Out of the box, MySQL replication does not allow true multi-master topologies. Since it only supports one pipeline, the replication service is an all-or-nothing matter. Using Tungsten Replicator, instead, not only you can define topologies with multiple masters easily, but you can also set filters and conditions for each pipeline. With asynchronous replication, conflict resolution is hard to implement. But what you can do is conflict PREVENTION. If you want to define a system of records (each source is authorized to modify some of the data) in your multi-master topology, Tungsten offers you tools to achieve your goal easily. This talk will show how you can define which sources can update each schema, and how Tungsten enforces the rules, according to your needs. Demos are done using star and fan-in topologies.