Many people aren't aware but recently Dual-Master Replication setups have become increasingly popular. That's because you get similar features and benefits of having a full-blown cluster (difficult to setup and maintain and requires I believe 3 servers just as controllers).
With a dual-master you just have a different off-set for the keys and you should be good, but of course there is the chance that at some point replication will halt because of an unexpected or unforseen error but still, it gives you some load balancing and redunancy.
At the very least if you're running MySQL at least make a slave server for live backups and data mining etc... Setting up a MySQL slave is ridiculously easy, I couldn't believe how fast it went once I figured it all out.
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