A Horizon Security Server has the same connection limitations as a Horizon Connection Server, which means it can support up to 2,000 simultaneous Horizon client connections. Despite this limit, it is important to remember that multiple Security Servers should be deployed to ensure both capacity and availability requirements are met.
Each Horizon Security Server is a stand-alone instance; therefore, there is no specific guidance with regard to how many can be deployed. A Horizon Security Server can only be paired with one Horizon Connection Server while a Connection Server can be paired with multiple Security Servers.