SWSA discovery

Overview

• Models of discovery– Broker Matchmaker P2P

• Structure of discovery– Discovery– Selection

• Role of semantics

Discovery ProcessGoal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

Request

• MatchmakingMatchmaking– (UDDI)(UDDI)

• BrokerBroker

• P2PP2P

Three Models of DiscoveryThree Models of Discovery

Matchmaker

Goal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

Request

MatchmakingMatchmaker

Report Info

Goal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

Brokering

Goal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

Request

P2P (1)

Report Info

Goal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

P2P (2)

Report Info

Katia 9

Provider Ad

Requester Pref Provider Only

Provider + Middle Agent

Provider+

Middle Agent +

Requester

Requester Only None “front Agent”

Matchmaker

P2P –1

UPNP

Requester + Middle Agent

Anonymizer

Broker

BrokerCMU Broker

WSMO Mediators?

Recommender

MatchmakerUDDI

Requester+

Middle Agent +

Provider

Black Board

P2P Gnutella JXTA

Introducer/

Bodyguard

Matchamker –1

Arbitrator

“Pure” P2P

Katia’s 28 Dimensions of discovery1. Direction: push vs pull

• In UDDI provider pushes, requester pulls• In P2P provider pulls, requester pushes

2. Amount Info in adv: capabilities vs parameters• Is there any discovery service that makes this difference?

3. Action for advertisement: broadcasting vs retaining• P2P does broadcasting • UDDI does retaining

4. Browsing MA DB? Yes vs no• UDDI supports persistent queries

5. Amount Info in request: capability only vs parameters• Is there any discovery service that makes this difference?

6. Does MA mediate transaction?• Broker vs registry

• Since some of the combinations are irrelevant there are 28 possible MA

Importance of Semantics

Goal

Abstraction to capabilities

Capability Description

Match

Advertisement

List of Providers

Selection

Potential Providers

Enactment

Store

Request

The transformation should preserve the semantics of the query: it should not identify capabilities do not lead to the satisfaction of the goal

Ask Mike Huhns

Matching requires the recognition of whether the required capabilities are “similar enough” to the requested capabilities, ie the services that they describe (their meaning) provide similar functionalities

Selection requires matching of own requirements visa vie the requirements of the providers and the functionality that they provide. The services selected are the one that provide the closest match.