And so we waited. Tick-tock, blink-blink, thirty seconds stretched themselves out one by one, a hole in human experience. -- The Bug

I think I've managed to fully track down the ?webapp hang. It is, apparently, a bug in the Warp web server's code intended to protect against the Slowloris attack. It assumes, incorrectly, that a web browser won't reuse a connection it's left idle for 30 seconds. Some bad error handling keeps a connection open with no thread to service it, leading to the hang.

Have put a 30 minute timeout into place as a workaround, and, unless a web browser sits on an idle connection for a full 30 minutes and then tries to reuse it, this should be sufficient.

I was chasing that bug, quietly, for 6 months. Would see it now and then, but not be able to reproduce it or get anywhere with analysis. I had nearly given up. If you enjoy stories like that, read Ellen Ullman's excellent book The Bug.

To discover that between the blinks of the machine’s shuttered eye—going on without pause or cease; simulated, imagined, but still not caught—was life.