KCNA Practice Test 3 — 30 Questions

Question 1

Which TWO of the following are benefits of implementing progressive delivery techniques (e.g., canary releases)?

Accepted Answer

Allows testing new features with a subset of users. Progressive delivery reduces risk by gradual rollout and provides the ability to test new versions with a subset of users. It does not eliminate the need for monitoring nor does it replace CI/CD pipelines.

Answer

Replaces the need for a CI/CD pipeline

Answer

Eliminates the need for monitoring and alerting

Answer

Guarantees zero downtime

Question 2

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?

Accepted Answer

Context propagation. Context propagation allows trace context to be passed between services, enabling distributed tracing correlation.

Answer

Exporter configuration

Answer

Span attributes

Answer

Sampling

Question 3

What does the 'kubectl logs' command retrieve?

Accepted Answer

Container logs. kubectl logs fetches the standard output and standard error logs from a container in a pod.

Answer

Audit logs

Answer

Cluster events

Answer

Node logs

Question 4

Which tool is commonly used for log aggregation in Kubernetes and is designed to be lightweight?

Accepted Answer

Fluent Bit. Fluent Bit is a lightweight log processor and forwarder, often used as a DaemonSet to collect logs.

Answer

Jaeger

Answer

Prometheus

Answer

Grafana

Question 5

A CI/CD pipeline includes image scanning. What is the primary security benefit of scanning container images in the CI phase?

Accepted Answer

It prevents vulnerable images from being deployed to production. Scanning images in CI catches vulnerabilities before the image is deployed, preventing vulnerable images from reaching production.

Answer

It reduces the time it takes to build images

Answer

It automatically fixes vulnerabilities

Answer

It ensures that the image is built only once

Question 6

Which THREE are common features of progressive delivery?

Accepted Answer

Feature flags to enable/disable features. Progressive delivery uses gradual rollout, feature flags, and analysis to reduce risk.

Answer

All-at-once deployment

Answer

Manual verification for every change

Question 7

A company wants to manage its Kubernetes resources using Git as the single source of truth, with automated synchronization. Which approach should they use?

Accepted Answer

GitOps with ArgoCD or Flux. GitOps is a practice where the entire system state is described declaratively in Git, and automated tools synchronize the cluster to match. ArgoCD and Flux are popular GitOps tools.

Answer

Using Helm charts without version control

Answer

Infrastructure as Code with Terraform

Answer

Using kubectl apply -f with a CI/CD pipeline

Question 8

Which open-source project provides a unified standard for collecting and exporting telemetry data (metrics, logs, and traces) from applications?

Accepted Answer

OpenTelemetry. OpenTelemetry (OTel) is the industry standard for observability data collection and export, providing vendor-agnostic instrumentation.

Answer

Prometheus

Answer

Jaeger

Answer

Fluentd

Question 9

Which command retrieves logs from a specific container named 'sidecar' in a multi-container pod?

Accepted Answer

kubectl logs pod-name -c sidecar. The -c flag specifies the container name.

Answer

kubectl logs pod-name sidecar

Answer

kubectl logs pod-name --container sidecar

Answer

kubectl logs sidecar pod-name

Question 10

A team is implementing a multi-cloud strategy to avoid vendor lock-in. Which Kubernetes feature is most helpful for abstracting the underlying cloud provider?

Accepted Answer

Kubernetes API. The Kubernetes API server provides a consistent interface regardless of the underlying infrastructure. Namespaces organize resources, Services provide networking abstractions, and ConfigMaps store configuration.

Answer

Services

Answer

ConfigMaps

Answer

Namespaces

Question 11

A DevOps team wants to adopt a deployment pattern where a new version of an application is gradually rolled out to a small subset of users before full deployment. Which progressive delivery technique should they use?

Accepted Answer

Canary deployment. Canary deployment releases the new version to a small percentage of users initially, then gradually increases traffic.

Answer

Rolling update

Answer

Blue-green deployment

Answer

Recreate deployment

Question 12

A team wants to deploy a serverless function using Knative. Which core primitive does Knative rely on to run serverless workloads on Kubernetes?

Accepted Answer

Service. Knative Serving uses the 'Service' resource to manage serverless workloads. 'Deployment' is a lower-level resource, 'Function' is not a Kubernetes resource, and 'Pod' is too granular.

Answer

Pod

Answer

Deployment

Answer

Function

Question 13

A developer wants to deploy a function that reacts to image upload events in a cloud storage bucket. The function should scale to zero when idle. Which architecture best fits this use case?

Accepted Answer

Implement a serverless function using a FaaS platform like AWS Lambda. FaaS (Function-as-a-Service) platforms like AWS Lambda are event-driven and can scale to zero when idle, making them ideal for sporadic event-triggered workloads.

Answer

Use a long-running virtual machine to process events

Answer

Deploy a container on Kubernetes with HorizontalPodAutoscaler set to minReplicas 0

Answer

Use a Kubernetes Job triggered by a CronJob

Question 14

Which of the following is a benefit of using a service mesh?

Accepted Answer

It provides observability and traffic management. A service mesh provides observability, traffic management, and security (mTLS) without changing application code. It does not reduce the number of microservices, replace Kubernetes, or provide storage.

Answer

It eliminates the need for Kubernetes

Answer

It provides persistent storage for stateful applications

Answer

It reduces the number of microservices needed

Question 15

A development team wants to implement GitOps for their Kubernetes deployments using ArgoCD. Which ArgoCD component is responsible for monitoring the Git repository for changes and syncing the desired state to the cluster?

Accepted Answer

Application Controller. The Application Controller in ArgoCD is the component that continuously monitors the Git repository and compares the desired state (in Git) with the live state (in the cluster). It triggers sync operations when differences are detected.

Answer

Repo Server

Answer

API Server

Answer

Redis Server

Question 16

A pod in the 'production' namespace is in a CrashLoopBackOff state. The pod has been running successfully for several days. You run 'kubectl describe pod app-pod -n production' and see the message: 'OOMKilled'. What is the MOST appropriate action to resolve this issue?

Accepted Answer

Increase the memory limit in the pod's container resource specification. The 'OOMKilled' status indicates the pod's container was terminated by the Linux kernel Out-of-Memory (OOM) killer because it exceeded its configured memory limit. Since the pod ran successfully for days, this suggests a gradual memory leak or increased workload demand. Increasing the memory limit in the pod's container resource specification allows the container to use more memory before being killed, directly addressing the root cause.

Answer

Increase the CPU request for the container

Answer

Delete the namespace and redeploy all workloads

Answer

Delete and recreate the pod to clear the crash loop

Question 17

A team wants to deploy a workload that must run on every node in a Kubernetes cluster, including new nodes added later. Which resource type should they use?

Accepted Answer

DaemonSet. A DaemonSet ensures that a copy of the pod runs on every node, and automatically runs on new nodes when they are added.

Answer

Deployment

Answer

Job

Answer

StatefulSet

Question 18

Which of the following is a core principle of cloud native architecture as defined by the CNCF?

Accepted Answer

Microservices. Microservices are one of the key architectural principles of cloud native applications.

Answer

Monolithic design

Answer

Single point of failure

Answer

Manual scaling

Question 19

A Deployment manages ReplicaSets. What is the primary benefit of using a Deployment over directly managing ReplicaSets?

Accepted Answer

Deployments support rolling updates and rollbacks. The primary benefit of using a Deployment over directly managing ReplicaSets is that Deployments provide declarative updates for Pods and ReplicaSets, including built-in support for rolling updates and rollbacks. This allows you to update the desired state (e.g., a new container image version) and have the Deployment controller automatically orchestrate the transition, while also enabling you to revert to a previous revision if the update fails. Directly managing ReplicaSets would require manual steps to scale down old ReplicaSets and scale up new ones, and it lacks the automated revision history and rollback capabilities that Deployments offer.

Answer

Deployments can expose services externally

Answer

Deployments automatically configure DNS

Answer

Deployments provide persistent storage

Question 20

Which THREE are core principles of the Twelve-Factor App methodology?

Accepted Answer

Explicitly declare and isolate dependencies. The Twelve-Factor App methodology mandates that dependencies must be explicitly declared and isolated via a dependency declaration manifest (e.g., Gemfile, package.json, requirements.txt) and a dependency isolation tool (e.g., Bundler, npm, pip). This ensures that the application never implicitly depends on system-wide packages, eliminating 'it works on my machine' issues and guaranteeing consistent behavior across all environments.

Answer

Store config in codebase for traceability

Answer

Tight coupling to backing services