• https://www.digitalocean.com/community/tutorials/an-introduction-to-haproxy-and-load-balancing-concepts

apt install haproxy
systemctl  restart haproxy
systemctl  status haproxy
haproxy -c -f /etc/haproxy/haproxy.cfg
tail -f /var/log/haproxy.log 
 
cp haproxy.cfg  haproxy.cfg.orig

/etc/haproxy/haproxy.cfg

	mode	tcp
	option	tcplog
frontend www
	bind 192.168.0.210:80
	default_backend nginx-backend
 
backend nginx-backend
	balance roundrobin
	mode tcp
	server nginx-1 172.16.0.106:80 check
	server nginx-1 172.16.0.112:80 check

• https://www.digitalocean.com/community/tutorials/an-introduction-to-haproxy-and-load-balancing-concepts
• https://www.digitalocean.com/community/tutorials/how-to-use-haproxy-as-a-layer-4-load-balancer-for-wordpress-application-servers-on-ubuntu-14-04
• https://www.haproxy.com/blog/haproxy-log-customization/

apt install nginx-light
systemctl restart nginx
systemctl status nginx

/etc/nginx/sites-enabled/default

upstream backend  {
#  ip_hash;
  server 172.16.0.106 max_fails=3  fail_timeout=15s weight=1;
  server 172.16.0.112 max_fails=3  fail_timeout=15s weight=1;
  server 172.16.0.113 max_fails=3  fail_timeout=15s weight=1 down;
}
server {
	listen 80 default_server;
	listen [::]:80 default_server;
//...
	location / {
	     proxy_pass  http://backend;
	     try_files $uri $uri/ =404;
	}
}

• https://www.digitalocean.com/community/tutorials/an-introduction-to-haproxy-and-load-balancing-concepts
• https://www.digitalocean.com/community/tutorials/how-to-set-up-nginx-load-balancing
• https://www.nginx.com/blog/tcp-load-balancing-udp-load-balancing-nginx-tips-tricks/