So on this graph, can someone explain why the red line (writing connections) could go above the green line (active connections)?
Isn't the "active connections" the sum of Reading + Writing + Waiting ?
Here using nginx 1.12.2 nginx-stable-trusty from launchpad (Ubuntu 14.04)
deb http://ppa.launchpad.net/nginx/stable/ubuntu trusty main
The graph reflects the figures returned by nginx status
Active connections: 215
server accepts handled requests
218305659 218305659 919815892
Reading: 0 Writing: 230 Waiting: 36