What are possible causes for App_Offline.htm not bringing the site down?

Question

Normally, I use App_Offline.htm for taking the site offline. But occasionally, when I do that, the site just hangs (like in: browsers wait forever, server gives no response at all). This seems to happen on an updateable site when I change something, like a control and afterward, when it doesn't go quick enough (site hangs), I place App_Offline.htm in the root of the website.

In most cases, this immediately takes down my site. But occasionally it doesn't. In those cases, I cannot just stop the website (when I restart, the behavior continues). Stopping the application pool doesn't let me restart the same app pool. The only two solution so far is restarting the whole IIS web service.

I'd like to prevent this from happening. Is this a bug in IIS not "breaking all actions" when App_Offline.htm is found? I use IIS 7 with Windows 2008 SP2 64 bit.

Answer 1

What I found was that my web.config file either had an error in it or was missing. When this is the case, app_offline.htm does not get processed.