Thursday, 29 November 2012

Personalization Server in a multi site, single image scenario


With Virtual Desktop Infrastructure (VDI) and provisioned XenApp servers becoming a massive trend I’m often asked by AppSense Engineers how they can build a configuration which allows them to manage a single master / gold image for each platform from an AppSense Personalization Server perspective.
Historically engineers needed to define the computers Personalization Server within the configuration.aemp file which was then baked into the gold image. This meant that if the strategy was to build a single master image and manage this moving forward the AppSense Engineer needed to either leverage the sites list within Personalization Server or implement some clever global server load balancing.

The sites list within Personalization Server was typically the easiest method because it had the lowest initial cost. No additional hardware or licenses were required and the customer was able to specify a single server or virtual server (sometimes referred to as a VIP) within the configuration and that satisfied the requirement. However, from a scalability perspective this is not ideal. It means every time the configpoll is triggered the entire site evaluation process starts again. Imagine a scenario where you have 20,000 users who all logon at roughly the same time in the morning so the configpoll comes around at roughly the same time for all 20,000 users. I’d rather not.Enter Environment Manager 8.3. AppSense have now included the ability to define Personalization Servers using group policy templates which ship with the product. Essentially what this means for engineers is that you can now enforce Personalization Server on a per computer (or per user) basis using any of the conditions built into Environment Manager. Genius! Furthermore, the group policy gives you an option to bypass the site rules which means each time the configpoll comes around the scalability concern I mentioned above no longer applies.
Now I simply include a node at computer startup which leverages an Else If condition to set the devices Personalization Server.
The Environment Manager agent enforces the Personalization Server settings in the following order:
  1. User enforced group policy
  1. Computer enforced group policy
  1. Setting the registry underwrite key
  1. Using the traditional configuration.aemp method.
You can find the ADM and ADMX templates in the following path:
  • %ProgramFiles%\AppSense\Environment Manager\Console\Templates\Group Policy
The only thing to remember is that the ADML file needs to be moved to a subdirectory called en-US in order for it to work correctly.