Abstract

Mobile agent technology has emerged as a promising programming paradigm for developing highly dynamic and large-scale service-oriented computing middlewares due to its desirable features. For this purpose, first of all, scalable location-transparent agent communication issue should be addressed in mobile agent systems despite agent mobility. Although there were proposed several directory service and message delivery mechanisms, their disadvantages force them not to be appropriate to both low-overhead location management and fast delivery of messages to agents migrating frequently. To mitigate their limitations, this paper presents a scalable distributed directory service and message delivery mechanism. The proposed mechanism enables each mobile agent to autonomously leave tails of forwarding pointers on some few of its visiting nodes depending on its preferences. This feature results in low message forwarding overhead and low storage and maintenance cost of increasing chains of pointers per host. Also, keeping mobile agent location information in the effective binding cache of each sending agent, the sending agent can communicate with mobile agents much faster compared with the existing ones.