Nginx also has a variety of options for outbound traffic management:
Distributing outbound connections among multiple servers
Configuring backup servers
Enabling persistent connections with backend servers
Limiting transfer rate while reading from backend servers
To enable most of these functions, the first thing you need is to declare your upstream servers explicitly.
Nginx allows you to declare upstream servers explicitly. You can then refer to them multiple times as a single entity from any part of the http
configuration. If the location of your server or servers changes, there is no need to go over the entire configuration and adjust it. If new servers join a group, or existing servers leave a group, it's only necessary to adjust the declaration and not the usage.
An upstream server is declared in the upstream
section:
http { upstream backend { server server1.example.com; server server2.example.com; server server3...