A Novel Framework for the Evaluation, Verification and Validation of Distributed Applications and Services

A recurrent problem encountered by distribute system designers is that of verifying, validating and evaluating the performance of complex software systems. The behavior of these systems generally depends on how the various software entities inter-relate and on the status of the underlying inter-network. Although many aspects of the distributed software engineering process have been addressed, there is still the need to investigate suitable simulation tools and methodologies that provide support to all seven OSI layers and are geared for modeling distributed applications over simulated inter-networks. In this paper we present such a simulation framework, illustrating its use and applicability through a number of example applications including application-level networking, mobile agent systems, GRID computing, and mobile services for 3G. Starting from the lessons learned from implementing those applications we propose a general methodology for the assessment of distributed systems and applications. Key-Words: Application-level simulation; simulation tools; parallel and distributed computing.