Enable storage auto-scaling for RDS MySQL

If your workload is unpredictable, you can enable storage autoscaling for an Amazon RDS DB instance. With storage autoscaling enabled, when Amazon RDS detects that you are running out of free database space it automatically scales up your storage. Amazon RDS starts a storage modification for an autoscaling-enabled DB instance when these factors apply:

Free available space is less than 10 percent of the allocated storage.

The low-storage condition lasts at least five minutes.

At least six hours have passed since the last storage modification.

The maximum storage threshold is the limit that you set for autoscaling the DB instance. You can't set the maximum storage threshold for autoscaling-enabled instances to a value greater than the maximum allocated storage.

Incorrect options:

Migrate RDS MySQL to Aurora which offers storage auto-scaling - Although Aurora offers automatic storage scaling, this option is ruled out since it involves significant systems administration effort to migrate from RDS MySQL to Aurora. It is much easier to just enable storage auto-scaling for RDS MySQL.

Migrate RDS MySQL database to DynamoDB which automatically allocates storage space when required - This option is ruled out since DynamoDB is a NoSQL database which implies significant development effort to change the application logic to connect and query data from the underlying database. It is much easier to just enable storage auto-scaling for RDS MySQL.

Create read replica for RDS MySQL - Read replicas make it easy to take advantage of supported engines' built-in replication functionality to elastically scale out beyond the capacity constraints of a single DB instance for read-heavy database workloads. You can create multiple read replicas for a given source DB Instance and distribute your application’s read traffic amongst them. This option acts as a distractor as read replicas cannot help to automatically scale storage for the primary database.