How To Configure a DLL Surrogate for Use with ASP

This article explains how to configure the registry to use in-process components outside the main process either on the same machine or on a remote server.

IMPORTANT: This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore it if a problem occurs. For information about how to do this, view the "Restoring the Registry" Help topic in Regedit.exe or the "Restoring a Registry Key" Help topic in Regedt32.exe.

DCOM provides a default DLL surrogate (Dllhost.exe) that can act as a host for your in-process components. The file Dllhost.exe is an executable component that you can run remotely and instruct to load any in-process component, providing the component with a surrogate parent process and security context.

Running In-Process Components Locally

To activate an in-process component in the context of a DLL surrogate, two settings must be configured in the registry. These settings can be made in the component's self registration code, or by using the following example surrogate.reg file: Since no surrogate name is provided in this case, the system-supplied surrogate, Dllhost.exe, will be used by default.

Running In-Process Components Remotely

To configure a surrogate process to run remotely, all the standard registry entries configured via the component's self registration routine need to be present on the client machine, plus the following entries: These entries specify whenever a client comes looking for the component, the component should actually be run on another machine specified by the RemoteServerName value.