180 likes | 289 Views
Welcome to the Design of SOA for Geospatial Science Workshop 2008!. Xuan Shi @ CGIS, GA Tech Rob Raskin @ JPL, NASA. Practical issues. Breaks at 10:15am and 4pm Lunch 12-1 Dinner on your own. Workshop Goals. Share and discuss experiences with others
E N D
Welcome to theDesign of SOA for Geospatial Science Workshop 2008! Xuan Shi @ CGIS, GA Tech Rob Raskin @ JPL, NASA
Practical issues • Breaks at 10:15am and 4pm • Lunch 12-1 • Dinner on your own
Workshop Goals • Share and discuss experiences with others • Understand and explore the complex mechanisms of system functions, communications, and interactions of components in geospatial Service Oriented Architecture (SOA) • Embrace the participation of scientists from varied research domains to share their data and computing resources toward a common Cyberinfrastructure. • Maintain and manage SOA into an ordered self-organization to avoid failure of the old SOA after the termination of UDDI. • Improve the design, development, implementation, operation, maintenance, and standards for SOA for GIScience.
Workshop Agenda 9:00am - 9:30am Xuan Shi and Rob Raskin, Welcome and Introduction 9:30am - 10:15am FGDC team, Best Practices in Geospatial Service-Oriented Architecture: An FGDC CAP Project 10:15am – 10:30amBreak 10:30am - 11:00am Nancy Wiegand, U. Wisconsin, “Design of Web 2.0/3.0 and SOA for Geospatial Science: Mashups for Fun and Profit!” 11:00am - 11:30am Carl Reed, OGC, “Enhancing Scientific Collaboration: OGC Standards, information sharing and models in a SOA Framework” 11:30am - Noon Bin Li, Central Michigan U., “RSS for Geo-Spatial Service Description and Discovery” Noon – 12:00 Lunch 1:00pm - 1:30pm Chris Mattmann, JPL, “A Service Oriented Architecture for Highly Distributed and Data-Intensive Geospatial Grid Software Systems” 1:30pm - 2:00pm Jim Tobias, CDC, “Public Health Distributed Geospatial Intelligence Network (PH-DGInet)” 2:00pm - 4:00pm Joint Discussion with Cyberinfrastructure Workshop 4:00pm - 4:30pm Break 4:30pm - 5:00pm Wenwu Tang, et al. U. Illinois, “Design and Implementation of a Service-oriented Agent-based Simulation Architecture” 5:00pm - 5:30pm Hiren Bhatt, et al., India, “A Grid based Architecture for Dynamic Reconfiguration of Geospatial Workflows” 5:30pm - 6:00pm Wrap-up
Current issues and future challenges in the research and development of Service Oriented Architecture (SOA) in IT mainstream and GIScience
Research context in GIScience • The “effective sharing of methods and tools has potentially much higher return than sharing of data, yet historically our interest in the GIS community has been almost entirely on the sharing of data.” --Goodchild (2003) • Web services technology provides the path for sharing of GIS methods and tools
Web services • As a solution to software interoperability, Web services technology replaces CORBA and DCOM. • A GIS software suite can be decomposed into functional components that are accessible through the interoperable Application Programming Interface (API) defined in the Web Services Description Language (WSDL).
Singh, M. P. and M. N. Huhns. 2005. Service Oriented Computing - Semantics, Processes, Agents. John Wiley & Sons, Ltd. Page 11-12.
What are “Services”? • In English, service means “work done for others” • For any others who want to consume “services”, a prerequisite is to find the required services.
How to find the “services”? • Within the Web Services Architecture (W3C, 2004), or the so-called Service Oriented Architecture (SOA), a service provider can publish the service into a service registry, and a service requester can find the service through the registry and consume the service by using the Simple Object Access Protocol (SOAP) to invoke the service.
Service discovery: Peer-to-Peer (P2P) • A Web service is a node in a network of peers, which may or may not be Web services. • At discovery time, a requester agent queries its neighbors in search of a suitable Web service. • If any service matches the request, then it replies. Otherwise each queries its own neighboring peers and the query propagates through the network until terminated by a hop count or other criterion. • P2P is impossible because under existing Web service technology, a service has an interface defined in WSDL and can be published into a service registry, and be invoked through the SOAP protocol. • There is no mechanism for a “service” to query its neighbors in search of a suitable Web service
Service discovery: the registry approach • A registry is an authoritative, centrally controlled store of information • UDDI is often seen as an example of the registry approach • The public UDDI Business Registry (UBR) was shutdown in early 2006 [ UDDI - Universal Description, Discovery, and Integration ]
Service discovery: the index approach • In contrast with a registry, an index is a compilation or guide to information that exists elsewhere. It is not authorative and does not centrally control the information that it references. • Google is often cited as an example of the index approach • The index approach is not feasible either and encounters varied challenges and problems [ Al-Masri, E. and Q. H. Mahmoud. 2008. Discovering Web Services in Search Engine. IEEE Internet Computing. May/June 2008 ]
Semantic Web Services (SWS) • WSDL has been criticized as it defines the service syntactic structure and interface definition, but lacks the semantics • Semantic Web services (SWS) thus have a comprehensive goal that enables the automatic and dynamic service discovery, matchmaking, composition, and invocation by enhancing services with semantic expressions
The central theme in SWS and SOA • David Martin and John Domingue wrote that the “central theme” of Semantic Web services (SWS) is the use of services • Michael Brodie wrote, “How will services discover the right services that meet specific requirements in such an environment? We’re far from that scale at the moment.” – IEEE Intelligent Systems. Sep./Oct. 2007 My question is, even if we’re far from discovering the right services at the moment, how can we “use” them in OWL-S and WSMO? – IEEE Intelligent Systems. Mar./Apr. 2008
Why has service discovery failed? • “[Web] services have little value if others cannot discover, access, and make sense of them.” - Ian Foster, “Service-Oriented Science,” Science, 6 May 2005 • A fundamental question is how to renovate Web service architecture to enable the realization of Semantic Web Services
Workshop topics • System research and engineering of geospatial Web services • Cybernetics for uncertainty reduction in SOA • Information theory and implication on geospatial SOA construction • Artificial intelligence for geospatial service discovery, matchmaking and integration • Service description and specification of geospatial Web services for data sharing and processing • Scalability, performance, and communication of geospatial Web services • Cognitive psychology and machine learning for service discovery and matchmaking • Ontology of geospatial Web services • Semantic Web and new standard generation for geospatial Web services
Today • Keynote speakers • FGDC winning team of best practice of geospatial SOA • Dr. Nancy Weigand Let’s begin