How to achieve Docker Swarm fault tolerance?

Question

Domain Name System

Let's say there are 4 Docker Swarm nodes on different machines.
The site is available on 4 different IPs.
What if the master node went down? It is assumed that all requests go through the main node.
Only one thought comes to me, it is necessary to create 4 A records for each machine for the domain.
Correct me if I'm wrong. I don’t know how to accurately formulate a query in Google, so I turn to you.

Answer 1

Attach one common IP address to all servers in the cluster or use an external load balancer. If it is impossible - that only RR DNS (what you described).