Q53 — AWS SAA-C03 Ch.1

Question 53 of 65 | ← Chapter 1

Q53. A company wants to move a multi-tiered application from on premises to the AWS Cloud to improve the application's performance. The application consists of application tiers that communicate with each other by way of RESTful services. Transactions are dropped when one tier becomes overloaded. A solutions architect must design a solution that resolves these issues and modernizes the application. Which solution meets these requirements and is the MOST operationally efficient?

• A. Use Amazon API Gateway and direct transactions to the AWS Lambda functions as the application layer. Use Amazon Simple Queue Service (Amazon SQS) as the communication layer between application services. ✓
• B. Use Amazon CloudWatch metrics to analyze the application performance history to determine the servers' peak utilization during the performance failures. Increase the size of the application server's Amazon EC2 instances to meet the peakrequirements.
• C. Use Amazon Simple Notification Service (Amazon SNS) to handle the messaging between application servers running on Amazon EC2 in an Auto Scaling group. Use Amazon CloudWatch to monitor the SNS queue length and scale up and down as required.
• D. Use Amazon Simple Queue Service (Amazon SQS) to handle the messaging between application servers running on Amazon E02 in an Auto Scaling group. Use Amazon CloudWatch to monitor the SQS queue length and scale up whencommunication failures are detected.

Correct Answer: A. Use Amazon API Gateway and direct transactions to the AWS Lambda functions as the application layer. Use Amazon Simple Queue Service (Amazon SQS) as the communication layer between application services.

Explanation

The most operationally efficient solution for this scenario would be option A: Using Amazon API Gateway to direct transactions to AWS Lambda functions as the application layer allows for a highly scalable and serverless architecture. This can automatically handle traffic bursts without the need for manual scaling or over-provisioning. Using Amazon Simple Queue Service (Amazon SQS) as the communication layer between application services provides a reliable and fault-tolerant messaging system that can handle temporary spikes in traffic. Option B is not as efficient because manually analyzing performance history and increasing EC2 instance sizes can lead to over-provisioning and higher costs. Option C also uses Amazon SNS for messaging, but does not provide the same level of scalability and reliability as Amazon SQS. Additionally, scaling up and down based on SNS queue length may not be a reliable indicator of overall system load. Option D uses Amazon SQS for messaging, but does not address the need for RESTful services or the modernization of the application architecture. Additionally, scaling up only when communication failures are detected may not be sufficient to handle sudden traffic spikes.