Keeping your data in more than one place is vital for business continuity, and databases are no exception. Backups are great, but they won’t help you when your normally-connected EU, US and Indian operations all want to continue operating during a major WAN outage. Multi-master replication systems like Bi-Directional Replication (BDR) for PostgreSQL can help solve some users’ availability challenges in a globally distributed environment… if it’s applied correctly. However, multi-master is not some magic high availability secret-sauce that can be applied to every problem. Learn about when to use – and not to use – multi-master replication in general, and BDR in particular.