Managing Dynamic User Communities in a Grid of Autonomous Resources

One of the fundamental concepts in Grid computing is the creation of Virtual Organizations (VO's): a set of resource consumers and providers that join forces to solve a common problem. Typical examples of Virtual Organizations include collaborations formed around the Large Hadron Collider (LHC) experiments. To date, Grid computing has been applied on a relatively small scale, linking dozens of users to a dozen resources, and management of these VO's was a largely manual operation. With the advance of large collaboration, linking more than 10000 users with a 1000 sites in 150 counties, a comprehensive, automated management system is required. It should be simple enough not to deter users, while at the same time ensuring local site autonomy. The VO Management Service (VOMS), developed by the EU DataGrid and DataTAG projects[1, 2], is a secured system for managing authorization for users and resources in virtual organizations. It extends the existing Grid Security Infrastructure[3] architecture with embedded VO affiliation assertions that can be independently verified by all VO members and resource providers. Within the EU DataGrid project, Grid services for job submission, file- and database access are being equipped with fine- grained authorization systems that take VO membership into account. These also give resource owners the ability to ensure site security and enforce local access policies. This paper will describe the EU DataGrid security architecture, the VO membership service and the local site enforcement mechanisms Local Centre Authorization Service (LCAS), Local Credential Mapping Service(LCMAPS) and the Java Trust and Authorization Manager.Comment: Talk from the 2003 Computing in High Energy and Nuclear Physics (CHEP03), La Jolla, Ca, USA, March 2003, 7 pages, LaTeX, 5 eps figures. PSN TUBT00

Grid in earth sciences

International audienceThe Earth Sciences (ES) community, with its mosaic of disciplines and players such as academia, industry, national surveys, international organizations, has specific requirements described next. In particular, any observation depends on four coordinates (three spatial dimensions and time) and then needs geospatial tools for its use. The data policy is very complex and strict, as many real-time data may be strategic for the country and/or have an economic impact. In addition, the ES community provides short-term and medium-term predictions of weather and natural hazards in real-time and requires for those tasks immediate availability of resources by advance reservation or pre-emption. Model simulations of a host of phenomena relating to the Earth and its space environment need access to various large sets of data distributed geographically in different data centres. The various sources of data, among others, include satellite missions, observational networks, large instruments and simulations