Question 1 of 8
A Service selector matches four Running Pods, but only two appear as ready backends. What would you inspect, and how does readiness affect normal Service routing?
Strong Interview Answer
I would compare the Service selector with Pod labels, then inspect each Pod's Ready condition and the Service's EndpointSlices. A Running Pod can still be unready. Under normal endpoint publication, unready Pods are not treated as ready Service backends, so failed readiness probes can explain the missing endpoints even when labels match. I would fix the readiness failure rather than changing the selector. `publishNotReadyAddresses` is a special-purpose exception for workloads that deliberately need unready addresses published.
What to Listen For
- Service selector
- Pod Ready condition
- readiness probe
- EndpointSlice
- publishNotReadyAddresses
Caution
A strong answer distinguishes Pod phase from readiness and does not assume that a matching label alone guarantees normal traffic eligibility.