Presentation on theme: "Grid Architectures Steve Fisher/RAL GridPP, Edinburgh, November 2001."— Presentation transcript:
Grid Architectures Steve Fisher/RAL firstname.lastname@example.org GridPP, Edinburgh, November 2001
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL2 GGF - GPA I will be talking about the GGF Grid Protocol Architecture Working Group (http://www- itg.lbl.gov/GPA/)http://www- itg.lbl.gov/GPA/ –It is THE body to address standardisation of Grid Architectures –Chaired by Bill Johnston, Ian Foster and Reagan Moore –Two meetings so far Some of my slides derived from: –Bill Johnstons summary of GGF3 –and talks given there
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL3 Revised Proposed Charter The role of the Grid Protocol Architecture Working Group is to provide a conceptual framework for discussing the interrelationships, completeness, and minimality of the protocol approach to Grid services that is coming out of GGF The GPA will initially have five work areas: –produce an initial overview architecture to provide a starting point –explore the issue of different views of Grids –establish a methodology for representing the architecture –document the relationship of the the GGF architecture to other, existing, Grid-like architectures from outside GGF –evolve the initial overview architecture
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL4 Issues How do we answer the question what is a minimal set of Grid functions/protocols and how do we represent their inter-relationships? –characterise existing Gird protocols and interfaces and where GF WGs are currently working –look at existing architecture representations –Is UML suitable? Important to make sure that we are considering a sufficient set of services –examine what is currently bring done, or trying to be done, with Grids as the first approach There are different views of Grids –will these all admit to a common architecture? –If not, how do they differ?
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL5 Is UML suitable? What is architecture? –divisions into sub-systems –and the control model Often represented by simple box and line diagrams –Just show the sub-systems and main communication –Easy to understand UML Component and Deployment diagrams –More notation More explicit Harder for the casual reader
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL6 UML Component Diagram Component Dependency
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL7 UML Deployment Diagram Shows software deployed in hardware Node Connection
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL8 More UML UML also offers class diagrams to expose an API And Sequence and Collaboration diagrams to show possible interactions of objects Oxford have EPSRC funding to work with DataGrid – they will be looking at the applicability of UML for architecture Will facilitate more UK input to GGF
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL9 Are all Grids the same? Grids originated for supercomputers Knowledge Grids? Grid and the web DataGrid(s)
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL10 Knowledge Based Data Grids The knowledge based Data Grid (Moore) grew out of the need to manage very complex data and inter-relationships –Data objects from many sources e.g. different imaging modalities and anatomical data about the brain –Information about the data objects (attributes) –Knowledge about the data objects (relationships) e.g. how do the observations from the different types of imaging - e.g. compositional and metabolic – relate to anatomical structure
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL11 Use Cases NIH Biomedical Informatics Research Network –Federation of multiple existing digital libraries –Support information discovery, data access, data movement, and data analysis on distributed resources NARA Persistent Archive –Build a data collection that maintains authenticity of digital data while technology evolves –Support information discovery, data access, and migration to new data encoding standards
Attributes Semantics Knowledge Information Data Ingest Services ManagementAccess Services (Model-based Access) (Data Handling System) MCAT/HDF Grids XML DTD SDLIP XTM DTD Rules - KQL Information Repository Attribute- based Query Feature-based Query Knowledge or Topic-Based Query / Browse Knowledge Repository for Rules Relationships Between Concepts Fields Containers Folders Storage (Replicas, Persistent IDs) National Partnership for Advanced Computational Infrastructure Knowledge-Based Data Grids
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL13 Queries across data sources from a common interface @SENSELAB: X1 := select output from parallel fiber ; @MEDIATOR: X2 := hang off X1 from Domain Map; @MEDIATOR: X3 := subregion-closure(X2); @NCMIR: X4 := select PROT-data(X3, Ryanodine Receptors); @MEDIATOR: X5 := compute aggregate(X4); "How does the parallel fiber output relate to the distribution of Ryanodine Receptors?" Sources: NCMIR UCSD / Yale Senselab KIND Mediator
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL14 Web Services Grids Web based Grid services represent the intersection of the commercial Web services (e.g. IBMs WebSphere) and scientific and engineering oriented Grid services Also driven by the desire to use commercial tools to facilitate the construction of portals – application / domain specific frameworks that present packaged Grid services to Grid end-users (e.g. scientists and engineers)
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL15 So are they different? I have seen nothing so far to distinguish these other types of grids –They may have some distinguishing services –But no fundamental differences
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL16 Layering A general layering approach based on increasing levels of abstraction (abstract machines) is useful for conceptualizing the services
=Globus service Problem Solving Environment Applications and Supporting Tools Tools to implement the human interfaces, and the mechanisms to express, organize, and manage the workflow of solving a problem Application Development Support Grid Common Services Local Resource s Application Codes Visualization Toolkits Collaboration Toolkits Instrument Management Toolkits Data Publication and Subscription Toolkits Grid Enabled Libraries Globus MPICORBACondorJava/JiniPRE/CORBAOLE/DCOM Grid Information Service Uniform Resource Access BrokeringGlobal Queuing Global Event Services Co- Scheduling Data Cataloguing Uniform Data Access Collaboration and Remote Instrument Services Communication Services Authentication Authorization Security Services Auditing / Accounting Fault Management Monitoring Communication Services Resource Manager CPUs Resource Manager Tertiary Storage Resource Manager On-Line Storage Resource Manager Scientific Instruments Resource Manager Network Monitors Resource Manager Highspeed Data Transport Resource Manager QoS collective resource fabric layers of increasing abstraction - taxonomy #1 (Johnston)
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL18 EDG Architecture (as circulated initially to GPA)
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL19 Comments on layering things in each layer use only those in same layer and below –BUT not only immediately below –i.e not an abstract machine model
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL20 EDG Architecture another view Collective Services Information & Monitoring Replica Manager Grid Scheduler Grid Application Layer Job Management Local Application Local Database Fabric services Configuration Management Configuration Management Node Installation & Management Node Installation & Management Monitoring and Fault Tolerance Monitoring and Fault Tolerance Resource Management Fabric Storage Management Fabric Storage Management Grid Fabric Local Computing Grid Data Management Metadata Management Object to File Mapper Underlying Grid Services Computing Element Services Authorisation, Authentication and Accounting Replica Catalog Storage Element Services SQL Database Service Service Index Slightly simplified version of a WP2 diagram
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL21 Comments on layering This diagram has layers referencing BOTH ways When you look at each service you rarely find a clean layering – especially as the services get more complex, they are implemented using many other services both above and below
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL22 Layering and client server It was a principle EDG defined early on that all services should be available – only restricted by policies. –Good anyone can compose new services easily –Bad policies are needed to keep things under control – e.g. modifying replica catalog Should we: –just say that these constraints are policy issues and not represent them in the architecture? –Or try to come up with a simple representation of constraints for the conceptual representation of the Grid architecture?
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL23 Set of Services EDG Architecture has been criticised as just a set of services This may be good however –Provided that we demonstrate that they are sufficient e.g. sequence or collaboration diagrams (UML) For each EDG service we define upon what services it depends –IS IT ARCHITECTURE OR IMPLEMENTATION? Architecture from EDG middleware standpoint But implementation from a user standpoint
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL24 Service and Protocols To a client the protocol is uninteresting: –only the API –service could be local Need to allow for migration to and/or integration of new services A service could respond to >1 protocol A service could support >1 security mechanism Makes it easy to introduce new services
Edinburgh, November 2001Grid architectures - Steve Fisher/RAL25 Need for openness We should have lots of overlapping services and use the ones we want – typically a VO would choose –Though a lot is dictated by the RB Do we want InterGrid or OpenGrid? We dont want to tie ourselves down in a fast moving world Need to watch industry –IBM –SUN –Microsoft SOAP, WSDL JINI, UDDI.NET, Passport etc.
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