1. A Testbed for Agent Mediated Service Composition
Agostino Poggi, Michele Tomaiuolo, Paola Turci
AOT Lab - DII, University of Parma

2. Outline Overview of the network infrastructure
Abstract Model
FIPA2000 reification
Evaluation and testing activities
Dynamic service composition in Agentcities
Provided services
Event organizer - demonstration held at the end of the project
Concluding discussion
AT2AI04 – Vienna, April 14th, 2004

3. Agentcities.RTD Project
Testbed for a Worldwide Agent Network: Research and Development
Motorola, Adetti, Agentscape, AEGIS, BT Exact, Broadcom Eirean, Communication Technologies, DFKI, EPFL, Fujitsu, Imperial College, Queen Mary College, Telecom Italia Lab, UPC, University of Parma
Time span: 2 years from July 2001
AT2AI04 – Vienna, April 14th, 2004

4. Objectives
Construct a worldwide, open network of platforms hosting agent-based services
Explore the deployment of agent technologies in an open environment
Realize a benchmark environment to validate and test compliance to relevant technology standards and provide input to the standards themselves
Enable the dynamic, intelligent and autonomous composition of services to achieve user and business goals
Complex agent-based applications are currently deployed on the network
Two prototype applications
The scope was not to advocate any particular technology or approach but was simply demonstrative of the network potentiality
AT2AI04 – Vienna, April 14th, 2004

5. The Network Backbone of 14 agent platforms
Deployed as a 24/7 test bed
Hosting services and prototype applications developed during the project
160 connected - 80 active platforms
Heterogeneous network
Zeus, FIPA-OS, Comtec, Agentworks, ...
2/3 are JADE, LEAP and BlueJADE
AT2AI04 – Vienna, April 14th, 2004

6. Network Architecture Main Features Three layer Model
Abstraction
Reification
Deployment
Abstract Model - defining the main elements found in the network
Actors
Services
Domains
Instantiated as Directories with domain Policies
Main Features
Structured around domains and policies
Arbitrary organizational structures
Abstract model + reifications
Bind in multiple technologies (WS/FIPA/GRID)
The Restaurants Directory is supported by the Members Directory
AT2AI04 – Vienna, April 14th, 2004

7. FIPA2000 Reification Mapping Network services - central node
Actors cast as FIPA agents
Agent directories as FIPA AMS services
Service directories as FIPA DF services
Network services - central node
Agent Platform Directory
Agent Directory
Service Directory
These services are based on
Database of active platforms
A polling agent which uses the data source of registered entities and regularly polls the instances found
Interfaces
FIPA standard interfaces, for agents
Web interfaces, for humans
Generic architecture for Agentcities network directory services (platforms, agents and services)
AT2AI04 – Vienna, April 14th, 2004

8. Evaluation and Testing Activities
Network survey - goal, register periodically and in a passive way data related to the network characteristics
Functional Test - goal, verify the functionality of the central unit and of the single connected platforms (e.g. connectivity matrix, burst test, etc)
Network Heterogeneity
Service test - goal, verify the functionality and potentiality of the services available on the network
Service Composition
AT2AI04 – Vienna, April 14th, 2004

9. Drawbacks
The deployed network services, based on this first reification, proved to be useful
Despite this, a number of issues need to be addressed :
Centralization, robustness and scalability
Services independence
Services registration
Services can only be registered locally
Registering a platform in the system requires a human to access a web site
AT2AI04 – Vienna, April 14th, 2004

10. Network Infrastructure: 2nd Reification
Platform Directory agent
Hierarchical structure
Platform registration
Platform Service agent
Each Agentcities platform should host a PS agent
The PS queries the PD service to obtain list of currently active platforms in the network
In the background the PS agent may proactively gain status information about the network
When requested, each PS agent provides
The platform ping service
Test results for remote platforms
Network Service agent
The main duty of a NS agent is to show one or more matrix of the network platforms
The NS agent makes use of the PD service to obtain a provisional list of up platforms to survey
AT2AI04 – Vienna, April 14th, 2004

11. Current Priorities Deployment Testing
Wide deployment of the new services on the project partners’ platforms
Automated procedure for the deployment of an Agentcities/OpenNET node
Make it easier for each partner to test basic network functionalities
Testing
More in deep tests of the new distributed architecture
AT2AI04 – Vienna, April 14th, 2004

12. Event Organizer - Demonstration Scenario
Agent generation and hosting service for businesses
Supported actions
Agent creation
Agent deployment
Advertisement (DF and Trade House)
Event Organizer - Demonstration Scenario
Advertisement, discovery and negotiation of products
Ontology independence
Constraint-based search
Federation
Multi-attribute negotiation
Servant agents
Typical auction-style trading activities
Concurrent auctions
Bidding strategies
History function
Constraint-based search
Ontology independence
Repository for ontologies
Ontology language (DAML+OIL)
Ontologies are centrally maintained
Role-based access control
Interface (FIPA and Web)
Security infrastructure to protect the access to the Banking Service
Two key functionalities:
A Certificate Authority service
A plug-in for agent security management
A set of services offered by a virtual agent-based banking institution
The payment service
The account management service
Authorization and authentication
Reference scenario of a demonstration held at the end of the project
AT2AI04 – Vienna, April 14th, 2004

13. Event Organizer - Agent-Based Web-Application
The EO enables small business in the entertainment area
Book all needed venues and services
Sell the tickets
Web interface
List a set of needed services
Fix desired constraints on each individual service and among different services
Agent-based application
Global goal is split into sub-goals, assigned to skilled solver agents
Solver agents return a list of services that fulfill local constraints
The organizer finds a solution that fulfills cross constraints
AT2AI04 – Vienna, April 14th, 2004

14. Event Organizer - Matchmaking
The Event Organizer uses the marketplace infrastructure (Trade House) to search for suitable venues
Service discovery is a two step process
Components required by the application are discovered using the global directory
Single services are discovered and negotiated on a marketplace
If found, a proper solution is proposed to the user as a list of services that allow the arrangement of the event
The constraint validation process is distributed between
Trade House, which checks the constraints regarding individual services
Event Organizer, which instead checks the constraints that link the features of different services
AT2AI04 – Vienna, April 14th, 2004

15. Event Organizer - Negotiation
The selected services are negotiated on the Trade House with their providers
The negotiation process involves the servant agents (buyer and sellers) hosted on the TH
If successful, the negotiation ends suggesting a point of balance between the contrasting interests
Can take into account multiple attributes of the traded good
A list of contracts is proposed to the user for final acceptance
Finally some tickets can be sold on an Auction House
AT2AI04 – Vienna, April 14th, 2004

16. Event Organizer - Final Demonstration
The demonstration included:
Nearly 200 agents deployed on servers hosted at 14 different geographical locations (FIPA HTTP MTP protocol)
25 different services, configured with real and realistic data
Each service was implemented independently by partners and run on their own node
Interoperation between services should have been achieved through the FIPA ACL, FIPA-SL and DAML+OIL ontologies
… but a lack on integration and of tools often forced developers to hard code the agreed interactions
The demonstration scenario was successful demonstrated
… but the overall system clearly remained brittle and sensitive to certain types of changes
Despite this fragility the demonstration represents a significant milestone
AT2AI04 – Vienna, April 14th, 2004

17. Conclusion
FIPA agents proved to be a feasible solution to achieve the dynamic composition of basic services
The proposed scenario can be easily adapted to different domains
The Event Organizer and the Trade House are domain and ontology agnostic
Custom JSP forms are needed to define constraints about new products
The SME Access can be upgraded adding more agent templates
New ad-hoc service providers can interact directly with the Trade House
AT2AI04 – Vienna, April 14th, 2004

18. Conclusion This kind of large test bed environment is essential
To progress theory into practice
To improve the understanding of the issues connected to large scale open system
Activities in the test bed are ongoing with a range of new projects using the infrastructure to extend current features
Integration with emergent technologies
AT2AI04 – Vienna, April 14th, 2004