Introspecting Agent-Oriented Design Patterns

1. 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

2. Outline • Introduction • Description of agents and behavior • Design Patterns • Pair Design Patterns • Mediation Design Patterns • Conclusion

3. 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.

4. 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.

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

6. Pair Design Patterns • Booking • Subscription • Call-For-Proposals • Bidding

7. Booking

8. Subscription

9. 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.

10. 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.

11. Mediation Design Patterns • Monitor • Broker • Matchmaker • Mediator • Embassy • Wrapper

12. 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.

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

14. 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.

15. Matchmaker Diagram

16. 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.

17. Mediator Diagram

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

19. 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.

20. Wrapper Diagram Client Client Wrapper Source request Translate and send Client request answer Translate and send Source answer

21. 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

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