SAA-C03 Question 93
Select 3A company is building a web application that requires high availability and scalability. The application is expected to experience unpredictable traffic patterns. The backend of the application consists of an Amazon RDS database and a fleet of Amazon EC2 instances running behind an Application Load Balancer (ALB). How can you design the architecture to ensure scalability and loose coupling?
- A
Use an Amazon SQS queue to decouple the web application from the backend EC2 instances.
- B
Configure Amazon Auto Scaling for the EC2 instances to handle traffic spikes automatically.
- C
Deploy the Amazon RDS instance in a Multi-AZ configuration for high availability.
- D
Replace the Application Load Balancer with a Network Load Balancer for improved traffic distribution.
- E
Use Amazon EFS to share session data across the EC2 instances.
Show answer and explanation
Correct answers: A, B, C
Explanation
To design a scalable and loosely coupled architecture, it is crucial to decouple components using services like Amazon SQS, configure Auto Scaling for dynamic capacity management, and ensure high availability for critical components like the database using Multi-AZ deployments. These measures allow the application to efficiently handle unpredictable traffic patterns while minimizing downtime and fostering loose coupling between components.
- A. Correct.
Using Amazon SQS ensures loose coupling by allowing the web application to continue processing requests even if the backend EC2 instances are overwhelmed or temporarily unavailable.
- B. Correct.
Amazon Auto Scaling automatically adjusts the number of EC2 instances based on demand, ensuring scalability during traffic spikes and cost savings during low traffic periods.
- C. Correct.
Deploying the Amazon RDS instance in a Multi-AZ configuration ensures high availability and fault tolerance for the database layer.
- D. Incorrect.
A Network Load Balancer is not appropriate for this use case as it operates at the transport layer (Layer 4) and is better suited for low-latency and high-throughput workloads. The ALB, which operates at the application layer (Layer 7), is more suitable for web traffic.
- E. Incorrect.
Amazon EFS is useful for sharing files, but it is not necessary for session management in this scenario. Instead, a session management solution like Amazon ElastiCache would be more appropriate.