Round robin load balancing

Getting ready

To test the load balancing, you'll need to be able to run multiple versions of your app, each on different ports.

How to do it...

We'll start off with a basic round-robin configuration, with our upstream servers coming locally. We'll define the upstream block directive at the http block level, outside of the server block:

upstream localapp { 
    server 127.0.0.1:8080; 
    server 127.0.0.1:8081; 
    server 127.0.0.1:8082; 
}  

Then, we'll define our server block directive:

server { 
    listen       80; 
    server_name  load.nginxcookbook.com; 
    access_log  /var/log/nginx/load-access.log  combined; 
    location / { 
        proxy_pass http://localapp; 
    } 
}  

How it works...

In our upstream block directive, we define the servers and the name of the backend servers. In our recipe, we simply defined these as three instances on the localhost on ports 8080, 8081, and 8082. In many scenarios, this can also be external servers (in order to horizontally...