Building scalable distributed systems that efficiently perform enterprise-critical functions is incredibly challenging. Microsoft developed COM+ to help. COM+ is a sophisticated runtime environment for COM components. It is designed to make the development of scalable systems easier and is the foundation for higher-level frameworks such as BizTalk and Site Server Commerce Edition. But you can't use COM+ effectively if you don't understand how it works. Transactional COM+ explains how COM+ works and shows readers how to use the technology to its fullest potential as a framework for developing scalable applications. It examines the theory behind COM+, including the nature of scalability, why traditional object-oriented models are inappropriate for scalable systems, and the importance of transactions. The book explores how the two basic atoms of context and causality are used to implement COM+ runtime services. It introduces apartments and activities and the role they play in controlling concurrency in a COM+ process. It also introduces transaction streams and explains how they are used to integrate objects and transactions. Ewald shows how just-in-time activation and object pooling together change the relationship between a client and an object and reveals the importance of HTTP and MSMQ as communication protocols that offer significant advantages over DCOM. Most important, the author explains the influence all these factors have on the design of scalable COM+-based systems. Practical in its approach, Transactional COM+ goes beyond the rationale behind the technology and the details of its implementation to present concrete guidelines for using COM+ to build applications that scale. 0201615940B04062001Ewald, Tim is the author of 'Transactional Com+ Building Scalable Applications', published 2001 under ISBN 9780201615944 and ISBN 0201615940.