There are two main communication paradigms in event-driven architectures used in microservices design.
- Queueing provides a messaging system to integrate two different services.
- Publish/subscribe messaging is a form of asynchronous service-to-service communication used in microservices architectures. In contrast to queueing, publish/subscribe messaging allows multiple consumers to receive each message in a topic.
They allow us to de-couple producers and consumers of messages. By combining publish/subscribe messaging systems with queueing systems, we can build fault-tolerant, scalable, resilient, and reactive application architectures. Amazon Web Services (AWS) offers a number of services which provide these two communication paradigms. In this article, we will learn how to program AWS services – Simple Notification Service (SNS) for publish/subscribe messaging and Simple Queue Service (SQS) for queueing using AWS SDK in Java.