nginx.conf

worker_processes auto; # Auto-detects the number of cores and launches that many worker processes

events {
    worker_connections 30000; # Increase if you need to handle more than 1,000 connections simultaneously
    use epoll; # Use efficient event model for Linux
    multi_accept on; # Accept as many connections as possible when they come in
}

http {
    sendfile on; # Allows Nginx to use the sendfile system call to serve static files
    tcp_nopush on; # Optimizes the amount of data sent at once
    tcp_nodelay on; # Disables Nagle's algorithm to improve network efficiency
    keepalive_timeout 0; # Allows persistent connections, which reduces latency for subsequent requests
    types_hash_max_size 2048; # Increases the maximum size of the types hash tables
    server_tokens off; # Hides Nginx version information from error pages and Server response header field

    access_log off;
    
    upstream api {
        least_conn; # Sends new requests to the server with the least number of active connections
        server localhost:8080; # api01
        server localhost:8081; # api02
    }

    gzip on; # Enables gzip compression to reduce the size of the HTTP response
    gzip_comp_level 5; # Sets the level of compression (1 is least, 9 is most)
    gzip_min_length 256; # Sets the minimum length of a response that will be gzipped
    gzip_proxied any; # Compress data even for clients that are connecting via proxies
    gzip_vary on; # Tells proxies to cache both gzipped and regular versions of a resource

    server {
        listen 9999;
        
        location / {
            proxy_pass http://api;
            proxy_set_header Host $host; # Passes the original host header to the backend
            proxy_set_header X-Real-IP $remote_addr; # Passes the original IP address of the client
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; # Passes the original "X-Forwarded-For" header
            proxy_set_header X-Forwarded-Proto $scheme; # Passes the original scheme of the client
        }
    }
}