MySQL Master Slave Database Replication

https://support.rackspace.com/how-to/set-up-mysql-master-slave-replication/
https://plusbryan.com/mysql-replication-without-downtime
http://www.webaugur.com/webdev/19-mysql-master-master-slave-s-database-replication.html
https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-in-mysql
https://www.digitalocean.com/community/tutorials/how-to-set-up-mysql-master-master-replication

https://www.digitalocean.com/community/tutorials/how-to-scale-web-applications-on-ubuntu-12-10