Application Integration
CoreAmazon Simple Queue Service (Amazon SQS)
Managed message queue service for durable asynchronous buffering between producers and consumers.
Key points
- Queues decouple producer rate and availability from consumer processing.
- Consumers must delete successfully processed messages and make repeated delivery safe.
- Visibility timeout, redrive policy, queue type, and Lambda event-source settings affect processing and recovery.
Best-known use cases
- Buffer bursty work for scalable consumers.
- Retain repeatedly failing messages in a dead-letter queue.
What candidates often confuse it with
- SQS buffers work for consumers; SNS fans a message out to subscriptions.
- A queue DLQ for an SQS-triggered Lambda belongs to the SQS redrive path, not the Lambda asynchronous-invocation DLQ setting.
Key takeaway
Choose SQS when work must wait durably until a consumer can process it, and design for repeated delivery.
Related services
- Amazon SNS
- AWS Lambda
- Amazon EventBridge
Relevant exam tasks
- D1.1 — Develop code for applications hosted on AWS
- 1.1.3 — Describe differences between tightly coupled and loosely coupled components
- 1.1.8 — Write code to use messaging services
- D1.2 — Develop code for AWS Lambda
- 1.2.3 — Handle the event lifecycle and errors by using code (for example, Lambda Destinations, dead-letter queues)