Product Documentation

Evaluating Application Delivery Methods

Oct 09, 2015

The application delivery method is a factor in determining the number of servers in a farm and their individual hardware requirements.

How you choose to deliver applications depends on your organization's needs and end-users' requirements. For example, some organizations use XenApp to streamline administration. In other organizations, the existing hardware infrastructure might affect the delivery method selected, as can the types of applications to be delivered. In addition, some end-users might run all applications while connected to the company network, while others might work in remote locations and run applications while disconnected from the network.

Method/Description Advantages Considerations

Installed on the server:

Applications are installed on the server, where the processing takes place, and accessed from the server. This is the traditional XenApp application delivery model. For many organizations, this provides the lowest cost of ownership for IT resources because it provides the greatest scalability.

  • This method provides a consistent user experience regardless of the user device.
  • You manage applications centrally.
  • User devices do not require extensive resources, such as excessive memory or hard drive space. This delivery method supports thin clients.
  • This method is effective for applications with components that are intertwined with the operating system (such as a .NET framework).
  • Farm servers require sufficient resources to support the applications.
  • Users must be connected to the server or network to run the applications (no offline access).

Streamed to server:

Executables for applications are put in profiles and stored on a file server or Web server (the App Hub); however, when launched, they stream to the server, and application processing takes place on the server. Unlike installed applications, streamed applications are stored in the App Hub and provide application isolation by design.

  • This method has similar advantages as for installed applications, including a consistent user experience, central management, and use of server resources instead of those of the user device.
  • In many cases, streaming to server lets conflicting applications, such as multiple versions of the same application, run on the same server without needing to silo them.
  • Updating applications is simplified because you update only a single application profile.
  • Farm servers require sufficient resources to support the applications.
  • Users must be connected to the server or network (no offline access).
  • Some applications are not candidates for profiling, such as those using a .NET framework.

Streamed to desktop:

Executables for applications are put in profiles and stored on a file server or Web server (the App Hub). When launched, the files required to execute the application are streamed to the user device, and application processing takes place on the user device instead of the XenApp server. When applications are streamed to the user device, the user experience is similar to running applications locally. After applications are cached on the user device, users can continue running the apps after disconnecting from the network (referred to as offline access).

  • Users can have the local application experience, but you manage the applications centrally.
  • Users might have a better experience when resource-intensive applications, such as graphics applications, are streamed to desktops.
  • Using application properties and Citrix policies and filters for Offline Applications, you control the applications and users that have offline access, as well as the license period for offline use.
  • User devices must have sufficient resources to run the applications locally; the user devices cannot be thin clients.
  • User devices must run Windows operating systems, including Windows 7, XP, or Vista.

Dual mode delivery:

When you select "streamed if possible, otherwise accessed from a server" (referred to as dual mode or fallback), XenApp tries to stream the application to the user device first, but uses the backup access method if streaming to desktop is not supported on the user device. For example, you can specify that some users, such as sales personnel, run applications streamed to desktop when they are accessing the applications from Windows devices, and run them as installed applications when they are accessing them from handheld mobile or kiosk-type devices.

  • This method provides the most versatility for application delivery, offering all the advantages of streaming to desktops for supported user devices, plus a backup delivery method for the rest.
  • You control delivery options centrally using Citrix policies and filters, such as the server's Load Balancing Policies for Streamed App Delivery.
  • For the backup method to occur, ensure that the application is either installed on the XenApp server or the streaming profile is configured for a target operating system that matches the server.

Choosing Between Published Desktops and Published Applications

Before selecting the method for delivering applications, decide if you want to publish the desktop or publish applications.
  • Publishing the desktop - Presents users with an entire Windows Server desktop when they log onto XenApp. (For security, the desktop should be locked down .)
  • Publishing applications - Publishes specific applications and delivers only those applications to users. This option provides greater administrative control and is used most frequently.

You can use policies to prevent users from accessing server drives and features with both methods of application delivery.