Introspecting Agent-Oriented Design Patterns Manuel Kolp, T. Tung Do, Stéphane Faulkner and T. T. Hang Hoang Presented by Rachel Bock, Sam Shaw, Nicholas Vance, Ashok Subramaniam, Nisha Mathew

Outline Introduction Description of agents and behavior Design Patterns ◦ Pair Design Patterns ◦ Mediation Design Patterns Conclusion

Agent Characteristics Autonomy – Agents have their own internal thread of execution. Situateness – Agents perform their actions in the context of a particular environment. Flexibility – Agents must act to ensure goals are achieved in a dynamic and unpredictable environment.

Sociality and Communication Multi-Agent System (MAS) – environment that contains multiple agents. Potentially huge number of agents. Each acts autonomously with its own goals. Problems arise involving coordination and collaboration. Design patterns exist to help tackle these issues.

Social Design Patterns Pair – direct interaction between negotiating agents Mediation – intermediate agents help other agents to reach agreement about an exchange of services

Pair Design Patterns Booking Subscription Call-For-Proposals Bidding

Booking

Subscription

Call-For-Proposals Agents Involved: Initiator, Participants Description – The initiator requests proposals for a specified service. To this request participants respond with their cost for the service. Of the proposals that the client receives he selects the one participator whose service he will use.

Bidding Agents Involved: Client, Service Provider Description – This pattern involves a iterative bidding process. In each iteration the Client receives bids from Service Providers for a requested service. Once all the bids are receive the client makes one of four choices. The choices are for the client to either publish the current bid, raise the bid, cancel the bidding process, or accept the bid as the one it will be using.

Mediation Design Patterns Monitor Broker Matchmaker Mediator Embassy Wrapper

Monitor Agents Involved: Subscriber, Monitor Description – The subscriber registers to receive notification of events that the monitor watches for. When a the event occurs the monitor notifies all the subscribers that have registered for notification of the event.

Broker The broker agent is an arbiter It is an intermediary that requests services from providers to satisfy the request of clients.

Matchmaker A matchmaker agent locates a provider for a given service requested by a client. It then lets the client interact directly with the provider(unlike brokers) This provider handles all interactions between clients and providers.

Matchmaker Diagram

Mediator A mediator agent coordinates the cooperation of service provider agents to satisfy the request of a client agent. Mediator differs from matchmakers. A matchmaker simply matches providers with clients. A mediator encapsulates interactions and maintains models of the capabilities of clients and providers over time.

Mediator Diagram

Embassy Mediation Pattern Embassy, external and local agents Embassy agent translates messages between local and external agents

Wrapper Mediation Pattern Incorporates a legacy system into a MAS Wrapper, legacy and system agents Wrapper agent interfaces system and legacy agents by acting as a translator.

Wrapper Diagram ClientWrapperSourceClient request Translate and send Client request answer Source answer Translate and send

Conclusion New enterprise applications exist in a changing environment. MAS architecture allow dynamic structures which can change at run-time. Patterns provides good approach to reuse architecture design knowledge. Social patterns

Reference Introspecting Agent-Oriented Design Patterns ◦ Manuel Kolp, T. Tung Do, Stéphane Faulkner and T. T. Hang Hoang