Nginx configuration for huge load of concurrent requests

nginx.conf

user  nginx;

# you must set worker processes based on your CPU cores, nginx does not benefit from setting more than that
worker_processes auto;

# number of file descriptors used for nginx
worker_rlimit_nofile 100000;

events {
    # determines how much clients will be served per worker
    worker_connections 4000;
    # optimized to serve many clients with each thread, essential for linux -- for testing environment
    multi_accept on;
    # accept as many connections as possible, may flood worker connections if set too low -- for testing environment
    use epoll;
}

http {
   server {

      # to boost I/O on HDD we can disable logs
      access_log off;
      error_log off;
      # copies data between one FD and other from within the kernel
      sendfile on;
      # send headers in one piece, it is better than sending them one by one
      tcp_nopush on;
      # don't buffer data sent, good for small data bursts in real time
      tcp_nodelay on;
      # number of requests client can make over keep-alive -- for testing environment
      keepalive_requests 100000;

      listen 4000;

      location /spring-r2dbc/ {
        proxy_pass http://spring-r2dbc:8080/;
      }
    
      location /spring-jdbc/ {
        proxy_pass http://spring-jdbc:8080/;
      }
    
   }
  
}

Code snippet Related to medium article:

https://blog.devgenius.io/an-epic-tale-comparing-jdbc-and-r2dbc-in-a-real-world-scenario-part-2-2-d908df49651c#823f-8a39553a5cf4