AWS Certified Solutions Architect - Associate / Question #1319 of 1019

Question #1319

A manufacturing firm must migrate a legacy monitoring system from an on-premises environment to AWS due to increasing operational costs. The system operates continuously and generates a steadily expanding dataset from real-time sensor inputs. What should a solutions architect recommend to address these requirements MOST cost-effectively?

A

Migrate the application layer to Amazon EC2 Spot Instances. Migrate the dataset to Amazon DynamoDB with on-demand capacity.

B

Migrate the application layer to Amazon EC2 On-Demand Instances. Migrate the dataset to Amazon RDS with on-demand instances.

C

Migrate the application layer to Amazon EC2 Reserved Instances. Migrate the dataset to Amazon Aurora Reserved Instances.

D

Migrate the application layer to Amazon EC2 Reserved Instances. Migrate the dataset to Amazon S3 Intelligent-Tiering.

Explanation

Option C is correct because:
- EC2 Reserved Instances: The system operates continuously, making RIs ideal due to their lower cost compared to On-Demand/Spot Instances. RIs suit predictable, long-term workloads.
- Aurora Reserved Instances: Aurora offers MySQL/PostgreSQL compatibility and scalability. Using RIs for Aurora reduces costs for steady database workloads, which aligns with the expanding dataset from real-time sensors.

Other options are incorrect because:
- A: Spot Instances are unreliable for continuous systems, and DynamoDB on-demand may cost more than RIs for steady data growth.
- B: On-Demand pricing for EC2/RDS is more expensive than RIs for long-term use.
- D: While S3 Intelligent-Tiering is cost-effective for storage, it’s unsuitable for real-time database queries required by monitoring systems. Aurora RIs better support real-time data processing.

Key Points: Use RIs for predictable, continuous workloads; Aurora suits real-time database needs; avoid Spot/On-Demand for steady-state systems.

Answer

The correct answer is: C