Which Pod specification field ensures the pod is scheduled only on nodes with matching labels?

Which Pod specification field ensures the pod is scheduled only on nodes with matching labels?

• A. nodeName
• B. nodeSelector
• C. schedulerName
• D. tolerations

Answer: (B)

Node labeling is used to describe characteristics of nodes, and the nodeSelector field in a pod spec enforces those characteristics during scheduling. The scheduler will only consider nodes whose labels match all the key-value pairs specified in the nodeSelector. For example, using: spec: nodeSelector: disktype: ssd means the pod will be scheduled only on nodes that have the label disktype=ssd. If no such node exists, the pod stays Pending. This is distinct from pinning a pod to a specific node by name, choosing a different scheduler, or tolerating taints. For more complex constraints, nodeAffinity offers more expressive rules, but nodeSelector provides the straightforward label-based constraint.

Node labeling is used to describe characteristics of nodes, and the nodeSelector field in a pod spec enforces those characteristics during scheduling. The scheduler will only consider nodes whose labels match all the key-value pairs specified in the nodeSelector. For example, using:

spec:

nodeSelector:

disktype: ssd

means the pod will be scheduled only on nodes that have the label disktype=ssd. If no such node exists, the pod stays Pending. This is distinct from pinning a pod to a specific node by name, choosing a different scheduler, or tolerating taints. For more complex constraints, nodeAffinity offers more expressive rules, but nodeSelector provides the straightforward label-based constraint.