Are there any IIS Application-Pool Usage Guidelines?

I've been looking at application pools lately, specifically with ASP.NET applications in mind and I've been struggling to find any best practices for use of application pools.

Of course alot depends of the size and scale of your destined apps in regards to memory limits etc, but I was more specifically thinking along the following lines...

If developing relatively small .net apps which need to be deployed underneath an existing site, should I as a best practice be creating a new virtual directory and application pool for each app?

Or should I just run them underneath the sites already present app pool?

Secondly are there any limits to the amount of app pools you can run (realistic开发者_C百科ally and again assuming small apps with memory limits auto-handled and not defined) on a standard web server?

With resilliance and optimisation in mind my initial thought is to create a new v dir and app pool per app under the parent site - I just wondered if anyone has any thoughts on best practice or links that may assist?

Cheers

For resilience, create a separate application pool for each application. That way if an event occurs in one application that causes the pool to stop, it is only THAT application affected, and not any others on your server.

This also helps in terms of security - the application pool controls the identity of the running application. You should only give just enough permissions for the application to run on the machine. If one application requires access to a specific folder on the server, that doesn't mean you should be giving the same access to all of your applications.