KCNA Cloud Native Architecture Practice Test 10 — 15 Questions

Question 1

In the context of resiliency patterns, which pattern is designed to prevent a cascade of failures by isolating each component so that a failure in one component does not affect others?

Accepted Answer

Bulkhead. The bulkhead pattern isolates resources (e.g., thread pools, connections) so that a failure in one part of the system doesn't bring down other parts. Circuit breaker is for handling failures of external calls, not isolation.

Answer

Retry

Answer

Circuit breaker

Answer

Timeout

Question 2

Which CNCF project maturity level indicates that a project has adopted the CNCF Code of Conduct and is considered early-stage?

Accepted Answer

Sandbox. The CNCF has three maturity levels: sandbox (early-stage), incubating (growing), and graduated (mature). Sandbox projects are early-stage and have accepted the CNCF Code of Conduct.

Answer

Incubating

Answer

Graduated

Answer

Experimental

Question 3

An application requires external configuration that varies between environments (dev, staging, prod). Following the 12-factor app methodology, how should this configuration be provided?

Accepted Answer

Use environment variables. The 12-factor app methodology (Factor III: Config) explicitly states that configuration should be stored in environment variables, not in code or version-controlled files. This keeps config strictly separate from code so the same build artifact can be deployed unchanged across dev, staging, and prod by simply changing environment variables.

Answer

Store configuration in a config file that is version-controlled

Answer

Use a centralized database for configuration

Answer

Hard-code the configuration in the application code

Question 4

In a multi-cloud scenario, an organization wants to avoid vendor lock-in by abstracting infrastructure provisioning. Which tool is specifically designed to manage infrastructure as code across multiple cloud providers?

Accepted Answer

Terraform. Terraform is a declarative infrastructure-as-code tool that uses provider plugins to manage resources across AWS, Azure, GCP, and many other platforms from a single configuration language (HCL). Its provider model and state file make it the canonical choice for multi-cloud, vendor-neutral infrastructure provisioning. This directly addresses the requirement to avoid vendor lock-in by abstracting provisioning.

Answer

Helm

Answer

Istio

Answer

ArgoCD

Question 5

Which of the following is a key difference between a service mesh and an API gateway?

Accepted Answer

Service mesh manages east-west traffic between services, while API gateway manages north-south traffic from external clients. A service mesh (Istio, Linkerd) operates at the data-plane level, intercepting east-west traffic between internal microservices for mTLS, retries, and observability. An API gateway (Kong, Apigee, AWS API Gateway) sits at the network edge and manages north-south traffic — external client requests entering the cluster — handling authentication, rate limiting, and routing.

Answer

Service mesh is only used in multi-cloud environments, while API gateway is for single-cloud

Answer

Service mesh provides authentication and authorization, while API gateway does not

Answer

Service mesh handles north-south traffic, while API gateway handles east-west traffic

Question 6

An organization wants to implement a serverless function that scales to zero when not in use. Which technology is specifically designed to achieve this on Kubernetes?

Accepted Answer

Knative. Knative is a Kubernetes-based platform specifically designed to run serverless workloads, and its Serving component includes scale-to-zero as a core feature — pods are removed when there is no traffic and recreated on demand. It builds on Kubernetes primitives but adds the autoscaling and request-driven activation needed for true serverless behavior. This makes it the purpose-built answer for scale-to-zero functions on Kubernetes.

Answer

Prometheus

Answer

Istio

Answer

Kubernetes Horizontal Pod Autoscaler (HPA)

Question 7

In event-driven architecture, which pattern is commonly used to decouple producers and consumers, allowing asynchronous communication?

Accepted Answer

Event broker (message queue or event bus). An event broker (message queue or event bus) decouples producers and consumers by allowing producers to publish events without knowing who consumes them, and consumers to subscribe and process events asynchronously. This enables loose coupling, scalability, and resilience. Examples include Apache Kafka, RabbitMQ, and cloud services like AWS EventBridge.

Answer

Shared database

Answer

Circuit breaker pattern

Answer

Synchronous REST API calls

Question 8

Which TWO of the following are features of a service mesh like Istio or Linkerd? (Select 2)

Accepted Answer

Traffic management (routing, load balancing). Option B is correct because a service mesh like Istio or Linkerd deploys sidecar proxies (Envoy in Istio, linkerd2-proxy in Linkerd) alongside each workload to intercept east-west traffic and provide fine-grained traffic management such as HTTP/gRPC routing, retries, timeouts, circuit breaking, and load balancing. Option C is correct because these sidecars also emit telemetry — request metrics (e.g., Prometheus-scraped latency/error counters), distributed traces (via Zipkin/Jaeger/OpenTelemetry), and access logs — giving uniform observability without changing application code. Option A is not a service mesh feature; container image building is handled by tools like Docker BuildKit, Buildah, or Kaniko in a CI pipeline. Option D, service discovery, is a related but distinct capability typically provided by the platform (Kubernetes Services/DNS, Consul) that the mesh consumes rather than being a defining feature of the mesh itself. Option E, auto-scaling, is performed by Kubernetes controllers such as the Horizontal Pod Autoscaler or KEDA, not by the service mesh data plane.

Answer

Container image building

Answer

Service discovery

Answer

Auto-scaling of services

Question 9

Which of the following is a primary goal of the Cloud Native Computing Foundation (CNCF)?

Accepted Answer

To foster and sustain the cloud-native ecosystem of open source projects. The CNCF is a vendor-neutral foundation under the Linux Foundation whose primary mission is to foster and sustain the cloud-native ecosystem by hosting and nurturing open source projects such as Kubernetes, Prometheus, Envoy, and containerd. It provides governance, legal, and marketing support to projects rather than developing them directly. This makes option C the correct description of its core goal.

Answer

To develop the Kubernetes container orchestration platform

Answer

To host proprietary cloud-native solutions

Answer

To provide commercial support for Kubernetes

Question 10

A company wants to adopt a GitOps workflow for managing their Kubernetes clusters. Which two tools are specifically designed for implementing GitOps on Kubernetes?

Accepted Answer

Flux. Flux (A) and ArgoCD (B) are the two tools specifically designed for GitOps on Kubernetes, as both run as controllers inside the cluster and continuously reconcile the cluster's live state with the desired state declared in a Git repository. Flux watches Git repositories and applies manifests automatically, while ArgoCD provides a declarative, Git-based continuous delivery model with drift detection and sync. Terraform (C) is an infrastructure-as-code provisioning tool that applies changes on demand rather than continuously reconciling from Git, so it is not a dedicated GitOps operator. Jenkins (D) is a general-purpose CI automation server, and Helm (E) is a Kubernetes package manager for templating and releasing manifests, neither of which implements GitOps reconciliation on its own.

Answer

Terraform

Answer

Jenkins

Answer

Helm

Question 11

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

Accepted Answer

III. Config. Factor III (Config) of the 12-factor app methodology explicitly states that configuration should be stored in environment variables, separating config from code so the same build can be deployed across environments. This allows credentials, endpoints, and environment-specific values to be injected at runtime rather than baked into the artifact.

Answer

IV. Backing Services

Answer

II. Dependencies

Answer

I. Codebase

Question 12

Which service mesh component is typically deployed as a sidecar proxy alongside application containers?

Accepted Answer

Envoy proxy. Envoy proxy is the most common sidecar proxy in service meshes like Istio and Linkerd. Istiod is the control plane component, Kiali is a visualization tool, and Prometheus is a monitoring system.

Answer

Kiali

Answer

Istiod

Answer

Prometheus

Question 13

In a microservices architecture, which pattern is used to prevent cascading failures by limiting the number of concurrent requests to a service?

Accepted Answer

Bulkhead. The bulkhead pattern isolates resources (e.g., thread pools, connection pools) for different services or operations so that a failure or overload in one area does not exhaust resources and cause cascading failures. By limiting the number of concurrent requests to a service, bulkheads contain the impact of slow or failing dependencies. This is analogous to watertight compartments in a ship.

Answer

Timeout

Answer

Retry

Answer

Circuit breaker

Question 14

You are implementing an API gateway pattern for a set of microservices. Which of the following is a typical responsibility of an API gateway?

Accepted Answer

Enforcing authentication and rate limiting. An API gateway sits in front of microservices and centralizes cross-cutting concerns such as authentication, authorization, rate limiting, request routing, and TLS termination. Enforcing authentication and rate limiting is a canonical gateway responsibility because it offloads these concerns from individual services. This lets each microservice focus on business logic while the gateway handles policy uniformly.

Answer

Managing container lifecycle and scaling

Answer

Directly accessing databases to serve requests

Answer

Storing application state and session data

Question 15

Which CNCF project is at the 'Graduated' maturity level and is widely used for container orchestration?

Accepted Answer

Kubernetes. Kubernetes is the correct answer because it is the CNCF Graduated project specifically designed and widely adopted for container orchestration. It automates deployment, scaling, and management of containerized applications, making it the de facto standard in cloud-native environments. Note that Prometheus, Envoy, and Helm are also CNCF Graduated projects, but they serve different functions (monitoring, service proxy/networking, and package management respectively), not container orchestration.

Answer

Prometheus

Answer

Envoy

Answer

Helm