Tuesday, 19 July 2011

Cascading Replication

Cascading Replication is now part of PostgreSQL 9.2, thanks to Fujii Masao.

The idea is that a streaming replication standby can also stream data onto other standbys. This allows a complex network of interrelated servers to fulfil the roles of High Availability, High Durability, Distributed data access capacity and Reporting requirements.

You can set up chained configurations like A -> B -> C.

or more complex arrangements like

This should make it much easier to reduce bandwidth for intercontinental replication.

Nice thing is that Hot Standby feedback works across the whole cluster, so you easily manage the interrelationships between servers.


  1. ... Hot Standby feedback works across the whole cluster ...

    Can you please explain that statement a bit more.

    Thanks to Fuji and you for the awesome feature.

  2. Wow, Hot Standby feedback (new in PG 9.1) passes up the chain --- that is quite an accomplishment.

  3. Hey, is that you in the snow photo above? I always assumed it was a nice stock photo.

  4. Gurjeet, I think Bruce just answered you.

  5. The photo to the side is me while climbing Mt.Toubkal in Morocco, taken at the time of my work on Point in Time Recovery. The photo at top isn't me, its the explorer Dr Mike Stroud, crossing the polar ice unaided.