Product Documentation

Designing a XenApp Deployment

Oct 09, 2015

XenApp is the central software component of the Citrix Windows Application Delivery Infrastructure. The goals of XenApp and the Citrix Windows Application Delivery Infrastructure are to deliver on-demand applications to both physical and virtual desktops, and to determine and provide the best method of delivery. XenApp offers three methods for delivering applications to user devices, servers, and virtual desktops:

  • Server-side application virtualization: applications run inside the Data Center. XenApp presents each application interface on the user device, and relays user actions from the device, such as keystrokes and mouse actions, back to the application.
  • Client-side application virtualization: XenApp streams applications on demand to the user device from the Data Center and runs the application on the user device.
  • VM hosted application virtualization: problematic applications or those requiring specific operating systems run inside a desktop in the Data Center. XenApp presents each application interface on the user device and relays user actions from the device, such as keystrokes and mouse actions, back to the application.
To provide these types of application delivery, you have many choices of deployment designs and XenApp features, which you can tailor for your users' needs. A typical process for planning a XenApp farm includes:
  1. Becoming familiar with XenApp and XenApp Setup by creating a small, one-server or two-server test farm.
  2. Deciding which applications to deliver to users.
  3. Determining how you want to deliver applications - this includes testing and evaluating the applications and peripheral requirements.
  4. Determining application to application communication, where to install the applications on XenApp servers, and which applications can be collocated.
  5. Determining the number of servers you need for applications.
  6. Determining the total number of servers you need for your farm and evaluating hardware requirements.
  7. Creating the network infrastructure design.
  8. Defining the installation processes.
  9. Creating and testing a pre-production pilot farm based on your farm design.
  10. Releasing the farm into production.

To help you understand how a XenApp deployment delivers applications so you can complete planning tasks, consider the following diagram.

A XenApp deployment consists of three deployment groups: user device (represented in this diagram by Citrix Receiver and Citrix Dazzle), Access Infrastructure, and Virtualization Infrastructure.
  • On the left of this diagram are Citrix Dazzle and Citrix Receiver, which represent the set of devices on which you can install client software. Citrix Dazzle provides your users with a selection of applications you have made available to them. Citrix Receiver manages the client software plug-ins that enable your users to interact with virtualized applications. When designing a XenApp deployment, you consider how your users work, their devices, and their locations.
  • Access Infrastructure represents secure entry points deployed within your DMZ and provide access to resources published on XenApp servers. When designing a XenApp deployment, you provide secure access points for the different types of users in your organization.
  • Virtualization Infrastructure represents a series of servers that control and monitor application environments. When designing a XenApp deployment, you consider how applications are deployed based on your user types and their devices, the number of servers you need, and which features you want to enable in order to provide the support, monitoring, and management your organization requires.

The following diagram shows the access infrastructure in greater detail.

In this access infrastructure diagram:
  • All of your users use Citrix Dazzle to choose applications they want to run. Citrix Receiver plug-ins run them.
  • Onsite users within your corporate firewall interact directly with the XenApp Web and Services Site.
  • Remote-site users access applications through sites replicated by Citrix Branch Repeater.
  • Off-site users access applications though secure access, such as Access Gateway.
  • The Merchandising Server makes available self-service applications to your users through Citrix Dazzle.
  • EasyCall Voice Services enables your users to initiate telephone calls by clicking on telephone numbers displayed in their applications.
  • The XML Service relays requests and information between the Access Infrastructure and the Virtualization Infrastructure.

The following diagram shows the virtualization infrastructure in greater detail.

In this virtualization infrastructure diagram:
  • The XML service relays information and requests.
  • Based on Active Directory profiles and policies, the XenApp servers invoke the correct application delivery type for the user. The XenApp servers provide server-side application virtualization and session management. Session and deployment configuration information are stored in data collectors and a central data store represented by the deployment data store.
  • The App Hub provides Streamed Application Profiles, which are client-side virtualization applications housed in your enterprise storage.
  • The VM Hosted Apps server isolates problematic applications inside a seamless desktop, which, depending on the user profile, can be virtualized on the user device or on the server. The desktop images are provisioned through Provisioning Server. Session and server configuration information are stored in the deployment data store.
  • Provisioning Services delivers desktops to servers, which are stored as desktop images in your image repository.
  • SmartAuditor provides session monitoring. Recorded sessions are stored in your enterprise storage and configuration information is stored in the deployment data store.
  • Service Monitoring enables you to test server loads so you can estimate how many servers you need for your deployment and to monitor those servers once they are deployed.
  • Power and Capacity Management enables you to reduce power consumption and manage server capacity by dynamically scaling the number of online servers.
  • Single Sign-on provides password management for virtualized applications. Passwords are stored in the account authority.

Planning for System Monitoring and Maintenance

When designing your XenApp farm, include a monitoring and management strategy to ensure the sustainability of your environment. Consider incorporating one or more monitoring tools into your environment and customizing them to provide alerts based on metrics associated with hardware, software, and usage requirements.

Designing for monitoring and management should include hardware, software, performance, and network areas. For hardware monitoring, Citrix recommends the hardware management tools provided by most server vendors.

Citrix EdgeSight is an excellent technology for monitoring XenApp farms. Citrix suggests customizing the default Resource Manager and EdgeSight metrics to meet your specific monitoring needs.