The thing we want Softgrid to do (Active Upgrade+)

This entry started as a comment on
http://blogs.technet.com/softgrid/archive/2007/09/25/methods-for-upgrading-or-updating-virtualized-applications.aspx

The thing with Active Upgrade is that (as the article points out), the user gets the update automatically on next launch of the application. This is a major step forward for application updates. However, it does not solve the whole application testing problem: before pushing changes to the users, I need to test the application. In order to test, both version need to coexist but with Softgrid it is not X and Y but X or Y. The fact that a rollback to an earlier version of an active upgrade is not possible adds to the complexity.

What I basically want is:
1) Make a parallel application branch Y (as it is called in the article) from version X
2) Test this branch (without impacting the existing version)
3) Update the parallel application branch if required (using active upgrade)
4) When tests are successful, use Active Upgrade to update the production version X

This scenario is inherently not feasible because in stage 1, a new asset directory and a new GUID is created so that settings are stored in a different location.

The scenario that comes closest to what I want is the following:
1) Make a parallel application branch Y
2) Test this branch
3) When tests are successful, apply exactly the same procedure to the original version X, but this time using active upgrade.

The main issue in this case is the fact that you need to record the exact upgrade scenario in order to apply it again in step 3.

An other workaround exists, though:
1) Make an active upgrade
2) Test this update by manually importing the SFT file on the client (instead of streaming it)
3) When successful, do the update centrally with active upgrade.

I hear you thinking: but we have a Test envionment in order to do application tests. Ok, right, do you have a test copy for every production database to name just one example of why production tests may be required.

Softgrid: Machine vs User Cache on the Client

Using Softgrid, applications are virtualized and packaged in (basically) on file, streamed to the user and launched locally on the client. On the client, these applications run in a 'bubble' so that it is isolated from other virtual applications. One of the nice consequences of virtualization is that some applications that would normally not be server-based computing (SBC) compliant can be made so. This is a consequence of the fact that on the client, a user cache exists.

Let me give the example of an INI file that is used by application X to store user-related data. Normally, on a terminal server, this INI file would be shared by all users and thus only one user would be able to use the application at one time. Using Softricity, this INI file is virtualized and is configured to be 'user configuration' (see also here). This way, changes to this file are stored in a cache specific to the user (in the user's profile). Every user has its own version of the INI file and no conflicts can arise.

Setting the INI file as 'user configuration' is automatically done by the sequencer during the sequencing process and it is because the sequencer has certain rules saying 'This type of file needs to be user-specific'. In my case, the files that need to be user-specific are not yet created at the time of sequencing (they are later created normal usage of it. No broblem you say?! When a file is created inside a virtual directory (a directory that does not exist locally on the client, but comes with the virtual environment) it is stored cache! Yes, but in machine cache, not user cache!

What I would need in this specific case is a possibility to define which types of files need to be cache machine-wide and which user-based, not on the sequencer (see this SeqTypes tool by VirtualApp) but on the client. Or in other words, I would like to have the SeqTypes tool available on the Softgrid client. Has anyone experience or more information on this?

Google and Virtualization

Check this post: http://www.virtualization.info/2007/06/google-acquires-application.html



Not much can be found on the website, but from the description, the idea sounds familiar...