KCNA Practice Test 50 — 15 Questions

Question 1

Which component is responsible for running containers in a Kubernetes node and implements the Container Runtime Interface (CRI)?

Accepted Answer

containerd. containerd is the correct answer because it is the container runtime that directly manages container lifecycle operations (create, start, stop, delete) on a Kubernetes node and implements the Container Runtime Interface (CRI), which is the gRPC-based protocol that kubelet uses to interact with container runtimes. Kubernetes requires a CRI-compliant runtime, and containerd is a graduated CNCF project that fulfills this role by exposing the CRI API via its `cri` plugin.

Answer

kubelet

Answer

etcd

Answer

kube-proxy

Question 2

Which Kubernetes resource provides a stable IP address and DNS name to access a set of pods?

Accepted Answer

Service. A Kubernetes Service provides a stable virtual IP address and a DNS name (e.g., my-svc.namespace.svc.cluster.local) that remains constant even as the underlying pods are created, destroyed, or scaled. This abstraction allows clients to reliably reach a set of pods without needing to track individual pod IPs, which are ephemeral. Services use label selectors to dynamically route traffic to matching pods, ensuring high availability and load balancing.

Answer

Ingress

Answer

EndpointSlice

Answer

NetworkPolicy

Question 3

Which three of the following are benefits of container orchestration? (Choose three.)

Accepted Answer

High availability through replication. Container orchestration provides high availability via replicas, scaling (both manual and autoscaling), and self-healing (restarting failed containers). Bare metal performance is not a direct benefit of orchestration; it is a characteristic of containers themselves. Manual deployment is the opposite of orchestration.

Answer

Manual deployment of containers to specific hosts

Answer

Bare metal performance

Question 4

Which THREE of the following are core principles of cloud native computing as defined by the CNCF? (Select 3)

Accepted Answer

Dynamic orchestration. The CNCF defines cloud native as using microservices, containers, dynamic orchestration, and DevOps. The three correct options are microservices, containers, and dynamic orchestration. DevOps is also a principle, but the question asks for three; the other options are not core principles.

Answer

Waterfall development

Answer

Monolithic architecture

Question 5

Which of the following best describes the purpose of the CNCF (Cloud Native Computing Foundation)?

Accepted Answer

To host and promote open source cloud native projects. The CNCF's mission is to make cloud native computing ubiquitous by fostering and sustaining open source projects.

Answer

To develop proprietary cloud native software

Answer

To define the 12-factor app methodology

Answer

To provide certification exams for Kubernetes administrators

Question 6

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

Accepted Answer

Microservices packaged in containers. The CNCF defines cloud native architecture as using microservices, containers, dynamic orchestration, and DevOps.

Answer

Monolithic application design

Answer

Manual scaling of applications

Answer

Static infrastructure provisioning

Question 7

Which TWO of the following are benefits of using a container orchestration platform like Kubernetes? (Choose two.)

Accepted Answer

Self-healing by restarting failed containers. Orchestration provides automated scaling and self-healing. Manual scaling and single-node deployment are not benefits.

Answer

Inability to manage container networking

Answer

Requirement to run applications on a single node

Answer

Manual rollback of application versions

Question 8

Which THREE of the following are benefits of using an event-driven architecture? (Choose three.)

Accepted Answer

Better resilience through decoupled components. Event-driven architecture enables loose coupling, scalability, and asynchronous processing.

Answer

Simpler debugging and tracing

Answer

Reduced need for monitoring

Question 9

Which of the following is a benefit of using an API gateway pattern?

Accepted Answer

It provides a single entry point for clients and handles cross-cutting concerns. API gateway can offload cross-cutting concerns like authentication from individual microservices.

Answer

It reduces the number of microservices needed

Answer

It replaces the need for a service mesh

Answer

It stores application state

Question 10

What is the primary purpose of an API gateway in a microservices architecture?

Accepted Answer

To act as a single entry point for external clients. An API gateway acts as a single entry point for clients, routing requests to appropriate microservices and providing cross-cutting concerns like authentication and rate limiting.

Answer

To manage service-to-service communication within a cluster

Answer

To replace DNS for service discovery

Answer

To directly connect databases to clients

Question 11

A Pod is stuck in Pending state. Which of the following is the MOST likely cause?

Accepted Answer

No node has enough resources to run the Pod. A Pod stuck in Pending state means the scheduler cannot place it on a node. The most common reason is insufficient resources (CPU, memory, or ephemeral storage) on any available node, causing the scheduler to leave the Pod unscheduled. This is indicated by the Pod's status remaining Pending and typically confirmed via `kubectl describe pod` showing events like '0/1 nodes are available: 1 Insufficient cpu'.

Answer

The Pod's container is crashing

Answer

The container image has a typo

Answer

The Pod's liveness probe is failing

Question 12

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's mission is to make cloud-native computing ubiquitous by fostering and sustaining an ecosystem of open source projects. Options A and B are incorrect because CNCF does not provide commercial support or host proprietary solutions. Option D describes a specific project goal, not the foundation's overarching purpose.

Answer

To develop the Kubernetes container orchestration platform

Answer

To host proprietary cloud-native solutions

Answer

To provide commercial support for Kubernetes

Question 13

Which tool is specifically designed for distributed tracing and was originally developed by Uber?

Accepted Answer

Jaeger. Jaeger was originally developed by Uber for distributed tracing.

Answer

Prometheus

Answer

Loki

Answer

Grafana

Question 14

Which component in a service mesh is responsible for collecting telemetry data and enforcing traffic policies?

Accepted Answer

Sidecar proxy (data plane). The sidecar proxy (often Envoy) intercepts all traffic and collects metrics, traces, and logs, and also enforces traffic management rules.

Answer

Control plane

Answer

Certificate authority

Answer

Service mesh ingress gateway

Question 15

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

Accepted Answer

Auto-scaling to zero when idle. Event-driven execution and auto-scaling to zero are key serverless characteristics.

Answer

Manual scaling based on predicted load

Answer

Always-on dedicated servers

Answer

Long-running stateful processes