Server - What is the minimum number of machines required for an nginx+keepalived cluster?

Question

I am studying the nginx+keepalived cluster and checked some online tutorials, but I don’t quite understand how many servers are needed.

Follow the tutorial, nginx+keepalived only needs to be installed on two machines to achieve the effect of "high availability load balancing".
Tutorial address: http://blog.csdn.net/l1028386...

I thought that at least four machines are needed, the first two are master-slave keepalived, the last two are nginx master-slave, and there are several web servers behind nginx.
That is, keepalived does load balancing for nginx, and nginx does load balancing for web servers.

I have two questions
1. How many machines are needed for an nginx+keepalived cluster?
2. If at least two are required, is it also applicable to the formal production environment?

Answer 1

You can use docker to implement multiple virtual servers and then configure keepalived to try it

Answer 2

At least two, in the same LAN.

keepalived must be deployed on the same machine as the service.