Rob Howard wrote a great article about Database Cache Invalidation. Implementing a cache invalidation strategy was a task for next week, and now we have a much better solution than we were going to have.

He even gives us arguments about why the approach we were going to use (a file watcher, with triggers to update the file) is not viable.

We got a sample up and running (based on Rob's sample code) within an hour, and implementing it should be fairly straightforward next week. The sample is also a good sample of one of the ways that HttpModules can be used.