My site is getting slow after 300+ active user but server is not running at full capacity.
I was using a Nginx sevrer with Apache in backed on a 2GB RAM UBUNTU server. but my server was getting slow after 220+ active users so I switched to 4GB RAM server but still the server goes very slow around 320+ users. all other files except PHP are loading quite fast but in case of PHP the waiting time is around 6-7 sec. I think there is some issue with either Apache or Nginx configuration.