When do I host different applications on the same application pool in IIS?

Question

It can be hosted more than one application in one application pool. That's what I know, but can we say every application should be hosted on a different application pool?

When can I use the same application pool for a different application?

Answer 1

Using the same application pool for more than one application is possible - though you need to take into account some aspects:

• security context
  IF an app needs a different setup security-wise it goes into a different pool

• resource usage
  IF an app takes lots of resources it might be better to use a separate pool

• restart scenarios
  IF an app has different cycle etc. regarding restart (like updates etc) it might be better to use a different pool

• inter-application communication performance
  IF two or more apps need to communicate very intensely it might be better performance-wise to have them in the same pool.

• stability
  IF an app is much less stable than the others then it should go into a different pool

In all other cases it is more a question of ease of administration (for example one app pool per site) whether to use the same app pool or not...