Grid Computing & Web Services: A Natural Partnership

1. Grid Computing & Web Services:A Natural Partnership Dave Angulo Department of Computer Science The University of Chicago and Mathematics and Computer Science Division Argonne National Laboratory Ian Foster Mathematics and Computer Science Division Argonne National Laboratory and Department of Computer Science The University of Chicago Address of Poznan Supercomputing & Networking Center Poznan, Poland February 7, 2002

2. Partial Acknowledgements • Open Grid Services Architecture work is performed by • Ian Foster, Globus Co-PI @ Argonne/UofC • Carl Kesselman, Globus Co-PI @ USC/ISI • Steve Tuecke, Globus Toolkit Architect @ANL • Jeff Nick, Steve Graham, Jeff Frey @ IBM • Globus Toolkit R&D involves many fine scientists & engineers at ANL, USC/ISI, and elsewhere (see www.globus.org) • Strong collaborations with many outstanding EU, UK, US Grid projects • Support from DOE, NASA, NSF, Microsoft

3. Partial Acknowledgements • Globus ToolkitTM • R&D involves • many fine scientists & engineers at ANL/UofC, USC/ISI, and elsewhere (see www.globus.org) • Led by • Ian Foster @ Argonne/UofC • Carl Kesselman @ USC/ISI • Open Grid Services Architecture work performed by • Ian Foster, Globus Co-PI @ Argonne/UofC • Carl Kesselman, Globus Co-PI @ USC/ISI • Steve Tuecke, Globus Toolkit Architect @ANL • Jeff Nick, Steve Graham, Jeff Frey @ IBM • Strong collaborations with many outstanding EU, UK, US Grid projects • Support from DOE, NASA, NSF, Microsoft, IBM

4. Grid Computing

5. The Grid Problem Resource sharing & coordinated problem solving in dynamic, multi-institutional virtual organizations

6. Why Grids? • A biochemist exploits 10,000 computers to screen 100,000 compounds in an hour • 1,000 physicists worldwide pool resources for petaflop analyses of petabytes of data • Civil engineers collaborate to design, execute, & analyze shake table experiments • Climate scientists visualize, annotate, & analyze terabyte simulation datasets • A home user invokes architectural design functions at an application service provider • An application service provider purchases cycles from compute cycle providers

7. Elements of the Problem • Resource sharing • Computers, storage, sensors, networks, … • Sharing always conditional: issues of trust, policy, payment, … • Coordinated problem solving • Beyond client-server: distributed data analysis, computation, … • Dynamic, multi-institutional virtual orgs • Community overlays on classic org structures • Large or small, static or dynamic

8. Grids: Why Now? • Moore’s law improvements in computing produce highly functional end systems • The Internet and burgeoning wired and wireless provide universal connectivity • Network exponentials produce dramatic changes in geometry and geography

9. Grids: Why Now? • Moore’s law improvements in computing produce highly functional endsystems • The Internet and burgeoning wired and wireless provide universal connectivity • Network exponentials produce dramatic changes in geometry and geography • 9-month doubling: double Moore’s law! • 1986-2001: x340,000; 2001-2010: x4000?

10. The Grid World: Current Status • Dozens of major Grid projects in scientific & technical computing/research & education • Deployment, application, technology • Considerable consensus on key concepts and technologies • Globus Toolkit™ has emerged as de facto standard for major protocols & services • Global Grid Forum has emerged as a significant force • And first “Grid” proposals at IETF

11. g g g g g g Selected Major Grid Projects New New

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13. g g g g g g Selected Major Grid Projects New New

14. g g Selected Major Grid Projects New New Also many technology R&D projects: e.g., Condor, NetSolve, Ninf, NWS See also www.gridforum.org

15. ~PBytes/sec ~100 MBytes/sec Offline Processor Farm ~20 TIPS There is a “bunch crossing” every 25 nsecs. There are 100 “triggers” per second Each triggered event is ~1 MByte in size ~100 MBytes/sec Online System Tier 0 CERN Computer Centre ~622 Mbits/sec or Air Freight (deprecated) Tier 1 FermiLab ~4 TIPS France Regional Centre Germany Regional Centre Italy Regional Centre ~622 Mbits/sec Tier 2 Tier2 Centre ~1 TIPS Caltech ~1 TIPS Tier2 Centre ~1 TIPS Tier2 Centre ~1 TIPS Tier2 Centre ~1 TIPS HPSS HPSS HPSS HPSS HPSS ~622 Mbits/sec Institute ~0.25TIPS Institute Institute Institute Physics data cache ~1 MBytes/sec 1 TIPS is approximately 25,000 SpecInt95 equivalents Physicists work on analysis “channels”. Each institute will have ~10 physicists working on one or more channels; data for these channels should be cached by the institute server Pentium II 300 MHz Pentium II 300 MHz Pentium II 300 MHz Pentium II 300 MHz Tier 4 Physicist workstations Grid Communities & Applications:Data Grids for High Energy Physics www.griphyn.org www.ppdg.net www.eu-datagrid.org

16. Grid Communities and Applications:Mathematicians Solve NUG30 • Community=an informal collaboration of mathematicians and computer scientists • Condor-G delivers 3.46E8 CPU seconds in 7 days (peak 1009 processors) in U.S. and Italy (8 sites) • Solves NUG30 quadratic assignment problem • 14,5,28,24,1,3,16,15, • 10,9,21,2,4,29,25,22, • 13,26,17,30,6,20,19, • 8,18,7,27,12,11,23 www.mcs.anl.gov/metaneos: Argonne, Iowa, NWU, Wisconsin

17. Grid Communities and Applications:Network for Earthquake Eng. Simulation • NEESgrid: national infrastructure to couple earthquake engineers with experimental facilities, databases, computers, & each other • On-demand access to experiments, data streams, computing, archives, collaboration NEESgrid: Argonne, Michigan, NCSA, UIUC, USC www.neesgrid.org

18. The 13.6 TF TeraGrid:Computing at 40 Gb/s Site Resources Site Resources 26 HPSS HPSS 4 24 External Networks External Networks 8 5 Caltech Argonne External Networks External Networks NCSA/PACI 8 TF 240 TB SDSC 4.1 TF 225 TB Site Resources Site Resources HPSS UniTree TeraGrid/DTF: NCSA, SDSC, Caltech, Argonne www.teragrid.org

19. Tier0/1 facility Tier2 facility Tier3 facility 10+ Gbps link 2.5 Gbps link 622 Mbps link Other link Intl. Virtual Data Grid Lab. www.ivdgl.org

20. Presenter mic Presenter camera Ambient mic (tabletop) Audience camera Access Grid • Collaborative work among large groups • ~50 sites worldwide • Use Grid services for discovery, security • www.scglobal.org Access Grid: Argonne, others www.accessgrid.org

21. Grid Architecture & Globus Toolkit™ • The question: • What is needed for resource sharing & coordinated problem solving in dynamic virtual organizations (VOs)? • The answer: • Major issues identified: membership, resource discovery & access, …, … • Grid architecture captures core elements, emphasizing pre-eminent role of protocols • Globus Toolkit™ has emerged as de facto standard for major protocols & services

22. The Critical Role of Protocols • Need for interoperability when different groups want to share resources • E.g., IP lets me talk to your computer, but how do we establish & maintain sharing? • How do I discover, authenticate, authorize, describe what I want to do, etc., etc.? • Need for shared infrastructure services to avoid repeated development, installation, e.g. • One port/service for remote access to computing, not one per tool/application • X.509 enables sharing of Certificate Authorities

23. Application Application Internet Protocol Architecture “Coordinating multiple resources”: ubiquitous infrastructure services, app-specific distributed services Collective “Sharing single resources”: negotiating access, controlling use Resource “Talking to things”: communication (Internet protocols) & security Connectivity Transport Internet “Controlling things locally”: Access to, & control of, resources Fabric Link Grid Architecture For more info: www.globus.org/research/papers/anatomy.pdf

24. Globus Project and Toolkit • Globus Project™ • R&D project at ANL, U.Chicago, USC/ISI • Emphasis on identifying and defining core protocols and services • O(40) researchers & developers • Globus Toolkit™ • A major product of the Globus Project • Open source software: reference implementation of core protocols & services • Growing open source developer community

25. Globus Toolkit: Evaluation (1) • Good technical solutions for key problems, e.g. • Authentication and authorization • Resource discovery and monitoring • Reliable remote service invocation • High-performance remote data access • This + good engineering is enabling progress • Good quality reference implementation, multi-language support, interfaces to many systems, large user base, industrial support • Growing community code base built on tools

26. Globus Toolkit: Evaluation (2) • Protocol deficiencies, e.g. • Heterogeneous basis: HTTP, LDAP, FTP • No standard means of error propagation • Significant missing functionality, e.g. • Databases, sensors, instruments • Programming tools: workflow, … • Virtualization of end systems (hosting envs.) • Little work on total system properties, e.g. • Dependability, end-to-end QoS, … • Reasoning about system properties

27. “Web Services” • Increasingly popular standards-based framework for accessing network applications • W3C standardization; Microsoft, IBM, Sun, others • WSDL: Web Services Description Language • Interface Definition Language for Web services • SOAP: Simple Object Access Protocol • XML-based RPC protocol; common WSDL target • WS-Inspection (WSIL) • Conventions for locating service descriptions • UDDI: Universal Desc., Discovery, & Integration • Directory for Web services

28. Transient Service Instances • “Web services” address discovery & invocation of persistent services • In Grids, must also support transient service instances, created/destroyed dynamically • E.g., to manage eBusiness workflow, video conference, or distributed data analysis • Significant implications for how services are managed, named, discovered, and used • In fact, much of our work is concerned with the management of service instances

29. Open Grid Services Architecture • Service orientation to virtualize resources • From Web services: • Standard interface definition mechanisms: multiple protocol bindings, multiple implementations, local/remote transparency • Building on Globus Toolkit: • The Grid service defines standard semantics for service interactions • Factory, registry, and mapper services • Reliable and secure transport • Multiple hosting targets: J2EE, .NET, “C”, etc.

30. OGSA Service Model • System comprises (a typically few) persistent services & (potentially many) transient services • All services adhere to specified Grid service interfaces and behaviors • Reliable invocation, lifetime management, discovery, authorization, notification, upgradeability, concurrency, manageability • Interfaces for managing Grid service instances • Factory, registry, mapper • Heavily leverage Globus Toolkit technology => Reliable secure mgmt of distributed state

31. The Grid Service • A (potentially transient) Web service with specified interfaces & behaviors, including • Creation (Factory) • Global naming (GSH) & references (GSR) • Lifetime management • Registration & Discovery • Authorization • Notification • Concurrency • Manageability

32. Factory • A Grid service with Factory interface can be requested to create a new Grid service instance • Reliable creation (once-and-only-once) • Create operation can be extended to accept Grid-service-specific creation parameters • Returns a Grid Service Handle (GSH) • A globally unique URL • Uniquely identifies the instance for all time • Based on name of a home mapper service

33. Mapper • A GSH is a stable name for a Grid service, but does not allow client to actually communicate with the Grid service • A Grid Service Reference (GSR) is a WSDL document that describes how to communicate with the Grid service • Contains protocol binding, network address, … • May expire (I.e. GSR information may change) • The Mapper interface allows a client to map from a GSH to a GSR • http get on GSH also returns a GSR

34. Lifetime Management • GS instances created by factory or manually; destroyed explicitly or via soft state • Negotiation of initial lifetime with Factory • SoftStateDestruction interface supports • GetTerminationTime message for inquiry • Notification interface also allows for lifetime notification • SetTerminationTime message for keepalive • Soft state lifetime management avoids • Explicit client teardown of complex state • Resource “leaks” in hosting environments • ExplicitDestruction interface also available

35. Discovery • A Grid service instance may maintain a set of service information • XML fragments encapsulated in standard <name, type, TTL-info> containers • Discovery interface allows clients to query the Grid service instance for this information • Query operation, plus supporting operations • Extensible query language support • See also Notification interfaces • Allows notification of service existence and about service information

36. Registry • The Registry interface may be used to discover a set of Grid service instances • Returns a WS-Inspection document containing the GSHs of a set of Grid services • Also returns policy associated with the set • Also available through Discovery interface • The RegistryManagement interface allows for soft-state registration of a Grid service • A set of Grid services can periodically register their GSHs into a registry service, to allow for discovery of services in that set

37. Authorization • Protocol binding handles authentication during invocation of Grid service operation • Gives service URI for authenticated subject • Grid service instance should apply authorization policy on all operations • May be site-, service-, instance-, etc., specific • OGSA defines standard interfaces for remote management of access control policy • OperationAuthorizationManagement • SubjectEquivalency

38. Notification Interfaces • NotificationSource for client subscription • One or more notification generators • Generates notification message of a specific type • Typed interest statements: E.g., Filters, topics, … • Supports messaging services, 3rd party filter services, … • Soft state subscription to a generator • NotificationSink for asynchronous delivery of notification messages • A wide variety of uses are possible • E.g. Dynamic discovery/registry services, monitoring, application error notification, …

39. Use of Web Services (1) • A Grid service interface is a WSDL portType • A Grid servicedefinition is a WSDL extension (serviceType) containing: • A set of one or more portTypes supported by the service • portType & serviceType compatibility statements, to support upgradability • For discovery of compatible services when interfaces are upgraded • Implementation version information

40. Use of Web Services (2) • A GSR is a WSDL document with extensions: • Extension to service element to reference serviceType • Service element extensions to carry the GSH, and the expiration time of the GSR • A GSH is an URL, with the following properties: • Globally unique for all time • http get on GSH + “.wsdl” returns GSR • Can derive GSH to Mapper from it • Registry returns WS-Inspection documents

41. (a) Simple Hosting Environment (b) Virtual Hosting Environment (c) Compound Services Registry Registry E2E Factory Factory E2E Reg Service Service Factory ... ... H2R H2R E2E H2R Factory Factory Mapper Mapper Mapper ... ... ... Service Service Service Service Service Service E2E S E2E S E2E S F F R R R R F F 1 2 M M M M F F S S S S S S S S S S S S Using OGSAto Construct Grid Environments In each case, Registry handle is effectively the unique name for the virtual organization.

42. OGSA and the Globus Toolkit • Technically, OGSA enables • Refactoring of protocols (GRAM, MDS-2, etc.)—while preserving all GT concepts/features! • Integration with hosting environments: simplifying components, distribution, etc. • Greatly expanded standard service set • Pragmatically, we are proceeding as follows • Develop open source OGSA implementation • Globus Toolkit 3.0; supports Globus Toolkit 2.0 APIs • Partnerships for service development • Also expect commercial value-adds

43. Globus Toolkit Refactoring • Grid Security Infrastructure (GSI) • Used in Grid service network protocol bindings • Meta Directory Service 2 (MDS-2) • Native part of each Grid service: • Discovery, Registry, RegistryManagement, Notification • Grid Resource Allocation & Mngt (GRAM) • Gatekeeper -> Factory for job mgr instances • GridFTP • Refactor control channel protocol • Other services refactored to used Grid services

44. Timeline • Summer 2002 – Alpha releases of high-level Grid Services • Late 2002, Early 2003 – Alpha release of new core Grid Services (MDS, GRAM, GridFTP)

45. Migration Paths • Globus ToolkitTM evolutionary in nature • Toolkit implementation may change • Underlying model of Grid Computing remains the same • Capabilities of future Toolkits will be superset of today’s Toolkit • New implementations integrate better with existing commodity technologies • In cases of radical departure from current implementations, migration paths will be provided • possibly maintain compatible APIs • possibly create gateways to today’s protocols

46. Summary:Evolution of Grid Technologies • Initial exploration (1996-1999; Globus 1.0) • Extensive appln experiments; core protocols • Data Grids (1999-??; Globus 2.0+) • Large-scale data management and analysis • Open Grid Services Architecture (2001-??, Globus 3.0) • Integration w/ Web services, hosting environments, resource virtualization • Databases, higher-level services • Radically scalable systems (2003-??) • Sensors, wireless, ubiquitous computing

47. Summary • The Grid problem: Resource sharing & coordinated problem solving in dynamic, multi-institutional virtual organizations • Grid architecture: Protocol, service definition for interoperability & resource sharing • Globus Toolkit a source of protocol and API definitions—and reference implementations • And many projects applying Grid concepts (& Globus technologies) to important problems • Open Grid Services Architecture represents (we hope!) next step in evolution

48. For More Information • The Globus Project™ • www.globus.org • Grid architecture • www.globus.org/research/papers/anatomy.pdf • Open Grid Services Architecture • www.globus.org/research/papers/ogsa.pdf • www.globus.org/research/papers/gsspec.pdf