What constitutes a "multiple-process site"?

Question

We have an ASP.Net web application which displays a chart using the .Net 3.5 Chart control and we are using the ChartHttpHandler to handle charting requests. The documentation for the ChartHttpHandler states:

memory: Store the rendered chart images in the memory space of the running process. Do not use this option in a server cluster or a multiple-process site.

What constitutes a "multiple-process site"? How would I know if the target web server will be such a beast?

Answer 1

Multi-process is referring to what IIS6 introduced as a Web Garden (whereas a cluster would be a Web Farm). This can be observed on MSDN's page describing modifying the worker process of a web farm: Performance Application Pool Settings.

As far as detecting, if you go to the AppPool's properties and look for the number of worker processes, this will tell you if you're running multi-process or not.

For example, IIs 7.5's settings can be found on the advanced properties of the AppPool:

As a follow-up, here's another article (from MSDN) describing how to configure web gardens in IIS6