Workflow Description for Open Hypermedia Systems

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Workflow Description for Open Hypermedia Systems. Sanjay Vivek, David C. De Roure Department of Electronics and Computer Science University of Southampton, UK. Outline. Brief history of third party link services What is workflow? Web Services and OHS - PowerPoint PPT Presentation

Text of Workflow Description for Open Hypermedia Systems

  • OutlineBrief history of third party link servicesWhat is workflow?Web Services and OHSWeb Services Flow Language(WSFL) and workflow conceptsRoles in OHSRecursive compositionSummary and Discussion

  • Simple Open Hypermedia architectureLink databasedocumentsNote the direction of this arrow!Separable hyperstructure

  • Open Hypermedia as a Link ServiceDocuments in native format

    Hypermedia Link service

    Customised hypermedia documents

    Query(before, during or after doc is delivered)

  • Proxy DLSProxyDLSclientLink serviceInternetThe Proxy DLS is an HTTP proxy that inserts links on-the-fly by querying the link service

  • DLS distributed architectureresolverresolverresolverresolverresolverconcurrencyfault toleranceaggregationQUERY

  • Linkbase migrationResolverResolverResolverserverserverLINK DATA

  • Mobile link resolution agentsAPIAPIAPIAPIAPIAGENT

  • Music content-based navigationLink ManagerAvailable Links InterfaceFeatureExtractorFeatureMatching +RetrievalLinkServiceD.L.S.FeatureAgentsDigital LibraryLink DatabaseFeature DatabaseStreaming media using RTSP over IPv6

  • Current Music IR architecture

  • But where does link data come from?DIY slide - Please label the boxes yourself

  • OverviewIntroduce workflow support for OHS Expose these OHS components as Web ServicesEnable integration and coordination with Web Services Flow Language (WSFL)

  • What is workflow?Workflow deals with the management, specification, and execution of operations (business processes) in organizations

  • IBM

  • IBM

  • Agent Technology: A Canonical ViewEnvironmentAgent

    InteractionsOrganisationalrelationshipsSphere of influenceJennings, CACM

  • WSFL and workflow conceptsXML language for the description of Web Services compositionsEssentially a specification to implement a business process modelUses a workflow engine like the MQSeries Workflow to consume WSFL

  • Web Services and OHS(i)To simplify the development and integration of distributed hypermedia services over the networkWeb services enable you to loosely couple processesWorkflow helps integrate new and existing servicesPrevious work (Haake) in CSCW context rather than web services

  • Web Services and OHS(ii)An example OHS model consists of the client, a link service, and a linkbase OHS components are clearly defined and can be described as a Web ServiceWorkflow helps sequence, coordinate, and manages conversations among Web services

  • WSFL and workflow concepts(ii)

  • WSFL and workflow concepts(ii)Each box is an activity and is a WebServiceProcessing logic is indicated by the directed edgesControl points ensure if certain conditions are met before processing the next activity

  • Roles in OHSEvery activity is implemented as a Web Service offered by a Web Service providerThe example OHS Model can be described in WSDL as follows:

  • Recursive CompositionEnables service providers to combine services into a single solution The end user will see the Web Service as a single entity and not as a composite of web services

  • Summary and DiscussionDeploy OHS services within a Web Service architecture and the usage of WSFL for coordination and interoperabilityTwo areas of possible research interestApplication InteractionReliability of servicesShould the OHS community be defining OHP in web services?

    The Web Services triangle , this particular picture from IBM. Note the publish-find-bind model.This is an IBM picture note WSFL Web Services Flow Language. IMHO Flow is key to Grid.