Zero Touch and the Cache

I had a chance to travel to Calgary earlier this week to speak at the Microsoft Bigger Better Basic conference.  One of the session I was scheduled for including a number of demos on the Smart Client technology.  So I'm sitting on the plane running through the demos just to make sure that I don' up in front of 600 people and I get to the Zero Touch Deployment (ZTD) demo.  This is a straightforward demo showing what happens if you move a .NET application onto a virtual directory.  The deployment is done by clicking on a link in a simple HTML page.  So sweat right?

So I get to the part where the HTML page is displayed, click on the link and...nothing happens.  That strikes me as a little strange, so I start checking on the normal stuff.  Does the file exists.  Is it really a .NET application.  Does the link in the HTML page point to the right place.  All looks good.  So now I go on to the more esoteric possibilities.  Do I have the appropriate permissions defined in the Framework Configuration Wizard.  Are there any settings in the virtual directory that might be giving me grief.  Has ASP.NET been installed in the virtual directory.  Still nothing.

Now I'm beginning to pull my hair out.  After another 15 minutes or so of puzzling, I try to view the source for the HTML page.  Nothing happens.  Fortunately, this is a situation that I'm familiar with.  If you can't view the source for a web page, your temporary Internet cache is full.  And then it hits me.  No room in the Internet cache means that the downloaded application doesn't have a place to live.  So I go into the Internet Options, clear out my cache and ZTD works like it's supposed to.  No damage (other than those haris that are still stuck between my fingers).

But this does bring out one of the biggest weaknesses in the ZTD model.  The downloaded application lives in the cache, along with other pages of stuff from the Internet.  It is too easy for a user to clear out the cache, thus removing the benefit of off-line functionality.  I believe that this situation will be corrected one of the future products (I can't remember whether it's Indigo, Whidbey or Longhorn).  The correction is the cache the ZTD applications in a different location and allowing a generally more granular level of cache clearing.  Can't come too soon for my taste.  ZTD is nice, but when in the hands of the uninitiated, it has the potential to generate some help desk traffic.