Chapter 9. Integration and Interoperability

by Michael Abbott

In This Chapter

• From Sockets To Distributed Objects: Integration Transports

• Integrate To…What?

• Common Integration Protocols And Systems

Integration means different things in different contexts. In software engineering, for example, integration typically refers to the act of taking modules that have been developed separately (often in isolation from each other) and making them work together as a system or at least attempting to.

Integration in the context of networked or distributed systems (and hence P2P systems) is fundamentally about communication. The need to tie or link systems to each other so that each can use the other's services and functionality or pass messages to each other drives much of today's IT work. Many of the most interesting problems in distributed systems arise from the need to integrate disparate systems, and many of the most innovative architectures and system design paradigms come from creative solutions to difficult integration problems.

Some of the things that make integration difficult and interesting include the following:

• The systems that need to be integrated are typically heterogeneous; that is, they run on different platforms (different hardware and/or different operating systems).

• Different network languages (protocols or transports) might need to be used. For example, an application that only understands HTTP might need to be linked or integrated to a system that only understands FTP. One of these applications must learn to speak the other's language, otherwise a proxy or intermediary must be used between the two applications to translate.

• Multiple businesses or vendors might be involved. In addition to the complicated matters of platform and network transport that must be dealt with, each organization might have their own integration methodology and preferred set of tools or vendors (not to mention financial or organizational agendas). Integration is sometimes a social engineering problem.

In this chapter, we provide an overview of and commentary on common integration technologies and issues, and how they relate to P2P.