SAP-C02 Question 474
Select 3A company is migrating its multi-tier application to AWS. The application consists of a web tier, an application tier, and a database tier. The company wants to ensure high availability and fault tolerance while minimizing costs. The database tier must use Amazon RDS with automatic failover, and the application tier should be stateless while scaling horizontally. Which of the following architectural decisions would meet these requirements?
- A
Deploy the application tier using an Auto Scaling group with Amazon EC2 instances and use Elastic Load Balancing to distribute traffic.
- B
Use Amazon RDS Multi-AZ deployment for the database tier to ensure automatic failover.
- C
Store session state in Amazon ElastiCache to maintain a stateless application tier.
- D
Deploy the web tier on Amazon EC2 instances in a single Availability Zone to reduce costs.
- E
Use Amazon DynamoDB Streams to store session data for the application tier.
Show answer and explanation
Correct answers: A, B, C
Explanation
The correct answers fulfill the requirements of the scenario by ensuring high availability, fault tolerance, and scalability while adhering to cost efficiency. Using an Auto Scaling group with Elastic Load Balancing ensures the application tier scales horizontally. Amazon RDS Multi-AZ ensures the database tier has automatic failover support, and Amazon ElastiCache provides efficient storage for session state, maintaining a stateless application tier. Deploying the web tier in a single Availability Zone and using Amazon DynamoDB Streams for session data do not align with the high availability and stateless requirements of the scenario.
- A. Correct.
This option is correct as using an Auto Scaling group with Elastic Load Balancing ensures horizontal scalability and high availability for the application tier.
- B. Correct.
This option is correct because Amazon RDS Multi-AZ deployment provides automatic failover and enhances fault tolerance for the database tier.
- C. Correct.
This option is correct because storing session state in Amazon ElastiCache allows the application tier to remain stateless, which is a best practice for scalability and fault tolerance.
- D. Incorrect.
This option is incorrect because deploying the web tier in a single Availability Zone does not ensure high availability and fault tolerance.
- E. Incorrect.
This option is incorrect because Amazon DynamoDB Streams is not an appropriate choice for session management in this specific scenario, as ElastiCache is more suited for low-latency session storage.