nginx.conf

worker_processes auto;
worker_rlimit_nofile 500000;

events {
    use epoll;
    worker_connections 1024;
}

http {
    access_log off;
    error_log /dev/null emerg;
    
    upstream api1 {
        server localhost:5001;
        keepalive 200;
    }

    upstream api2 {
        server localhost:5002;
        keepalive 200;
    }
    
    server {
        listen 9999;

        location ~ /clientes/(1|2|3)/ {
            proxy_buffering off;
            proxy_set_header Connection "";
            proxy_http_version 1.1;
            proxy_set_header Keep-Alive "";
            proxy_set_header Proxy-Connection "keep-alive";
            proxy_pass http://api1;
        }
        
        location ~ /clientes/(4|5)/ {
            proxy_buffering off;
            proxy_set_header Connection "";
            proxy_http_version 1.1;
            proxy_set_header Keep-Alive "";
            proxy_set_header Proxy-Connection "keep-alive";
            proxy_pass http://api2;
        }
    }
}