XenApp Streaming has been around a while now, with the most current release included in XenApp 6. For those of you who aren’t too familiar with streaming it allows an administrator to capture an application install as a package (.profile extension) which is then saved to a file share.
From there users can launch the application at which time it is streamed in real time and executes locally where the streaming client is running. In some cases this is then delivered via ICA in a “Streamed to server” environment. With the streamed to server XenApp administrators can avoid unnecessary silos of XenApp servers.
So whats the big deal?
Good question, streaming allows applications to be isolated in that they have no ability to modify or write to the underlying operating system, either in the file system or the registry.
So whats the big deal?
Another good question! The benefit of this is that applications that may not have been compatible on a single system in the past, can now be delivered and run concurrently. For example this would allow a user to run Office 2003, 2007 and 2010 applications all on the same system. All without ever having to install the application once!
From an administrative standpoint, it allows a single streamed package to be maintained. Lets say a service pack is released for the users application, this can be applied to the application package and users will receive the updated package the next time they launch the application. This can even be done without an outage as users currently in the application would not be affected. This simplifies things for an administrator as now they only have to update a single instance of the application rather than every copy for every user!
Another plus, is stability of the system running the streamed applications. We all know with every application that gets installed, and possibly later uninstalled, operating system performance degrades over time. This is due to applications modifying the underlying OS. As stated previously streaming does not modify anything and is completely isolated in its package, therefore leading to a cleaner system and hopefully more stable system.
Great you say- are there any drawbacks?
With streaming it can be a lot more tricky to troubleshoot an application that does not work. Although if it works it will tend to stay working as the application package is read only. Additionally some applications that are improperly coded will often fail in an isolated streamed package as the restrictions will not be conducive to the improper application calls.
Some applications will flat out not work. I’ve been having lots of fun trying to get Office 2010 to work and it appears the changes to MS licensing are causing me grief. This is a good example where even though the application streams, there is a license lookup that fails currently in the streamed environment. I am still investigating this and will have a solution when I find one.
What about App-V?
Microsoft has their own streaming software called App-V. This was originally known as softgrid. The technology is effectively the same but handles things a little differently so some applications that don’t work in Citrix packages may work in Microsoft and vice versa. The nice thing is that XenApp supports publishing App-V packages natively within a XenApp farm.