That's right, you tie up an Apache process/thread to proxy each connection, so pretty soon you run out of them. And the whole point of Node.js is to run I/O asy

That's right, you tie up an Apache process/thread to proxy each connection, so pretty soon you run out of them. And the whole point of Node.js is to run I/O asynchronously without tieing up a thread for it. A better alternative would be to run e.g. Varnish in front of both Apache and Node.js. Then you can forward requests to any backend server you like in an efficient manner (using pipe mode for long polling requests).