Citrix 3 1 Change of XenDesktop XenApp architecture

With XenDesktop 7 the underlying architecture of XenApp and XenDesktop changes significantly. The first major shift is that the concept of a Farm no longer exists. Remember that with IMA, all your XenApp servers were also controllers; they elected a data collector among themselves and exchanged information continuously. With FMA, every server is no longer a controller. You have one VDA installed on every resource (server, desktop, physical machine or virtual machine) and dedicated Delivery Controllers. Because IMA is gone and was the backbone of the Farm, the Farm concept disappears with it.

Features that were removed or changed

  • No more shadow taskbar / ICA-based user shadowing. Previously, with XenApp (and to a lesser extent with XenDesktop), administrators could shadow users over ICA to help troubleshoot. That capability was removed; Microsoft Remote Assistance is used instead.
  • Citrix App Streaming dropped. Citrix used to have its own app virtualization streaming technology. It was discontinued in favor of full support for Microsoft App-V, which is now the application streaming component used with XenApp and XenDesktop.
  • Citrix App Hub renamed to Delegated Administration, with a much more robust implementation.

These architecture changes pave the way for an environment in which the same Delivery Controller manages both XenApp and XenDesktop workloads from a single console. The convergence is essentially complete in XenDesktop 7.x. See you in the next video.

Summary

This lesson covers the major architectural evolution of Citrix XenDesktop and XenApp, moving away from the decentralized farm model where every server acted as a controller. The new architecture introduces dedicated centralized controllers managing resources while servers function as pure delivery nodes (physical or virtual). This shift simplifies management, removes legacy concepts like the farm backbone, and standardizes infrastructure administration through delegated administration components.

Key points

  • The farm concept has been eliminated—servers are no longer all controllers
  • New model uses dedicated centralized controllers managing resources while other servers act as pure endpoints
  • Legacy application virtualization technology has been deprecated in favor of Microsoft application platform support
  • App Streaming (App-V) and application delivery mechanisms remain core components
  • Delegated Administration has replaced previous administrative models and is now more robust
  • Remote Assistance features have been enhanced with better performance and management capabilities

FAQ

What is the main architectural change from the old Citrix farm model?

The old model used distributed controllers where every server in the farm acted as both a controller and resource. The new architecture introduces dedicated centralized controllers that manage resources while other servers function as pure delivery nodes (physical machines, virtual machines, or workstations).

What happened to the farm concept in the new Citrix architecture?

The farm concept no longer exists. The farm backbone and the requirement for distributed controllers have been completely replaced by a centralized controller model that simplifies infrastructure management.

Which application virtualization technologies are still supported?

Citrix has deprecated proprietary application virtualization in favor of full support for Microsoft application platform technologies, including App-V streaming components and centralized application delivery mechanisms.