ASP.NET MVC app restarts itself

Question

We are encountering an issue where our ASP.NET MVC app is restarting for an unknown reason. The cause of the shut down is

"A subdirectory in the Bin application directory was changed or renamed."

The file in question turned out to be C:\Users\Jason\AppData\Local\Temp\Temporary ASP.NET Files\root\f691a68c\a1593a1e\hash\hash.web.

Something noteworthy is that we are starting up a NServiceBus client in Application_Start and if we comment out that line, our web app doesn't restart itself. The the questions are: 1) What does hash.web do and 2) Is this issue NServiceBus related?

Answer 1

are you using log4net in your application at all? in some of our environments we had log4net logging files to the same directory as the app (i.e. bin directory) and it would cause the application to restart. moving the log files out of that directory resolved the issue.

Answer 2

You need to figure out what is touching the hash.web file: a likely cause is a virus scanner. Monitor the file with Process Monitor.

If possible, exclude the Temporary ASP.NET Files directory and subdirectories from automatic virus scanning as well as the web content directories.

In .NET 2.0 it is possible to disable FileChangesMonitoring through the HKLM\Software\Microsoft\ASP.NET\FCNMode key, a value of 1 will disable file change monitoring. The drawback of disabling this is that if you disable it, the application will not restart if you change web.config etc.

Of Interest: ASP.NET File Change Notifications, exactly which files and directories are monitored?