Comment 3 for bug 691165

What Martin said. My first guess is that Conch is almost certainly doing all the crypto in the same thread that runs the event loop, so if that takes non-negligible time then it will delay processing of the next connection. Some profiling of that code will probably find the culprit fairly easily.

I can rule out one possibility: I'm fairly sure that the XML-RPC call to the Launchpad database for SSH keys for that username is not blocking in that code; at least it wasn't when I wrote it :)