Multi-agents based dynamic request placement strategies in distributed information systems

In this paper we propose several strategies for dynamic query placement in order to reduce the response time of services on the Internet. These strategies are based on the cooperation of multi-agents, which are organized as a community of cognitive agents, and a community of reactive agents. Reactive agents propose services. Cognitive agents are able to cooperate and to learn about the state of reactive agents. They have the responsibility of placing the queries that they receive. We also develop a model of knowledge, which enable cognitive agents to characterize the quality of service of the reactive agents on the Internet. When a query is submitted to a cognitive agent, it uses its knowledge on the state of the system, possibly by cooperating with other cognitive agents. In order to facilitate the composition of complex services, we also define a new subcontractor agent type.