GLOBAL TRANSACTION IDENTIFIERS ARE IN!
I am very happy and especially proud to announce that the replication team has delivered global transaction identifiers to MySQL 5.6.5 Development Milestone Release (DMR). It is a very useful, big, impressive and game-changing feature that will make life easier for many of our users. With this feature in place, it is much simpler to track replication progress through the replication topology thus it removes part of the burden of deploying and administering complex multi-tier replication topologies. Actually, as stated before, this feature is an enabler, as it gives the user so much more flexibility when it comes to deploying replication and tracking the data that is replicated. In particular, it is a foundation for reliable and automated fail/switch over with slave promotion, reducing the need for 3rd party HA infrastructure (which adds cost and complexity). In fact, my good colleague Chuck has already written a couple of utilities that build on global transaction identifiers and implement automated fail/switch over. You should have a look at that as well!
Having said that, lets have a look at what is under the hood.