Software Architecture: Foundations, Theory, and Practice

Chapter 5. Connectors

Designing and implementing the functionality and managing the data of modern large, complex, distributed, multilingual software systems is undoubtedly very difficult. As discussed in the preceding chapters, early software architectural models of system components, their key services, their abstract behaviors, and their nonfunctional properties are indispensable in this endeavor. However, experience has shown time and again that making architectural design decisions that pertain to integrating those components effectively and ensuring the components' proper interaction in a system is just as important. Moreover, arriving at such design decisions can be even more challenging than those restricted to the development of functionality. The particular importance in modern systems of mechanisms for assembling functional components and supporting their interaction, that is, software connectors, mandates that they be treated and studied separately. We will do just that in this chapter, and will return to this subject repeatedly throughout the remainder of the book.

Simply put, software connectors perform transfer of control and data among components. Connectors can also provide services, such as persistence, invocation, messaging, and transactions, that are largely independent of the interacting components' functionalities. These services are usually considered to be "facilities components" in widely used middleware standards such as CORBA, DCOM, and RMI. However, recognizing ...