In this chapter, we will discuss an introduction to sagas. Sagas are just one of the many design patterns supported by NServiceBus (NSB). NSB is an Enterprise Service Bus (ESB) that brings many design features and benefits to the end-to-end enterprise. We will briefly look at these features and enter into a brief discussion of some of the design patterns that NSB supports. From this point, we will introduce the saga design pattern and provide a brief introduction to its purpose. The rest of the book will lead into a drill-down of the saga pattern and its use, as well as discuss many more of the features of NSB.
In this chapter, we will study the following:
A brief introduction to ESBs
Additional patterns
The publish-subscribe pattern
The request-reply pattern
The DataBus pattern
Timeout patterns
Message mutation patterns
Message encryption patterns
The ScaleOut pattern
The saga design pattern
Sagas – what are they good for?