This paper makes several contributions to the understanding of service discovery systems. First, we provide a generic model of the structure and behavior of first-generation service discovery systems, and we show how our model can represent the designs for several, specific service discovery systems. Our model provides a deep analysis of the common elements and behaviors in modern service discovery systems. Further, should an industry standards group choose to develop a unified specification for service discovery, our model should provide helpful input to the process. We also identify issues that designers should attempt to resolve in the next generation of service discovery systems. Second, we propose a set of service goals that we believe service discovery systems should strive to satisfy, along with an analysis of the factors that might interfere with meeting service goals. Such service goals could be cast into test assertions that serve to evaluate the behavior or measure the performance of designs and implementations of service discovery systems. Finally, we identify and suggest possible solutions to performance issues that can arise in dynamic service discovery systems. Identifying possible performance issues can alert users to the potential for unexpected behavior when service discovery technology is deployed at large scale. Further, implementers of service discovery systems can consider our suggested solutions when developing software to embody related processes in a service discovery system.
