Spring Cloud Stream is the framework of choice to build message-driven microservices for the Cloud.
Spring Cloud Stream allows programmers to focus on building microservices around the business logic of event processing, leaving infrastructure concerns, listed here, to the framework(s):

• Message broker configuration and channel creation
• Message-broker-specific conversions for message
• Creating binders to connect to the message broker

Spring Cloud Stream fits hand in glove into the microservices architecture. The typical microservices needed in use cases of event processing or data streaming can be designed with a clear separation of concerns. Individual microservices can handle business logic, define the input/output channels and leave the infrastructure concerns to the framework.

Typical stream applications involve the creation of events, processing of events, and storing down to a data store. Spring Cloud Stream provides three simple kinds of applications to support typical stream flows:

• Source: Source is the creator of events, for example, the application that triggers a stock price change event.
• Processor: Processor consumes an even, that is, processes a message, does some processing around it, and creates an event with the result.
• Sink: Sink consumes events. It listens on to a message broker and stores the event to a persistent data store.