Your supervisor asks you to create a decoupled application whose process includes dependencies on EC2 instances. In the application you would be using Polling Strategy to trigger messages once the defined criteria are fulfilled. Which of the following would you include in the architecture?

Answer options:

A.An SQS queue as the messaging component between the Instances and servers
B.An SNS topic as the messaging component between the Instances and servers
C.An Elastic Load balancer to distribute requests to your EC2 Instance
D.Route 53 resource records to route requests based on failure

Answer – A
The AWS Documentation mentions the following.
Amazon Simple Queue Service (SQS) is a fully managed message queuing service that enables you to decouple and scale microservices, distributed systems, and serverless applications. SQS eliminates the complexity and overhead associated with managing and operating message-oriented middleware and empowers developers to focus on differentiating work. Using SQS, you can send, store, and receive messages between software components at any volume, without losing messages or requiring other services to be available.
SQS is a distributed queuing system. Messages are NOT pushed to receivers. Receivers have to poll or pull messages from SQS.
SNS is a distributed publish-subscribe system. Messages are pushed to subscribers as and when publishers send them to SNS.
Option B is incorrect since this is a push-based notification service.
Option C is incorrect since there is no mention in the question of adding any fault tolerance.
Option D is incorrect since there is no mention in the question of adding any failure detection.
For more information on AWS SQS, please refer to the below link-
https://aws.amazon.com/sqs/