What is a conflict?
Readers of this blog know that one of my favorite tools, Tungsten Replicator, can easily create multi-master replication topologies, such as all-masters, star, fan-in. While this is good news for system designers and ambitious DBAs, it also brings some inconvenience. When you allow updates to happen in more than one master, you risk having conflicts. You may have heard this term before. For the sake of clarity, let's define what conflicts are, before analyzing each case in detail.
You have a conflict when several sources (masters) update concurrently the same data in asynchronous replication.
It's important to stress that this happens with asynchronous replication. In a truly synchronous cluster, where all data is kept consistent through 2-phase …[Read more]