You want to build a decoupled, highly available and fault-tolerant architecture, including buffered request for your application in AWS. You decide to use EC2, the Classic Load Balancer, Auto Scaling, and Route 53. Which one of the following additional services should you involve in this architecture?

Answer options:

A.AWS SNS
B.AWS SQS
C.AWS API Gateway
D.AWS Config

Answer – B
The Simple Queue Service can be used to build a decoupled architecture.
AWS Documentation further mentions the following.
Amazon Simple Queue Service (SQS) is a fully managed message queuing service that makes it easy to decouple and scale microservices, distributed systems, and serverless applications. Building applications from individual components that perform a discrete function improves scalability and reliability. It is the best practice design for modern applications.
• Scalability – Amazon SQS can process each buffered request (p. 202) independently, scaling transparently to handle any load increases or spikes without any provisioning instructions.
For more information on the Simple Queue Service, please visit the following URL-
https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-dg.pdf