Change AWS RDS Instance Size

Vertical scaling in Amazon RDS involves changing the instance type to one with different computational, memory, and storage resources. Here’s a step-by-step guide for vertical scaling of an RDS instance running MySQL:

Preparation Steps:

1. Backup Data: Ensure you have a recent snapshot or backup of your database. Amazon RDS automated backups can be useful here.
2. Maintenance Window: Identify a maintenance window where user impact will be minimal, as the scaling operation may result in downtime.
3. Performance Metrics: Check your current resource utilization to select an appropriate instance type for scaling down.
4. Test Environment: If possible, replicate the scaling process in a test environment to identify any potential issues.

Scaling Operation:

1. Login to AWS Console: Navigate to the RDS section.
2. Select Database: Go to the “Databases” tab and click on the DB instance that you want to scale.
3. Modify Instance: Click on the “Modify” button.
4. Choose Instance Type: Scroll down to the “DB instance class” section and select the new instance type you want to switch to.
5. Apply Changes: You have two options here:

• Apply immediately: Your changes will be applied as soon as possible, resulting in immediate downtime.
• Apply during the next maintenance window: Your changes will be applied automatically during your next scheduled maintenance window, minimizing unplanned downtime.

1. Confirm and Modify: Review the changes and click on the “Modify DB Instance” button to initiate the scaling operation.

Post-Scaling Steps:

1. Monitor: Keep an eye on performance metrics to ensure that the new instance is operating as expected.
2. Update DNS if Necessary: If the RDS endpoint has changed, update your application configurations to point to the new endpoint.
3. Update Alarms and Monitoring: Adjust any CloudWatch Alarms or custom monitoring settings to suit the new instance type.
4. Optimization: You might also need to optimize database queries or configurations to better suit the new hardware.
5. Rollback Plan: Be prepared to rollback in case the new instance type does not meet your requirements.

Resources

• AWS Documentation: Modifying an AWS RDS DB Instance
• Contact Duane