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DAML-S: Semantic Markup for Web Services. DAML-S Web Services Coalition presented by: Terry R. Payne Carnergie Mellon University. http://www.daml.org/services/. DAML-S Web Services Coalition. CMU: Anupriya, Ankolekar, Massimo Paolucci, Terry Payne, Katia Sycara BBN: Mark Burstein
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DAML-S: Semantic Markup for Web Services DAML-S Web Services Coalition presented by: Terry R. Payne Carnergie Mellon University http://www.daml.org/services/
DAML-S Web Services Coalition CMU: Anupriya, Ankolekar, Massimo Paolucci, Terry Payne, Katia Sycara BBN: Mark Burstein Nokia: Ora Lassila Stanford KSL: Sheila McIlraith, Honglei Zeng SRI: Jerry Hobbs, David Martin, Srini Narayanan [Yale: Drew McDermott & Manchester: Ian Horrocks] Slides courtesy of Sheila McIlraith, Stanford KSL
What is DAML-S? • DAML-S: A DARPA Agent Markup Language for Services • DAML+OIL Ontology for (Web) services • AI-inspired markup language: • tailored to the representational needs of Services • expressive power • well-defined semantics • ontologies support reuse, mapping, succinct markup, ... • Release of DAML-S version 0.5 June,2001 • http://www.daml.org/services/
DAML+OIL (Ontology) RDFS (RDF Schema) RDF (Resource Description Framework) XML (Extensible Markup Language) Layered Approach to Language Development • The first major application of DAML+OIL • Layer exists above DAML+OIL • Future versions will build upon emerging layers (e.g. DAML-Rules etc) DAML-S (Services)
DAML-S Objectives • Provide: • an upper ontology for describing properties & capabilities of agents & (Web) services in an unambiguous, computer interpretable markup language. • Desiderata: • an ontology of Web services • ease of expressiveness • enables automation of service use by agents • enables reasoning about service properties and capabilities
Automation Enabled by DAML-S • Web service discovery Find me a shipping service that transports goods to Dubai. • Web service invocation Buy me 500 lbs. powdered milk from www.acmemoo.com • Web service selection, composition and interoperation Arrange food for 500 people for 2 weeks in Dubai. • Web service execution monitoring Has the powdered milk been ordered and paid for yet?
PresentingService Profiles DAML-S: • Service Profile • Presented by a service. • Represents “what the service provides” • One can derive: • Service Advertisements • Service Requests
DAML-S Service Profile (Overview) • High-level description of a service and its provider • description of service (human readable) • specification of functionalities service provides • functional attributes (requirements and capabilities) • Profile used for • populating service registries • automated service discovery • matchmaking
DAML-S Service Profile (Overview) Functionality Description Provenance Description Functional Attributes
DAML-S Service ProfileProvenance Description • Information and Provenance about the Service • serviceName & textDescription • intendedPurpose & role of 3rd Party Actors • Details about • 3rd Party Actors • Requesters • Providers
DAML-S Service ProfileFunctionality Description • Specification of what the service provides • High-level functional representation in terms of: • preconditions • accessConditions • inputs • outputs • conditionalOutputs • effects Summarizes the top-level Composite Process (described by Service Model)
DAML-S Service ProfileFunctional Attributes Provide supporting information about the service, including: • geographical scope Pizza Delivery only within the Pittsburgh area • quality descriptions and guarantees Stock quotes delivered within 10 secs • service types, service categories Commercial / Problem Solving etc • service parameters Average Response time is currently ...
DescribingService Models DAML-S: • Service Process • Describes how a service works. • Facilitates • (automated) Web service invocation • composition • interoperation • monitoring
DAML-S Service Model (Overview) • Service Model may be used to • to perform a more in-depth analysis of whether the service meets its needs; • to compose service descriptions from multiple services to perform a specific task; • during the course of the service enactment, to coordinate the activities of the different participants; • to monitor the execution of the service. • For non-trivial services, the first two tasks require a model of action and process, the last two involve, in addition, an execution model.
DAML-S Service Model“How does it work?” • Each service is conceived as simple or composite process (event/action) • Associated with each service is a set of inputs, outputs, preconditions and effects (function and action metaphor) • Composite processes are compositions of simple or other composite processes in terms of constructs such as sequence, if-then-else, fork,... • Data flow and Control flow should be described for each composite service • A black box and glass box view are given of each composite service
Function/Dataflow Metaphor Input: Output: • confirmation # • ... • customer name • origin • destination • weight • pickup date • ... Acme Book Truck Shipment Y truck available + valid credit card ? N • failure notification • …
AI-inspired Action/Process Metaphor Output: • confirmation # • ... Input: • customer name • origin • destination • pickup date • ... • goods at location • if successful • credit card debited... Effect: Acme Book Truck Shipment Y truck available + valid credit card ? Preconditions: N • knowledge of • the input • ... • failure notification • … Output: <no effect> Effect:
Composite Process Output & Effects AcmeTruckShipping • confirmation no. • ... • customer name • location • car type • dates • credit card no. • ... www.acmecar.com book car service ? Input & Preconditions • failure notification • … ? • confirmation no. • ... • confirmation no. • dates • room type • credit card no. • ... www.acmehotel.com book hotel service • confirmation no. • ... ? • customer name • flight numbers • dates • credit card no. • ... www.acmeair.com book flight service ? • failure notification • … • failure notification • errror information • …
Confirm Shipping Region truck available + valid credit card N Y Get Quote Get Shipping Dates Book Truck Shipment Composite Process (cont) AcmeTruckShipping ExpandedAcmeTruckShipping Acme Truck Shipping Service expands
Composite Process (cont) expand AcmeTruckShipping ExpAcmeTruckShipping
Supporting aService Grounding DAML-S: • Service Process • Provides a specification of service access information. • Specifies: • communication protocols, transport mechanisms, etc. • E.g., SOAP, HTTP forms, KQML, OAA ACL, Java RMI, RPC, etc. Under Construction …
Upper Ontology of Services Review:
Related Work • Related Industrial Initiatives • These XML-based initiatives are currently complementary to DAML-S. • DAML-S intends to build on top of these efforts exploiting increased expressiveness, semantics, inference that enables automation. • Related Academics Efforts • Process Algebras (e.g., Pi Calculus) • Process Specification Language (Hoare Logic, PSL) • Planning Domain Definition Language (PDDL) • Business Process Modeling (e.g., BMPL) • Service Description Languages (e.g., LARKS)