1.7. Primary use-cases for UDR

If changes are only ever made on one node and the others are just used for read scalability (including temporary tables on standbys), seamless major version upgrades or combining data from different nodes UDR is sufficient. These scenarios cover a large number of replication scenarios.

Using UDR can noticeably reduce the likelihood of application incompatibilities as compared to BDR. Only one database will be written to, which prevents conflicts and such. On the other hand, a BDR setup can make failover much easier, because there is no need to change the setup.