Concurrent connection and performance?

Question

I have a Comet application that may have many instances open at once. This means many concurrent connections. It shouldn't be too hard to vary the connection hostname in order to overcome browser concurrent connection limit. My question is: How would this fair on an average internet connection? Will I run into performance issues?

Answer 1

Normally comet applications don't pass a lot of data, but do hold connections open a long time, so it should be ok on the client side. On the server side, you may have issues if you exceed the number of available TCP ports, but "holding a connection open" is more accounting than transfer. The short answer would be: "depends on how much data you want to push about". Watch out for session limits of hardware firewalls, etc., though. Some good hints here: http://www.metabrew.com/article/a-million-user-comet-application-with-mochiweb-part-1

Just in case answer: If you're hosting this from a home system, look forward to trouble, because home routers usually have issues with high numbers of open sessions overflowing their firewall/anti-ddos/whatever pools.