Question #876
A business needs to automatically launch and terminate Amazon EC2 instances based on fluctuating application demand while maintaining cost efficiency. Which AWS service should they use to dynamically adjust the number of instances?
Amazon RDS
Amazon EC2 Spot Instances
AWS Storage Gateway
Amazon EC2 Auto Scaling
Explanation
Amazon EC2 Auto Scaling (D) is designed to dynamically launch or terminate EC2 instances to match fluctuating application demand. It uses scaling policies (e.g., target tracking, step scaling) to automatically add instances during traffic spikes and remove them during lulls, optimizing costs and performance.
Other options are incorrect because:
- A: Amazon RDS is a managed database service and does not handle EC2 instance scaling.
- B: EC2 Spot Instances provide cost-effective pricing for spare EC2 capacity but do not automatically adjust instance counts.
- C: AWS Storage Gateway integrates on-premises storage with AWS and is unrelated to EC2 scaling.
Key Points: EC2 Auto Scaling ensures high availability and cost efficiency by maintaining optimal instance counts. Spot Instances reduce costs but require separate management. The question focuses on dynamic scaling, making Auto Scaling the only valid choice.
Answer
The correct answer is: D