Middle-Agents Organized in Fault Tolerant and Fixed Scalable Structure

Abstract

Agents in a multi-agent system usually use middle-agents to locate service providers. Since one central middle-agent represents a single point of failure and communication bottleneck in the system, therefore a structure of middle-agents is used to overcome these issues. We designed and implemented a structure of middle-agents called dynamic hierarchical teams that has user-defined level of fault-tolerance and is moreover fixed scalable. We prove that the structure that has teams of size lambda has vertex and edge connectivity equal to lambda, i.e., the structure stays connected despite lambda-1 failures of middle-agents or lambda-1 communication channels. We focus on social knowledge management describing several methods that can be used for social knowledge propagation and search in this structure. We also test the fault-tolerance of this structure in practical experiments.