Booking.com guys thought a sparkling thought: “if the only purpose of master is to serve binlogs… why should it be a full-featured DB instance?”. So they got themselves a different approach: http://blog.booking.com/mysql_slave_scaling_and_more.html
A neat approach with many benefits. Two things to mention:
- this is a concern when the common replication technique starts being a PITA (with GTID, promoting a new master in MySQL shouldn’t be a problem). So this is not what you should rush for for your 2-slave setup
- this approach applies to pretty much any replication task – not necessarily MySQL, not even necessarily DB replication at all
Anyways, nice idea to remember.