A company runs development and test EC2 instances only during business hours (Monday to Friday, 8 AM to 6 PM). What is the simplest way to cut these environments' costs by roughly 70%?
Show answer and explanation
Answer: C
The AWS Instance Scheduler solution uses EventBridge rules and Lambda to stop tagged instances at the end of each scheduled window and start them again at the next one. With 50 running hours a week instead of 168, about 70% of On-Demand hours disappear, and the environments come back exactly when developers arrive.
Why the other options are wrong
- A. Spot capacity can be reclaimed at any time with little notice, which is poor behavior for environments that must be dependably available when teams start work.
- B. A reservation discounts each billable hour but keeps charging for every hour of the week that the instances exist, while scheduling removes roughly 118 billable hours a week outright.
- D. Halving the size saves at most about 50% and cuts the capacity available to testers, whereas stopping idle hours saves more and affects nobody.