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

[gnusys]

My Current settings are higher except the worker_process

worker_processes  1;
worker_rlimit_nofile 69152;
worker_shutdown_timeout 10s;
thread_pool iopool threads=32 max_queue=65536;


I think the issue is that nginx accumulate ESTABLISHED and CLOSE_WAIT and
FIN_WAIT1

>From successive netstat -apn listing I see that it is the CLOSE_WAIT that is
sky-rocketing first

then eventually ESTABLISHED and FIN_WAIT1


The million dollar question is why Apache httpd is handling this situation
of attack quite well on the same server while having Nginx as a reverse
proxy hangs the web stack by TCP state exhaustion?

The symptoms are similar to what is mentioned at
https://blog.cloudflare.com/this-is-strictly-a-violation-of-the-tcp-specification/

Only thing is that I don't know what must be changed in the config etc to
fix this problem in nginx

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,282613,282645#msg-282645