Re:Call me maybe: MongoDB (2013)
by twic on Saturday July 05, 2014 @07:17PM
(#7993268)
No multi-master replication. You can have many read-only slaves replicating a single master, but all your writes have to go to the master, and if the master goes down, you can't write at all until one of the slaves is promoted to become a new master.
There are third-party tools which add multi-master replication, but all seem to suffer from some combination of complexity, flakiness, project deadness, or project immaturity. Postgres-XC seemed the best last time i looked, but it does seem quite complex.
Work is currently underway to bring multi-master replication into core PostgreSQL, under the name "bi-directional replication":
I have no idea if or how this interacts with Postgres-XC. I would imagine the end-game will be that by ~2016, there will be both tightly-coupled (synchronous, immediately consistent, like Postgres-XC) and loosely-coupled (asynchronous, eventually consistent, like BDR) multi-master replication in core PostgreSQL.
That's a long time to wait given that there are noSQL and newSQL databases which have that right now, but when it arrives, it will bring PostgreSQL's huge baggage train of other good stuff with it.
There are third-party tools which add multi-master replication, but all seem to suffer from some combination of complexity, flakiness, project deadness, or project immaturity. Postgres-XC seemed the best last time i looked, but it does seem quite complex.
Work is currently underway to bring multi-master replication into core PostgreSQL, under the name "bi-directional replication":
https://wiki.postgresql.org/wiki/BDR_Project
I have no idea if or how this interacts with Postgres-XC. I would imagine the end-game will be that by ~2016, there will be both tightly-coupled (synchronous, immediately consistent, like Postgres-XC) and loosely-coupled (asynchronous, eventually consistent, like BDR) multi-master replication in core PostgreSQL.
That's a long time to wait given that there are noSQL and newSQL databases which have that right now, but when it arrives, it will bring PostgreSQL's huge baggage train of other good stuff with it.