FATOMAS-a fault-tolerant mobile agent system based on the agent-dependent approach

Fault tolerance is fundamental to the further development of mobile agent applications. In the context of mobile agents, fault-tolerance prevents a partial or complete loss of the agent, i.e., it ensures that the agent arrives at its destination. We present FATOMAS, a Java-based fault-tolerant mobile agent system based on an algorithm presented in an earlier paper (2000). Contrary to the standard "place-dependent" architectural approach, FATOMAS uses the novel "agent-dependent" approach. In this approach, the protocol that provides fault tolerance travels with the agent. This has the important advantage to allow fault-tolerant mobile agent execution without the need to modify the underlying mobile agent platform (in our case ObjectSpace\´s Voyager). In our performance evaluation, we show the costs of our approach relative to the single, non-replicated agent execution. Pipelined mode and optimized agent forwarding are two optimizations that reduce the overhead of a fault-tolerant mobile agent execution.