Fujitsu Laboratories of Europe © 2004 What is a (Grid) Resource? Dr. David Snelling Fujitsu Laboratories of Europe W3C TAG - Edinburgh September 20, 2005 WSRF Chair GGF VC Next GRID Fujitsu Unicore OGSA

Fujitsu Laboratories of Europe © 2004 Motivation Grids Convergence with Web Services Web Services as the protocol and infrastructure Exploit existing tools and skills Resources are at the core of Grid Hardware components, Software capabilities, Data sets, People, Network connections, Running applications,... The Grid model of resources is still evolving Consistency (or otherwise) of Models Cases: W3C, WSRF, OGSA

Fujitsu Laboratories of Europe © 2004 Outline Sanity Check: One or two slides telling you what you already know, so that I know my use of terminology is correct. This acts as the first of three perspectives. Reality Check: Look at the similarity of the W3C Architecture to the reality. WSRF Resources: Overview the WSRF notion of a WS-Resource. OGSA Resources: Using the current view of OGSA (a moving target still) as a starting point, look at the notions of naming, persistence, authenticity, and mobility of resources in this context.

Fujitsu Laboratories of Europe © 2004 Sanity Check Resource Reference - URI Opaque N-to-1 Scheme based semantics Equality {true, } Resolved to access the resource A Thing, real or logical Stateful Modifiable via the representation Information Resource special case Metadata and content Distinct from the resource Processing based on scheme

Fujitsu Laboratories of Europe © 2004 Reality Check Resource Reference - URI Interaction Context is part of identification Processing

Fujitsu Laboratories of Europe © 2004 WS-Resource A Resource: State represented as an XML document This is not typically all of the resources state! Has a well-defined identity and lifecycle Known to, and acted upon, by one or more Web services. Many Possible Instances Files, Database tables, EJB Entities, XML documents, Compositions of multiple data sources, Virtualized executions of applications, etc. A WS-Resource (Resource + WS) has: Identity: Can be uniquely identified/referenced Lifetime: Often created & destroyed by clients (optional) State: Part of the state can be projected as XML Type: Its Web service interface (including the representation)

Fujitsu Laboratories of Europe © 2004 WS-Resource Interaction context Interface Web Service message id message id address resource Run-time environment Endpoint Reference Note: The interaction is with the whole WS-Resource not just its XML representation.

Fujitsu Laboratories of Europe © 2004 OGSA Specifications SYSTEMS MANAGEMENT UTILITY COMPUTING GRID COMPUTING Core Services Basic Profile WS-Addressing Privacy WSRF-RAP Generic Mgmt WS-Security Naming OGSA-EMSOGSA Self Mgmt Others... GGF-URData Model HTTP(S)/SOAP Discovery SAML/XACML WSDLWSRF-RL Trust WS-DAI VO Management Information Distributed query processing ASP Data Centre Use Cases & Applications CollaborationMulti MediaPersistent Archive WSRF-RP X.509 NotificationService GroupsWS-I BP

Fujitsu Laboratories of Europe © 2004 Toward OGSA Resources PropertyW3CWSRFOGSA Processes messages YesYesYes Stateful behavior YesYesYes Representation independent of state YesYesYes Resolvable references SchemeSchemeService Operational interfaces ImplicitWSDLWSDL Managed resource lifetime NoOptionalYes Mobile resources NoNoYes Unique abstract name NoNoYes Resources may be servers and clients NoNoYes

Fujitsu Laboratories of Europe © 2004 Observations Grid Notions of Resource are Close to the Reality of W3C Resources Notions of State and Representation Align Grid Resources are Generally Extensions of W3C Resources Grid Adds Client Side Management No Serious Inconsistencies

Fujitsu Laboratories of Europe © 2004 Extra Slides OGSA Profile Definition

Fujitsu Laboratories of Europe © 2004 OGSA Profiles Aim Provide interoperability guidance. Formalize the OGSA Architecture Continue to show direction in standards developmentContents Collections of Specifications Clarifications supporting interoperability Compliance Points If you support X, you MUST do it this way. You MUST support X. Profile Types Recommendation Proposed Recommendation Candidate

Fujitsu Laboratories of Europe © 2004 Profile Status Details Required for Recommendation Makes references to only completed standard specifications Multiple, independent, interoperable implementations exist Required for Proposed Recommendation References specifications that are stable E.g. GGF Proposed Recommendation or OASIS Committee Draft, W3C-CR,... May contain referenced specifications that are evolving if there are commitments from multiple implementers to support them. Required for Informational At least one implementation exists for a draft version of the specification Commitment from multiple implementers to develop to the final specification