Leading the pervasive adoption of grid computing for research and industry © 2005 Global Grid Forum The information contained herein is subject to change without notice GFS-WG – Resource Namespace Service GGF13 March 14, 2005 in Seoul Manuel Pereira

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Session Agenda −Overview of RNS −Latest revisions to specification

Resource Namespace Service Service Description Three Tier Naming Architecture Operations Basic Naming Components Document Style Messaging Recent Revisions

RNS Service Description Previous data oriented concept referred to as a virtual filesystem directory service (VFDS) A WSRF compliant Web service capable of providing namespace services for any addressable entity by registering an Endpoint Reference Easily accessible, hierarchically managed, name Utilizes document style messaging Intended to facilitate namespace services for a wide variety of Grid services

RNS Operations Naming Operations −create −delete −list −lookup −update Implicit Operations −move −rename −mkdir Extensibility Operations −deleteProperty −insertProperty −listProperties −updateProperty

RNS Basic Naming Components Virtual Directories Junctions −Virtualized References −Endpoint References −Referrals −Aliases

RNS Three-Tier Naming Architecture Human Interface Names Virtualized References Endpoint References

RNS Three-Tier Naming Architecture Human Interface Names Virtualized References Endpoint References

RNS Three-Tier Naming Architecture Human Interface Names Virtualized References Endpoint References Alias Junction Service Referral Junction (delegate RNS) Virtualized Reference Junction Endpoint Reference Junction Virtual Directory

RNS Three-Tier Naming Architecture Human Interface Names Alias Junction Service Referral Junction (delegate RNS) Virtualized Reference Junction Endpoint Reference Junction Virtual Directory 2 nd Level of Indirection 1 st Level of Indirection

RNS Document Style Messaging Beyond Traditional RPC WSRF Compliant Service RNS IteratorContext RNS Entry

RNS IteratorContext RNS defines a stateful resource referred to as an IteratorContext, which maintains stateful properties for use with iterative operations: QNameDescription ChildCount Integer value that denotes the number of subentries found in the current working directory. DirectoryName String representing the name of the current working directory. DirectoryOID Integer representing the Object ID of the current working directory. DirectoryPath String representing the full path of the current working directory. IteratorIndex Integer representing the current index or marker corresponding to a current iterator operation; can be queried between iterator messages. [default value is “0”] Since directories may contain a very large number of subentries, the list operation enables the caller to specify the maximum number of subentries allowable per message exchange (IteratorMaxAtOnce). If this parameter property is specified as a non-zero value, then an IteratorContext will automatically be constructed and returned to the caller using standard WSRF mechanisms for stateful resource interaction.

RNS Entry QNameDescription Basic Properties AliasCount Number of known aliases of Entry ChildCount Number of subentries corresponding to Entry, if and only if Entry is a Virtual Directory; zero or NULL otherwise. Description Optional description of Entry ModificationTime DateTime ( xsd:dateTime ) representation of the last modified timestamp of Entry Name String representation of the human interface name of Entry OID Service instance unique Object ID of Entry. PID Service instance unique Object ID of the parent object to Entry Type String value denoting a type of entry; valid values are: Junction, Alias, Logical, Referral, and VirtualDirectory Reference Properties – Properties that host target information EPR Used to set or add a single Endpoint Reference EPRs Used to retrieve all Endpoint References associated with Entry LogicalReference Used to set or add a single Logical Reference LogicalReferences Used to retrieve all Logical References associated with Entry TargetOID The Object ID of the target entry, if and only if Entry is an Alias; zero or NULL otherwise. All of the following properties MUST be implemented to represent properties of a namespace entry by an RNS service implementation.

RNS Recent Revisions Logical Name Virtualized References vs Endpoint References IteratorContext OID clarification Behavioral description of an Alias EndOfList property

RNS Recent Revisions Logical Name −The format of logical names are not mandated by the specification