Skip to main content

Remediation

Change the Default Master Username​

To replace the default master username for an existing AWS Redshift Cluster, you must create a new cluster with a custom master username and migrate your data from the old cluster.

From Command Line​

  1. Retrieve cluster configuration

    Use the describe-clusters command to obtain the current configuration of the cluster you plan to replace:

    aws redshift describe-clusters \
        --region {{region}} \
        --cluster-identifier {{cluster-id}}

    The output will include metadata such as node type, database name, and current master username, which you will need when creating the new cluster.

    Example:

    {
        "Clusters": [
            {
                "PubliclyAccessible": true,
                "MasterUsername": "awsuser",
                "DBName": "awsclusterdb",
                "ClusterStatus": "available"
            }
        ]
    }

  2. Create a new cluster

    Use the configuration information from the previous step to launch a new cluster with a custom master username:

    aws redshift create-cluster \
        --region {{region}} \
        --cluster-identifier {{new-cluster-id}} \
        --node-type {{node-type}} \
        --master-username {{custom-username}} \
        --master-user-password {{password}} \
        --no-publicly-accessible

  3. Migrate data

    Unload the data from the old cluster and reload it into the new cluster.

  4. Update applications

    Update your application configurations to use the endpoint of the new cluster.

  5. Delete the old cluster

    Once the data migration is complete and applications point to the new cluster, delete the old cluster using the following command:

    aws redshift delete-cluster \
        --region {{region}} \
        --cluster-identifier {{old-cluster-id}} \
        --final-cluster-snapshot-identifier {{final-snapshot-id}}