Using WSDL/UDDI and DAML-S in Web Service Discovery Aphrodite Tsalgatidou National and Kapodistrian University of Athens

WS Discovery: The problem … Service Provider (1) Service Description Service Requestor (3) Description of Req. needs Service Broker (2) Publishing (4) Matchmaking Invocation/ Binding

WS Discovery: Requirements DescriptionPublishing Description of Req. Needs Matchmaking HOW DAML-S, XML, keywords, … Scalable, Secure, Available, … DAML-S, XML, keywords,… Scalable, Secure, Available, By composition, keywords, inference WHO Program, Developer, Business user Program, Developer, Business user Developer, Business user Program, Developer, Business user WHEN/HOW LONG N/APersistent, With lease N/ADesign-time, run- time, persistent query, volatile query WHAT See next slide WHERE N/ALocal, Corporate, Global N/ALocal, Corporate, Global

WHAT reqs: more specifically W3C Stack LayerAttributes Business level agreements Service level agreements CompositionConversations, Transactions Orchestration PresentationType of output (e.g. WAP) PolicyPreconditions, Effects, Domain(s), Cost, Security, Constraints (geographical, time or based on other attributes), Performance, Reliability, Information about the service provider Implementation DescriptionNetwork address Interface Descriptionservice Name, Short service description, input/output messages, Operations, bindings, interaction pattern, synchronicity, exceptions XML Schema

WSDL/UDDI DescriptionPublishing Description of Requestor Needs Matchmaking HOW DAML-S, XML, keywords, … Scalable, Secure, Available, … DAML-S, XML, keywords, … Scalable, Secure, Available, By composition, keywords, inference… WHO Program, Developer, Business user Program, Developer, Business user Developer, Business user Program, Developer, Business user WHEN/HOW LONG N/APersistent, With lease N/ADesign-time, run- time, persistent query, volatile query WHAT See next slide WHERE N/ALocal, Corporate, Global N/ALocal, Corporate, Global

WSDL/UDDI and WHAT reqs W3C Stack LayerAttributes Business level agreements Service level agreements CompositionConversations, Transactions Orchestration PresentationType of output (e.g. WAP) PolicyPreconditions, Effects, Domain(s), Cost, Security, Constraints (geographical, time or based on other attributes), Performance, Reliability, Information about the service provider Implementation DescriptionNetwork address Interface Descriptionservice Name, Short service description, input/output messages, Operations, bindings, interaction pattern, synchronicity, exceptions XML Schema

The DAML-S approach DescriptionPublishing Description of Req. Needs Matchmaking HOW DAML-S, XML, keywords, … Scalable, Secure, Available, … DAML-S, XML, keywords,… Scalable, Secure, Available, By composition, keywords, inference WHO Developer, Business user Program, Developer, Business user Developer, Business user Program, Developer, Business user WHEN/HOW LONG N/APersistent, With lease N/ADesign-time, run-time, persistent query, volatile query WHAT See next slide WHERE N/ALocal, Corporate, Global N/ALocal, Corporate, Global

DAML-S and WHAT reqs W3C stack LayerAttributes Business level agreements Service level agreements CompositionConversations, Transactions Orchestration PresentationType of output (e.g. WAP) PolicyPreconditions, Effects, Domain(s), Cost, Security, Constraints (geographical, time or based on other attributes), Performance, Reliability, Information about the service provider Implementation DescriptionNetwork address Interface Descriptionservice Name, Short service description, input/output messages, Operations, bindings, interaction pattern, synchronicity, exceptions XML Schema

Evaluation of DAML-S (1/2) Issues related to the language specification Issues inherited from the Semantic Web

Evaluation of DAML-S (2/2) Generality of descriptions Possible inconsistency between the ServiceProfile and the ServiceModel Lack of tools that enable the definition of all three aspects of a Daml-s description Lawlessness in ontologies Inability to compare preconditions and effects Tricky comparison on the non-functional attributes Maturity issue

Future Work Expand the survey by examining composition and standards (such as BPEL4WS, WSCL, WSRP, …) and see how they can be combined with other standards in order to meet the specified requirements Examine DAML-S 0.9, OWL Investigate the merging of UDDI/WSDL and DAML-S activities Extend our discovery mechanism prototype to address as many requirements as possible and evaluate the standards