Links or suggestions for high-volume request/filter design

I need to create a very light-weight filter that does very elementary
processing of HTTP requests + some SQL Server access to log the request.

I don't want or need the full overhead of ASP.NET or anything else that
could slow processing. Is a filter the way to go? Something else? Does
anyone have any suggestions or samples illustrating how to approach this?
The issue is that 40% of my web server processing is tied up in what is
essentially a counter - I would like to offload this to something
lightweight and let my web server handle the heavy-lifting in terms of
requests that require complex logic.

Thanks for all suggestions/help.
K