The OGSI specification successfully addresses a number of very important issues associated with distributed systems (i.e., lifecycle, naming, references, and state management). At the same time, some incoherence exists when the specification adopts some of the Web services concepts: instance addressing, stateful services concepts (i.e., referencing and state representation), and Web services best practices guidelines (e.g., the document-centric view). These issues can be sorted out with the emergence of stateful Web services and correlations , in addition to the maturity of WS-Addressing and related specifications. The OGSI specification handles many key grid services required behaviors, it is extensible, and it achieves maximum interoperability across service implementations . Several software frameworks available today are based on the OGSI specification. The Globus GT3 is the most prominent and practical implementation of this specification. In a later chapter, we will explore in great detail exactly how the Globus Grid Toolkit and other middleware providers have implemented the OGSI specifications. |