How to fix Error: Error creating Redshift Cluster: ClusterAlreadyExists in Terraform

Confirm the cluster is actually present in your AWS account and region:

aws redshift describe-clusters --cluster-identifier my-cluster-name --region us-east-1

If the command returns cluster details, the cluster exists. If it returns a ClusterNotFound error, the cluster may be in a transient deletion state.

If you own the cluster and want Terraform to manage it, import it into your state:

terraform import aws_redshift_cluster.my_cluster my-cluster-name

Replace "my_cluster" with your resource name and "my-cluster-name" with the actual cluster identifier. This brings the existing cluster under Terraform management without modifying it.

List Redshift resources in your state to see what is already tracked:

terraform state list | grep redshift_cluster
terraform state show aws_redshift_cluster.my_cluster

If the resource exists in state, remove it and re-import:

terraform state rm aws_redshift_cluster.my_cluster
terraform import aws_redshift_cluster.my_cluster my-cluster-name

Modify your Terraform configuration to use a different cluster identifier that is not already in use:

resource "aws_redshift_cluster" "my_cluster" {
  cluster_identifier = "my-cluster-${formatdate("YYYY-MM-DD-hhmm", timestamp())}"
  database_name      = "mydb"
  master_username    = "admin"
  node_type          = "dc2.large"
  number_of_nodes    = 2
}

Cluster identifiers must be 1-63 alphanumeric characters (lowercase) and unique within your account.

If the cluster is in a deletion state, wait for AWS to fully remove it before retrying:

aws redshift describe-clusters --cluster-identifier my-cluster-name --region us-east-1

Repeat this command until it returns a ClusterNotFound error. Cluster deletion can take 5-15 minutes. Once deleted, you can reuse the identifier.

If you want to recreate the cluster from scratch, delete it first:

aws redshift delete-cluster --cluster-identifier my-cluster-name --skip-final-cluster-snapshot --region us-east-1

Use --final-cluster-snapshot-identifier to save a snapshot before deletion. After deletion completes, you can run terraform apply to create a new cluster with the same identifier.