A HorizontalPodAutoscaler has already raised a Deployment to its maximum replicas, but several of the new Pods remain in Pending state with a message that no node has enough allocatable CPU to schedule them. Every existing node is already fully committed. Which cluster component is responsible for resolving this by adding capacity?
- AThe HorizontalPodAutoscaler raising the replica ceiling
- BThe cluster autoscaler watching for unschedulable Pods Correct
- CA LimitRange loosening per-container requests
- DThe kube-scheduler retrying placement more aggressively
Why A is wrong: Tempting because the HPA is already involved, but it only adjusts replica count and is at its maximum; adding still more Pods cannot help when no node has capacity to run them.
Why B is correct: Correct because the cluster autoscaler detects Pods that cannot be scheduled for lack of node resources and provisions additional nodes so the pending Pods can be placed.
Why C is wrong: Tempting because request sizing affects scheduling, but a LimitRange sets defaults and bounds for container requests and limits and cannot create the extra node capacity the Pods need.
Why D is wrong: Tempting because the scheduler is what leaves the Pods Pending, but it can only place Pods onto existing nodes and has no ability to add nodes to the cluster.