My web server was down between 10:30 this morning and about an hour ago, when I noticed it. Bummer.

The apparent cause was the failure of certain of the server threads to exit, causing the server to attempt to kill them with SIGTERM and restart. So the server committed suicide (servercide? httpuku?). But it was unable to come back up because some threads (the same ones that wouldn't exit) were still listening on port 80 and so the server was unable to bind. Seven hours later when I finally noticed, the threads had exited.

Nasty.