Product Documentation

Core concepts

Mar 14, 2014

If you already have experience with a XenDesktop or XenApp environment, it will be helpful to you to identify the concepts and components introduced in this release and learn how they work and communicate with each other. Under the new architecture, XenDesktop and XenApp are unified, including management and delivery components, to give administrators a unified management experience.

This figure shows the key components in a typical deployment.

The core components of this release shown in the illustration are:

Director — Director is a web-based tool that enables IT support and help desk teams to monitor an environment, troubleshoot issues before they become system-critical, and perform support tasks for end users. You can also view and interact with a user's sessions using Microsoft Remote Assistance.

Receiver — Installed on user devices, Citrix Receiver provides users with quick, secure, self-service access to documents, applications, and desktops from any of the user's devices including smartphones, tablets, and PCs. Receiver provides on-demand access to Windows, Web, and Software as a Service (SaaS) applications.

StoreFront — StoreFront authenticates users to sites hosting resources and manages stores of desktops and applications that users access.

Studio — Studio is the management console that enables you to configure and manage your deployment, eliminating the need for separate management consoles for managing delivery of applications and desktops. Studio provides various wizards to guide you through the process of setting up your environment, creating your workloads to host applications and desktops, and assigning applications and desktops to users.

License server — License server manages your product licenses. You must create at least one license server to store and manage your license files.

Delivery Controller — Installed on servers in the data center, the Delivery Controller consists of services that communicate with the hypervisor to distribute applications and desktops, authenticate and manage user access, and broker connections between users and their virtual desktops and applications. The Controller manages the state of the desktops, starting and stopping them based on demand and administrative configuration. In some editions, the Controller allows you to install Profile management to manage user personalization settings in virtualized or physical Windows environments. Each site has one or more Delivery Controllers.

XenServer — XenServer is an enterprise-class virtual machine infrastructure solution that creates the foundation for delivering virtual desktops and offers advanced management features. Multiple VMs can run on XenServer, which takes advantage of the advanced virtualization features of the latest virtualization-enabled processors from Intel and AMD. For more information about XenServer, see the XenServer documentation in eDocs.

Virtual Delivery Agent (VDA) — Installed on server or workstation operating systems, the VDA enables connections for desktops and apps. For Remote PC Access, install the VDA on the office PC.

Machine Creation Services (MCS) — A collection of services that work together to create virtual servers and desktops from a master image on demand, optimizing storage utilization and providing a pristine virtual machine to users every time they log on. Machine Creation Services is fully integrated and administrated in Citrix Studio.

Windows Server OS machines — VMs or physical machines based on Windows Server operating system used for delivering applications or hosted shared desktops to users.

Desktop OS machines — VMs or physical machines based on Windows Desktop operating system used for delivering personalized desktops to users, or applications from desktop operating systems.

Remote PC Access — User devices that are included on a whitelist, enabling users to access resources on their office PCs remotely, from any device running Citrix Receiver.

Additional components provide the following features:

Secure delivery — When users connect from outside the corporate firewall, this release can use Citrix NetScaler Gateway (formerly Access Gateway) technology to secure these connections with SSL. NetScaler Gateway or NetScaler VPX virtual appliance is an SSL VPN appliance that is deployed in the demilitarized zone (DMZ) to provide a single secure point of access through the corporate firewall.

WAN optimization — In deployments where virtual desktops are delivered to users at remote locations such as branch offices, Citrix CloudBridge (formerly Citrix Branch Repeater or WANScaler) technology can be employed to optimize performance. Repeaters accelerate performance across wide-area networks, so with Repeaters in the network, users in the branch office experience LAN-like performance over the WAN. CloudBridge can prioritize different parts of the user experience so that, for example, the user experience does not degrade in the branch location when a large file or print job is sent over the network. HDX WAN Optimization with CloudBridge provides tokenized compression and data deduplication, dramatically reducing bandwidth requirements and improving performance. For more information, see the Citrix CloudBridge documentation.

Basic concepts

Master Image

A master image is an image used by the provisioning technology to create virtual machines (VMs) for your users. Depending on the provisioning technology used, the master image can also be used to create a machine to host applications and desktops. The master image, created and stored on your hypervisor, contains the operating system and common applications and settings you are providing to your users, such as:

  • Anti-virus software.
  • Citrix plug-ins.
  • Other default programs.

With a master image, all users start with desktops that are created from the master image. Depending on the machine catalog type, any user customization and system updates performed on the desktop are either persisted or discarded when users log off.

Applications and desktops on the master image are securely managed, hosted, and run on machines within your datacenter, providing a more cost effective application delivery solution.

Provisioning methods

This release supports these provisioning methods:

  • Machine Creation Services (MCS)—This method uses a master image within your environment to manage virtual machines, enabling you to manage and update target devices through one master image. Machine Creation Services is fully integrated and administrated in Citrix Studio.
  • Provisioning Services (PVS)—This method allows computers to be provisioned and re-provisioned in real-time from a single shared-disk image. Provisioning Services manages target devices as a device collection. The desktop and applications are delivered from a Provisioning Services vDisk imaged from a master target device, and enables you to leverage the processing power of physical hardware or virtual machines.

    Provisioning Services is managed through its own console.

  • Existing images—This method manages and delivers desktops and applications that you have already migrated to virtual machines in the data center. You must manage target devices on an individual basis or collectively using third-party electronic software distribution (ESD) tools.

Select your provisioning method when creating a Machine Catalog.

Machine catalogs

A machine catalog is a collection of virtual machines and physical machines managed as a single entity. Machine catalogs specify:

  • The virtual or physical machines available to host applications or desktops
  • The Active Directory computer accounts assigned to those virtual machines or computers
  • In some cases, the master image that is copied to create the virtual machines

There are two catalogs:

  • Windows Server OS Machine catalog—Virtual or physical machines based on Windows Server operating system used for delivering applications or hosted shared desktops to users.
  • Desktop OS Machine catalog—Virtual or physical machines based on Windows Desktop operating system used for delivering personalized desktops to users, or applications from desktop operating systems.

Delivery Groups

Machines within machine catalogs are organized into Delivery Groups. Delivery Groups deliver the same set of applications or desktops to groups of users.

In a Delivery Group, you can:

  • Assign specific teams, departments, or types of users to desktops or applications.
  • Use machines from multiple catalogs.
  • Allocate a user to multiple machines.
  • Allocate multiple users to one machine.
Server OS machines support:
  • Desktop and applications Delivery Groups that host both desktops and applications.
  • Application Delivery Groups that host only applications.

Desktop OS machines support:

  • The same as Server OS machines.