Can I change the class of my Aurora RDS Reserved Instance?

Question

Currently I have a db.r5.2xLarge RDS Reserved Instance (Aurora Postgres).

I'm thinking about moving to db.r6g.2xLarge, if I do that will my reserved instance discount still apply?

I looked up on AWS documentation but coudn't find a clear answer.

Answer 1

RDS offers size-flexible reserved instances, which allow you to change the size within a class (e.g. r5.2xlarge -> 2* r5.xlarge), but they need to stay within a class.

Because of this, that wouldn't apply to your modification. The other (bigger) problem is that Aurora is not in the list of supported DB Engines for this:

Size-flexible reserved DB instances are available for the following Amazon RDS database engines:

• MariaDB
• MySQL
• Oracle, Bring Your Own License
• PostgreSQL

— Source

tl;dr: The discount won't apply anymore if you go through with your proposed change.

Answer 2

Size-flexible reserved DB instances are available for the following Aurora database engines:

Aurora MySQL

Aurora PostgreSQL

Source