@Retention(value=RUNTIME)
@Target(value={METHOD,TYPE})
public @interface HaHotStateRequired

When a REST method (or its containing class) is marked with this annotation requests to it will fail with a 403 response if the instance is not in MASTER mode (or has recently switched or is still rebinding). Guards the method so that when it returns the caller can be certain of the response. For example if the response is 404, then the resource doesn't exist as opposed to not being loaded from persistence store yet.