RDS Multi-AZ DB Cluster (MySql Community) "Migration-failed" status

When a Multi-AZ DB cluster enters the "Migration-failed" state after deleting a reader replica, it means that the deletion process encountered an issue during the migration of the data. To resolve this and allow cluster modification, reboot, or deletion, you can follow these steps:

1. Identify the cause: First, you should investigate the cause of the migration failure. Review the event logs and the error messages associated with the failed migration. This information can help you understand the underlying issue and guide you in resolving it.

2. Retry the deletion: In some cases, retrying the deletion of the reader replica can resolve the migration failure. Use the AWS Management Console, AWS CLI, or SDKs to attempt deleting the reader replica again.

3. Modify the cluster: If retrying the deletion doesn't resolve the issue, you can try modifying the cluster. Sometimes, modifying certain parameters of the cluster can trigger a successful migration and resolve the "Migration-failed" state. For example, you can modify the DB instance class, allocate more storage, or adjust other configuration settings.

4. Reboot the cluster: Rebooting the DB cluster can also help resolve the migration failure. Use the appropriate method to reboot the cluster, such as the AWS Management Console, AWS CLI, or SDKs.

5. Restore the cluster from a snapshot: If the above steps don't work, you can attempt to restore the cluster from a snapshot. This process involves creating a new DB cluster using a snapshot of the original cluster. Be sure to carefully follow the steps for restoring a cluster from a snapshot, as it may involve downtime and reconfiguration.

6. Contact AWS Support: If you have exhausted the above options and the cluster status remains stuck in the "Migration-failed" state, it's advisable to reach out to AWS Support for further assistance. They can investigate the issue more thoroughly, provide specific guidance based on your cluster configuration, and help you resolve the problem.

Remember to take proper precautions and backups of your data before attempting any modifications or restorations to ensure data integrity and minimize potential data loss.