Is it possible in this world to achieve DNS Level Load Balancing? For example, I have a Server A (111.222.333.444) and Server B (555.666.777.888), and there be some third party DNS hosting (like CloudFlare) which could decide if Server A is down (or not responding) then divert all traffic to Server B. This is not a true load balancing, rather a traffic diversion, I don't know. But is it possible?
I know DNS propagation takes time, but services like CloudFlare barely take a few minutes to divert to other server.
Any ideas? Thanks.