KCNA Practice Test 44 — 15 Questions

Question 1

A company uses OpenTelemetry to instrument their microservices. They want to ensure that traces from one service can be correlated with those from another service across network calls. Which OpenTelemetry concept enables this correlation?

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

Accepted Answer

Context propagation. Context propagation is the OpenTelemetry mechanism that carries trace context (trace ID, span ID, sampling flags) across service boundaries via headers such as W3C Trace Context. This allows spans from different services to be stitched into a single distributed trace.

Answer

Exporter configuration

Answer

Span attributes

Answer

Sampling

Question 2

Which component is responsible for ensuring that containers are running as specified in a Pod's specification on a node?

Accepted Answer

kubelet. The kubelet is the primary node agent that runs on each node in a Kubernetes cluster. It is responsible for ensuring that containers described in Pod specifications (PodSpecs) are running and healthy. The kubelet watches for Pod assignments from the API server, creates or terminates containers via the container runtime, and continuously reports the node and Pod status back to the control plane.

Answer

Container runtime

Answer

kube-proxy

Answer

kube-scheduler

Question 3

Which TWO statements about containers compared to virtual machines are correct? (Select 2)

Accepted Answer

Containers have lower overhead than virtual machines. Option A is correct because containers do not run a full guest OS or hardware emulation layer; they are just isolated processes on the host kernel, so CPU, memory, and storage overhead is significantly lower than running a hypervisor plus a complete VM. Option B is correct because containers are lightweight by design and share the host operating system kernel through features like namespaces and cgroups, rather than booting their own kernel. Option C is incorrect because virtual machines do not share the host OS kernel; each VM runs its own guest OS and kernel on virtualized hardware. Option D is incorrect because it is containers, not VMs, that share the host kernel; each container does not run its own operating system kernel. Option E is incorrect because VMs generally provide stronger isolation than containers, since the hypervisor separates each VM from the host and from other VMs, whereas containers share the same kernel.

Answer

Virtual machines share the host OS kernel

Answer

Each container runs its own operating system kernel

Answer

Virtual machines provide weaker isolation than containers

Question 4

A pod is stuck in 'Pending' state. After running 'kubectl describe pod', you see the event: '0/3 nodes are available: 3 Insufficient cpu'. What is the most likely cause?

Accepted Answer

The pod's CPU request exceeds the available CPU on all nodes. The pod is stuck in 'Pending' state because the Kubernetes scheduler cannot find a node that satisfies the pod's resource requirements. The event '0/3 nodes are available: 3 Insufficient cpu' explicitly indicates that every node in the cluster lacks sufficient allocatable CPU capacity to meet the pod's CPU request. This means the sum of CPU requests across all pods on each node, plus the new pod's request, exceeds the node's CPU capacity, causing the scheduler to leave the pod unscheduled.

Answer

The pod is exceeding its memory limit

Answer

The network plugin is not installed

Answer

The container image is too large

Question 5

Which TWO of the following are common characteristics of serverless computing? (Choose two.)

Accepted Answer

Auto-scaling to zero when idle. Option A (Auto-scaling to zero when idle) is correct because serverless platforms such as AWS Lambda, Azure Functions, and Google Cloud Functions provision no compute instances when there are no invocations, so you pay nothing during idle periods and capacity scales down to zero automatically. Option B (Event-driven execution) is correct because serverless functions are invoked in response to events — HTTP requests via API Gateway, object uploads to S3, messages in SQS, database changes, or scheduled timers — rather than running continuously. Option C is incorrect because manual scaling based on predicted load describes traditional provisioned servers or reserved capacity, not the automatic, demand-based scaling of serverless. Option D is incorrect because serverless abstracts away servers entirely; there are no always-on dedicated servers allocated to the customer. Option E is incorrect because serverless functions are designed to be short-lived and stateless, with state externalized to services like DynamoDB, S3, or Redis rather than held in long-running processes.

Answer

Manual scaling based on predicted load

Answer

Always-on dedicated servers

Answer

Long-running stateful processes

Question 6

Which component runs on every worker node and is responsible for maintaining the lifecycle of pods?

Accepted Answer

kubelet. The kubelet is the primary node agent that runs on every worker node in a Kubernetes cluster. It is responsible for ensuring that containers are running in a Pod as expected, by interacting with the container runtime (e.g., containerd or CRI-O) to start, stop, and monitor Pods based on PodSpecs received from the API server. Without the kubelet, the node cannot manage Pod lifecycles.

Answer

container runtime

Answer

kube-scheduler

Answer

kube-proxy

Question 7

You run the command 'kubectl get pods -n default' and see no pods listed. However, you are sure there should be pods. What is the most likely cause?

Accepted Answer

The current kubectl context is connected to a different cluster. `kubectl` uses the current context defined in the kubeconfig file to determine which cluster and namespace to communicate with. If the context points to a different cluster (e.g., a test or staging cluster), the `kubectl get pods -n default` command will query that cluster's API server, which may have no pods in the `default` namespace, even though the intended cluster has pods. This is a common misconfiguration when working with multiple clusters.

Answer

All pods are in the 'kube-system' namespace

Answer

The kube-apiserver is down

Answer

The pods are in the 'Pending' state and not listed

Question 8

In event-driven architecture, which component is responsible for decoupling event producers from consumers?

Accepted Answer

Event broker. The event broker (e.g., Apache Kafka, RabbitMQ, or AWS EventBridge) acts as an intermediary that receives events from producers and forwards them to consumers. By decoupling the two, the producer does not need to know the consumer's location or status, and the consumer does not need to be actively listening when the event is published. This enables asynchronous, scalable, and fault-tolerant communication in event-driven architectures.

Answer

Event consumer

Answer

Event producer

Answer

API gateway

Question 9

Drag and drop the steps to scale a Kubernetes Deployment horizontally into the correct order.

Accepted Answer

Run `kubectl scale` deployment, then check pods are created, then verify deployment status, then monitor rollout, then adjust resources if needed.. Scale command, check pods, verify deployment, monitor rollout, and adjust resources if needed.

Answer

Check pods are created, then run `kubectl scale` deployment, then verify deployment status, then monitor rollout, then adjust resources if needed.

Answer

Run `kubectl scale` deployment, then verify deployment status, then check pods are created, then monitor rollout, then adjust resources if needed.

Answer

Monitor rollout, then run `kubectl scale` deployment, then check pods are created, then verify deployment status, then adjust resources if needed.

Question 10

Which of the following is a benefit of container orchestration?

Accepted Answer

Self-healing of failed containers. Container orchestration platforms like Kubernetes provide self-healing capabilities by automatically restarting failed containers, rescheduling them on healthy nodes, and replacing or terminating containers that fail health checks. This ensures high availability and reduces manual intervention, which is a core benefit of orchestration.

Answer

Requires a hypervisor for each container

Answer

Manual scaling of containers

Answer

Static infrastructure with no changes

Question 11

Drag and drop the steps to create a ConfigMap from a file in Kubernetes into the correct order.

Accepted Answer

Prepare the file, then create the ConfigMap, then verify it, then describe it, then use it in a Pod.. The correct sequence to create a ConfigMap from a file in Kubernetes is: first prepare the configuration file, then create the ConfigMap using kubectl create configmap, next verify the ConfigMap with kubectl get configmaps, then optionally describe it with kubectl describe configmap, and finally use it in a Pod as environment variables or volume mounts. This order ensures the ConfigMap is available and correctly configured before consumption.

Answer

Prepare the file, then create the ConfigMap, then describe it, then verify it, then use it in a Pod.

Answer

Prepare the file, then create the ConfigMap, then use it in a Pod, then verify it, then describe it.

Answer

Create the ConfigMap, then prepare the file, then verify it, then describe it, then use it in a Pod.

Question 12

Match each cloud native concept to its definition.

Accepted Answer

Microservices: An architectural style that structures an application as a collection of loosely coupled services.. The correct matches are: Microservices with loosely coupled services, Service Mesh with service-to-service communication, Serverless with cloud provider managing resources, and Orchestration with automated management. Common confusions include swapping definitions between Microservices and Service Mesh, or between Serverless and Orchestration.

Answer

Microservices: A dedicated infrastructure layer for handling service-to-service communication.

Answer

Serverless: The automated configuration, coordination, and management of computer systems.

Question 13

In Flux CD, which component is responsible for reconciling the cluster state with the source of truth defined in a Git repository?

Accepted Answer

Kustomize controller. The Kustomize controller in Flux CD is responsible for reconciling the cluster state with the desired state defined in a Git repository. It continuously monitors Kustomization custom resources, fetches the referenced source artifact (e.g., from a GitRepository), builds the manifests using Kustomize, and applies them to the cluster. This controller ensures that the actual state matches the declared state, making it the core reconciler for GitOps workflows in Flux.

Answer

Source controller

Answer

Helm controller

Answer

Notification controller

Question 14

You create a Deployment with 'replicas: 3' and update the pod template without changing the selector. After the update, you notice that only the new Pods are running, but old Pods have been terminated. What is the default update strategy?

Accepted Answer

RollingUpdate. The default update strategy for a Deployment in Kubernetes is RollingUpdate. When you update the pod template (e.g., changing the container image), the Deployment controller creates new ReplicaSets with the updated template and gradually scales down the old ReplicaSet while scaling up the new one, ensuring zero downtime. Since only new Pods are running and old Pods have been terminated, this confirms the default behavior of a rolling update, which replaces Pods incrementally without manual intervention.

Answer

OnDelete

Answer

BlueGreen

Answer

Recreate

Question 15

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

Accepted Answer

Auto-scaling to zero. The defining characteristic of FaaS is that functions are event-driven and the platform automatically scales the number of running instances from zero up to meet demand, then back down to zero when idle. This means you pay only for actual execution time, not for idle capacity. Auto-scaling to zero is what fundamentally separates FaaS from container-as-a-service or VM-based models.

Answer

Stateful execution

Answer

Always running instances

Answer

Manual scaling