KCNA Kubernetes Fundamentals Practice Question
Which TWO of the following are functions of the kube-controller-manager?
⚠ Common exam trap
CNCF often tests the distinction between control plane components by listing overlapping responsibilities, so the trap here is confusing the kube-controller-manager's role in managing controllers (like the node controller and ReplicaSet controller) with the kube-scheduler's scheduling function or kube-proxy's network rule implementation.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Running the node controller to monitor node health
The kube-controller-manager is a core control plane component that runs controller processes, including the node controller, which monitors node health by checking the NodeStatus and NodeLease objects. If a node becomes unreachable (e.g., the node controller fails to receive a heartbeat within the --node-monitor-grace-period, default 40 seconds), it marks the node as Unhealthy and eventually taints it to trigger pod eviction. This makes option D correct because the node controller is a built-in controller within the kube-controller-manager.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Serving the Kubernetes API
Why it's wrong here
The API is served by kube-apiserver.
- ✗
Implementing network rules for Services
Why it's wrong here
Network rules and service implementation are handled by kube-proxy on each node.
- ✗
Scheduling pods to nodes
Why it's wrong here
Pod scheduling is performed by the kube-scheduler, not the controller manager.
- ✓
Running the node controller to monitor node health
Why this is correct
The node controller periodically checks node status and responds to node failures.
- ✓
Managing ReplicaSets to ensure the desired number of pods are running
Why this is correct
The replication controller (and Deployment controller) ensures the correct number of pod replicas are running.
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Same concept, more angles
2 more ways this is tested on KCNA
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. Which two of the following are Kubernetes controllers that run inside the kube-controller-manager? (Select TWO)
medium- A.kubelet
- ✓ B.Replication controller
- C.etcd
- ✓ D.Node controller
- E.kube-scheduler
Why B: The kube-controller-manager is a control plane component that runs controller processes to regulate the state of the cluster. The Replication controller (option B) is a legacy controller that ensures a specified number of pod replicas are running at all times, and the Node controller (option D) is responsible for monitoring the health of nodes and managing node lifecycle events. Both are built-in controllers that run inside the kube-controller-manager binary.
Variation 2. Which TWO of the following are functions of the kube-controller-manager?
easy- ✓ A.Managing replication and ensuring the desired number of pods are running
- B.Storing cluster state
- C.Exposing the Kubernetes API
- ✓ D.Monitoring node health and responding to node failures
- E.Assigning pods to nodes
Why A: The kube-controller-manager runs controller processes that regulate the state of the cluster. The replication controller (part of the controller manager) ensures that the actual number of pod replicas matches the desired count specified in a ReplicaSet or ReplicationController, automatically creating or terminating pods as needed. Additionally, the node controller within the kube-controller-manager periodically checks node health via the Node Lifecycle Controller, which monitors heartbeats (NodeStatus updates) and responds to node failures by tainting the node and evicting pods after a configurable timeout (default 5 minutes).
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This KCNA practice question is part of Courseiva's free CNCF certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the KCNA exam.