Enterprise SOA

What is ESA?

Now we are at the doorway of ESA. The simple view of composite applications and SOA leaves many questions unanswered about how the reusable parts will be constructed, who will build them, what tools will be used, and what will make them work together. Here are just a few questions that must be answered to derive the full business value from composite applications:

• How should the portions of the stack be distributed across this architecture?

• How should the portions of the stack talk to each other?

• What is the right structure for each portion of the stack?

• When should multiple structures for a portion of the stack be supported?

• How should the UIs be constructed?

• How should the process orchestration take place?

• How should development methods change?

• Where is the persistence?

• How is distributed data managed?

• How can complexity be managed?

• How can the process of adapting applications be simplified?

• How can developers be made more productive?

• What is the right division of labor?

• Who should solve all of these problems?

The rest of this book is dedicated to answering questions such as these in great detail. To get started, let's look at a few different areas more closely. For example, in a composite application, the data is distributed over many repositories. How can one version of the truth be assembled? How can changes that affect records in many repositories be synchronized?

There are all sorts of different forms of process logic. There is workflow, which happens within an application; ...