Which statement correctly distinguishes liveness and readiness health checks?

• A. Liveness checks readiness; readiness checks route traffic.
• B. Liveness checks that downstream dependencies are healthy.
• C. Readiness checks that endpoint is alive.
• D. Liveness checks the endpoint is deployed and responds; readiness checks the downstream dependencies to route traffic.

Answer: (D)

Two health checks serve different purposes: liveness verifies the process is alive and able to respond, so if it fails, the system restarts the instance to recover from a crash or hang. Readiness checks verify the service is prepared to handle traffic, which usually means it has started up properly and its dependencies (like downstream services) are reachable. If readiness fails, traffic is not routed to that instance, but the process stays up and can recover once ready.

The statement that liveness ensures the endpoint is deployed and responds while readiness verifies downstream dependencies to route traffic matches this distinction. It captures why liveness is about the ongoing health of the process, and readiness is about being able to handle requests and be considered for routing.