KCNA Scheduling and Scaling 5

Question 1

Which `kubectl` command scales a Deployment named `web` to 10 replicas immediately?

Accepted Answer

kubectl scale deployment web --replicas=10

Answer

`kubectl scale` is the dedicated imperative command for adjusting the replica count of a Deployment, ReplicaSet, or StatefulSet.

Question 2

What happens to pods on a node after `kubectl cordon <node>` is executed?

Accepted Answer

Existing pods continue running; no new pods will be scheduled on the node

Answer

`cordon` marks the node as unschedulable (SchedulingDisabled) but does not touch currently running pods.

Question 3

Which metric server component must be installed for HPA to scale based on CPU and memory metrics?

Accepted Answer

metrics-server

Answer

HPA's built-in resource metrics (CPU/memory) rely on the `metrics-server` add-on, which aggregates resource usage from kubelets.

Question 4

A pod spec sets `resources.requests.cpu: 500m`. What does this guarantee?

Accepted Answer

The scheduler will only place the pod on a node with at least 500 millicores of allocatable CPU available

Answer

CPU requests are used by the scheduler to find nodes with sufficient allocatable capacity; they do not cap actual usage.

Question 5

What is the difference between `kubectl drain` and `kubectl cordon`?

Accepted Answer

drain cordons the node AND evicts all pods; cordon only prevents new scheduling

Answer

`drain` first cordons the node (marks it unschedulable) and then safely evicts all pods while respecting PodDisruptionBudgets.

(KCNA) Kubernetes and Cloud Native Associate Practice Test