Declarative Internet-scale Computing CoreGRID WP3 - Barcelona

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Irma Manning
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1 Declarative Internet-scale Computing CoreGRID WP3 - Barcelona Savas Parastatidis School of Computing Science University of Newcastle upon Tyne savas@parastatidis.name blog/web:

2 What is the Grid? Neo, the Grid is everything you would like it to be IBM: on-demand computing HP: utility computing Microsoft: seamless computing ORACLE: 10g Sun: Sun Grid Engine Intel: or whatever makes money HPC community: Interconnected (super)computers More Virtual organisations, Integration of distributed resources, Universal computer, Interconnection technologies for supercomputers Or if you are a researcher/academic A new set of interesting problems in distributed computing applied at a large scale Service-orientation, Computational resources, Data resources, Integration, Protocol, Policies, Contracts, Service-level agreements, QoS, etc. etc. etc. 2

3 What Grid? The Newcastle team: Internet-scale, service-oriented distributed computing (using Web Services as the infrastructure) 3

4 WS-GAF Motivation Milestones OGSI release WS-GAF paper WS-RF release Community concerns over WS specification instability Focus on creating applications and demonstrating ideas Internet-scale applications Distinction between production and experimental deployments Ideas and approach are now part of the UK e-science Strategy whitepaper for a Web Services-based National Grid infrastructure 4

5 WS-GAF Simplicity and Minimalism Composability No changes in the semantics/characteristics of Web Services Synergy with existing WS specifications and practices Avoid effort involved in influencing WS community Avoid risk associated with not being able to influence WS community Focus from the low-level networking to the more important highlevel services (application-domain specific) Supporting tools Do not need anything other than existing industry and open-source provided WS tools and platforms (e.g., ASP.NET, Axis, etc.) Education materials Industry investment Performance and scalability Encourages large granularity, loose coupling (richer, fewer message exchanges) 5

6 WS-GAF Applications Needed to build Grid applications using Web Services in order to demonstrate claims Aims Define the characteristics of a typical Grid application Demonstrate the applicability of the WS-GAF approach in building Grid applications Learn from the challenges of constructing a truly global, distributed, scalable, loosely-coupled application Tools.NET 2.0 Beta 1 (now Beta 2) &.NET 1.1 VS.NET 2005 Beta 1 (now Beta 2) & VS.NET 2003 Web Services Enhancements 2.0 SP1 (now SP3) 6

7 Searching for White Dwarfs Jim Gray s SkyServer and Edinburgh s SuperCOSMOS archive Utilise computational resources Visualise 7

8 Logistics in Chemical Engineering VOs GOLD UK e-science pilot project Use RFIDs to identify bottles with chemicals Bottles may reside in larger containers Containers move between organisations Security/trust Databases continuous queries large amount of information 8

9 Lessons learned Asynchrony Hiding remoteness vs explicit messaging Data Ad-hoc model vs semantics/model integration Process Ad-hoc operation orchestration vs contract agreement Metadata Relational vs semantics/contracts Contracts Interfaces vs protocols 9

10 MEST and SSDL

Service Orientation Built around the concepts of service and message A service is the logical manifestation of some physical or logical resources (like databases, programs, devices, humans, etc.

11 Service Orientation Built around the concepts of service and message A service is the logical manifestation of some physical or logical resources (like databases, programs, devices, humans, etc.) and/or some application logic that is exposed to the network and A message is a unit of communication for exchanging information. All communication between services is facilitated through the exchange of messages Service-orientation helps architects achieve the following properties (but do not guarantee them) Scalability, encapsulation, maintenance, re-use, composability, loose coupling, etc. 11

12 Cluster 12

13 Intra-Organisation 13

14 Inter-Organisation 14

15 Service-orientation vs Resource-orientation Service-orientation Resource-orientation Object-orientation 15

16 Service-orientation Web Services 16

17 MEST Message Transfer (MEST) architectural style An architectural style for service-oriented applications Recognise the architectural benefits of REST but aims to be simpler and more flexible No concepts like client, server, consumer, rpc, method, operation, etc. Capture behaviour through models and make it available as part of the service description Dynamic agreements Protocol evolution 17

18 REST Resource Resource Resource Resource Resource 18

19 From REST to MEST behaviour endpoint Resource Service 19

SOAP Service Description Language SOAP-centric

the component model XInclude for modularisation

and protocols No need for articles like interface,

20 SOAP Service Description Language SOAP-centric WS-Addressing first class citizen XML Infoset as the component model XInclude for modularisation Protocol framework extensibility Focus on messages and protocols No need for articles like interface, inheritance, and operation

21 Components vs MEST Components Focus on Operations Interfaces Types Shared understanding Inheritance MEST Focus on Metadata Modelling Protocols Contracts Semantics Imperative? Declarative? Advantages Scalability De-coupling Focus on message-orientation Autonomy Versioning Interoperability & adoption Etc. Use SOAP 21

22 CoreGRID Primitive components: Services Definition of Composite Components: Orcestration, messageorientation Definition of interfaces: No interfaces, just protocols External references: Not required, everything is defined using WS specs Specification of Grid aspects: GGF high-level services specs (parallelism through asynchrony) 22

23 Summary Components are from the 90s :-) Services are the new components and they are cool! Service-orientation as an architectural paradigm for building Internet-scale applications Focus on messages Recognise the value of modelling, semantics, and metadata The Internet becomes the application platform Domain-specific languages are used to build applications for the Internet 23

Grid Services and the Globus Toolkit

Grid Services and the Globus Toolkit Lisa Childers childers@mcs.anl.gov The Globus Alliance Copyright (C) 2003 University of Chicago and The University of Southern California. All Rights Reserved. This