Comparison of two middleware data dissemination services in a wide-area distributed system

Abstract

The paper provides an experimental comparison of two middleware data dissemination services: a distributed object based service, and a message based service. The paper compares these two services in the context of a common application: a wide area network collaboratory, namely the Upper Atmospheric Research Collaboratory (UARC). UARC is an example of an application that reliably streams data from a set of suppliers to a set of receivers. This comparison highlights the tradeoffs between ease of implementation and performance for a data streaming middleware service. By relying on a rigid language primitive, namely remote method invocation, the object based dissemination service gave up the control over its transport policies. In contrast, the lower level socket based service was specifically constructed to provide a flexible interface to its applications. This flexibility allowed the middleware to better support data delivery to a heterogeneous set of receivers. This is important in a wide area distributed system where hosts are connected together over a broad spectrum of network links. The paper provides a concrete example of the effects of high level design choices in the implementation of a wide area distributed system's communication middleware.