ASP .NET has a fast and easy way to take an application offline using a reserved file called App_Offline.htm. When ASP.NET services any application request, if it finds a file named App_Offline.htm in the application's root directory, it serves the contents of that file rather than the typical response.
This feature can be quite handy when doing occassional updates. To use it, simply copy the App_Offline.htm file to the root directory of the web application, perform your updates, and then delete the App_Offline.htm file when you're done updating. The App_Offline.htm file can contain any static content you want to show users.
Be sure to read this caveat.
- Limitations: The App_Offline.htm file's size must be greater than 512 bytes for this to work. If the file size is less than 512 bytes, you must turn off the "Show Friendly Error Messages" option in Internet Explorer → Advanced.
There are other ways to turn off applications; however, this is quite easy and straightforward.