoCD

Question 12

Which command would you use to apply a manifest file 'deployment.yaml' to a Kubernetes cluster?

Accepted Answer

kubectl apply -f deployment.yaml. The 'kubectl apply' command is used to apply or update resources from a manifest file.

Answer

kubectl run deployment.yaml

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kubectl set image deployment.yaml

Answer

kubectl create -f deployment.yaml

Question 13

Which of the following is a key principle of the 12-factor app methodology related to managing configuration?

Accepted Answer

Use environment variables for configuration. The 12-factor app methodology states that configuration should be stored in environment variables (or external to the code) to vary between deployments without changing code. Hardcoding is the opposite. ConfigMaps are Kubernetes-specific but the principle is broader. Secrets are for sensitive data but not the only way.

Answer

Store configuration in the application code

Answer

Embed configuration in the build process

Answer

Use a configuration file in the application directory

Question 14

In a service mesh architecture, which component is responsible for intercepting and managing traffic between microservices?

Accepted Answer

Sidecar proxy. The sidecar proxy (usually Envoy) is deployed alongside each service instance and handles all incoming and outgoing traffic, enabling observability, traffic management, and security. The control plane manages configuration but does not handle data plane traffic. The API gateway is a separate component for external traffic. The service registry is a pattern but not a specific service mesh component.

Answer

Control plane

Answer

API gateway

Answer

Service registry

Question 15

Which GitOps tool is a CNCF graduated project that synchronizes Kubernetes clusters with a Git repository?

Accepted Answer

Argo CD. Argo CD is a CNCF graduated project for GitOps on Kubernetes.

Answer

Tekton

Answer

Jenkins X

Answer

Flux

Question 16

A pod is in CrashLoopBackOff state. 'kubectl logs pod' shows 'Error: cannot connect to database at db-service:5432'. The database Service exists and is reachable from other pods. What is the most likely cause?

Accepted Answer

The application's configuration has incorrect database connection details. The error indicates the application cannot connect to the database. Since other pods can reach the database, the issue is specific to this pod. A common cause is that the pod's configuration (e.g., environment variables, config file) contains wrong connection details, such as incorrect service name, port, or credentials.

Answer

The kube-proxy is not functioning

Answer

The pod's resource limits are too low

Answer

The database pod is not running

Question 17

What is the primary purpose of the CNCF (Cloud Native Computing Foundation)?

Accepted Answer

To host and support open-source cloud-native projects. The CNCF hosts, supports, and sustains open-source cloud-native projects, ensuring they are vendor-neutral and fostering community collaboration. It does not develop projects itself but provides a governance model.

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To develop proprietary cloud software

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To define cloud-native standards only

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To certify cloud providers

Question 18

Which component in an event-driven architecture is responsible for decoupling event producers from consumers?

Accepted Answer

Event broker. An event broker (or message broker) acts as an intermediary that receives events from producers and delivers them to consumers, allowing loose coupling. The API gateway handles synchronous requests. The service mesh handles service-to-service communication. The config server manages configuration.

Answer

Config server

Answer

API gateway

Answer

Service mesh

Question 19

Which THREE of the following are true about the Open Container Initiative (OCI)? (Choose 3)

Accepted Answer

OCI defines both an image spec and a runtime spec. The OCI defines the image spec and runtime spec, ensuring interoperability between container tools. containerd is an OCI-compliant runtime. Docker images are OCI-compliant. Docker itself is not a runtime spec but a platform that uses runtimes.

Answer

Docker is an OCI runtime specification

Answer

OCI is governed by the Cloud Native Computing Foundation (CNCF)

Question 20

Which TWO statements about container images are correct? (Choose two.)

Accepted Answer

Container images can be stored in a registry like Docker Hub. Container images are built in layers and can be stored in registries. They are not immutable once built (they can be overwritten), and they include only the application and dependencies, not a full OS kernel.

Answer

Container images include a full operating system kernel

Answer

Container images are immutable once built

Answer

Container images can only be built on Linux