ThreadAbortException occurs when deleting images on a background thread. ASP.NET 4

I'm using VS2010 and ASP.NET 4. I have a single, long-running background thread running in the application, which is designed to 'cleanup' the least recently used files in a folder. It uses an EventWaitHandle to eliminate uneeded CPU usage, but stays running for the life of the app.

After 24-40 deletions or so, the application restarts. This happens under both IIS Express and the WebDev server, with the debugger attached. No exceptions are thrown on the background thread, but a ThreadAbortException occurs on all threads, and the app restarts. No Redirect calls are made anywhere.

These files are located in an 'imagecache' folder in the root, not any folder that should cause a app restart. No folders are created or deleted.

The restart seems to occur a timed interval after a certain threshold of deletions occur.

Any idea why t开发者_开发问答his is happening and how I can stop it? Restarting every 10 seconds ins't acceptable for me :)

Perhaps it's an IIS application pool recycle ? Have a look on the recycle settings to see if it might be something there.

Another option depends on how you start the background thread. If it's from an aspx page then it might be the Request thread timing out. If it's from the global.asax then this is not an option.

An asp.net application is to service client requests, not to run background tasks (although there are many kludges that allow this).

Can you put the thread into a service?