This is a very interesting change in CF9 (and 9.0.1), which has slipped under the radar for the most part as far as I can tell.
Did you know there is now a setting in the DSN page of the CF Admin (for most DB drivers) that allows you to set a maximum timeout for queries against that DSN? It's a new feature enabled for the DataDirect drivers udpated in CF 9. The caveat? It is ONLY settable there, not in CFQUERY itself, which is a shame (the existing TIMEOUT attribute is not the same and generally does not work). Still, the value of this even at the DSN level is too important to ignore for some challenges. More on that (and some other thoughts) in a moment.
As for the setting, it's in the "Advanced Settings" section for a DSN in the CF 9 Admin, and it's called "Query Timeout". This should not to be confused with the older settings, "Timeout" (which is about inactive connections) or "Login Timeout" (which is about logging in to the connection). The screenshot at right shows all 3. (This blog entry continues, with more information below it.)
I've run a test (more below), and it really does do the job, which is huge. Why? Because it's been a long-time issue that if a CFQUERY got hung up waiting for a response, that request thread (doing the CFQUERY) is then hung until the query finishes, which can sometimes be many minutes, or even hours or days, due to some odd situations. More important, a thread waiting for a query with no timeout can't be terminated (by the JVM, or CF, or the monitoring tools) because the thread was in a native thread state.
With this new option specified, if the request exceeds the timeout, the request does now fail, with a JDBC error, "Execution timeout expired." The same test does NOT timeout with the older cfquery TIMEOUT attribute.
Here are some other notes on the new feature: