With XenApp 6.5 (or XenDesktop 5.5 and higher), session pre-launch was announced as a solution that would make the a seamless session open in the background so the users would not have to wait when clicking an icon.
Although this idea seems awesome, there are many points to remember when setting Session Pre-Launch.
What it is:
Session Pre-Launch is an invisible application that launches as soon as your Receiver is authenticated. When the application list is loaded, the receiver recognize the “Pre-Launch application” and connects instantly without showing a “Progress Bar” to the user.
How to create it:
The pre-launch apps are created by selecting one of your “already published” and choose “Other Task > Create pre-launch application”
Doing this will copy all the application settings to make sure “Session Sharing” is possible.
This “Pre-launch app” will appear as a new application and you will be able to Customize it. (change it’s name and configured users)
The name you will give it will only be seen by Citrix Administrators since it will only appear in the AppCenter. (users cannot see this app as part of their application list)
Important stuff to know:
- Session Pre-Launch uses session sharing to make the applications open right away when the user clicks his icons
- This means fast application launching will happen only for an application that is on the same server (or Silo) than the “Pre-Launch app” (Session Sharing)
- !!!IMPORTANT !!!
This also means that the session needs to be done opening when the user clicks his icons
- If your users session take 2 minutes to open… the user must not click an icon within this first 2 min. or he will end up having 2 sessions
*** It is important to optimize the loading time even with session sharing. (anything longer than 15 sec. is probably too long
*** It is a new session, if you automatically launch scripts or apps… they will be launched (it might affect the user if something is displayed)
- If the Session Pre-Launch is not done loading… the user will open a second session and he will see the “Citrix Loading Progress Bar” (like when they click 2 icons without waiting for the session to open)
2. With concurrent connection licenses, users that have the “Pre-Launch” application will use a license instantly when they log on their Workstation. (you might not want to publish “pre-launched apps” to everybody.)
3. Session Pre-Launch is enabled with a Registry key (enabled by default with receiver 3.x)
*Setting “State” to 0 will disable Session Pre-Launch
4. There are known issues with Receiver 3.4 (supposed to be fixed with Receiver 3.4 Cummulative Update 2)
- When enabling session Pre-Launch in an environment where XenApp Published Desktops are used, the Receiver will reconnect to it’s own session making the Published Desktop go away for the user.
- I usually recommend to disable the session Pre-Launch registry key on XenApp servers.
5. It is recommended to set the “Pre-Launch Terminate Timer Interval” and “Disconnect Timer Interval” to close a “Pre-Launched session” if it is not used.
This feature is a really cool feature that can help the user experience… as long as the administrator understands what’s happening.