Abstract
Current technological advances and the increasing diffusion of its use for scientific, financial and social activities, make Internet the de facto platform for providing worldwide distributed data storage, distributed computing and communication. It creates new opportunities for the development of new kinds of applications, but it will also create several challenges in managing the information distributed on the Internet and in guaranteeing its “on-time” access through the network infrastructures that realize the Internet. Many researchers believed and still believe that the mobile agents could propose several attractive solutions to deal with such challenges and problems. This chapter presents the core concepts of mobile agents, and attempts to provide a clear idea of the possibility of their use by introducing the problems they cope with, the application areas where they provide advantages with respect to other technologies and the available mobile agent technologies.
TopBackground
The ideas and the work that contributed to the development of mobile agent technologies came from network based computing, distributed operating systems and multi-agent systems.
In fact, the idea of dispatching a program for execution on a remote computer is quite old. Usually, the motivation has been either that the local computer did not have the capacity to execute the program or that the remote computer had direct access to some resource such as an attached peripheral that cannot be efficiently exported via the network. Initially, such schemes were employed both to enable low power computers to submit batch jobs on mainframes (Boggs, 1973) and to control printers (Press, 1985), then some executable scripts were dispatched among networks of computers to permit distributed real time processing (Crowley-Milling et al., 1974; Ousterhout, 1994). An additional step towards mobile agents was fostered by the research done in the distributed operating systems area to support the migration of active processes and objects along with their state and associated code at the operating system level with the goal of improving the load balancing across network nodes (Jul et al., 1988; Douglas & Ousterhout, 1991; Thiel, 1991; Lea et al., 1993).
Key Terms in this Chapter
Strong Mobility: Strong mobility is the ability of a mobile agent system to allow the migration of both the code and the complete execution state of an agent.
Multi-Agent System: A multi-agent system (MAS) is a loosely coupled network of software agents that interact to solve problems that are beyond the individual capacities or knowledge of each software agent.
Killer Application: A killer application is an application that can prove the core value of some technology.
Mobile Agent: A mobile agent is an active process able to decide to transport its state from a machine to another machine where it will continue its activity.
Weak Mobility: Weak mobility is the ability of a mobile agent system to allow the migration of the code of an agent without the complete execution and to restart the execution of such an agent through some initialization data.
Access Control List: An Access Control List (ACL) is a list of permissions attached to a resource that specifies which users or system processes are granted access to such a resource.
Process Migration: Process migration is the act of transferring a process between two machines.