Im trying to debug why an app server of ours all of its apache children lockup and stop serving requests. These are mod_perl app servers.
The problem is that to find out what the current requests are you need to make a http request to find out the server-status (using mod_status).
You could hook into one of the earlier phases in the mod_perl lifecycle and dump the requests at that point. Add a hook at the end to mark a particular request as completed (maybe add the response headers), and now you know what's currently running.
Not what you're lookng for exactly, but you could restart Apache, script fetching the status every (N seconds/minutes) until it crashes, and then look at the most recent?
I've since found out that one possible route is to stop incoming traffic to this website (iptables rule on the local box would be easy enough) then get a pid list of the apache children and send a HUP to a couple of the children, then do a localhost server-status (as you now have a few freed up children to serve requests).