Which is the safe procedure of creating a new RDS read replica in a new region?

Question

I have a master RDS instance and 2 read replicas in one region.

I want to create a Disaster Recovery plan and create another read replica in another region.

When I will create the read replica in the new region, I would like to terminate the one of the two replicas in the main region [so the budget would be the same].

Is it as simple as that?

The procedure will be transparent to the application level?

Should I take under consideration anything else?

Answer 1

When you create a read replica always keep in mind if your parent RDS instance is Multi AZ then Amazon RDS automatically creates a primary DB Instance and synchronously replicates the data to a standby instance in a different Availability Zone (AZ) then the read replica creation will be from the secondary copy of your RDS instance.

But if your parent RDS instance is not a Multi AZ then please schedule the read replica creation at off time when the traffic to your application is low as this may slow down the application while the read replica creation in progress.

Above is the only case you need to be aware while creating read replicas for first time. Other than that above process described by you is very simple to do.