Maximum concurrent Socket.IO connections

Question

This question was asked earlier, but not quite recently, and not with a clear answer.

Using Socket.io, is there a maximum number of concurrent connections that you can support before you need to add another server?

Does anyone know of any active production environments that use websites (especially socket.io) on a massive scale? I would really like to know which setting is best for maximum connections?

Since websites are built on top of TCP, I understand that if the ports are not shared between connections, you will be bound by a port limit of 64K. But I also saw 512K connections using Gretty . Therefore, I do not know.

Answer 1

This article can help you with this: http://drewww.imtqy.com/socket.io-benchmarking/

I wondered the same question, so in the end I wrote a little test (using an XHR poll) to see when the connections started to fail (or lag). I found (in my case) that sockets started acting on about 1400-1800 concurrent connections.

This is a short text that I made, similar to the test I used: https://gist.github.com/jmyrland/5535279

Answer 2

This guy seems to have had over 1 million concurrent connections on a single Node.js. server.

http://blog.caustik.com/2012/08/19/node-js-w1m-concurrent-connections/

It’s not clear to me how many ports he used, though.