Commercial multi-master replication for PostgreSQL

According to an announcement by EnterpriseDB, the commercial xDB-Replication software for the open source PostgreSQL database now offers the option to use multi-master replication. The feature is still in beta and is only available for 64-bit Linux; it is designed to work with PostgreSQL from version 8.4. EnterpriseDB plans to support other operating systems such as Solaris, Windows, HP-UX and 32-bit Linux in the future.

Multi-master replication allows multiple computers to write into the same database tables, which accelerates data write operations. With the more basic master-slave replication, only one computer ("master") accepts new or modified data and then passes it on to all the others ("slaves"). All slaves can read.

Multi-master replication also requires one main computer to be the reference for all other masters. From this computer, the other masters can initially, or after a crash, obtain all data including schema definitions. During operation, every computer will pass its modified data on to this master server, which will forward it to the other masters.

As well as the EnterpriseDB technology, there are free products that offer multi-master replication, such as Bucardo, Postgres-XC and rubyrep.

(djwm)