That's pretty impressive! How much memory does it need per connection? I think that's the primary metric I'd use to assess Cometworthiness (once all the basic stuff is taken care of, e.g. delivering 1000 outbound events per second takes the same amount of CPU regardless of whether there is only one outbound connection or 100 000 of them).
My main point was that it would be hard to tell if someone somewhere had an HTTP implementation that could handle 250 000 concurrent HTTP connections per 64MB of RAM while yours only handled, say, 5000 per 64MB. (I suspect the former number is achievable; I know the latter is.)
I can confirm from experience that writing an HTTP server that scales well without eating memory or CPU is dramatically harder than just writing an HTTP server. However, it's very easy to do better than apache-mpm-prefork. (No need, though; lighttpd and nginx should both do better at that, I have heard that perlbal does too, and I suspect from experience that twisted.web does as well, although I haven't measured it.)
My main point was that it would be hard to tell if someone somewhere had an HTTP implementation that could handle 250 000 concurrent HTTP connections per 64MB of RAM while yours only handled, say, 5000 per 64MB. (I suspect the former number is achievable; I know the latter is.)
I can confirm from experience that writing an HTTP server that scales well without eating memory or CPU is dramatically harder than just writing an HTTP server. However, it's very easy to do better than apache-mpm-prefork. (No need, though; lighttpd and nginx should both do better at that, I have heard that perlbal does too, and I suspect from experience that twisted.web does as well, although I haven't measured it.)