Rightsize Aurora MySQL Clusters

Opportunity Name

Rightsize Aurora MySQL Clusters

AWS Resource Type

RDS (Aurora MySQL Cluster)

Opportunity Description

Resize Aurora MySQL instances that are running on underutilized servers to achieve cost savings.

Criteria for identifying the opportunity

• Find Aurora MySQL Instances that:

  • Are not burstable instances

  • Are not serverless

  • Cost more than US$100 per year

• Determine if a smaller server in the same family can be used and all of the following are true:

  • The CPU utilization would not exceed 100% utilization

  • The observed NetworkThroughput is met

  • The target instance’s number of database connections is supported

Potential savings (range in % on annual basis)

The degree of cost savings will depend upon the amount of overprovisioning found. Many AWS instance types are 2x the cost of the next smaller version of the same family, which means that in many cases resizing will lead to a 50% reduction in cost for that specific RDS instance.

What happens when the Fixer is executed?

The instance is resized to a smaller instance size in the same server family.

Is it possible to rollback once CloudFix implements the fixer?

Yes, the Rollback resizes the instance to its original size.

Triggering of the rollback is automated based on DML latency p99 values exceeding their prior values by 10% during any one-hour evaluation period over the course of 31 days, but the execution of the resizing does not occur until the next maintenance window.

Can CloudFix implement the fix automatically once I accept the recommendation?

The fix is automated, but the change is not applied until the next maintenance window.

Does this fix require downtime?

Yes. Resizing requires a restart of the instance.

Additional Resources

• CloudFix Knowledge Base

• AWS Instance Types

• AWS Instance Pricing

• Estimating AWS RDS Costs