Install and configure PowerDNS with geo backend (CDN/geographic DNS blancing)

The Geo backend can be used to distribute queries globally using an IP-address/country mapping table, several of which are freely available online or can be acquired for a small fee.

This allows visitors to be sent to a server close to them, with no appreciable delay, as would otherwise be incurred with a protocol level redirect. Additionally, the Geo backend can be used to provide service over several clusters, any of which can be taken out of use easily, for example for maintenance purposes.

The Geo backend is in wide use, for example by the Wikimedia foundation, which uses it to power the Wikipedia global load balancing.

This tutorial has been tested on Debian 7.x (wheezy).

1. Install PowerDNS server and the Geo backend

apt-get install pdns-server pdns-backend-geo
Continue reading

Simple load balancing using Pound

The Pound program is a reverse proxy, load balancer and HTTPS front-end for Web server(s). Pound was developed to enable distributing the load among several Web-servers and to allow for a convenient SSL wrapper for those Web servers that do not offer it natively.

1. Install the pound package

apt-get install pound
Continue reading