Question

You deploy an application with a Deployment whose Pod template applies the labels app=payments and tier=backend. You then create a ClusterIP Service with the selector app=payments. A teammate later adds a second, unrelated Deployment whose Pods carry the labels app=payments and tier=frontend in the same namespace. What is the effect on traffic sent to the Service?

Accepted Answer

The Service load-balances traffic across Pods from both Deployments, because both sets of Pods match the selector app=payments.

Answer

The Service only routes to the original backend Pods, because a selector implicitly requires all Pod-template labels to match.

Answer

The Service stops routing entirely and reports an error, because two Deployments cannot share the app=payments label.

Answer

The Service routes only to whichever Deployment was created first, ignoring Pods added afterward.