Relationship between threads,appdomains,worker process

Question

What is the exact relationship, in IIS7 and ASP.Net, between :

• IIS Worker processes
• Threads
• AppDomains
• Applications
• incoming requests

I'm hoping for an answer in a format similar to :

"Each IIS worker process hosts many appdomains which each spawn a single thread in response to each request...." etc. , and any nuances mentioned.

Thanks in advance.

Answer 1

Each worker process hosts several AppDomains (at least one per ASP.NET app, i.e. a Website or Virtual Directory). An incoming request is assigned a thread from thread pool when it comes.

Answer 2

Fritz Onion's book Essential ASP.NET has a chapter on HTTP Pipeline where he talks about relationship of all of the above during http request.