Technical Relationship between WSMX & Globus Toolkit Matthew Moran, Kashif Iqbal

1. Technical Relationship between WSMX & Globus Toolkit Matthew Moran, Kashif Iqbal Digital Enterprise Research Institute, Galway {Matthew.moran, Kashif.Iqbal}@deri.org 14 Jan 2005

2. Agenda • Setting the scene • Introduction & motivation • Distributed computing • Framework for comparison • Semantic Web Services • Rationale and research focus • WSMX • Grid Computing • Rationale and research focus • Globus Toolkit • WSMX and Globus Toolkit • Conclusions

3. Introduction • Two distinct research communities • Semantic Web Services • Grid Computing • Domain of both is distributed computing systems • General – do Grid and SWS fit together? • SWS on Grid – or – Grid on SWS • Specific – WSMX and Globus Toolkit • What is the relationship? • Complementary or competing architectures? • If complementary, how do they fit?

4. Distributed Computing Systems • Motivation • The need for system and data integration across heterogeneous and autonomous systems • Many previous efforts (more that are not listed) • TP Monitors – CICS, • Excellent for transaction processing; tight code coupling • Client Server and RPC • More flexible, still tight code coupling • Corba and DCOM • Object oriented rather than business process or document integration • UML a suitable modelling paradigm • Web Services • Great potential but where are the semantics? • BPM a suitable modelling paradigm

5. Distributed Computing Systems • Functional requirements • Synchronous and asynchronous message exchange • Heterogeneous and autonomous system integration • Publish and deploy services • Discover and invoke services • Data and process mediation • Non functional requirements • Transparency • Availability • Maximise resource usage • Throughput • Security • Transaction processing • Reliability

6. Framework for Comparison • Agree on terminology • Service • Resource • Publish and deploy • Discovery • Service level agreements (SLA) • Negotiation • Functional and non-func requirements • Architecture • Messaging • Domain of interest

7. Semantic Web Services • What is the application area for SWS? • Application and process integration • Inter- and intra- business • Focus on business documents and processes • WS not an artificial homogeneity • SWS addresses service discovery, composition • Problems with WS do they address? • Absence of formal semantics • Focus for the SWS research community? • Description, discovery, composition, invocation, mediation

8. WSMX • Mission • To develop an execution environment for dynamic discovery, selection, mediation and invocation of Semantic Web Services • To be the middleware for Semantic Web Services • Conceptual model provided by WSMO • Ontology, Goal, Service, Mediator • Describe concepts from perspectives of both the requester and provider • Multiple execution semantics possible • For example, discovery or mediation only.

9. WSM* Family SemanticWeb Services WSMO: Conceptual Model WSML: Language WSMX: Architecture & Ref. Implementation

10. WSM* Family SemanticWeb Services WSMO: Conceptual Model Ontology WSML: Language Syntax & semantics WSMX: Architecture & Ref. Implementation Event-basedFramework Discovery Composition Invocation Mediation

11. WSMX • Available functionality • Backend adaptors • Accept and parse WSML messages • Store services, goals, mediators, ontologies • Simple discovery • Data mediation • Simple invocation • Functionality in development • Choreography component • WSMO Editor

12. Grid Overview • What is the application area for Grid? • Traditionally: computational grids • Potential: for business processes and SOA • IBM dream of computing on demand • WS and Grid • Globus toolkit takes advantage of widely accepted WS standards to implements its services • WS Addressing to make stateful services • Research community focus for Grid? • Resource management, security, high throughput, managed availability amongst others

13. What is a Grid? Evolving definition … • ’98: hardware and software infrastructure that provides dependable, consistent and pervasive access to high-end computational capabilities • ’00: coordinated resource sharing and problem solving in dynamic, multi-institutional organizations • ’02 checklist. A grid: • Coordinates resources that are not subject to centralized control, … • … using standard, open, general-purpose protocols and interfaces, … • … to deliver non-trivial qualities of service.

14. What Kinds of Applications? • Computation intensive • Interactive simulation (climate modeling) • Very large-scale simulation and analysis (galaxy formation, gravity waves, battlefield simulation) • Engineering (parameter studies, linked component models) • Data intensive • Experimental data analysis (high-energy physics) • Image and sensor analysis (astronomy, climate study, etc.) • Distributed collaboration • Online instrumentation (microscopes, x-ray devices, etc.) • Remote visualization (biology) • Engineering (large-scale structural testing, chemical engineering) • Business grids

15. What Types of Problems? • Security: • Hard to keep track of authentication data across institutions • Monitoring/discovery: • Hard to monitor system and app. status across institutions • Accessing computing/processing power • Too many ways to submit jobs • Moving data • Too many ways to store & access files and data • Managing data • Too many ways to keep track of data • Managing systems • System packaging/distribution

16. Grid and Web Services Convergence The definition of WSRF means that the Grid and Web services communities can move forward on a common base.

17. What Is the Globus Toolkit? • A Grid development environment • Develop new OGSA-compliant Web Services • Develop applications using Java or C/C++ Grid APIs • Secure applications using basic security mechanisms • A set of basic Grid services • Job submission/management • File transfer (individual, queued) • Database access • Data management (replication, metadata) • Monitoring/Indexing system information • Tools and Examples • The prerequisites for many Grid community tools

18. Globus Toolkit and Web Services • Web services have major advantages for Grids • Standard interface definition • Good commercial tooling (eventually) • However, not a silver bullet or complete solution … • Globus Alliance working to advance specs … • OGSI/WSRF, OGSA-DAI, WS-Agreement, etc. • WSDL 2.0, WSDM, WS-Security, etc. • … and implementation • Implementations of low-level specifications • WS-based interface to existing services • New WS-based services

19. WU GridFTP JAVA WS Core (OGSI) Pre-WS GRAM MDS2 GSI WS GRAM (OGSI) RFT (OGSI) OGSI C Bindings WS-Index (OGSI) WS-Security RLS OGSI Python Bindings (contributed) CAS (OGSI) OGSI-DAI SimpleCA pyGlobus (contributed) XIO Security Data Management Resource Management Information Services WS Core Components in Globus Toolkit 3.2

20. Deployment View

21. Theory -> Practice

22. GT3 Security Infrastructure (GSI) MJFS OGSI/WSRF

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

24. WSMX and Globus – Common • Both distributed computing systems • Both use WS standards as foundation technology • WSDL • SOAP • Both provide approaches to B2B integration • Despite current differences in focus, both face the same kind of problems • Semantics – service discovery • Service availability management • Security • Service Level Agreements (SLA)

25. WSMX and Globus – Differences • Different research communities • Different functionalities offered right now • WSMX provides SOA event driven framework • Globus is a loose toolkit • WSMX addresses service description, discovery, invocation and mediation at data and process • Globus provides resource life-cycle mgt, soft-state, real-time service information, service notification interface, security including delegated security, access to system data and files

26. WSM* Family SemanticWeb Services WSMO: Conceptual Model WSML: Language WSMX: Architecture & Ref. Implementation

27. WSM* Family SemanticWeb Services WSMO: Conceptual Model Ontology WSML: Language Syntax & semantics WSMX: Architecture & Ref. Implementation Event-basedFramework Discovery Composition Invocation Mediation

28. WSM* and Globus SemanticWeb Services Globus WSMO: Conceptual Model Ontologies WSML: Language Syntax WSMX: Architecture & Ref. Implementation Event-basedFramework Discovery Composition Invocation Mediation

29. WSM* and Globus SemanticWeb Services Globus WSRF WSMO: Conceptual Model WS-Addressing Ontologies WSML: Language Syntax SLA Mgt WSMX: Architecture & Ref. Implementation ServiceFactory Monitoring Soft-statemgt Event-basedFramework Discovery Composition ResourceMgt Security Invocation Mediation

30. WSMX and Globus – Do the fit? • Complementary or competitive • complementary • WSMX in Globus – or – Globus in WSMX • Neither – they address different functionalities • GT3 is implemented as a set of WS • For GT3 services to be available to WSMX, they need to be described in terms of WSMO • A GT3 client could choose to use WSMX as its discovery and execution engine while using the GT3 core services for resource mgt, security etc.

31. GT1 Grid GT2 OGSI Started far apart in apps & tech Have been converging WSRF WSDL 2, WSDM WSDL, WS-* Web HTTP Convergence ofGrid and Web Services • The definition of WSRF means that Grid and Web • communities can move forward on a common base • Support from major WS vendors, especially in management space: e.g. HP, IBM

32. Scenarios • Stock exchange statistics example • Scenario 1 • WSMX only for discovery • Scenario 2 • WSMX for discovery choreography and invocation

33. Conclusion • WSMX is an execution environment for SWS has a particular focus • Description, discovery, mediation, invocation, etc. • Globus is a toolkit providing various services that have immediate relevance for computational grids but growing relevance for business process integration • Both technologies are based on WS standards  facilitates interoperability • Little overlap between service offered