I may be missing something, but I don't see any mention of 2 nodes in that blog post. In fact, BDR is designed to be run with many more nodes. That being said,

I may be missing something, but I don't see any mention of 2 nodes in that blog post. In fact, BDR is designed to be run with many more nodes. That being said, it's an asynchronous multi-master, suitable for geo-distributed architectures. Everyone has their own concept of what multi-master is, sadly. The other thing is that "PG 9.6 brought ..." might suggest this is built into PostgreSQL 9.6. That's not quite the case - we're working on moving it into core, but that takes time. For now it's an extension (plug-in). PG 10 will however include pglogical, which is another step in that direction.