Introduction to Messaging Systems

People have different styles of learning. This chapter will give you the necessary context to help you achieve a better understanding of the book.

The goal of any Enterprise Integration is to establish unification between separate applications to achieve a consolidated set of functionalities.

These discrete applications are built using different programming languages and platforms. To achieve any unified functionality, these applications need to share information among themselves. This information exchange happens over a network in small packets using different protocols and utilities.

So let us say that you are adding a new campaign component to an existing e-commerce application that needs to interact with a different application to calculate loyalty points. In this case, you will be integrating your e-commerce application with a different application using enterprise integration strategies.

This chapter will help you understand messaging systems, one of the common ways of establishing enterprise integration. It will walk you through various types of messaging system and their uses. At the end of this chapter, you will be able to distinguish between different messaging models available today and understand different design considerations for enterprise application integration.

We will be covering the following topics in this chapter:

• Principles of designing a good messaging system
• How a messaging system works
• A point-to-point messaging system
• A publish-subscribe messaging system
• The AMQP messaging protocol
• Finally we will go through the messaging system needed in designing streaming applications