consistentring

Table of Contents

• Overview

Overview

Represents a consistent hashing ring that can be used to route traffic based on percentages in nginx. Idea being that you can use a session id to route X number of users to the new site, and X number of users to the existing site. If the session id is a randomly generated uuid, then roughly 75% would go to the bbc, 25% to google for the example below

lua_package_path "/tmp/?.lua;;";
init_by_lua '
	require "org/greencheek/continuum"
        routing = continuum:new(
		{
        		_www = 75,
        		_www2 = 25
    		}
        )

';

server {
    listen       80;
    server_name  localhost;

    location ~/consistentroute/(.*) {
            set $route $1;
            content_by_lua '
                local route = routing:get(ngx.var.route)
   		local res = ngx.location.capture(route)
                ngx.say(res.body)
            ';
    }

    location _www {
		internal;
        proxy_pass http://www.bbc.co.uk/;
    }

    location _www2 {
		internal;
		proxy_pass http://www.google.co.uk/;
    }
}

# This consistently returns google
curl localhost/consistentroute/google.co.uk

# This consistently returns bbc
curl localhost/consistentroute/bbc.co.uk