Question #1789
A company’s application runs on Amazon EC2 instances and uses AWS Lambda for processing events. The production environment operates continuously due to global users, while the non-production environments are used only on weekdays during business hours. The company wants to minimize costs without affecting production reliability.
Which solution is MOST cost-effective?
Use On-Demand Instances for production. Purchase Scheduled Reserved Instances for non-production instances to match their usage schedule.
Use Reserved Instances for production. Deploy non-production instances on Spot Instances and terminate them after hours.
Use Compute Savings Plans for production. Use On-Demand Instances for non-production and shut them down during off-hours.
Use EC2 Instance Savings Plans for production. Use Reserved Instances for non-production and stop them when inactive.
Explanation
The correct answer is C. Here's why:
- Compute Savings Plans provide significant discounts (up to 66%) for production environments with steady-state usage, aligning with continuous operation needs.
- On-Demand Instances for non-production allow flexibility. Shutting them down during nights/weekends stops compute charges, reducing costs without long-term commitments.
Why other options are incorrect:
- A: Scheduled Reserved Instances (RIs) require fixed schedules, which may not perfectly align with dynamic non-production usage. On-Demand for production misses Savings Plans discounts.
- B: Spot Instances risk interruptions, which may disrupt non-production workflows. Reserved Instances for production are valid, but Savings Plans offer broader flexibility.
- D: EC2 Instance Savings Plans are less flexible than Compute Savings Plans. Reserved Instances for non-production incur costs even when stopped, reducing savings.
Key Points:
- Use Savings Plans (Compute or EC2) for steady workloads.
- Stop/start On-Demand instances for part-time environments to optimize costs.
- Avoid Reserved Instances for non-production if usage is intermittent.
Answer
The correct answer is: C