A company launched its application on 20 large EC2 instances, but monitoring now shows that peak usage only needs about 5. Which cloud-economics practice should the company apply to fix this?
Show answer and explanation
Answer: B
Right-sizing means aligning both the number and the type of instances with observed workload behavior. Since peak demand is roughly a quarter of the provisioned fleet, cutting to the appropriate count and size removes the ~75% of spend that provisions nothing but idle headroom.
Why the other options are wrong
- A. Reserved Instances only discount what you already have; committing to 20 when 5 are needed simply freezes the waste at a lower unit price.
- C. Upsizing every instance moves cost in the wrong direction and increases the overprovisioning problem.
- D. Returning on-premises does not shrink the workload's actual needs and forfeits the cloud's ability to adjust capacity when demand shifts.