1. DSTT Report - OGC Services May 8, 2002Page 1 Allan Doyle DSTT Report OGC Services DSTT Report OGC & GRID Services Allan Doyle NASA/II May 8, 2002

2. DSTT Report - OGC Services May 8, 2002Page 2 Allan Doyle “If you don’t understand first off and it makes your mind go numb, you’re safe to ignore it, it will never work” Dave Winer at InfoWorld Next Generation Web Services Conference, January 2002

3. DSTT Report - OGC Services May 8, 2002Page 3 Allan Doyle Info OGC Services http://www.intl-interfaces.net/servicemodel GRID Services http://www.globus.org/ogsa/

4. DSTT Report - OGC Services May 8, 2002Page 4 Allan Doyle 1999200020012002 OpenGIS® Abstract Spec Topic 12 - The OpenGIS Service Architecture Architecture SIG WWW Mapping SIG Basic Service Model Discussion Paper Web Registry Services Discussion Paper CEOS WTF-GOFC WMT-1 IP2000 (WMT-2)IP2001 (OWS-1)OWS 1.2 OpenGIS® Catalog Interface Implementation Specification 1.0 OpenGIS® Catalog Interface Implementation Specification 1.1 ebXML Microsoft.NET UDDI CEOS WTF (??) NASA Industry OGC Google ECHO Grid Services Services Time Line J F M A M J J A S O N D Servicemodel Ad Hoc GCMD (SERFs)

5. DSTT Report - OGC Services May 8, 2002Page 5 Allan Doyle A.Search for Services first Decision support community view ? B.Search for Data first Science community view ? Technical Challenges Data vs. Services … Client Application GetFeature GetMap GetCoverage Service Catalog WFS Feature Data Store WMS Map Data Store WCS Coverage Data Store Fusion Services Geocode GeoParse GeoLink Data Catalog http://foo.org/wms.cgi?REQUEST=… Develop metadata and discovery mechanisms that can support both service-centric and data-centric modes.

6. DSTT Report - OGC Services May 8, 2002Page 6 Allan Doyle Interface Type Metadata Type Hierarchies Interface Instance Metadata Data Type Metadata Data Instance Metadata Combinations of Data/Interface Services & Service Metadata Controlled Vocabularies Catalogs & Registries End-user WMS Single Service WMS WFS Multiple Service Same Data Coord Trans. Service Only No Data FTP Data Only No Service Catalog Service Inventory Access http: //ce os.o rg 100, 50,2 300, 75.4 X=5 6 Directory Inventory Large Data System i n t e r n e t Interface Type Metadata Type Hierarchies Interface Instance Metadata Data Type Metadata Data Instance Metadata Combinations of Data/Interface Services & Service Metadata Controlled Vocabularies Catalogs & Registries Interface Type Metadata Type Hierarchies Interface Instance Metadata Data Type Metadata Data Instance Metadata Combinations of Data/Interface Services & Service Metadata Controlled Vocabularies Catalogs & Registries End-user WMS Single Service WMS WFS Multiple Service Same Data Coord Trans. Service Only No Data FTP Data Only No Service Catalog Service Inventory Access http: //ce os.o rg 100, 50,2 300, 75.4 X=5 6 Directory Inventory Large Data System i n t e r n e t Technical Challenges Metadata & Vocabularies

7. DSTT Report - OGC Services May 8, 2002Page 7 Allan Doyle OGC Services HTTP GET/POST based interfaces Service instances provide their own metadata service descriptions (“Capabilities”) via XML Filter parameters allow selection of subsets of source data Output formats advertised by each service instance http://ceos.org 100,50,2 300,75.4 X=56 WMS maps WFS feature data WCS coverage data M11 <gml:LineString srsName="EPSG:4326"> 0,5.0 20.6,10.7 80.5,60.9 motorway 11

8. DSTT Report - OGC Services May 8, 2002Page 8 Allan Doyle OGC Service Registry Concepts Registry should be able to handle any kind of service. Should allow searches against more criteria than WMT-1 catalog Each service’s metadata should be composed of common elements where possible Initially described in the IP2000 Basic Service Model WMS maps WFS feature data WCS coverage data M11 <gml:LineString srsName="EPSG:4326"> 0,5.0 20.6,10.7 80.5,60.9 motorway 11 Metadata Registry M11 <gml:LineString srsName="EPSG:4326"> 0,5.0 20.6,10.7 80.5,60.9 motorway 11 Metadata

9. DSTT Report - OGC Services May 8, 2002Page 9 Allan Doyle OWS1 Service Model Issues Two competing registry information models: UDDI and ebXML Two competing means of constructing registries: XML database and OGC Stateless Catalog Three competing Metadata content models: R4, R7, and R8 Not enough consensus, fragmented results WMS maps WFS feature data WCS coverage data M11 <gml:LineString srsName="EPSG:4326"> 0,5.0 20.6,10.7 80.5,60.9 motorway 11 Metadata Registry M11 <gml:LineString srsName="EPSG:4326"> 0,5.0 20.6,10.7 80.5,60.9 motorway 11 Metadata

10. DSTT Report - OGC Services May 8, 2002Page 10 Allan Doyle Navigating the Web Services Industry The Web Services industry Big players see big money Much jockeying for position & mindshare Many overlapping/competing standards Not many cross-vendor deployments yet Very complex set of issues (for what seems like a simple concept!) OASIS WS-I W3C         Standards Organizations W3C World Wide Web Consortium OASIS Organization for the Advancement of Structured Information Standards WS-I Web Services Interoperability Organization IETF Internet Engineering Task Force Global Grid Forum Major Vendors Microsoft. NET (not an acronym…) Sun ONE (Open Network Environment) IBM Websphere (Based on Apache web server) Acronyms SOAP Simple Object Access Protocol UDDI Universal Description, Discovery and Integration ebXML Electronic Business using eXtensible Markup Language WSDL Web Services Description Language OGSA Open Grid Services Architecture Microsoft Sun IBM

11. DSTT Report - OGC Services May 8, 2002Page 11 Allan Doyle Some key points Most real, operational web services exist on intranets and extranets. There is little evidence of web services on the “open” internet. Web services are not about “the web”. Web services are producer-oriented tools. Consumers of web services see a carefully controlled entry point. End- users generally see portals.

12. DSTT Report - OGC Services May 8, 2002Page 12 Allan Doyle The Eight Fallacies of Distributed Computing How does the GRID measure up? Peter Deutsch Essentially everyone, when they first build a distributed application, makes the following eight assumptions. All prove to be false in the long run and all cause big trouble and painful learning experiences. 2.Latency is zero 3.Bandwidth is infinite 4.The network is secure 5.Topology doesn't change 6.There is one administrator 7.Transport cost is zero 8.The network is homogeneous –http://java.sun.com/people/jag/Fallacies.htmlhttp://java.sun.com/people/jag/Fallacies.html 1. The network is reliable

13. DSTT Report - OGC Services May 8, 2002Page 13 Allan Doyle How hard is it to wrap an OGC service in a GRID wrapper? How hard is it to build OGC services that are clients of GRID services? Can an OGC service be moved to where the data is? Can an OGC service be moved to where the compute cycles are available? Wrapping network service

14. DSTT Report - OGC Services May 8, 2002Page 14 Allan Doyle Think of this model portal GRID Web