You can add additional Frontend servers to the Cluster at any moment.
Install and Configure the CommuniGate Pro software on a Frontend Server computer. Since Frontend Servers do not access Account data directly, there is no need to make the SharedDomains file directory available ("mounted" or "mapped") to any Frontend Server.
Specify the addresses of all Backend Servers using the Frontend Server Settings->General->Cluster WebAdmin page.
To add a Frontend Server to your Dynamic Cluster, stop it, and restart it with the --ClusterFrontend Command Line option (it can be added to the CommuniGate Pro startup script). The Server will poll all specified Backend Server IP Addresses until it finds the active Cluster Controller.
Use the WebAdmin interface to verify that the Frontend Server is running. Use the Domains page to check that all Shared Domains are visible.
When Frontend Servers try to open one of the Shared Domain accounts, the Controller directs them to one of the running Backend Servers, distributing the load between all available Backend Servers.