Semantic Brokering over Dynamic Heterogeneous Data Sources in InfoSleuth

InfoSleuth1 is an agent-based system for information discovery and retrieval in an open and dynamically changing environment. It implements a brokering function which combines reasoning over both the advertised syntax and semantics of agents in the InfoSleuth domain. The brokering function in a distributed or agent-based system matches processes requiring a service (requesters) with processes that can provide services (service providers). The brokering function must consider two aspects of a potential service provider: (1) whether the potential provider understands the syntax of the request and (2) whether the potential provider provides the semantic capabilities that match the expectations of the requester. The syntax and semantics describing offered services of a particular agent needs to be expressed to the broker in terms of a common vocabulary more complex that needed to express simple syntactic capabilities. The broker must reason over this expressed knowledge in order to dynamically determine which agent can best provide the requested services. Robustness and scalability considerations dictate that the brokering function must be distributable across a group of collaborating processes. This requires expanding the functionality of individual brokers to allow them to advertise their capabilities to other brokers, as well as receive advertisements from other brokers. Additionally, multibrokering requires the ability of brokers to make information requests to other brokers for agent capability information. Our multibroker design is a peer-to-peer system that allows several brokers to collaborate in execution of the brokering function when answering a given request. Each broker has the ability to reason over their stored knowledge about agents, find other brokers, and dynamically determine which of those other brokers they should interact with during the process of matching a request with a service.