I am running apache-2.4.7 with Ubuntu 14.04, I have 2 cores, 2GB RAM on my server.
I have ssl enabled and activated on my website.
I usually push notifications to users, so sometimes maybe 150-200 users visit the website within 20 seconds.
The problem is, when i push a notification to users, or when i have big traffic the server responds very slowly for establishing a connection, i checked the cpu and memory usage and they both are working with less than 20% of their capabilities in the peak time.
I read data to my website from a json file on the same server and there are some mysql queries.
The htop
command when i have 200 online user on the website as Google Analytics claims