Book Image

SOA Made Simple

Book Image

SOA Made Simple

Overview of this book

SOA is an industry term which is often preached like a religion rather than taught like a technology, and over time, grasping the concept has become unnecessarily difficult. Many companies proclaim that they don't know where to begin with SOA, while others have begun their SOA effort but haven't reaped the benefits they were convinced it would bring. "SOA Made Simple"ù unveils the true meaning of Service Oriented Architecture and how to make it successful so that you can confidently explain SOA to anyone! "SOA Made Simple"ù explains exactly what SOA is in simple terminology and by using real-life examples. Once a simple definition is clear in your mind, you'll be guided through what SOA solves, when and why you should use it, and how to set up, design and categorize your SOA landscape. With this book in hand you'll learn to keep your SOA strategy successful as you expand on it. "SOA Made Simple"ù demystifies SOA, simply. It is not difficult to grasp, but for various reasons SOA is often made unnecessarily complex. Service-orientation is already a very natural way of thinking for business stakeholders that want to realize and sell services to potential clients, and this book helps you to realize that concept both in theory and practice. You'll begin with a clear and simple explanation of what SOA is and why we need it. You'll then be presented with plain facts about the key ingredients of a service, and along the way learn about service design, layering and categorizing, some major SOA platform offerings as well as governance and successful implementation. After reading "SOA Made Simple"ù you will have a clear understanding of what SOA is so you can implement and govern SOA in your own organization.
Table of Contents (17 chapters)
SOA Made Simple
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Index

Elementary services


Elementary services are the smallest possible components that qualify as services. Splitting elementary services in smaller components yields components that violate the design principles you learned about in Chapter 3, Service Design. For example, splitting a DocumentService that is capable of storing and retrieving documents into a separate service that only stores the document, and another service that only stores the metadata violates the principle that services should be isolated or autonomous.

Realization

Elementary services in the information layer can be implemented in several ways:

  • Existing applications such as packaged applications, custom developed systems, and legacy systems that are exposed as services using connectors, adapters, and so on. This can be coined as service-enablement of existing systems. An elementary service is implemented by one system, although a system can implement more than one elementary service.

  • New functionality is created as a service...