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Grid ENabled Integrated Earth system model |
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Grid Technologies
The GENIE system will require the application and development of a number of Grid technologies. This will use and drive computing research underway at Imperial College and Southampton into component-based software techniques, problem solving environments, portals, intelligent service-oriented Grid middleware and databases, funded by EPSRC and the e-Science Core Technology programme.
(1) Component Wrapping: A component repository will be set up to store the meta-data and source code relating to the `wrapped' science components. The science source code (e.g. FORTAN77/90, C & C++) will be packaged into individual software components. Imperial College and Southampton will develop an XML Schema to capture the meta-data for the science components.
(2) Computation: Computational resources within the collaboration will be formed into a virtual organisation using middleware such as Globus. These resources will comprise traditional supercomputers, Beowulf clusters and Condor pools. We envisage using Web services as the communication mechanism between resources while using Java wrapped components within a computational resource.
(3) Meta-Scheduler: The meta-scheduler collects information relating to the currently available computational resources, the science components, and the application definition (provided by the user) to minimise the overall execution time by instantiating components on the most appropriate execution platforms. The user generates the application definition by browsing the existing component meta-data stored within the distributed component repositories. The performance of a component on a particular platform is obtained by interrogating its performance database, generated and enhanced whenever a component is executed. By understanding the application structure and exposing the data flows between components we are able to optimally map components to potentially distributed resources and re-distribute the components should circumstances dictate, e.g. the availability of better resources.
(4) Automated Data archiving, querying and post-processing: This will facilitate collaborative sharing of simulation results between partners in the project. Sharing, re-use and exploitation of these data sets requires the ability to locate, assimilate, retrieve and analyse large volumes of data produced at distributed locations. We will use open standards to provide transparent access to the data along with open source/ commercial database systems to provide a robust, secure and distributed back-end for the data handling.
Database system: The underlying database system will use the XML and XML Schema to specify the portable database infrastructure that underlies our system, and binary formats for the bulk data. This will allow for automated generation and population of the underlying open source/ commercial database system (e.g. Storage Resource Broker, DB2, SQL Server, Oracle, Tamino), whilst retaining the flexibility to add new metadata dynamically as part of the post-processing analysis. The post-processing facility will be integrated into the GENIE Portal and will allow for user queries to the distributed databases, and re-use of simulation results to seed new calculations.
Data post-processing and database integration: Analysis and post-processing tools for the distributed data resulting from Grid-based simulation runs will allow for new information and knowledge to be deduced from simulation data.
(5) GENIE Portal: The portal will be the web-based mechanism for authenticating users, browsing the component and data repositories, composing simulations, executing them, monitoring their progress, and analysing the results. It will leverage significant and ongoing activity at Southampton in Problem Solving Environment development and at Imperial College in the London e-Science Core Technology project EPIC (`e-Science Portal at Imperial College', funded by DTI). It will also enable users to monitor an ongoing simulation.