Upgrade AWS Postgres Aurora from 12.13 to 13.3 using Terraform:

Terraform Providers AWS
1

Upgrade AWS Postgres Aurora from 12.13 to 13.3 using Terraform:
During the upgrade process, I am getting bellow error. I t seems I can not upgrade this Aurora cluster in-place, as it is trying to destroy the existing PG & create a new PG with family of PG13 from PG 12.
Does anyone know how to fix this error/issue? - Thanks - Arif

aws_rds_cluster_parameter_group.cluster_parameter_group: Modifications complete after 0s [id=tf-aurora-rds-cluster-outline-pg]
╷
│ Error: Failed to modify RDS Cluster (tf-aurora-aurora-tf-outline-cluster): InvalidParameterCombination: Cannot upgrade aurora-postgresql from 12.13 to 13.3
│ status code: 400, request id: 94d766dd-259e-4cf8-8ffc-9d6d0f31543d
│
│ with aws_rds_cluster.postgresql,
│ on main.tf line 116, in resource “aws_rds_cluster” “postgresql”:
│ 116: resource “aws_rds_cluster” “postgresql” {

2

According to Upgrading the PostgreSQL DB engine for Aurora PostgreSQL - Amazon Aurora 12.13 must upgrade to 13.8 or later.

3

Yes, thank you, I have upgraded it to 13.9, but this is not the root cause.