tracking - php matchmaker -

I was thinking that it would be nice to have a simple matchmaker code in PHP. The idea is that the app connects to the server or is a specific webpage, the webpage takes it from the IP and the final X IPS and prints it on the page (first of its)

The problem occurs when the 5 PPL Hits the page, the second one, how do I manage it? Can not I use global / shared memory? So I write the IP in a file and write / write them (the same second 10x) would be bad? I think it's OK to be slow but I want to be optimized if possible.

Is it better to store in a mysql db?

I would suggest using the APC to remember the information in memory. It is only 1 server With multiple servers, you should see something like a memkhed.