Nginx hang and do not respond with large number of network connection in FIN_WAIT state

[gnusys]

Its a shared server and I am unable to modify the domains CloudFlare/DNS
settings. 

As said the question mostly is why Nginx is freezing for the same setup and
traffic while Apache handles it just fine.

If its an issue with the Nginx setting, what should I change? or is it a bug
in Nginx?

Nginx was used as a reverse proxy on the server just to ease off situations
like this and the server use limit_conn and limit_requests etc setting and
low timeouts, but the TCP state exhaustion is making the server unusable

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,282613,282653#msg-282653