Re:Bi-Directional Replication for PostgreSQL v1.0
by pgaddict on Friday August 12, 2016 @12:51PM
(#12277050)
Those are solutions for very different types of deployments.
BDR is asynchronous multi-master, without global transaction management etc.
XL is a distributed database with global transaction management, strong consistency, etc.
Say you have geographically distributed application (managing customers in US, EU, ...). You can deploy a node in each area and direct local users to this node with low latency etc. It also means "no conflicts" (which is a major concern in multi-master), and the changes will asynchronously replicate to the other nodes.
XL would perform poorly in this scenario (at least I believe so), and it's meant more for local deployments, when hitting vertical scalability limits.
BDR is asynchronous multi-master, without global transaction management etc.
XL is a distributed database with global transaction management, strong consistency, etc.
Say you have geographically distributed application (managing customers in US, EU, ...). You can deploy a node in each area and direct local users to this node with low latency etc. It also means "no conflicts" (which is a major concern in multi-master), and the changes will asynchronously replicate to the other nodes.
XL would perform poorly in this scenario (at least I believe so), and it's meant more for local deployments, when hitting vertical scalability limits.