1. Designing and Building Grid Services GGF9 Chicago October 8, 2003 Organizers: Ian Foster, Marty Humphrey, Kate Keahey, Norman Paton, David Snelling

2. Open Grid Services Architecture Service-oriented architecture –Key to virtualization, discovery, composition, local-remote transparency Leverage industry standards –Internet, Web services Distributed service management –A “component model for Web services” A framework for the definition of composable, interoperable services “The Physiology of the Grid: An Open Grid Services Architecture for Distributed Systems Integration”, Foster, Kesselman, Nick, Tuecke, 2002

3. More Specifically A standard substrate: the Grid service –OGSI = Open Grid Service Infrastructure –Web services interfaces and behaviors that address key distributed system issues … supports standard service specifications –Resource mgt, dbms, workflow, security, … –Target of current & planned GGF efforts –OGSA wg defines “OGSA compliance” … and arbitrary application-specific services based on these & other definitions

4. OGSI Specification Defines WSDL conventions and extensions –For describing and naming services –Working with W3C WSDL working group to drive OGSI extensions into WSDL 1.2 Defines fundamental interfaces (using extended WSDL) and behaviors that define a Grid Service –A unifying framework for interoperability & establishment of total system properties http://www.ggf.org/ogsi-wg

5. OGSI: Standard Web Services Interfaces & Behaviors 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. Service registry Service requestor (e.g. user application) Service factory Create Service Grid Service Handle Resource allocation Service instances Register Service Service discovery Interactions standardized using WSDL Service data Keep-alives Notifications Service invocation Authentication & authorization are applied to all requests Open Grid Services Infrastructure (OGSI)

7. OGSI Implementations Globus Toolkit version 3.0 (Java, C client) U Virginia OGSI.NET (.NET) LBNL pyGlobus (Python) U Edinburgh (.NET) U Manchester (PERL) Fujitsu Unicore (Java)

8. Web Services: Basic Functionality OGSA Open Grid Services Architecture OGSI: Interface to Grid Infrastructure Applications in Problem Domain X Compute, Data & Storage Resources Distributed Application & Integration Technology for Problem Domain X Users in Problem Domain X Virtual Integration Architecture Generic Virtual Service Access and Integration Layer - Structured Data Integration Structured Data Access Structured Data RelationalXMLSemi-structured Transformation Registry Job Submission Data TransportResource Usage Banking BrokeringWorkflow Authorisation

9. Issues Design methodologies & principles Tooling Application requirements Benchmarking Reuse Debugging Service orchestration Scalability Interoperability

10. Issues What makes for a good Grid service (or a bad service)? How to organize service data? How to factor problems into services? Views on service lifetime and granularity? Experiences with building Grid services? How to teach Grid service design?

11. Workshop 20 position papers received, 12 selected for presentation by organizers Program emphasizes discussion –13:00-15:00 – Intro, 4 talks –15:30-17:00 – 4 talks –17:30-19:00 – 4 talks –19:00-19:30 – Discussion and wrapup

12. Grid Services & Resource Mgmt (Chair: Dave Snelling) C. Eric Wu, Design and Implementation of Manageability Services for Common Management Model Kate Keahey, Matei Ripeanu, Karl Doering: Dynamic Creation and Management of Runtime Environments in the Grid Lavayna Ramakrishnan: Policy Management for OGSA Applications as Grid Services Jim Pruyne, Vijay Machiraju: Quertermaster: Grid Services for Data Centre Resource Reservation

13. Data Intensive Grid Services (Chair: Marty Humphrey) Mario Antonioletti, et al.: Experiences of Designing and Implementing Grid Database Services in the OGSA-DAI Project Nedim Alpdemir, et al.: An Experience Report on Designing and Building OGSA-DQP: A Service- Based Distributed Query Processor for the Grid Savas Parastidis, Paul Watson: Experiences with Migrating myGrid Web Services to Grid Services William Allcock, Ravi Madduri: Lessons learned producing an OGSI compliant Reliable File Transfer System.

14. Service Deployment and Control (Chair: Kate Keahey) Glen Wasson and Marty Humphrey: Attribute- Based Programming for Grid Services Dennis Gannon, et al.: Building Grid Services for User Portals Deepti Kodeboyina and Beth Plale: Experiences with OGSA-DAI: Portlet Access and Benchmark Laura Pearlman, et al.: Experiences using Grid Services for Control

15. Questions Shareability of service instances –Are services designed to support the interaction of a single requester or shared by many? Lifetime and granularity of services –Does a service instance represent a single task, several at a time, or several in sequence? Scope of use of service instance model –Were situations encountered in which it was not clear what to represent as service instances, and how was this resolved? Representing stateful interactions –Sometimes a context approach (e.g. as in WS- transaction) might seem more suitable than using service instances. How were such situations addressed?

16. Questions, contd. Design of SDEs –There are issues relating, for example, to the granularity of SDEs, materialisation vs computation, etc. Were such issues encountered, and if so, how were they resolved? Performance –Were design decisions made because of potential performance implications? What were these, and how were they resolved? Security –Were design decisions made because of potential security implications? What were these, and how were they resolved? Interfaces and operation extensibility –Any issues with the OGSI interfaces? Extensibility?