WS-RT Update Ian Robinson
WS-RT and WSRF Page 2 WS-ResourceTransfer – from Roadmap document [1] WS-Transfer (Sep 2004) WS-Metadata Exchange 1.1 (new) WS-ResourceTransfer (new) [1] - IBM, MS, HP, Intel, March 2006
WS-RT and WSRF Page 3 WS-ResourceTransfer – Aug WS-Transfer (Sep 2004) (To be updated Sep 2006) WS-Metadata Exchange 1.1 (Aug 2006) X WS-ResourceTransfer (Aug 2006) WS-RT: WS-MEX:
WS-RT and WSRF Page 4 Materials published Aug 2006 WS-MEX 1.1: WS-RT 1.0 spec: WS-RT / WSRF demo: - incl XSLT transformation WS-RT messages -> WSRF - intention to contribute to Apache Muse.
WS-RT and WSRF Page 5 WS-MetadataExchange 1.1 Primary changes from MEX 1.0: - Removal of wsmex:Get in favour of WS-Transfer Get - Support for W3C REC level of WS-Addressing (same as WSRF)
WS-RT and WSRF Page 6 WS-RT – Goals and Principles Goals: - Define new spec that satisifes requirements of both WS-Transfer and WS- ResourceProperties / WS-ResourceLifetime - Ensure simple strategy for accomodating existing WS-Transfer and WSRF implementations Principles - A resource (instance) is referenced through an EPR - Each resource instance has an XML resource representation. - Define new versions of the WS-Transfer CRUD operations that can operate on fragments of the XML representation of the resource. - None of the CRUD operations are mandatory.
WS-RT and WSRF Page 7 WS-RT – What does it specify? Defines extensions to WS-Transfer for “fragment-level” support to Get / Put /Create Defines a number of dialects in which the “fragment syntax” can be expressed - QName dialect is based on WS-ResourceProperty syntax - XPath Level 1 Minimal subset of XPath. No function libraries; resolution to single node-set - Full XPath Defines resource metadata, such as lifetime metadata
WS-RT and WSRF Page 8 Example resource representation F T13:30:15 C: MyDrive-C D: MyDrive-D
WS-RT and WSRF Page 9 WS-RT Expression Dialects The “QName” dialect - Simple QName that references immediate children of root e.g. d:DiskCapacity - This is equivalent to WSRF resource property. - Suitable for constrained resources with no XPath processing capability The “XPath Level 1” dialect - A restricted XPath dialect. No function libraries Expressions evaluate to 0 or 1 nodes only. Doesn’t support computed values. - e.g. d:Disk/d:Volume[1]/d:Label - Suitable for less constrained resources and/or more complex resource representations. The “XPath” dialects - Full XPath; Expressions may evaluate to multiple node-sets - Not supported with ‘Put’ or ‘Create’ - e.g. d:Disk/d:Volume - Suitable for queries and complex Get operations.
WS-RT and WSRF Page 10 CRUD: (Retrieve) Get request [Headers] [Action] [Body] xs:any *
WS-RT and WSRF Page 11 CRUD: (Retrieve) Get response [Headers] [Action] [Body] xs:any +
WS-RT and WSRF Page 12 CRUD: (Update) Put request [Headers] [Action] [Body] xs:any ? +
WS-RT and WSRF Page 13 CRUD: (Update) Put response [Headers] [Action] [Body]
WS-RT and WSRF Page 14 CRUD: (Create) Create request [Headers] [Action] [Body] resource metadata ? xs:any ? xs:any *
WS-RT and WSRF Page 15 CRUD: (Create) Create response [Headers] [Action] [Body] wsa:EndpointReferenceType No change from WS-Transfer CreateResponse message
WS-RT and WSRF Page 16 Resource metadata May be specified as part of wsrt:Create May be queried using WS-Mex May be updated using a combination of WS-Mex (to retrieve an EPR to a metadata resource) and wsrt:Put (to update the metadata resource).
WS-RT and WSRF Page 17 WS-RT Metadata lifetime metadata ? dialect metadata *... ( xs:dateTime | xs:duration | xs:duration ) ModeType * xs:positiveInteger ? *
WS-RT and WSRF Page 18 CRUD: (Delete) No new message semantics – nothing beyond WS-Transfer delete. Deletes entire resource Any further use of the resource EPR results in wsa:DestinationUnreachable fault.