In Part One of my blog, I explained the new Session-only role that XenApp 6.5 introduces and the benefits of using it. Today, I will explain how you can design your enterprise farm using XenApp Controllers and Session-only servers across multiple sites and zones.

IMA Data Store
It is recommended to host the IMA data store at your main data center or largest site to keep network traffic to a minimum. All member servers in remote sites should be configured to use this IMA data store.

Zone / Site Configuration
Each zone in your farm requires at least one XenApp Controller to serve as the Zone Data Collector (ZDC). It is recommended to have a second XenApp Controller to serve as the Backup Data Collector in the event the primary ZDC fails. In addition, for a large environment you may want to reserve another XenApp Controller to act as a dedicated XML server to service Web Interface application resolution requests. The remaining XenApp servers in your farm should be configured in Session-only mode, as their primary role is to host XenApp user sessions.

In a single-zone, multi-site scenario, it is recommended to have at least one XenApp Controller at each site in the case of a network link failure between sites. In this case, the XenApp Controller at that remote site should be configured with a lower-election priority so that it will assume the role of the Data Collector for that site until the link is restored and the preferred Data Collector re-assumes the role.

 Administration Console
For best performance, it is recommended to run the Citrix AppCenter console local to the data center hosting the IMA data store. If you have delegated Citrix administrators at remote sites, the AppCenter console should be published on a XenApp server local to the IMA data store and remote administrator should access the AppCenter console over HDX.

The following is a sample XenApp 6.5 farm design:


Figure 1. Sample deployment using the Session-only model

See my final post of this blog series where I share some test results demonstrating the savings in resource utilization and server provisioning time for XenApp 6.5 servers.