Question

A frontend Deployment reports intermittent 502 errors when calling the 'payments' Service. The Service selector matches the pods, and `kubectl get endpoints payments` shows several IPs listed. However, inspecting `kubectl get endpointslices -l kubernetes.io/service-name=payments -o yaml` reveals that some endpoints have `conditions.ready: false` while their pods show STATUS Running. What is the most likely cause of the endpoints being marked not ready?

Accepted Answer

The affected pods are failing their readiness probe, so kube-proxy excludes them from load balancing even though the containers are running.

Answer

The Service is missing a targetPort, so the EndpointSlice controller cannot populate ready addresses.

Answer

CoreDNS is returning stale records, causing the EndpointSlice to mark addresses as not ready.

Answer

The pods are on a node that is cordoned, which automatically sets their EndpointSlice condition to not ready.