D'Agents: Applications and performance of a mobile‐agent system

Abstract D'Agents is a general‐purpose mobile‐agent system that has been used in several information‐retrieval applications. In this paper, we first examine one such application, operational support for military field personnel, where D'Agents greatly simplifies the task of providing efficient, application‐specific access to remote information resources. After describing the application, we discuss the key differences between D'Agents and most other mobile‐agent systems, notably its support for strong mobility and multiple agent languages. Finally, we derive a small, simple application that is representative of many information‐retrieval tasks, including those in the example application, and use this application to compare the scalability of mobile agents and traditional client/server approaches. The results confirm and quantify the usefulness of mobile code, and perhaps more importantly, confirm that intuition about when to use mobile code is usually correct. Although significant additional experiments are required to fully characterize the complex mobile‐agent performance space, the results presented here help to answer the basic question of when mobile agents should be considered at all, particularly for information‐retrieval applications. Copyright © 2002 John Wiley & Sons, Ltd.