2004-11-174 From distributed resources … Present situation: cross-national projects users and resources in different domains separate access to each resource
2004-11-175 … to World Wide Grid Future: multinational projects resources location is irrelevant “plug-n-play” access to all the resources
2004-11-176 Grid history: users’ perspective Metacomputing is a decades old idea –Previous attempt, including Condor, failed to appeal to users Progress in commercial hardware has always been faster than in Open Source-like middleware easier to buy a bigger supercomputer/cluster –Globus Toolkit 1 was heading into oblivion in early 2000 Physicists in Europe and USA realized that the time (Y2K) for metacomputing is ripe –MONARC project (CERN) developed a multi- tiered model for distributed analysis of data –Particle Physics Data Grid (PPDG) and GriPhyN projects by US physicists started using Grid technologies –Globus was picked up by the CERN-lead EU DataGrid (EDG) project –EDG failed to satisfy user demands; many simpler solutions appeared, triggered by physicists: NorduGrid (Northern Europe and others) Grid3 (USA) GLite (EU, a prototype)
2004-11-1714 Characteristics of HEP computing Eventindependence Event independence –Data from each collision is processed independently: trivial parallelism –Mass of independent problems with no information exchange Massivedatastorage Massive data storage –Modest event size: 1 – 10 MB (although some are up to 1-2 GB) –Total is very large – Petabytes for each experiment Mostlyreadonly Mostly read only –Data never changed after recording to tertiary storage –But is read often! A tape is mounted at CERN every second! Resilience rather than ultimate reliability –Individual components should not bring down the whole system –Reschedule jobs on failed equipment Modestfloatingpointneeds Modest floating point needs –HEP computations involve decision making rather than calculation
2004-11-1715 Very demanding tasks Data-intensive tasks –Large datasets, large files –Lengthy processing times –Large memory consumption –High throughput is necessary Very distributed user base –Distributed computing resources of modest size –Produced and processed data are hence distributed, too –Issues of coordination, synchronization and authorization are outstanding HEP is by no means unique in its demands, but they are first, they are many, and they badly need it
2004-11-1716 Other applications Medical and biomedical: –Image processing (digital X-ray image analysis) –Simulation for radiation therapy –Protein folding Chemistry –Quantum –Organic –Polymer modelling Climate studies Space sciences Physics: –High Energy and other accelerator physics –Theoretical physics, lattice calculations of all sorts –Neutrino physics –Combustion Genomics Material sciences Even warfare
2004-11-1718 IT progress: some facts Network vs. computer performance: –Computer speed doubles every 18 months –Network speed doubles every 9 months 1986 to 2000: –Computers: 500 times faster –Networks: 340000 times faster 2001 to 2010 (projected): –Computers: 60 times faster –Networks: 4000 times faster Slide adapted from the Globus Alliance Bottom line: CPUs are fast enough; networks are very fast – gotta make use of it!
2004-11-1719 The Grid Paradigm Distributed supercomputer, based on commodity PCs and fast WAN Access to the great variety of resources by a single pass – certificate A possibility to manage distributed data in a synchronous manner A new commodity Supercomputer Workstation PC Farm The Grid Drainage Water Electricity Internet Grid Radio/TV
2004-11-1720 Wider scope: a Grid System A Grid system is a collection of distributed resources connected by a network Examples of Distributed Resources: Desktop Handheld hosts Devices with embedded processing resources such as digital cameras and phones Tera-scale supercomputers Slide adapted from A.Grimshaw
2004-11-1721 Characteristics of a generic Grid system Numerous Resources Ownership by Mutually Distrustful Organizations & Individuals Potentially Faulty Resources Different Security Requirements & Policies Required Resources are Heterogeneous Geographically Separated Different Resource Management Policies Connected by Heterogeneous, Multi-Level Networks Slide adapted from A.Grimshaw
2004-11-1722 Desktop Cycle Aggregation Desktop only United Devices, Entropia, Data Synapse Cluster & Departmental “Grids” Single owner, platform, domain, file system and location SUN SGE, Platform LSF, PBS Enterprise “Grids” Single enterprise; multiple owners, platforms, domains, file systems, locations, and security policies SUN SGE EE, Platform Multicluster Global Grids Multiple enterprises, owners, platforms, domains, file systems, locations, and security policies Legion, Avaki, Globus Graph borrowed from A.Grimshaw WARNING! Not everything that has “G” in the name is Grid! (SGE, Oracle 10g, Condor-G etc) Grid paradigm is overloaded
2004-11-1724 Globus: the toolkit provider The first and only provider of a Grid toolkit (libraries and API) –An academic research project in USA and now Europe –Free software, open code –Supports Grid testbeds since late 90’s Grid features: Heterogeneous Non-interactive Single logon Optimized file transfer protocol Information schema To do: Global resource management Data management User management, accounting To do: Global resource management Data management User management, accounting
2004-11-1725 Gatekeeper (factory) Reporter (registry + discovery) User process #2 Proxy #2 Create process Register User process #1 Proxy Authenticate & create proxy credential GSI (Grid Security Infrastructure) Reliable remote invocation GRAM (Grid Resource Allocation & Management) The Globus Toolkit v2 in One Slide Grid protocols (GSI, GRAM, …) enable resource sharing within virtual organizations; toolkit provides reference implementation ( = Globus Toolkit 2 services) l Protocols (and APIs) enable other tools and services for membership, discovery, data management, workflow, … Other service (e.g. GridFTP) Other GSI- authenticated remote service requests GIIS: Grid Information Index Server (discovery) MDS-2 (Monitoring and Discovery Service) Soft state registration; enquiry Slide adapted from the Globus Alliance
2004-11-1726 Data Grids –Distributed management of large quantities of data: physics, astronomy, engineering High-throughput computing –Coordinated use of many computers Collaborative environments –Authentication, resource discovery, and resource access Portals –Thin client access to remote resources & services And combinations of the above Slide adapted from the Globus Alliance Globus-Based Grid Tools & Applications
2004-11-1727 Some architectural thoughts Storage User Interface Information Server Data location server Workload manager Information Server
2004-11-1728 Some Grid projects (past and present) US projects Slide adapted from Les Robertson European projects Many more are starting Only few develop actual Grid solutions
2004-11-1729 Some Grid projects timeline Other Grid-related projects do not develop Open Source-like (i.e., free) software/middleware, as of today –Most notably, Legion/Avaki: Globus competitor, widely used by businesses –Entropia: like SETI@Home –IBM, Platform: Globus-based –Sun Grid Engine EE: enterprise Grids 20002001200220032004200520062007200820092010 LCG EDGEGEE GriPhyN, PPDGVDT CROSSGRID DataTAG NorduGrid GlobusGT2GT3GT4
2004-11-1730 What Grid can do today Simplest Grid: users access distributed resources using a single certificate More complex Grid: users’ tasks are distributed between different resources by a broker Even more complex Grid: not only tasks, but massive amounts of data are also distributed and managed (not quite there yet, only prototypes ??? Broker(s) ??? Broker(s) MSS SE MSS ???
2004-11-1731 What is missing Common policies, or ways of mutually respecting such Grid accounting systems and Grid economy Serious security solutions; role-based access control Full-blown distributed data management systems Tools and methods for system-wide applications environment deployment STANDARDS!
2004-11-1732 Functionality, standardization Custom solutions 1990199520002005 OGSA, WSRF Real standards Multiple implementations Web services, etc. Managed shared virtual systems Computer science research Globus Toolkit Defacto standard Single implementation Internet standards The emergence of Open Grid standards 2010 Slide adapted from the Globus Alliance
2004-11-1733 Open Grid Services Architecture Standard interfaces & behaviors for distributed system management Service orientation: Grid Services, in analogy to Web Services –Web services: persistent –Grid services: transient (issues: e.g., how are they discovered?) –Extending WSDL to GSDL (work with W3C) Standard service specifications –Resource management –Data management –Workflow –Security –etc. Paves the road towards interoperability and true modularity of Grid structures
2004-11-1734 The Grid or many Grids? Globus Toolkit 2 is a basis for great many Grid solutions –Which use some common tools and utilities: GSI, GridFTP –But they also differ a lot, architecturally and technologically –There are several non-interoperable GT2-based Grid systems! No satisfactory ready-made solutions developers invent their own Being financed from different sources, developers and users are not always encouraged to adopt rival project’s solution Instead of “How should I use Grid?”, users ask “Which Grid should I use?” Grid standards body: Global Grid Forum (GGF) –Heavily oriented towards commercial implementations –No effective standards since 2001 Globus introduced the “Open Grid Services Architecture” (OGSA) –Not yet used by any of the development projects –Perhaps the first set of standards endorsed by GGF –Globus Toolkit 3 is released New step by Globus: “Web Services Resource Framework” (WSRF) –We face Globus Toolkit 4 very soon…
2004-11-1735 Meanwhile: ATLAS Production System uses 3 Grids
2004-11-1736 HEP community stirred a world-wide Grid interest –Next big thing after the dot-com?.. Despite a slow start and much hype, some real work is under way –Rather, the next big thing after the WWW ! Still, no complete solution exists –Data management? –Accounting? –Security? –Standardization? With courage and patience, we should go Grid Conclusion
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