I'm planning in regards to a chat system for this site. I'm considering doing ajax pushing. The customer will initiate an association towards the server by calling chat.php. chat.php is going to do an infinite loop(30 sec). On obtaining a new message it'll return paper the content towards the client and exits the bond. The ajax script on obtaining a responseText calls chat.php once more. My real question is the scalability of these a method(php driven COMET) for 500 concurrent chat processes on the hosting that is shared package.

My real question is the scalability of these a method(php driven COMET) for 500 concurrent chat processes on the hosting that is shared package.

You will not have the ability to pull off this on hosting that is shared. Odds are the Apache instance around the server is set up having a much lower concurrent connection limit. Even when it had not been, getting 500 active PHP instances on the hosting that is shared account will get observed and can seriously degrade the knowledge for everybody else around the shared machine.

PHP is most likely not the very best tool with this job. If you wish to get it done with PHP, you are have to a VPS or devoted hardware. Honestly, even when you don't use PHP, you are have to a VPS or devoted hardware to implement an answer that better fits the issue (just like a background process for everyone the chat demands directly, something you cannot do on hosting that is shared).