Amazon RDS cross region bi-directional data replication

Question

I have a Amazon RDS MySQL database in the us-east-1 region. I have a few read replicas in that region for the master db as well. I'm working on a new app which will require the same data from that db but I would like to host the app and create a new db instance in us-west-2 for latency reasons. I still want to host the original application in us-east 1 though.

Is it possible in Amazon RDS to create a cross region bidirectional database so the db in us-west-2 is a replica of the one in us-east-1 that I can also write to?

I rather not use Amazon Aurora right now if possible but if that's the only answer then I guess it's something I will have to do.

Answer 1

Amazon RDS does not support multi-master clusters across regions.

From Working with Aurora Multi-Master Clusters - Amazon Aurora:

You can't enable cross-region replicas from multi-master clusters.

Both Aurora and the non-Aurora databases in Amazon RDS can provide multi-region read replicas, but these are one-way replicas.

Answer 2

If you happen to be using Aurora MySQL - take a look at Write Forwarding.

This allows replicas to send writes to the primary cluster and then (depending on your selected consistency option) waits for relevant changes to be replicated back to itself and other region replicas.

This can help get around the cross-region limitations of Multi-Master and lets you at least simulate a 2-way replication across AWS regions.