Backend & systems·Resilience and failure handling
the instance says "not yet" while the cache warms, so the load balancer keeps traffic off it until it is genuinely able to serve.
Readiness probe
A health check whose failure means "stop sending traffic", without restarting the instance. This is the probe that may legitimately consider dependencies, since removing one instance from rotation is recoverable. Conflating it with liveness is one of the most common Kubernetes configuration mistakes.