In Chapter 1, VMware Horizon Infrastructure Overview, we discussed some of the roles of Horizon Connection Server. These roles include the following:

• Managing connections between end user Horizon client connections and Horizon-managed resources, including Horizon desktops and Microsoft RDS servers
• Authenticating user connection requests and providing access to assigned resources
• Hosting the Horizon Administrator console for the VMware Horizon infrastructure
• Working in tandem with VMware vCenter and Horizon Composer to manage, deploy, and maintain virtual desktops

The following diagram shows the placement of the Horizon Connection Server in a simple Horizon environment. For now, only the Horizon Connection Server is displayed; later chapters will add respective Horizon Servers to this diagram:

The Horizon Connection Server authenticates the clients and provides them with access to the appropriate resources. Depending on the configuration of the Horizon Connection Server instance, the clients may connect directly to the remote resource, or the connection may be tunneled through the Horizon Connection Server instance. The behavior of a Horizon client connection will be discussed further in this chapter; again in Chapter 4, Implementing Horizon Security Server, when discussing Horizon Security Server; and once more in Chapter 5, Implementing Horizon Unified Access Gateway, when discussing Horizon Access Point.

Horizon Connection Server also hosts the Horizon Administrator console, the central management point for Horizon resources. The following screenshot shows the dashboard presented to a Horizon administrator upon login:

The Horizon Administrator console provides a web-based GUI for performing a variety of tasks, including the following:

• Integrating Horizon with your vSphere infrastructure
• Creating Horizon desktop or application pools, which will then create any required virtual machines within the linked vSphere virtual infrastructure
• Entitling clients with access to the Horizon pools or applications packaged using ThinApp
• Performing maintenance on Horizon pools
• Monitoring the status of the Horizon infrastructure

It is important to note that while the virtual machines created by Horizon appear in vSphere in the same format as a typical virtual machine, you should not edit their configuration within vCenter (or any other vSphere administration consoles) directly. Horizon maintains configuration information about the virtual machines within a Microsoft Active Directory Lightweight Directory Services (MS LDS) database installed on each Horizon Connection Server instance, and any changes made to those virtual machines within the vCenter console may lead to problems that prevent the virtual machine from being managed by Horizon or available for client connections. 

The entire life cycle of virtual machines that were created by Horizon must be managed using only Horizon administrative tools.