Kubernetes Container Orchestration Scheduling and Scaling 5

Question 1

Which HPA behavior field prevents rapid oscillation by limiting how quickly scale-down can occur?

Accepted Answer

spec.scaleDown.stabilizationWindowSeconds

Answer

The scaleDown stabilizationWindowSeconds (default 300s) makes HPA look back over the window and use the highest replica count seen to avoid thrashing.

Question 2

A pod is scheduled on a node, but the node's kubelet rejects it because the pod's resource requests exceed actual node capacity. What is the most likely cause?

Accepted Answer

The node's allocatable capacity was not reflected in the API server cache at scheduling time

Answer

Stale node capacity data in the scheduler's cache can cause it to assign a pod to a node that no longer has sufficient allocatable resources.

Question 3

What Kubernetes object can you use to run a batch job that scales the number of parallel workers based on work items remaining?

Accepted Answer

Job with completions and parallelism

Answer

A Job's spec.completions and spec.parallelism fields control how many pods run in parallel to complete a fixed number of work items.

Question 4

Which label on a node is typically used as the topology key for zone-aware pod spreading in cloud environments?

Accepted Answer

topology.kubernetes.io/zone

Answer

Cloud providers set topology.kubernetes.io/zone on nodes, making it the standard key for zone-based topology spread constraints.

Question 5

You want only pods from a specific team's namespace to use high-performance nodes. Which combination achieves this with least privilege?

Accepted Answer

Taint nodes and use a MutatingAdmissionWebhook to inject tolerations into pods in the team's namespace

Answer

A MutatingAdmissionWebhook can automatically inject tolerations into pods in specific namespaces, avoiding manual toleration configuration in every pod spec.

Kubernetes Container Orchestration Practice Test

Kubernetes Container Orchestration Practice Test

Kubernetes Container Orchestration Scheduling and Scaling 5