how proxy server works?

[huiwq1990]

I want to deploy HA proxy servers, and I find the document, and want some help to figure out some questions:
The scene: proxy server has three replications and proxy agent has two replications.
Does the picture means every agent maintains a connection to every server, so every agent has three connections to every server? If it works like this, how to setup proxyserver's load balancer to make sure the connections located to the three servers.