Possible Duplicate:
How do you do Load Testing and Capacity Planning for Web Sites
I know it's a very open question, but I think it can be answered more or less. I will soon release a service. The topology:
-> one VPS with nginx / eAccelerator / php-fpm , with 4Gb RAM and apparently with an excellent internet connection. This is the entry point, it is a simple PHP application that builds the startup code by including code & HTML chunks. That is, the PHP app ONLY does includes from disk. No sessions, no URL access, no anything. Just conditional includes.
-> one VPS with tomcat, postgresql, same configuration: 4Gb RAM, same server farm. Accessed directly by the clients.
I'd like to know what kind of performance to expect, specially from server (1). I am running a 1000-users beta. Do you think this will be more or less enough IF stuff is properly written, optimized and configured? Make all assumptions you want or find missing, don't worry, I will learn from every answer and extrapolate. It will be very valuable to me if somebody can post actual cheap VPS performance numbers. I don't know in what terrain I'm moving!
Thanx in advance!