Why does my DCAM show multiple instances of dllhost.exe?
The applications under Microsoft COM+ run under the process called dllhost.exe (formerly known as Mtx.exe in NT4). In fact, on a computer that has IIS installed, the associated applications of the inetinfo.exe (web services) process run under dllhost.exe as well. Prior to IIS 4, all Internet Server API (ISAPI) applications shared the resources and memory of the inetinfo.exe process. This included ASP technology. Running the applications in the same process space, provided faster performance and fewer resources were used. However, this made the server process vulnerable to crashes due to unstable components running in the same space. It also made the development of new applications difficult to debug.
By default, inetinfo.exe runs in its own process to protect it from misbehaving applications, although this can be modified. The applications under Microsoft COM+ run under the dllhost.exe process and there is usually a dllhost.exe process running for every website that is running 'out of process' on the server. The Data Access Server (DAS) for OM/SM is a COM+ application that runs in its own dllhost.exe process.