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Experience and prospects for various control strategies for self-replicating multi-agent systems
- In SEAMS ’06: Proceedings of the 2006 international workshop on Self-adaptation and selfmanaging systems
, 2006
"... ABSTRACT Distributed cooperative applications (e.g., e-commerce) are now increasingly being designed as a set of autonomous entities, named agents, which interact and coordinate (thus named a multi-agent system). Such applications are often very dynamic: new agents can join or leave, they can chang ..."
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ABSTRACT Distributed cooperative applications (e.g., e-commerce) are now increasingly being designed as a set of autonomous entities, named agents, which interact and coordinate (thus named a multi-agent system). Such applications are often very dynamic: new agents can join or leave, they can change roles, strategies, etc. This high dynamicity creates new challenges to the traditional approaches of fault-tolerance. As relative importance of agents may evolve during the course of computation and problem solving, we need to dynamically and automatically identify the most critical agents and to adapt their replication strategies (e.g., active or passive, number of replicas), in order to maximize their reliability and their availability. One important issue is then: what kind of information could be used to estimate which agents are most critical agents? In this paper, we will first introduce our prototype architecture for adaptive replication. Then, we will discuss various kinds of information and strategies to estimate criticality of agents: static dependences, dynamic dependences, roles, norms, and plans. Some preliminary measurements and future directions will also be presented.
On fault tolerance in law-governed multi-agent systems
- In Proceedings of the 5th International Workshop on Software Engineering for Large Scale Multi-Agent Systems (SELMAS’2006
, 2006
"... Abstract. The dependability of open multi-agent systems is a particular concern, notably because of their main characteristics as decentralization and no single point of control. This paper describes an approach to increase the availability of such systems through a technique of fault tolerance know ..."
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Abstract. The dependability of open multi-agent systems is a particular concern, notably because of their main characteristics as decentralization and no single point of control. This paper describes an approach to increase the availability of such systems through a technique of fault tolerance known as agent replication, and to increase their reliability through a mechanism of agent interaction regulation called law enforcement mechanism. Therefore, we combine two frameworks: one for law enforcement, named XMLaw, and another for agent adaptive replication, named DimaX, in which the decision of replicating an agent is based on a dynamic estimation of its criticality. Moreover, we will describe how we can reuse some of the information expressed by laws in order to help at the estimation of agent criticality, thus providing a better integration of the two frameworks. At the end of the paper, we recommend a means to specify criticality monitoring variation through a structured argumentation approach that documents the rationale around the decisions of the law elements derivation.
Towards reliable multi-agent systems - an adaptive replication mechanism. Multiagent and Grid Systems (MAGS) An International Journal. Accepté pour publication avec révisions mineures
"... Abstract. Distributed cooperative applications are now increasingly being designed as a set of autonomous entities, named agents, which interact and coordinate (thus named a multi-agent system). Such applications are often very dynamic: new agents can join or leave, they can change roles, strategies ..."
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Abstract. Distributed cooperative applications are now increasingly being designed as a set of autonomous entities, named agents, which interact and coordinate (thus named a multi-agent system). Such applications are often very dynamic: new agents can join or leave, they can change roles, strategies, etc. This high dynamicity creates new challenges to the traditional approaches of fault-tolerance. In this paper, we will focus on crash failures, with usual preventive approaches by replication. But, as criticality of agents may evolve during the course of computation and problem solving, static design is not appropriate. Thus we need to dynamically and automatically identify the most critical agents and to adapt their replication strategies (e.g., active or passive, number of replicas), in order to maximize their reliability and their availability. In this paper, we describe a prototype architecture, supporting adaptive replication. We also discuss and compare various control strategies for replication, one using agent roles, and another using inter-agent dependences as types of information to infer and estimate criticality of agents. Experiments and measurements are also reported.
Adaptation to Connectivity Loss in Pervasive Computing Environments
"... Pervasive computing environments aim at providing users with advanced services, dynamically composed our of networked services. In these open environments, availability of specific networked service instances cannot be guaranteed over time as users move and services leave and join the network accord ..."
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Cited by 4 (1 self)
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Pervasive computing environments aim at providing users with advanced services, dynamically composed our of networked services. In these open environments, availability of specific networked service instances cannot be guaranteed over time as users move and services leave and join the network accordingly. A major challenge in pervasive environments is thus to maintain services functionalities despite the dynamics of the environment, which induces connectivity loss with service instances. In this paper, we analyse the requirements to make distributed composite services able to face connectivity loss, i.e., able to dynamically adapt their configuration according to the networking environment. We then discuss the adaptation of relevant techniques that originate in the fault tolerance domain to the specifics of pervasive computing. 1
A multi-agent approach to reliable air traffic control
- In 2nd International Symposium on Agent Based Modeling and Simulation (ABModSim’08
, 2008
"... Air Traffic Control (ATC) is going to be a typical critical socio-technical system in which controllers use a large number of distributed software tools to provide safety ATC services. The reliability of these services relies on the availability of the various tools. In the process of integrating mo ..."
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Air Traffic Control (ATC) is going to be a typical critical socio-technical system in which controllers use a large number of distributed software tools to provide safety ATC services. The reliability of these services relies on the availability of the various tools. In the process of integrating more and more sophisticated tools in their daily work, controllers need to feel confident in the reliability of their tool set. This paper presents a multiagent approach to this reliability problem. We propose an agent-based decision-aided system that helps controllers in using their multiple software tools in situations where some tools are not available due to technical incidents. As it is critical to conduct experiments on real air traffic, we build and test our Multi-Agent System (MAS) in a simulation environment, thus develop an Agent-Based Simulation (ABS). Experimental work on this ABS has demonstrated the significance of our system to air traffic controllers. 1
Agents Based Visualization and Strategies
, 2006
"... This paper describes a flexible visualization architecture based on software agents, which enables the abstraction and reuse of rendering strategies. Using a reification of the rendering environment, the system is able to add new rendering strategies (such as distributed rendering or progressive ren ..."
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This paper describes a flexible visualization architecture based on software agents, which enables the abstraction and reuse of rendering strategies. Using a reification of the rendering environment, the system is able to add new rendering strategies (such as distributed rendering or progressive rendering) to an existing pipeline, without any modification of the other components (controls components, display components, rendering algorithms, etc.). The ability of changing strategies on the fly leads to a better adaptability to runtime constraints. The system uses an agent-based graphic pipeline, where each agent/component can be located on different computers; communications between agents use XML/RPC and data stream in order to easily integrate existing code in the system. Agents can add specific behavior to graphic pipelines, such as saving environments to reuse them, adapt information and knowledge from another pipeline, and generally modify and improve the entire system. Various visualization and control clients exist, enabling collaboration between platforms such as PDAs, Windows, Linux, MacOS X, and Web (using Java applets).
Specification of an Exception Handling System for a Replicated Agent Environment
"... Exception handling and replication are two mechanisms that increase software reliability. Exception handling helps programmers control situations in which the normal flow of a program execution cannot continue. Replication handles system failures. Exceptions handling and replication do not apply in ..."
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Exception handling and replication are two mechanisms that increase software reliability. Exception handling helps programmers control situations in which the normal flow of a program execution cannot continue. Replication handles system failures. Exceptions handling and replication do not apply in the same way to the same situations and thus are two complementary mechanisms to increase software reliability. The paper proposes a specification of an execution history oriented exception handling system for an agent language and middleware providing replication. This paper proposes an original signaling algorithm adapted to replicated agents and a rationale of how exception handling and replication mechanisms can combine to increase programmers’ capability to achieve reliable agent-based applications. 1.
Combining Exception Handling and Replication for Improving the Reliability of Agent Software
"... Abstract. Exception handling and replication are two complementary mechanisms that increase software reliability. Exception handling helps programmers in controlling situations in which the normal execution flow of a program cannot continue. Replication handles system failures through redundancy. C ..."
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Abstract. Exception handling and replication are two complementary mechanisms that increase software reliability. Exception handling helps programmers in controlling situations in which the normal execution flow of a program cannot continue. Replication handles system failures through redundancy. Combining both techniques is a first step towards building a trustworthy software engineering framework. This paper presents some of the results from the Facoma project. It proposes the specification of an exception handling system for replicated agents as an adaptation of the Sage proposal. It then describes its implementation in the Dimax replicated agent environment.
Location Monitoring In Mobile Agents System: A Survey
"... Mobile agent technology is emerging as a new paradigm in the area of distributed and mobile computing. Mobile agents play an important role in the development of active and dynamically managed networks and distributed systems. Mobile agents are the intelligent programs that act autonomously on behal ..."
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Mobile agent technology is emerging as a new paradigm in the area of distributed and mobile computing. Mobile agents play an important role in the development of active and dynamically managed networks and distributed systems. Mobile agents are the intelligent programs that act autonomously on behalf of a user and can migrate from one host to another host in a network in order to satisfy the requests made by their clients. In any mobile agent system, the ability to communicate with agents in real-time, as agents move from one node to another, is essential for retrieving any data or information that they have collected, and for supporting coordination and cooperation among them. So the critical problem in managing a mobile agent system is to track the location of the agents. Communication with a mobile agent incorporates the ability to locate it. Thus locating agents efficiently is the issue central to any mobile agent system. This paper surveys various mobile agent location monitoring techniques, proposed by various authors.
Submission to EUROCONTROL Programme CARE INO III Towards Fault-Tolerant Cooperative Air Traffic Management Detailed Description of the project proposal
, 2006
"... 1.1 Context, background and motivation 1.1.1 Air traffic control challenges The design of future air traffic management (ATM) systems appears as a grand challenge. Because of its very large scale, complexity, and dynamicity, we believe that the future of air traffic management lies in hybrid distrib ..."
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1.1 Context, background and motivation 1.1.1 Air traffic control challenges The design of future air traffic management (ATM) systems appears as a grand challenge. Because of its very large scale, complexity, and dynamicity, we believe that the future of air traffic management lies in hybrid distributed cooperative control systems, including human experts (air traffic controllers) and also intelligent computer support through artificial agents. Such artificial agents could implement various roles and functions: e.g., assistants of human experts, training support, local decision support systems, information servers, monitoring and analysis of human activities (local and aggregated), etc. The concepts of multi-agent systems [1], where various agents interact and coordinate to achieve complex goals appears as a very promising conceptual framework for such challenges. 1.1.2 Fault-tolerance As a distributed application, air traffic management control includes possibility of partial failures, as this is a fundamental characteristic of distributed applications. The fault tolerance research community has developped solutions (algorithms and architectures), notably based on the concept of replication, applied for instance to data bases. But, these techniques are almost always applied explicitely and statically.
