Application performance of Nginx

[nikhilagrawal577]

We are using Nginx open source flavour. We are running few lua scripts in
nginx layer.
Nginx is very slow in processing those programs. We required to increase
number of instance to support load.

We want to check why nginx is slow ? 
How do we check performance of Nginx application ? Not talking about
stub-module.
Metrics like:
1. CPU breakdown of Nginx app
2. Response time 
3. Memory breakfown of nginx app

Regards,
Nikhil

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,294926,294926#msg-294926