HDX MediaStream Flash Redirection and Single-User VSI Testing

In the first blog in this series we covered software preparations that installed and tested individual applications. In this blog, we’ll cover configuring HDX MediaStream Flash redirection as well as single-user testing, leading up to full single-server testing of the system which will be covered in part three.

HDX MediaStream Flash redirection is important to overall performance, since it allows you to move the processing of Adobe Flash Player to user devices rather than using network server resources. Users see the same high-definition experience when using their endpoint devices to access Flash content, including animations, videos, and applications. By moving the processing to the user device, HDX MediaStream for Flash reduces server and network load, resulting in greater scalability.

Once HDX MediaStream Flash redirection has been configured, single-user VSI testing helps ensure that everything is in place before larger multi-user testing takes place.

HDX MediaStream Flash Redirection for Login VSI testing

The Adobe Flash plug-in is required to be installed on the XenDesktop master vDisk image and at the Login VSI launcher client. Citrix HDX MediaStream Flash for XD 5.6 requires the minimum use of Adobe Flash 10.1. The default version of Adobe Flash that ships with the Login VSI 3.5 agent is so you will need to uninstall and reinstall the newer Flash plug-in on the VDA as well as the launcher.

The most current Adobe plug-in is what’s known as a universal installer. The universal installer is the same executable for both 32-bit and 64-bit Windows. Citrix HDX Flash Virtual Desktop Agent (VDA) only supports the 32bit version of Adobe Flash for Internet Explorer at this time. If you are running a 64bit Windows 7 as the client virtual machines with the VDA, then the 32-bit Internet Explorer version along with the 32-bit version of Adobe Flash will be used.

More information on Flash V2 plugins and its requirements are located in the link below. It is a best practice to ensure that both the launcher and the VDA are one the same Adobe Flash version number. At the time of this writing, version 11.1 is available and version 11.3 is currently the latest Adobe Flash version.


There are two types of Flash plugins that need to be loaded for Flash Redirection to successfully occur. The first Flash plug-in is for the VDA which uses the Adobe Flash Active X installable MSI. This may also be known as the Flash Player for Windows Internet Explorer.

The second Flash plugin is known is known as the Adobe Flash Player for Windows-Other Browsers or NSAPI (Netscape Plugin Application Programming Interface) and is in an exe format. This plugin is loaded on VSI launcher clients.

Naming each of these appropriately to match their installed locations will greatly save in any potential errors that can occur during installation and future testing. Additional information on HDX MediaStream can be found at the link below.


After the installation, a quick check into Control Panel-> Flash Player on the Launcher and VDA will confirm that you have the correct Adobe Flash version installed and ready.

On the VDA you will notice the Adobe Flash plugin will say ActiveX Version as shown in the screenshots below. It’s also a good practice to disable Adobe Flash updates during your tests which can be done here as well.

On the VSI launcher client you will see that the plug-in version is loaded. It’s also a good practice to disable Adobe Flash updates during your tests which can be done here as well.

More information on Adobe Flash can be found in the administration guide using the link below.


For VMs that have Internet access, the link below will download the base plug-in and then stream down the remaining needed components.


For VMs that can’t access the Internet to download the entire Adobe NS APIPA, the link below will provide you the entire 11.1 exe file.


Enabling HDX Flash Redirection on VSI Launcher

After installation on user’s devices, no further configuration is needed to enforce that HDX MediaStream Flash Redirection is ready for use by your users—absent any overriding of policy settings on the client. If you want to change the default settings on the user device, you can do so with the Group Policy Object Editor.

Configure Enable HDX MediaStream for Flash on the user device to determine whether Flash Redirection is enabled on your users’ Windows devices.

In the Group Policy Object Editor, expand either the Computer Configuration or User Configuration node as shown below.

Next, expand the Administrative Templates and Classic Administrative Templates (ADM) nodes and select HDX MediaStream for Flash – Client.

From the Setting list, select Enable HDX MediaStream for Flash on the user device and click the link to edit policy setting.

Select Enabled and check the forced button. This setting will force the launchers to use client side processing every time throughout the test and will save time having to change each launcher’s setting manually. More detailed steps can be found at the link below.


Once this process is applied to the Login_VSI_XD_Launchers computer, each of launchers will need to be rebooted. A simple reboot of the launchers from the VSI console can help make this process easy and fast. Confirmed configured settings are shown below.

Creating the VSI intranet Website redirection

By default, the websites created on the Login VSI client that is installed in the VDA will not work with HDX MediaStream for Flash. The websites and flash content need to be copied from the Login VSI Target Setup Lib folder to an internal Microsoft IIS or Apache Server. The video below demonstrates how to perform this configuration step.


Once the websites are configured and tested, you can create the Login VSI medium user workload test. It is most important to make sure that you have saved the test configuration prior to starting and that the custom settings show the new URL for the webserver as shown below.

Applying XenDesktop Flash Policy

The last step is to apply the Flash policy to the desktop group. Applying the Flash policies below will enforce client side Flash during the Login VSI test. Apply the policy to the desktop group that has been created for Login VSI as shown below.

To verify that the policy is applied correctly, we can launch a test session as a Login_VSI user. By selecting the preferences, the optimized content button should be checked as in the example below.

Conducting a Single-User Login VSI Test

The system should now be ready to conduct a single-user test under the control of Login VSI. At this point, it is assumed that Login VSI and XenDesktop virtual machines are configured and that other testing prerequisites have been satisfied. Once all settings such as, Group Policy, Flash installs, and XD policies are applied then you can start the Login VSI Medium Flash test.

The reason for conducting a single-user test is simple: application verification. Since the applications have been tested at the VM console level prior to converting our image to a Citrix Provisioning Server vDisk, we know they work manually. However, automation testing with Login VSI goes well beyond the launching of manual applications. For this process, I usually start with a Medium Flash Login VSI test and allow my launcher to make a connection to the XenDesktop session.

From there, I wait throughout the entire duration of the Login VSI Medium workload test, and observe every application for issues with launching, executing a task, and closing. This process helps confirm that that all aspects of Microsoft Office, Internet Explorer, Adobe Reader, Adobe Flash, Bull Zip Printing, and anything else in the workload executes cleanly and without any applications pop-ups or unforeseen issues. While this extra step may seem tedious, it provides an increased level of confidence. If a single-user automation test runs through to completion, then a test with two thousand users should have a very high rate of success. Once a single-user test has executed successfully, more ambitious Login VSI tests with larger numbers of users can be launched, with an anticipation of success.

Verifying That HDX MediaStream Flash Direction is Working

As the test is being run, you can verify Flash redirection is working on the launcher by pulling up task manager and searching for Pseudocontainer.exe or pseudocontainer2.exe for Flash V2. In Flash V2 you can also verify Flash redirection is working by right clicking in the flash movie trailer (shown below), and you will see the About Citrix HDX MediaStream Flash redirection appear. As the Flash websites and movie trailers start, the ActiveX pseudocontainer.exe, or pseudocontainer2.exe redirection will execute on the launcher and the Flash client rendering will be offloaded.

The pseudocontainer process will stay active for the whole duration of the movie and will change in processor percentage on the launcher. During our scalability testing the launcher CPU ranged between 1 to 5 percent CPU utilization for the duration of the movie trailer. The percentage of CPU utilization may vary with other Flash based applications as well. Again, while this amount of CPU offloading may not seem significant, it can make a big difference over hundreds of desktops running on an individual blade server.