This chapter will examine some common uses of an ESB in integration scenarios. The ESB concept already has a number of uses that solve some very common and challenging integration problems. While this is not an exhaustive list of all the integration patterns that are in use today, it should be enough to give you an idea of how an ESB can be used in real integration scenarios. For more information on integration patterns using an ESB, please visit this book’s web page on the O’Reilly site, http://www.oreilly.com/catalog/esb.
In this chapter we will examine the following integration patterns:
VETO and VETRO, which are commonly used ESB patterns that use message itineraries to perform Validate, Enrich, Transform, (Route,) and Operate functions.
Two-step XRef transformation, which is a commonly used pattern for data transformation using a data cross-reference pattern. This pattern includes a two-step process for transformation: one step that uses XSLT transformation for structure and form, and another that uses a database lookup to translate the content.
Flexible and scalable integration between an enterprise portal and a number of backend systems.
An enterprise portal caching system using a “cache-forward” integration pattern.
Federated query, which is a distributed data retrieval pattern using an ESB to query multiple backend applications and data sources across an enterprise.
The Preface describes this book’s use ...