A peer-to-peer approach to resource discovery in multi-agent systems

Abstract

multi-agent system is a network of software agents that cooperate to solve problems. In open multi-agent systems, the agents that need resources provided by other agents are not aware of which agents provide the particular resources. We propose a fully distributed approach to this resource discovery problem. Each agent A maintains a limited size local cache in which it keeps information about k different resources, that is, for each of the k resources, it stores the contact information of one agent that provides it. The agents in the cache of agent A are called A's neighbors. An agent searching for a resource contacts its local cache and if there is no information for the resource, it contacts its neighbors, which in turn contact their neighbors and so on until the resource is found in some cache. We consider variations of this flooding-based search and develop and verify by simulation analytical models of their performance for both uniformly random resource requests and for requests in the case of hot spots. Finally, we introduce two approaches to the problem of updating the caches: one that uses flooding to propagate the updates and one that builds on the notion of an inverted cache.