DEA-C01 Question 92
Single answerA retail company processes customer orders and uses an event-driven architecture to handle order processing. When an order is placed, an event is published to Amazon SNS, triggering downstream services. One service stores the order details in Amazon DynamoDB, while another service sends order confirmation emails using Amazon Simple Email Service (SES). Recently, the company noticed that some orders are stored in DynamoDB, but confirmation emails are not sent. What is the BEST way to ensure that all events are processed reliably for both services?
- A
Use Amazon SQS queues as subscribers to Amazon SNS for each downstream service.
- B
Switch to a monolithic architecture to simplify processing for downstream services.
- C
Enable message retries in Amazon SNS to ensure all subscribers receive the event.
- D
Use Amazon EventBridge instead of Amazon SNS for event delivery.
Show answer and explanation
Correct answer: A
Explanation
Using Amazon SQS queues as subscribers to Amazon SNS ensures reliable message delivery by decoupling the downstream services. Each service can independently process events from its dedicated SQS queue, even if one service is temporarily unavailable. This approach aligns with best practices in event-driven architectures and ensures all events are reliably processed.
- A. Correct.
Attaching Amazon SQS queues to Amazon SNS ensures reliable delivery of events by decoupling the services. Each service can independently process messages from its SQS queue, ensuring no events are lost.
- B. Incorrect.
Switching to a monolithic architecture would not solve the reliability issue and goes against the principles of scalability and decoupling in event-driven architectures.
- C. Incorrect.
Amazon SNS does not natively support retries for downstream services; retries depend on the individual subscriber's implementation. This does not guarantee reliable delivery.
- D. Incorrect.
Amazon EventBridge is an alternative to Amazon SNS for event-driven architecture, but it does not inherently solve this specific issue of reliable delivery to multiple downstream services.