Web Services Components of the Transactional Web James

Web Services Components of the “Transactional Web” James Snell jasnell@us. ibm. com

Overview n n What is the “Transactional Web” The Web Services Stack Web Service Description Language (WSDL) n Universal Description, Discovery and Integration (UDDI) n n n Web Services and the Semantic Web Discussion/Q&A

What is the “Transactional Web” n n Today: “The eye-ball Web” - the architecture of the Web is geared towards delivering information visually. Tomorrow: “The transactional Web” – the architecture of the Web geared towards intelligently exchanging information between applications.

What is the “Transactional Web” n n “Web Services” (plural) is a blanket term representing all of the technologies that enable the “transactional web” to exist. “Web Service” (singular) is a term referring to a collection of application operations accessible over a network using Web Services technologies.

WSAH (Web Services Acronym Hell) DIME eb. XML JABBER SOAP-SEC SOAP SAML WSDL SOAP-RP XML-ENC XML-RPC XMLP DISCO XLANG CPP-CPA WSFL XSD WSEL UDDI DSML P 3 P DAML-S X-KISS XKMS XML-DIGSIG DISCO PKI TWC (Tylenol with Codeine - which is what you’ll need after reading about all of these)

The Web Services Stack Wire Protocols Description Discovery SOAP Blocks Agreements SOAP/XMLP Process XML WSDL Extensions HTTP/SMTP/BEEP WSDL Registry (UDDI) TCP/IP XML Inspection The Web Services Stack helps us understand how each of the various pieces fit into the “Big Picture”

The Web Services Stack n Wire Protocols Primary Role: provide a standard, flexible communications channel n Secondary Role: provide a standard, flexible wire-level data representation n n Advantage: interoperability at the lowest level

The Web Services Stack n Description n n Primary Role: provide a standard, flexible way to describe what and how a Web service does what it does. Advantage: interoperability

The Web Services Stack n Discovery n n Primary Role: provide a standard, flexible way to discover where a Web service is located and where to find more information about what the Web service does (the description) Advantage: interoperability, dynamic integration

WSDL - Overview n WSDL is a simple XML grammar for describing how to communicate with a Web service n n It defines the messages (both abstract and concrete) that are sent to and from a service It defines logical collections of messages (“port type”, “interface”) It defines how a given “port type” is bound to particular wire protocols It defines where the service is located

WSDL - Overview <definitions> <types> <!-- XML Schema --> </types> <message name=“get. Quote_In” /> <message name=“get. Quote_Out” /> <port. Type name=“Stock. Quote. Service. Interface”> <operation name=“get. Quote”> <input message=“get. Quote_In” /> <output message=“get. Quote_Out” /> Definition of data types Definition of messages Definition of port type Definition of the bindings </operation> </port. Type> <binding name=“Stock. Quote. Service. Binding” type=“Stock. Quote. Service. Interface”> <soap: binding transport=“http: //schemas. xmlsoap. org/soap/http” /> … </binding> Definition of the service <service name=“Stock. Quote. Service”> <port name=“Stock. Quote. Service. Port” binding=“Stock. Quote. Service. Binding”> <soap: address location=“http: //www. acme. com/services/stockquote” /> </port> </service> </definitions>

WSDL Overview n n WSDL is extensible. WSDL was created by IBM and Microsoft The intent was to create something that worked, not something that was complete n Creating a formal Web Services “data model” was not a priority n n WSDL is RDF-compatible (not RDFcompliant)

UDDI Overview n UDDI is: A Web Services API for publishing and discovering the existence of Web services n A registry for managing information about Web services n A coalition of organizations working together to manage UDDI registries and to further develop the Web Services API for accessing those registries. n

UDDI Overview n UDDI is built around a “Yellow-pages” like data model: Business Entity Identities Business Services Categories Service Bindings TModels

UDDI Overview n TModel = “Technology Model” TModel Instance Abstract metadata definition relating to some aspect of the UDDI registration Implementation specific metadata conforming to a given TModel = Abstract Class

UDDI Overview n TModels n Categories & Identifiers n n n Categorization and Identification taxonomies are TModels Categories and Identifiers are TModel Instances Keyed Referenced n n n Examples: NAICS, UNSPSC, D&B # WSDL Port Types n n n Name + Value + TModel WSDL Port Types are TModels WSDL Services that are bound to a Port Type are TModel Instances WSFL Business Processes n n WSFL Flow Models are TModels WSFL Global Models are TModel instances TModels represent the extent of UDDI’s semantic description capabilities.

UDDI Overview n n n UDDI has only limited extensibility through TModels UDDI was created by IBM, Microsoft and Ariba (many companies have joined the effort) The intent was to put something together that worked.

UDDI Overview n n UDDI Version 1. 0 – September 2000 (in production) UDDI Version 2. 0 – June 2001 UDDI Version 3. 0 - In development UDDI will be presented to a standards body after Version 3. 0

Web Services and the Semantic Web n Complimentary Goals n Semantic Web n n It’s about making links between information more intelligent. Transactional Web (Web Services) n It’s about improving the way information is exchanged

Web Services and the Semantic Web n Different Points of View n Semantic Web n n Derives the puzzle-pieces from the big picture Transactional Web n Derives the big picture from the puzzle-pieces

Web Services and the Semantic Web n Meeting in the middle n Semantic Web n n Provides a formal data-model for Web Services Transactional Web n Provides a technology foundation for the Semantic Web

Discussion / Q&A ?