Thanks for that, Brian. I should add that while this article was from 2001, since CF7 we now have application.cfc and its onapplicationstart method. That does change things a bit, in that one could safely create an application variable there and it really would be created only once, at the start of the application. For that reason, I suppose it may no longer be so "wrong" to see application.dsn--but again, that's only if you're using this feature. Otherwise, it may be better to stick with the request scope as discussed in the article.

Very informative! I've been wondering what the request scope is for such a long time and no other resource did such a great job of explaining it.

A read asked by email: "don't you also need to lock request vars?" The answer is no. They're not shared by any other user. More particularly, they're not shared by any other "thread".

The request scope, like the variables scope, is local to the running program and belongs only to it. It's a single thread of execution, so there's no risk of conflict with other threads, as with the "shared scope" variables, server, application, and session.