nginx.md

Nginx

install

sudo apt install nginx

Config as a load balancer

The default method of nginx in round-robin.

• edit /etc/nginx/sites-available/VHOST and add this to the file. you can also remove other lines

upstream servers_address  {
  least_conn; #for least connected method
  ip_hash; #for hp_hash method
  server server1_ip_or_url weight=1 max_fails=4 fail_timeout=30;
  server server2_ip_or_url weight=2;
  server server3_ip_or_url weight=4;
  server server4_ip_or_url weight=8;
}

• then add:

server {
  listen 80;
  location / {
    proxy_pass  http://servers_address;
    proxy_set_header HOST $host;
    
  }
}

• restart nginx

{% hint style="info" %} default weight is 1. wight 2 will be sent twice traffic as much weight 1. Also wight 8 sent 8 times traffic to a specific server as much weight 1. This sample will also work on weight 2 or 3 {% endhint %}

{% hint style="info" %} ip_hash is a method that respond to the clients based on their IP addresses. It's beside round-robin and least connected. {% endhint %}

{% hint style="info" %} max_fails is a maximum amount of attempts that nginx send data to server if down. fail_timeout is it's timeout :)) {% endhint %}

{% hint style="info" %} least connected is the method that nginx won't route traffic to a busy server. {% endhint %}