The simplest way to get more performance from our database is to increase the instance size of our RDS instance; this can be done with very little effort in RDS as we are able to initiate an instance resize from the management console, CLI, or SDK. Once initiated, the instance is shut down and the instance type is changed; this is essentially done in the same way as with EC2 instances. For a single instance RDS, this means that the service will see a disruption as the instance needs to be shut down. In a Multi-AZ deployment, the secondary instance will be resized first, then the traffic will be redirected to the secondary while the master instance is resized.

With an Aurora cluster, the instance replicas are replaced with larger ones and one of the larger instances is promoted to primary, while the smaller instances are shut down. With highly available options, the instance type resize happens transparently in the background:

1. To change the instance type, select the instance that you have created and click on Modify:

2. Next, select the new instance type and proceed to the next step:

3. In the next step, you will see a summary of changes that will show how the database will be modified. You need to select Apply during the next scheduled maintenance window or Apply immediately if you would like to resize it right away, then click on Modify DB instance:

As you can see, it is very easy to change the instance size from the management console.