What does a readiness health check endpoint do?

• A. Checks readiness of downstream dependencies to route real traffic.
• B. Checks liveness of the endpoint.
• C. Verifies deployment status.
• D. Measures response latency under load.

Answer: (A)

A readiness check is used to signal that a service is prepared to handle real traffic. It does this by verifying that essential downstream dependencies are available and initialized—such as database connections, caches, or external services—and that any required configuration is loaded. When the readiness check passes, the orchestration layer or gateway is allowed to route requests to this instance; if it fails, traffic is kept away to prevent errors. This is different from a liveness check, which only asks whether the process is still running, not whether it can actually serve requests. It’s also not a measure of deployment status or performance under load, which are handled by other checks and tests.