How to prevent IIS from shutting down Web Site when not in use?

Question

I have a web application hosted under IIS. It is a data warehouse, and during its startup process it requires instantiating a large set of items in memory (takes roughly ~20

Answer 1

Check Idle Time-out settings under process model in screenshot. That setting is causing app pool shutting down when remain idle for 20 mins. You can set it to 0 to keep it running all time even when its idle i.e. not processing any requests.

Note: Keeping app pool running all time will consume server's precious memory. It may become critical especially if application is leaking memory.