A sentinel approach to fault handling in multi-agent systems
Fault handling in Multi-Agent Systems (MAS) is not much addressed in current research. Normally, it is considered difficult to address in detail and often well covered by traditional methods, relying on the underlying communication and operating system. In this paper it is shown that this is not necessarily true, at least not with the assumptions on applications we have made. These assumptions are a massive distribution of computing components, a heterogeneous underlying infrastructure (in terms of hardware, software and communication methods), an emerging configuration, possibly different parties in control of sub-systems, and real-time demands in parts of the system.
The key problem is that while a MAS is modular and therefore should be a good platform for building fault tolerant systems, it is also non-deterministic, making it difficult to guarantee a specific behaviour, especially in fault situations. Our proposal is to introduce sentinels to guard certain functionality and to protect from undesired states. The sentinels form a control structure to the MAS, and through the semantic addressing scheme they can monitor communication, build models of other agents, and intervene according to given guidelines.
As sentinels are agents themselves, they interact with other agents through agent communication. The sentinel approach allows system developers to first implement the functionality (by programming the agents) and then add on a control system (the sentinels). The control system can be modified on the fly with no or minimal disturbance to the rest of the system.
The present work is conducted in cooperation with Sydkraft, a major Swedish power distribution company. Examples are taken from that venture, and it is shown how problems can be solved by programming DA-SoC agents, developed here.
KeywordsMulti-Agent Systems Fault Tolerance Semantic Addressing Sentinel
Unable to display preview. Download preview PDF.
- Boman M., and Ekenberg L., Eliminating Paraconsistencies in 4-valued Cooperative Deductive Multidatabase Systems with Classical Negation, in Proceedings of the Second International Working Conference on Cooperating Knowledge Based Systems, University of Keele, England, June 1994, ISBN 0-952-17892-3.Google Scholar
- Burns A., and Wellings A., Real-Time Systems and Their Programming Languages, Addison-Wesley, 1990, ISBN 0-201-17529-0.Google Scholar
- Chen L., and Avizienis A., N-version programming: a fault-tolerance approach to reliability of software operation. In Digest of Papers, The Eight Annual International Conference on Fault-Tolerant Computing, Toulouse, France, 1978.Google Scholar
- Fisher M., Representing and Executing Agent-Based Systems, Proceedings of the ECAI'94 Workshop on Agent Theories, Architectures, and Languages, August 8–12, 1994, Amsterdam, The Netherlands.Google Scholar
- Gustavsson R., Akkermans H., Hägg S., Ygge F., Kozbe B., Lundberg C., and Carlsson B., Societies of Computation (SoC) — A Framework for Open Distributed Systems, Phase II: 1995–98, University of Karlskrona/Ronneby, Research Report 8/95, ISSN 1103-1581.Google Scholar
- Hägg S., and Ygge F., An Architecture for Agent-Oriented Programming with a Programmable Model of Interaction, in Proceedings of the Seventh Annual Conference on AI and Cognitive Science '94, Trinity College, Dublin, Ireland, September 8–9, 1994.Google Scholar
- Hägg S., and Ygge F., Agent-Oriented Programming in Power Distribution Automation — An Architecture, a Language, and their Applicability, PhL. Thesis, LUNFD6/(NFCS3094)/l-180/(1995), Lund University, Sweden, May 1995.Google Scholar
- Hägg S., Adaptation in a Multi-Agent System through Semantic Addressing, in Proceedings of the Workshop on Decentralized Intelligent and Multi-Agent Systems (DIMAS'95), Krakow, Poland, November 1995.Google Scholar
- Ingrand F. F., and Georgeff M., Procedural Reasoning System, User Guide, 1991, available from the Australian Artificial Intelligence Institute, 1 Grattan Street, Carlton, Victoria 3053, Australia.Google Scholar
- Societies of Computation (SoC), Internet Home Page, http://www.sikt.hk-r.se/∝oc.Google Scholar
- Somers F., Intelligent Agents for High-Speed Network Management, in Proceedings of The First International Conference and Exhibition on The Practical Application of Intelligent Agents and Multi-Agent Technology (PAAM'96), London, England, April 22–24, 1996.Google Scholar
- Tanenbaum A. S., Distributed Operating Systems, Prentice-Hall, 1995, ISBN 0-13-1439340.Google Scholar
- Wittig T., ed., ARCHON an architecture for multi-agent systems, Ellis Horwood, 1992, ISBN 0-13-044462-6.Google Scholar