AWS Certified Solutions Architect – Associate (SAA-C03)Design Resilient ArchitecturesMedium
A company is building a new microservices application where different services need to communicate with each other asynchronously in a decoupled manner. When a critical event occurs in one service, multiple other services need to be notified and process the event independently. The company requires a simple, fully managed publish/subscribe messaging service that can deliver messages to various types of endpoints, including other AWS services. Which AWS service should be used?
- AAmazon SQS (Simple Queue Service) FIFO queue.
- BAWS Step Functions.
- CAmazon SNS (Simple Notification Service).
- DAmazon MQ for Apache ActiveMQ.
Show answer & explanationAnswer & explanation
Correct answer: C. Amazon SNS (Simple Notification Service).
Amazon SNS is a fully managed publish/subscribe messaging service that enables you to send messages to a large number of subscribers simultaneously. It's ideal for decoupling microservices, allowing one service to publish an event and multiple other services (subscribers) to receive and process it independently, supporting various endpoint types.
Why the other options are wrong
- A. SQS FIFO queues guarantee message ordering and exactly-once processing but are point-to-point (one consumer per message) and not designed for broadcasting to multiple independent subscribers.
- B. AWS Step Functions orchestrates workflows and state machines, not a publish/subscribe messaging service for general service-to-service communication.
- D. Amazon MQ is a managed message broker for open-source message queues (like ActiveMQ), which offers more control but also more operational overhead than SNS for simple pub/sub needs.
Amazon SNS
A fully managed publish/subscribe messaging service that enables you to send messages to a large number of subscribers simultaneously.
- Decouples publishers from subscribers.
- Supports various endpoint types (SQS, Lambda, HTTP/S, email, mobile push).
- Scales automatically to handle high message throughput.
Memory trick: SNS is like a loudspeaker, broadcasting news to everyone who tunes in.