I have a quick question for something I couldn't find while searching. I'm a total server noob so please don't get angry.
When I track CPU usage using ssh top I can the user process causing about 20 percent of CPU load when calling a website that is hosted on my server.
I have a VPS server with 8 cores and 16gigs of ram and realize that that 20 percent is just one core but still, I am surprised that one visitor can cause 20 percent usage of one of the cores.
What happens if let's say 50 users visit the site at the same time? That would in theory overload the CPU, right?
The server is running Plesk with an nginx as reverse proxy.
The process causing the load is PHP fpm and nginx barely shows up while looking at the ssh top screen.
Is that kind of short spike (2 seconds or so) normal for one visitor? And if so, how many wordpress websites can I host on this server with Let's say 20 concurrent visitors per site?
Thanks so much for your help.