SAA-C03 Question 189
Select 3A company is designing a highly available and scalable e-commerce application on AWS. The application needs to handle sudden spikes in traffic during promotional events. The architecture must ensure decoupling between components to improve fault tolerance and scalability. Which of the following design patterns should the company implement?
- A
Use an Amazon SQS queue between the front-end application and the order processing service.
- B
Directly connect the front-end application to the database using a tightly coupled architecture.
- C
Implement an Amazon SNS topic to fan out order confirmation events to multiple downstream systems.
- D
Use Amazon EC2 Auto Scaling groups to ensure the front-end application can scale horizontally.
- E
Store application state in the local file system of the EC2 instances to improve performance.
Show answer and explanation
Correct answers: A, C, D
Explanation
To build a highly available and scalable e-commerce application, it is essential to use distributed design patterns that promote decoupling and scalability. Amazon SQS and SNS enable loose coupling and scalable message-driven architectures, while EC2 Auto Scaling ensures horizontal scaling based on traffic. Avoid tightly coupled architectures or storing state locally, as these hinder scalability and fault tolerance.
- A. Correct.
Using Amazon SQS decouples the front-end application from the order processing service, allowing for asynchronous communication and better fault tolerance during traffic spikes.
- B. Incorrect.
Directly connecting the front-end application to the database introduces tight coupling, making the architecture less scalable and more prone to failures during sudden traffic spikes.
- C. Correct.
Amazon SNS enables a fan-out pattern, where messages (e.g., order confirmations) can be sent to multiple downstream systems simultaneously, improving scalability and decoupling.
- D. Correct.
Amazon EC2 Auto Scaling groups automatically adjust the number of EC2 instances based on demand, ensuring the application can scale horizontally during traffic spikes.
- E. Incorrect.
Storing application state in the local file system of EC2 instances is not recommended for distributed systems, as it couples the state to specific instances and reduces reliability and scalability.