ASP.NET 2.0 compiler slowness

Here is an interesting problem I worked on a couple of weeks ago for a customer who raised a call with Technical Support: they had an ASP.NET 2.0 application written with Visual Studio 2005, and while working on it they found that when changing a code file contained in App_Code folder and then building the site from the Visual Studio menu command, this took up to 7 minutes to complete… and if they then run a page pressing SHIFT+F5 it took about 25 seconds to compile and display the page. If they just modified the HTML layout of the pages everything worked fine; moreover, it’s interesting to note that if they simply modified and saves their files without building the solution in Visual Studio, but just browsed the page (thus relying on ASP.NET to compile on the fly their code) again everything worked as expected. This seems quite clearly a problem with Visual Studio. It turned out that this project was originally build with Visual Studio 2003 and ASP.NET 1.1, and they decided to upgrade it to ASP.NET 2.0; they used the upgrade wizard provided by Visual Studio 2005, which will turn on batch compilation (<compilation batch=”true” /> in web.config) when it…

I just realized that my last post is 20 days old… I spent this time working on support calls I own (or course, that’s my job!), reading documentation and playing to get ready for the upcoming releases I’m quite sure you already heard about (Vista, Ajax, IIS 7, Internet Explorer 7…), reading some good books in my spare time (currently I’m almost done with The Twelfth Card by Jeffery Deaver) and among other things I’ve been searching (and found) a new home. (well, actually my girlfriend decided where we’ll go to live for the next years, I guess you know how this king of things works…). While I had to deal with the contracts and terminology I’m not familiar with, I realized that sometimes people tend to give some things and facts for granted, while other people may not know what we are talking about… This also apply to our business: I had some conversations with our customer getting “Application Server Unavailable” errors in their ASP.NET sites, and then we discovered that they tried to execute two different CLR versions (usually ASP.NET 1.1 and 2.0) in the same worker process… This is not allowed, and I always thought this was clear, but a couple of customers…