I have to build a simple chat system in PHP using Comet.
I don't know what would be the best approach to this project.
What is the best technique (cross-browser would be nice) to use, and how to implement it? What libraries can I use that already have comet support. (I don't want to use the Bayeux Protocol)
I already have a PHP backend running for the chat system, but I need some ideas for the interaction between client and server.
Thank you all in advance. My regards.
You may want to look at WebChat2 This project uses comet, AJAX, and a custom HTTP server to communicate with IRC via sockets.
chart & Long point-by-point discussion
Unfortunately, there's no information for PHP in there, though you could potentially wrap your existing back-end with a comet server on some other platform.
There is a similar SO question about this, looks like FastCGI is your best bet.
php is not a good match for comet, because there is no way to have light weight request handlers. You would have to lock up a full process for each user connected. It could work with very few users, but not for anything with even moderate traffic.
来源：https://stackoverflow.com/questions/1190744/comet-php-how-to-use-comet-with-a-php-chat-system