Multi-availability zone architecture can provide redundancy for a more resilient infrastructure. DMS instances can be configured in clusters that cross availability zones. For more information, see the AWS documentation.
References:
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_ReplicationInstance.html
In AWS Console -
In Terraform -
References:
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/dms_replication_instance