Scott Watermasysk

Still Learning to Code

App_Offline and ASP.NET 2.0

We encountered a data corruption error on the CS.org database (not a CS bug). To run some quick fixes this morning I tried to use the new ASP.NET App_Offline.htm feature.

The way app_offline.htm works is that you place this file in the root of the application. When ASP.NET sees it, it will shut-down the app-domain for the application (and not restart it for requests) and instead send back the contents of the app_offline.htm file in response to all new dynamic requests for the application. When you are done updating the site, just delete the file and it will come back online.

Unfortunately, I had yet to be pointed to ScottGu’s work around for a minor IE 6 issue.

One thing I pointed out in the talk that you want to keep an eye on is a feature of IE6 called “Show Friendly Http Errors”. This can be configured in the Tools->Internet Options->Advanced tab within IE, and is on by default with IE6. When this is on, and a server returns a non HTTP-200 status code with less than 512 bytes of content, IE will not show the returned HTML and instead substitutes its own generic status code message.

However, tonight when we need to put the database in single user mode and run the fix script, we were able to quickly copy over an updated App_Offline.htm file with a little more content.

It is a very simple thing, but can be very helpful and is a very nice touch to your ASP.NET toolset.

See Scott’s full post for more details.