CKA Resource Monitoring 5

Question 1

A VerticalPodAutoscaler (VPA) is set to 'updateMode: Auto'. What does this mean for running pods?

Accepted Answer

VPA will evict and recreate pods with updated resource requests when recommendations change

Answer

In Auto mode, VPA evicts pods and allows the controller to recreate them with the updated resource requests generated by its recommendation engine.

Question 2

What is the purpose of 'ephemeral-storage' as a resource type in Kubernetes pod specs?

Accepted Answer

To limit the amount of local disk space a container can use for writable layers, logs, and emptyDir volumes

Answer

Ephemeral storage requests and limits control how much local node disk space a container may consume through its writable layer, logs, and emptyDir volumes not backed by memory.

Question 3

Which cAdvisor metric tracks the cumulative number of times a container has been throttled due to CPU limits?

Accepted Answer

container_cpu_cfs_throttled_periods_total

Answer

The container_cpu_cfs_throttled_periods_total metric counts the total number of CFS scheduling periods during which the container was CPU-throttled.

Question 4

How does kubectl top differ from Prometheus when monitoring Kubernetes resource usage?

Accepted Answer

kubectl top shows only current instantaneous metrics from Metrics Server, while Prometheus stores historical time-series data

Answer

kubectl top fetches a single current snapshot from the Metrics Server API with no history, whereas Prometheus scrapes and stores time-series data enabling historical queries and alerting.

Question 5

A pod specification sets requests.memory=128Mi and limits.memory=256Mi. What QoS class is assigned to this pod?

Accepted Answer

Burstable

Answer

Because the memory request (128Mi) does not equal the limit (256Mi), the pod is classified as Burstable rather than Guaranteed.

(CKA) Certified Kubernetes Associate Practice Test

(CKA) Certified Kubernetes Associate Practice Test

CKA Resource Monitoring 5