I was looking for an introductory book on peer-to-peer (P2P) application and their application to grid computation. Web services was a bonus, as it is something I don’t usually play with.

Content and opinions

The book is split in four parts. The first chapter is an introduction to distributed systems, with the definitions and some examples of what is and what is not a centralized (by opposition to decentralized) application or framework. For people novice to P2P, the examples and the problems are well presented.

The first part goes into details of a distributed environment. The P2P solution is thus exposed, with its specific aspects, social (P2P has not a good reputation, to say the least) or routing (accessing peer behind firewalls, routers). As web services are one of the main subjects of the book, they are presented next. The last chapter tackles grid computing through its evolution, the current definition of a grid and the Globus Toolkit 2 architecture. Those chapters are really interesting because they lay down the ground for the remaining of the book.

The second part is about several P2P technologies that can be used, as well as some specific issues. Jini and Gnutella are the first ones to be exposed. They were not developed to answer to the same questions: Jini is about Remote Objects and Gnutella is about file sharing. These technologies introduce the issues of scalability and security ; the first tackles the use of more nodes in the grid, the second the protection of the grid. Finally, Freenet and JXTA are exposed. The first is dedicated to fiel storage on a distributed data grid, the second is a generic P2P framework. The chapters on the different technologies do not bring more information than what can be found on tutorials on the net, but they explain them in a clear way. Scalability and security are aspects that are sometimes forgotten in the design of a distributed system, so their presence in this part of the book helps remembering them.

Part three tackles Jini, JXTA and web service deployement. The first two chapters have some code samples that can be used ; for web service, there is only some XML fragments. Several formats are exposed in this chapter with their advantages and drawbacks.

Finally, the fourth chapter presents web services applied to grid systems. This gives grid services. The Globus toolkit 3 can be used for those grid services, and the future version 4 is introduced as well. This part is the shortest, maybe because these special services are not widely used, and a lot should still be explored to have a clear software designed (which may be used by the Globus toolkit 4, according to the book).

Conclusion

The good writting style of the book helps reading the book, as some pages can be difficult to understand. The final goal is to present grid services, with the underlying frameworks and tools that are grid (and P2P) systems and web services. The beginner is taken from the basics to advanced concepts, which can be applied to concrete grids.

If grid computation, how they can be done, and web services are of interest to you, I suggest you read this book.