SAA-C03 Question 521
Select 3A company is migrating its on-premises application to AWS. The application consists of a web tier, an application tier, and a database tier. The web tier requires high availability, the application tier needs to handle dynamic scaling based on demand, and the database tier must ensure durability and automatic backups. Which combination of AWS services will meet these requirements?
- A
Use Amazon EC2 instances with an Auto Scaling group for the web tier, and deploy them across multiple Availability Zones.
- B
Use Amazon RDS with Multi-AZ deployments for the database tier.
- C
Use Elastic Load Balancing (ELB) to distribute traffic across the web tier.
- D
Use Amazon DynamoDB for the application tier to handle dynamic scaling.
- E
Use Amazon EC2 Spot Instances for the database tier to reduce costs.
Show answer and explanation
Correct answers: A, B, C
Explanation
To meet the application requirements, the web tier needs Auto Scaling and distribution across multiple Availability Zones to ensure high availability. Elastic Load Balancing (ELB) efficiently distributes incoming traffic. The database tier needs durability and backups, which are provided by Amazon RDS with Multi-AZ deployments. Using Spot Instances for the database tier risks data durability, and DynamoDB is not a suitable replacement for the application tier's compute needs.
- A. Correct.
This is correct. Using an Auto Scaling group across multiple Availability Zones ensures high availability for the web tier.
- B. Correct.
This is correct. Amazon RDS with Multi-AZ deployment ensures durability and provides automatic backups for the database tier.
- C. Correct.
This is correct. Elastic Load Balancing (ELB) ensures traffic is distributed across instances in the web tier, enhancing availability and scalability.
- D. Incorrect.
This is incorrect. While Amazon DynamoDB supports dynamic scaling, it is not suitable for general-purpose compute tasks that the application tier may require. Instead, EC2 instances or AWS managed services like AWS Lambda would be more appropriate.
- E. Incorrect.
This is incorrect. Spot Instances are cost-effective but not ideal for the database tier because they can be terminated if capacity is no longer available, which puts durability at risk.