1. OGSI Evolution: WS-Resource Framework and WS-Notification Carl Kesselman Globus Alliance @ USC/ISI carl@isi.edu

2. 2 WS-Resource Framework www.globus.org/wsrf Context OGSA/I introduced two years ago (GGF4) Grid over Web services Convergence of requirements from: Grid computing Systems Management Business computing OGSI concerns threatened ubiquity Solution: Evolve OGSI to provide key middleware for scientific & commercial needs Grid Computing Systems Management Business Computing Web Services

3. 3 WS-Resource Framework www.globus.org/wsrf Web Services and Stateful Resources State appears in almost all applications Data in a purchase order Current usage agreement for resources Metrics associated with work load on a server There are many possible ways Web services might model, access and manage state OGSI v1.0 defined one approach WS-Resource Framework proposes an evolution of that approach Ad-hoc approaches can be used per-application

4. 4 WS-Resource Framework www.globus.org/wsrf Building large-scale systems by composition of many heterogeneous components demands that we extract and standardize common patterns Approach to resource identification Resource lifetime management interfaces Resource inspection and monitoring interfaces Base fault representation Service and resource groups Notification And many more… Standardization encourages tooling & code re-use Support to build services more quickly & reliably Why Standardize An Approach?

5. 5 WS-Resource Framework www.globus.org/wsrf OGSI Overview Naming and bindings (basis for virtualization) Every service instance has a unique name, from which can discover supported bindings Lifecycle (basis for fault resilient state management) Service instances created by factories Destroyed explicitly or via soft state Information model (basis for monitoring & discovery) Service data (attributes) associated with GS instances Operations for querying and setting this info Asynchronous notification of changes to service date Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

6. 6 WS-Resource Framework www.globus.org/wsrf Grid Web However, despite enthusiasm for OGSI, adoption within Web community turned out to be problematic Started far apart in apps & tech OGSI GT2 GT1 HTTP WSDL, WS-* WSDL 2, WSDM Have been converging ? Convergence of Grid and Web Services

7. 7 WS-Resource Framework www.globus.org/wsrf Concerns Too much stuff in one specification Does not work well with existing Web services tooling Too object oriented

8. 8 WS-Resource Framework www.globus.org/wsrf Convergence of Grid and Web Services Grid Web The definition of WSRF means that Grid and Web communities can move forward on a common base WSRF Started far apart in apps & tech OGSI GT2 GT1 HTTP WSDL, WS-* WSDL 2, WSDM Have been converging

9. 9 WS-Resource Framework www.globus.org/wsrf A family of Web services specification proposals WS-Resource Framework (WSRF): Introduces a design pattern to specify how to use Web services to access stateful components WS-Notification: Introduces message-based publish- subscribe to Web services WS-Service Group WS-Renewable References WS-Notification Modeling Stateful Resources with Web Services WS-Base Faults WS-Resource Properties WS-Resource Lifetime Introduced January 20 To be released Documents Announced at GlobusWorld

10. 10 WS-Resource Framework www.globus.org/wsrf Document Authors WSRF: CA, Fujitsu, HP, Globus, IBM Strong participation from systems management companies WS-Notification: CA, Fujitsu, HP, Globus, IBM + Akamai, Sonic, SAP, Tibco Strong participation from messaging companies Author notes: IBM: Both Web service & OGSI authors HP: WSMF authors

11. 11 WS-Resource Framework www.globus.org/wsrf Concerns Addressed By WSRF and WS-Notification Too much stuff in one specification è WSRF partitions OGSI v1.0 functionality into a family of composable specifications Does not work well with existing Web services tooling è WSRF tones down the usage of XML Schema Too object oriented è WSRF makes an explicit distinction between the service and the stateful resources acted upon by that service

12. 12 WS-Resource Framework www.globus.org/wsrf What is a WS-Resource? Web service: Operation execution component made available at an endpoint address Implementation often stateless, but accesses state WS-Resource: Web service + associated resource Equivalently: A resource with an associated WS A WS-Resource has: Identity: Can be uniquely identified/referenced Lifetime: Often created & destroyed by clients State: Can be projected as an XML document WS-Resource type = Web service interface WS-Resources are not just for physical devices Jobs, subscriptions, logical data sets, etc.

13. 13 WS-Resource Framework www.globus.org/wsrf Interface Web Service WSDL Run-time environment Web Services Model

14. 14 WS-Resource Framework www.globus.org/wsrf Interface Web Service message Invoking a Web Service address Endpoint Reference Run-time environment Web Services Model

15. 15 WS-Resource Framework www.globus.org/wsrf context Interface Web Service message id message Using a Web service to access a resource id address resource Run-time environment Endpoint Reference WS-Resource Framework Model Address Resource id

16. 16 WS-Resource Framework www.globus.org/wsrf context Interface Web Service message id message Using a Web service to access a resource id address resource Endpoint Reference WS-Resource Framework Model Run-time environment

17. 17 WS-Resource Framework www.globus.org/wsrf Any Web service capable of bringing a WS-Resource into existence Typically by creating a resource, associating it with a service, and assigning the pair an identifier (e.g. Endpoint Reference) A pattern, not a particular operation Request message customized for particular type of resource(s) to be created Response message of a factory operation usually includes an EPR that refers to the new WS-Resource May create one or many WS-Resources WS-Resource Factory

18. 18 WS-Resource Framework www.globus.org/wsrf Interface Web Service message Creating / Locating a WS-Resource address Endpoint Reference resource Endpoint Reference Web Service either locates or creates a WS- Resource addres s id WS-Resource Framework Model Run-time environment

19. 19 WS-Resource Framework www.globus.org/wsrf Service Composition Transports Messaging Description Quality of Experience (QoX) HTTP/HTTPS SMTP RMI / IIOP XSD WSDL SOAP XML WS-AddressingWS-RenewableReferences WS-MetadataExchange WS-Policy WS-ServiceGroup WS-Resource Properties JMS WS-Security WS-ReliableMessagingWS-Transaction WS-ResourceLifetime WS-BaseFaults WS-Notification BPEL4WS How these proposals relate to other Web services standards

20. 20 WS-Resource Framework www.globus.org/wsrf Open Grid Services Architecture Define a service-oriented architecture … the key to effective virtualization … to address vital Grid requirements AKA utility, on-demand, system management, collaborative computing … building on Web services standards extending those standards where needed

21. 21 WS-Resource Framework www.globus.org/wsrf OGSA Services can be defined and implemented as Web services OSGA can take advantage of other Web services standards OGSA can be implemented using standard Web services development tools Grid applications will NOT require special Web services infrastructure Network OGSA Enabled Storage OGSA Enabled Servers OGSA Enabled Messaging OGSA Enabled Directory OGSA Enabled File Systems OGSA Enabled Database OGSA Enabled Workflow OGSA Enabled Security OGSA Enabled Web Services WS-Resource Framework & WS-Notification are an evolution of OGSI OGSI – Open Grid Services Infrastructure How these proposals relate to OGSA Web Services OGSA Architected Services Applications WS-Service Group WS-Renewable References WS-Notification Modeling Stateful Resources with Web Services WS-Base Faults WS-Resource Properties WS-Resource Lifetime

22. 22 WS-Resource Framework www.globus.org/wsrf From OGSI to WSRF: Refactoring and Evolution OGSIWSRF Grid Service ReferenceWS-Addressing Endpoint Reference Grid Service HandleWS-Addressing Endpoint Reference HandleResolver portTypeWS-RenewableReferences Service data defn & accessWS-ResourceProperties GridService lifetime mgmtWS-ResourceLifetime Notification portTypesWS-Notification Factory portType Treated as a pattern ServiceGroup portTypesWS-ServiceGroup Base fault typeWS-BaseFaults

23. 23 WS-Resource Framework www.globus.org/wsrf OGSI Overview Naming and bindings (basis for virtualization) Every service instance has a unique name, from which can discover supported bindings Lifecycle (basis for fault resilient state management) Service instances created by factories Destroyed explicitly or via soft state Information model (basis for monitoring & discovery) Service data (attributes) associated with GS instances Operations for querying and setting this info Asynchronous notification of changes to service date Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

24. 24 WS-Resource Framework www.globus.org/wsrf WSRF & WS-N Overview Naming and bindings (basis for virtualization) Every service instance has a unique name, from which can discover supported bindings Lifecycle (basis for fault resilient state management) Service instances created by factories Destroyed explicitly or via soft state Information model (basis for monitoring & discovery) Service data (attributes) associated with GS instances Operations for querying and setting this info Asynchronous notification of changes to service date Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

25. 25 WS-Resource Framework www.globus.org/wsrf WSRF & WS-N Overview Naming and bindings (basis for virtualization) Every resource can be uniquely referenced, and has one or more associated services for interacting with it Lifecycle (basis for fault resilient state management) Service instances created by factories Destroyed explicitly or via soft state Information model (basis for monitoring & discovery) Service data (attributes) associated with GS instances Operations for querying and setting this info Asynchronous notification of changes to service date Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

26. 26 WS-Resource Framework www.globus.org/wsrf WSRF & WS-N Overview Naming and bindings (basis for virtualization) Every resource can be uniquely referenced, and has one or more associated services for interacting with it Lifecycle (basis for fault resilient state management) Resources created by services following factory pattern Resources destroyed immediately or scheduled Information model (basis for monitoring & discovery) Service data (attributes) associated with GS instances Operations for querying and setting this info Asynchronous notification of changes to service date Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

27. 27 WS-Resource Framework www.globus.org/wsrf WSRF & WS-N Overview Naming and bindings (basis for virtualization) Every resource can be uniquely referenced, and has one or more associated services for interacting with it Lifecycle (basis for fault resilient state management) Resources created by services following factory pattern Resources destroyed immediately or scheduled Information model (basis for monitoring & discovery) Resource properties associated with resources Operations for querying and setting this info Asynchronous notification of changes to properties Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

28. 28 WS-Resource Framework www.globus.org/wsrf WSRF & WS-N Overview Naming and bindings (basis for virtualization) Every resource can be uniquely referenced, and has one or more associated services for interacting with it Lifecycle (basis for fault resilient state management) Resources created by services following factory pattern Resources destroyed immediately or scheduled Information model (basis for monitoring & discovery) Resource properties associated with resources Operations for querying and setting this info Asynchronous notification of changes to properties Service Groups (basis for registries & collective svcs) Group membership rules & membership management Base Fault type

29. 29 WS-Resource Framework www.globus.org/wsrf WS-Resource Framework Capabilities Clarifies how stateful resources are addressed Specifies how to use XML to describe and access a resources properties Defines how a resource is created and messages to destroy resources Provides a message subscription and notification mechanism for Web services Defines how to organize groups of resources and services Adds a fault tolerance capability to WS-Addressing Defines a standard, extensible format for Web services error messages In publicly released specifications

30. 30 WS-Resource Framework www.globus.org/wsrf Specifies the representation of the address of a Web service deployed at a given network endpoint EndpointReference (EPR) is an XML serialization of a network-wide pointer to a Web service EPRs can be used to pass around service references An EPR contains: Service address (wsa:Address) Reference properties (wsa: ReferenceProperties): can be used to define a resource associated with service address Metadata associated with the Web service such as service description information Policy information related to the use of the service WS-Addressing

31. 31 WS-Resource Framework www.globus.org/wsrf WS-ResourceProperties Resource state and metadata Projected as an XML document Query and Set operations WS-ResourceLifetime Synchronous or scheduled (soft-state) destruction Provides for cleanup of resource instances resource 5A34C1DE03 Power6.2 400 256 1 WS-Resource Framework Model

32. 32 WS-Resource Framework www.globus.org/wsrf Subscriber indicates interest in a particular Topic by issuing a subscribe request Broker (intermediary) permits decoupling Publisher and Subscriber Subscriptions are WS-Resources Various subscriptions are possible Publisher need NOT be a Web Service Notification may be triggered by: WS Resource Property value changes Other situations Broker examines current subscriptions Brokers may Transform or interpret topics Federate to provide scalability Broker Subscriber Publisher subscribe SS S notify WS-Notification

33. 33 WS-Resource Framework www.globus.org/wsrf Network R R R A Service Level Scenario: Resource management & scheduling Storage R R R Computers R R R Notification Grid Scheduler WS-Resource used to model physical processor resources WS-Resource Properties project processor status (like utilization) Local processor manager is front-ended with A Web service interface Other kinds of resources are also modeled as WS-Resources J J J WS-Notification can be used to inform the scheduler when processor utilization changes Grid Jobs and tasks are also modeled using WS-Resources and Resource Properties Grid Scheduler is a Web Service Service Level Agreement is modeled as a WS-Resource (WS-Agreement) Lifetime of SLA Resource tied to the duration of the agreement Bringing it All Together

34. 34 WS-Resource Framework www.globus.org/wsrf Globus Toolkit ® and WS-Resource Framework 3.2 Improved robustness, scalability, performance, usability 3.2 March 4.0 Q2 4.0 Q3 4.2 Q1 05 4.2 Q4 Numerous new WSRF-based services 4.2 4.0 WSRF; some new functionality; further usability, performance enhancements 2004 2005 Note: We are not waiting for finalization of WSRF specs

35. 35 WS-Resource Framework www.globus.org/wsrf Globus Toolkit != WSRF/OGSI WSRF/OGSI impl is just one small part of GT GT = Services for execution mgt, data mgt, monitoring, and discovery l E.g. GRAM, GridFTP, RFT, RLS, OGSA-DAI, etc. GT services are largely unaffected by WSRF Changing thin middle layer of some services Interfaces and semantics largely unchanged But not interoperable due to protocol changes GT3 work in GRAM & RFT will transition easily Pre-WS components continue to be supported GridFTP, RLS

36. 36 WS-Resource Framework www.globus.org/wsrf Stabilize the services around WSRF Usability, performance, reliability, scalability, documentation, internationalization Leverage Apache even more l Axis, WS-Security, WS-Addressing, … Bring to fruition new functionality in pipeline Data access & integration (OGSA-DAI) Enhanced GridFTP Community scheduling framework Monitoring & discovery capabilities GT2 GT3 bump >> GT3 GT4 bump Globus Priorities for 2004

37. 37 WS-Resource Framework www.globus.org/wsrf Summary WSRF is straight-forward evolution of OGSI OASIS WSRF TC continues the standards process started by GGF OGSI WG Addresses concerns raised with OGSI Reflects its broader applicability GT4 will start migration of Globus infrastructure to WSRF Impact at low level, not high level services