KCNA Practice Test 2 — 30 Questions

Question 1

A team wants to visualize metrics from Prometheus in a dashboard. Which tool is commonly used for this purpose?

Accepted Answer

Grafana. Grafana is the most popular visualization tool for Prometheus metrics, offering rich dashboards.

Answer

Alertmanager

Answer

Jaeger UI

Answer

Kibana

Question 2

Which TWO are benefits of using a service mesh? (Choose two.)

Accepted Answer

Observability of service-to-service communication. Service mesh provides observability (e.g., metrics, tracing) and traffic management (e.g., routing, retries) between services.

Answer

Automatic database scaling

Answer

Container image building

Answer

Load balancing of external requests

Question 3

Which component of the OpenTelemetry architecture is responsible for receiving data from instrumented applications and processing it before export?

Accepted Answer

OpenTelemetry Collector. The OpenTelemetry Collector receives, processes, and exports telemetry data.

Answer

OpenTelemetry SDK

Answer

OpenTelemetry API

Answer

OpenTelemetry exporter

Question 4

Which TWO of the following tools are commonly used for distributed tracing in cloud-native environments? (Select two.)

Accepted Answer

Zipkin. Jaeger and Zipkin are popular open-source distributed tracing systems.

Answer

Grafana

Answer

Fluentd

Answer

Prometheus

Question 5

Which of the following is the correct definition of a Service Level Indicator (SLI)?

Accepted Answer

A quantitative measure of a specific aspect of the service's reliability. An SLI is a specific metric that measures a particular aspect of service reliability, such as request latency or error rate.

Answer

A formal contract between a service provider and a customer

Answer

A target value or range for a metric, agreed upon with stakeholders

Answer

A tool for aggregating logs from multiple sources

Question 6

Which THREE of the following are important considerations when defining SLOs (Service Level Objectives)? (Select three.)

Accepted Answer

They must be aligned with business impact. SLOs should be based on SLIs, define a target (e.g., 99.9%), and include a measurement window. Cost is not a direct consideration for SLO definition.

Answer

They should include an error budget

Answer

They should minimize infrastructure cost

Question 7

Which CNCF project is primarily focused on providing a unified way to define and manage cloud-native applications using declarative configuration stored in Git?

Accepted Answer

ArgoCD. GitOps uses Git as the single source of truth for declarative infrastructure and application configuration. ArgoCD is a CNCF graduated project that implements GitOps for Kubernetes. Flux is also a GitOps tool but ArgoCD is more widely recognized as the primary GitOps project.

Answer

Helm

Answer

Prometheus

Answer

Envoy

Question 8

In GitOps with ArgoCD, what happens when the desired state in Git differs from the live state in the cluster?

Accepted Answer

ArgoCD syncs the cluster to match Git if auto-sync is enabled. ArgoCD detects drift and can automatically sync the cluster to match Git, enabling self-healing.

Answer

ArgoCD reports an error and stops working

Answer

ArgoCD deletes the Git repository

Answer

ArgoCD automatically reverts the changes in Git

Question 9

What is the primary purpose of a container registry in a CI/CD pipeline?

Accepted Answer

To store and distribute container images. A container registry stores built container images and provides a mechanism to push and pull images. It is a central component in the CI/CD workflow for image distribution.

Answer

To store source code

Answer

To manage Kubernetes secrets

Answer

To run unit tests

Question 10

Which TWO of the following are common log aggregation tools used in Kubernetes environments? (Select two)

Accepted Answer

Fluentd. Fluentd and Fluent Bit are both popular log aggregators and forwarders in Kubernetes. Loki is a log storage system, not an aggregator.

Answer

Loki

Answer

Prometheus

Answer

Jaeger

Question 11

Which THREE are valid container runtimes that implement the Kubernetes CRI? (Choose three.)

Accepted Answer

Docker (via dockershim, deprecated). containerd, CRI-O, and Docker (via dockershim, deprecated) implement CRI. rkt is discontinued and not CRI-compliant; runc is a low-level runtime, not a CRI implementation.

Answer

runc

Answer

rkt

Question 12

Which TWO of the following are recommended practices for achieving observability in a Kubernetes cluster?

Accepted Answer

Include correlation IDs in structured logs to enable tracing across services.. Including correlation IDs in structured logs is a key observability practice that enables distributed tracing across microservices. In Kubernetes, where requests often traverse multiple pods and services, correlation IDs allow you to link logs from different components into a single transaction flow, which is essential for debugging and understanding system behavior.

Answer

Use a single centralized logging solution to aggregate logs from all components.

Answer

Store all debug logs for a minimum of 90 days for compliance.

Answer

Disable leader election for monitoring components to reduce complexity.

Question 13

You run 'kubectl logs my-pod' and see: "Error from server (BadRequest): container "my-container" in pod "my-pod" is waiting to start: PodInitializing". What does this mean?

Accepted Answer

The Pod is in the process of initializing and logs are not yet available. The error 'PodInitializing' indicates that the pod's init containers are still running or the main container is waiting for init containers to complete. During this phase, the container has not started, so logs are not yet available. Option D correctly identifies that the pod is initializing and logs cannot be retrieved until the container enters the 'Running' state.

Answer

The container is running but producing no output

Answer

The container runtime is failing to start the container

Answer

The container has crashed and is restarting

Question 14

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

Accepted Answer

OCI defines the container image format specification. The Open Container Initiative (OCI) defines the Image Specification, which standardizes the format and content of container images. This ensures that any OCI-compliant image can be run by any OCI-compliant runtime, enabling interoperability across different container platforms.

Answer

OCI is governed solely by Docker Inc.

Answer

OCI only applies to Linux containers

Question 15

A DevOps engineer wants to deploy a stateful application that requires stable network identities and persistent storage. Which Kubernetes resource is most appropriate?

Accepted Answer

StatefulSet. StatefulSet is the correct choice because it is designed specifically for stateful applications that require stable, unique network identities (via headless Services and ordinal hostnames) and persistent storage (via PersistentVolumeClaims that persist across Pod rescheduling). Unlike Deployments, StatefulSet guarantees ordered, graceful deployment and scaling, which is essential for applications like databases or distributed systems that rely on stable identities.

Answer

DaemonSet

Answer

Deployment

Answer

ReplicaSet

Question 16

An application deployment in Kubernetes uses a Deployment object. During a rolling update, the new ReplicaSet fails to become healthy. What is the default behavior of the Deployment controller?

Accepted Answer

It pauses the rollout and keeps the old ReplicaSet running. By default, the Deployment controller will stop the rollout if the new pods are unhealthy, and the old ReplicaSet remains running.

Answer

It continues the rollout, ignoring the health check failures

Answer

It automatically rolls back to the previous revision

Answer

It scales down the old ReplicaSet to zero

Question 17

In the context of the 12-factor app methodology, which factor emphasizes storing configuration in environment variables?

Accepted Answer

Config. Factor III of the 12-factor app methodology states that config should be stored in environment variables to keep it separate from code.

Answer

Backing services

Answer

Dependencies

Answer

Codebase

Question 18

A team wants to ensure that at least 99.9% of all requests to their application complete within 500ms over a 30-day window. How should this requirement be classified?

Accepted Answer

Service Level Objective (SLO). An SLO is a target level of reliability, expressed as a percentage of a metric over a time window.

Answer

Service Level Agreement (SLA)

Answer

Service Level Indicator (SLI)

Answer

Key Performance Indicator (KPI)

Question 19

A company uses Prometheus for monitoring and wants to alert when the average CPU usage over 5 minutes exceeds 80%. Which PromQL query would correctly define this alert rule?

Accepted Answer

avg(rate(node_cpu_seconds_total{mode!="idle"}[5m])) > 0.8. The query should calculate the average CPU usage rate over 5 minutes and compare it to 0.8 (80%).

Answer

avg(rate(node_cpu_seconds_total{mode="idle"}[5m])) > 0.8

Answer

avg(node_cpu_seconds_total{mode!="idle"}[5m]) > 0.8

Answer

sum(rate(node_cpu_seconds_total{mode!="idle"}[5m])) > 0.8

Question 20

In a CI/CD pipeline, what is the difference between continuous delivery and continuous deployment?

Accepted Answer

Continuous delivery requires manual approval for production deployment; continuous deployment automates it. Continuous delivery ensures code is always in a deployable state but requires manual approval for production deployment. Continuous deployment automatically deploys every change to production without manual intervention.

Answer

Continuous delivery automatically deploys to production; continuous deployment does not

Answer

There is no difference; the terms are used interchangeably

Answer

Continuous deployment runs tests; continuous delivery does not