Question 910
At Pinecrest logistics, in a sandbox Kubernetes cluster during a recovery tabletop exercise: Pod dispatch-api in fulfillment cannot schedule on worker-c; events report untolerated taint special=dedicated:NoSchedule. Work only within the stated target and verify before declaring success. Which Kubernetes behavior best explains the required change or diagnosis?
Explanation
Correct Answer
A NoSchedule taint excludes Pods lacking a matching toleration even if the Node has free resources. This explains the stated condition. The corresponding action is: Run kubectl -n fulfillment describe pod dispatch-api and compare Pod tolerations with kubectl describe node worker-c taints. The direct acceptance evidence is: Verify the exact toleration or deliberate taint removal and confirm that the Pod schedules to an eligible node.
Incorrect Answers
This principle describes a separate cause: HPA CPU utilization is computed from reported metrics relative to requests; missing metrics or requests can prevent scaling decisions. The reported condition is governed by: A NoSchedule taint excludes Pods lacking a matching toleration even if the Node has free resources. The two mechanisms should not be conflated.
NetworkPolicy allows only explicitly selected paths once Pod ingress or egress isolation applies, and both directions may matter. That explanation applies to a different technical failure. Here the controlling principle is: A NoSchedule taint excludes Pods lacking a matching toleration even if the Node has free resources.
The offered statement is true for this other mechanism: Cluster DNS search domains and dnsPolicy control short-name resolution; resolving a public hostname is not proof of Kubernetes Service resolution. It does not explain the facts described here, which follow from: A NoSchedule taint excludes Pods lacking a matching toleration even if the Node has free resources.