In my current role as a Sales Engineer covering some of the largest enterprise accounts, I have been preaching about the XenApp and XenDesktop 7.x architecture and benefits for about 1.5 yrs now. While the 7.x architecture was most definitely a step in the right direction, some of the earlier releases definitely had some gaps that needed to be addressed. And I would constantly hear about these gaps from my customers, who would then typically shoot down migration till these gaps were addressed by Citrix. I want to highlight some of the common themes as to why customers were not ready to move to the 7.x architecture and zxhow they’ve been addressed in XenApp 7.6:

No Local Host Cache under the new FMA architecture

In older versions of XenApp, with the Local Host Cache feature, users were able to enumerate and connect to applications and published desktops even if there was a database connectivity issue or a database outage. With the XenApp/XenDesktop 7.x FMA architecture prior to the 7.6 release, a database connectivity issue or outage meant that users lost the ability to access applications and desktops during the period of the outage. While larger customers addressed this issue by investing in highly available SQL infrastructures, smaller customers found this to be cost prohibitive in some cases.

Connection leasing creates a lease file that holds information about a users active session, which is then replicated to all the other controllers within the site. In the event of a DB failure, XenApp and Xendesktop can reference the user’s connection history and provide the user access to a previous connection.

One can argue that the connection leasing methodology is in some ways better than the old local host cache as you no longer have to deal with corrupt/stale cache issues and recreating the cache on all your servers.

For a quick overview of Connection Leasing check out this video on Citrix TV

Here’s another great blog by Paul Stansel, that goes over various powershell commands to tweak Connection Leasing parameters

No Anonymous User Access

This was another feature than was available in XenApp 6.5 and earlier, most commonly used by healthcare customers which enabled users to launch applications without first having to authenticate to Receiver or Storefront, thus enabling users to access applications from any available device. XenApp 7.6 reintroduces this feature. A Server OS based delivery group within XA/XD 7.6 can now be configured to allow anonymous access. However, a separate Unauthenticated storefront store would be required.













You can find a brief video that shows the configuration and demo of this feature here

Lack of support for Session pre launch and linger

For any user that is used to running local applications on their desktops and laptops, the first thing they would complain about in a Citrix environment was the launch time for the initial application. Depending on the environment, this could range from 5 seconds to in some cases, minutes. To address this issue, XenApp 6.x introduced session pre-launch and session linger. With this feature enabled and configured, when the user logs in to his desktop and authenticates to receiver, a session is already established. As a result when the user launches a published application, it launched instantly. In earlier versions of XenApp/XenDesktop 7.x, this feature was not available. 7.6 brings back both session pre launch and linger and its stronger than ever with even more configurable parameters (see below)





















Inability for administrators to create application folder hierarchy within Studio and Storefront

The average enterprise customer typically has hundreds (and sometimes thousands) of applications published via XenApp. Back in the XA 6.x (and earlier) releases, administrators had the ability to create folder hierarchies to organize applications to simplify management of these applications. Also when it came to user access, administrators were also able to group applications in folders based on departments, application suites etc that made things more intuitive for the end users. This feature has been brought back in XenApp 7.6 and should make a lot of administrators (and users) very very happy!

Application folders








Again, another video that goes over this feature in XenApp 7.6

Feature  gaps within Edgesight, particularly application usage reporting and license utilization reporting.

Back in mid 2013, Citrix introduced the new Edgesight and Director, which was completely rebuilt from the ground up. The new version no longer required a separate infrastructure and is agent less. There was also a lot of focus on incorporating dashboards in order to make it easier for administrators to find the information they need without having to dig through numerous reports. Overall, the redesign of Edgesight resulted in a more intuitive UI, and a reliable monitoring environment with less infrastructure requirements. However, there were some major gaps when compared to Edgesight 5.4. The two that I constantly heard about from customers were hosted application usage reporting and license utilization monitoring. These have now been added to XenApp/XenDesktop 7.6.

You can check out the full list of enhancements in Edgesight and Director here.

For more on Hosted Application Usage Reports, check this blog.

Virtual IP Loopback

While most applications work easily within a XenApp environment, some enterprise customers still have to support applications that require the end user application instance to have a unique IP address. This was possible in XA 6.x.

With Virtual IP loopback in XA 7.6, the XA server allocates a unique IP address to each session or a specific application, and as a result administrators are now able to support applications that require this functionality.














I truly believe that there will be much wider adoption of the 7.6 release because it is so much more than addressing feature gaps and includes a number of key enhancements that further enhance the end user experience, improve scalability and reduce overall costs! Lets take a look at these features:

User Experience Enhancements

In addition to session pre launch and linger, some of the other key enhancements that improve the overall user experience include:

  • A new HTML5 Receiver for Chrome OS that supports printing, USB, clipboard, touch, webcam and 2-way audio!
  • DirectX Video Acceleration which allows the backend servers to utilize GPUs to decode H264 videos.
  • USB 3.0 Plug and Play
  • HDX Realtime Optimization Pack for Lync 1.5: The new HDX Realtime Optimization Pack (1.5) now supports HD audio and video within a XenApp and XenDesktop session and supports Windows, Mac and Linux endpoints. The current release supports Lync 2013 backend with a Lync 2010 client on the published desktop/VDI instance.
  • New enhancements to Receiver on iOS and Android: The new receiver for iOS and Android include significant improvements whereby the hosted applications behave like native applications. There are improved gestures for application switching and closing and improved keyboard popup sensing. In session application switching has also improved significantly and now shows live previews of open applications, much like the behavior of a native application.

Security Enhancements

  • XenApp and XenDesktop are now FIPS 140-2 complaint and has achieved Common Criteria evaluation. Both XA and XD support end to end TLS encryption.
  • Clipboard Control: Unlike previous versions, administrators now have the ability to granularly control what content end users are able to cut/copy/paste when using XA/XD. The settings are extremely easy to configure via Citrix Policies. If the end user is connecting securely through a Netscaler, these settings can be further controlled based on the endpoint the user is connecting from and IP address information.

Migration Scripts From XenApp 6.5 to XenApp 7.6

  • With the XA/XD 7.6 release, customers also have access to powershell migration scripts that automate the migration of XA 6.5 IMA farm settings  to an XA/XD 7.6 FMA site. It also automates the migration of existing apps and policies from XA 6.5 to XA 7.5. Citrix Technology Professionals Jarian Gibson and Andrew Morgan worked on a blog together detailing the capabilities of this script that is definitely worth a read!

AppDNA Enhancements

  • XenApp and XenDesktop Platinum edition includes AppDNA, the market-leading product for assessing compatibility of Windows applications with any version of Windows desktop, Windows Server, XenApp,XenDesktop, and App-V among other things. AppDNA in XA/XD 7.6 adds even more compelling features including the ability to either manually or automatically analyze application dependencies! Even more bang for the buck!

Universal Print Server 7.6

  • Universal Print Server (UPS) introduced in XenApp 6.5 simplifies printer management by not having to install drivers on the XenApp servers/XD VM’s and instead print on the print server itself. The print traffic between the XA/XD VMs and the print servers is heavily compressed and optimized for the WAN. The code enhancements in the latest version of UPS makes the solution much more scalable and robust!

Final Thoughts

The XA/XD 7.6 release clearly proves that Citrix takes customer feedback seriously and makes every effort to make the necessary changes to address the feedback provided! XA/XD 7.6 is packed with amazing new features that make business sense for most enterprise customers. Moreover, most of the significant gaps have now been addressed. I believe XA/XD 7.6 will gain significant adoption. I would strongly encourage every XA customer to take a look at this release, kick the tires in a lab environment and start planning the production migration!

Some resources worth checking out!!


One thought on “Why Every Citrix Administrator running XenApp 6.5 Should Consider Upgrading to XenApp 7.6”

Leave a Reply

Your email address will not be published. Required fields are marked *