I have an RDS DatabaseCluster set up using CDK that's deployed and running with the default instance type. I want to upgrade the instance type to something larger and deploy it with (hopefully) no downtime. The RDS docs has a Scaling Your Amazon RDS Instance Vertically and Horizontally blog post but it only specifies steps to modify it using the console and not Cloudformation/CDK.
I tried modifying the instance type in the console and then made the changes in CDK and deployed but still got the following error:
The specified DB Instance is a member of a cluster. Modify the DB engine version for the DB Cluster using the ModifyDbCluster API (Service: AmazonRDS; Status Code: 400; Error Code: InvalidParameterCombination; Request ID: [RequestID]; Proxy: null)
How do I update the instance types for an RDS cluster defined using Cloudformation/CDK?