A company is running an order processing system on Amazon EC2 instances. The company wants to migrate microservices-based application. Which…

A microservices architecture relies on decoupled, independent components. AWS Lambda provides serverless compute, allowing developers to run code for individual microservices without provisioning or managing servers. Amazon SQS is a managed message queue service that enables asynchronous communication between these microservices, effectively decoupling them. For an order processing system, one Lambda function can place an order message on an SQS queue, and another function can be triggered to process it. This combination is a common, highly scalable, and resilient pattern for building event-driven microservices on AWS.

C. AWS Migration Hub: This is a service for planning and tracking the migration process itself; it does not run the application's architecture.

D. AWS AppSync: This is a managed GraphQL service for building data-driven APIs, which is a more specific use case than the fundamental components required for backend microservice communication.

E. AWS Application Migration Service: This service is used for rehosting (lift-and-shift) servers, which is the opposite of re-architecting an application into microservices.

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1. AWS Documentation. (2023). What is AWS Lambda? - Use cases. AWS. Retrieved from https://docs.aws.amazon.com/lambda/latest/dg/welcome.html#lambda-use-cases.

The "Asynchronous invocations" section states

"For asynchronous workflows

you can use Lambda to... process events from other AWS services like Amazon SQS." This directly supports the SQS and Lambda combination for asynchronous microservices.

2. AWS Documentation. (2023). What is Amazon SQS? - Benefits. AWS. Retrieved from https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/welcome.html#sqs-benefits.

The documentation highlights that SQS enables decoupling of microservices

stating it allows you to "send

store

and receive messages between software components at any volume... without losing messages or requiring other services to be available."

3. AWS Whitepapers & Guides. (2022). Serverless Architectures with AWS Lambda: Overview and Best Practices.

In the section "Microservices

" this whitepaper explicitly describes the pattern: "Each AWS Lambda function is a microservice that is invoked by a defined event... For example

a new message in an Amazon SQS queue can invoke a Lambda function."

4. AWS Documentation. (2023). What Is AWS Application Migration Service?. AWS. Retrieved from https://docs.aws.amazon.com/mgn/latest/ug/what-is-mgn.html.

This document clarifies that AWS Application Migration Service (MGN) is for "lift-and-shift" migrations

which confirms it is an incorrect choice for a re-architecture project.