Round robin DNS with host reachability check?

Question

Domain Name System

There are 3 frontends with the same domain.
DNS is now giving out IP in order.
But it also issues an IP if the host is not available.
Maybe there are already paid services offering dns services with checking hosts?
Or do you need to make your own (lbnamed) in the cloud?

Answer 1

60 seconds)?
Never think that everyone's DNS record will be updated before 8 hours.

Answer 2

Round robin DNS is more for load balancing, it will not help you with fail-over (what you probably want).
DNS requests are actively cached by users and any provider's DNS servers.