The TRADEr : Integrating Trading Into DCEK

Abstract

Client support for locating, accessing, and using arbitrary services in open system environments emerges as one of the most interesting, complex, and practically relevant tasks of realising realistic open distributed systems applications. In the context of Open Distributed Processing (ODP), current standardisation eeorts for a trading function play an increasingly important role for open system integration. In addition to ongoing ODP standardisation activities oocial and de{facto standard system environments such as, e.g., the OSF Distributed Computing Environment (DCE), support ef-cient development and portability of distributed system applications. Therefore, time seems now ready to analyse and evaluate the use of such platforms also for developing eecient implementations of higher{level system support services, e.g., an ODP trading function. This paper rst elaborates on the speciic potential of OSF DCE for supporting implementations of ODP trader functions. It then presents an architecture and reports on experiences with such an implementation in the context of system support for general service access, management and coordination in open distributed environments within the TRADE project. Finally, the paper draws the attention to still existing limitations and deeciencies of OSF DCE for realising ODP trader functions and proposes respective extensions to OSF DCE both at a conceptual and a concrete systems implementation level. According to such prototype implementation experiments , ODP trading functions can be integrated smoothly into a uniform standard system support platform (like DCE) and can be implemented eeciently by extending DCE by additional trading functions which speciically support service management, mediation and access for open distributed applications.