How does the replica server work?

The first question is: what gets replicated? The connection broker stores all its information relating to the end users, desktop pools, virtual desktop machines, and other View-related objects, in an ADAM database. Then, using the Lightweight Directory Access Protocol (LDAP) (it uses a method similar to the one AD uses for replication), this View information gets copied from the original connection server to the replica server.

As both the connection server and the replica server are now identical to each other, if your connection server fails, then you essentially have a backup that steps in and takes over, so that end users can continue to connect to their virtual desktop machines. Also, as the replica server is another instance of a connection server within your environment, you can scale up and manage additional end users.

As with the other Horizon components, you cannot install the replica server role on the same machine that is running as a connection server or any of the other Horizon View components.