WLCG Information System

Not specified

The grid information system provides detailed information about grid services in the interest of a multitude of grid clients and services. The grid information system has a hierarchical structure of three levels. The fundamental building block used in this hierarchy is the Berkeley Database Information Index (BDII). The resource level BDII is usually co-located with a given grid service and provides information about that service. Each grid site in EGI runs a site level BDII. This aggregates the information from all the resource level BDIIs running at that site. A top level BDII aggregates all the information from all the site level BDIIs and hence contains information about all grid services published by any site. A site may run its own top level BDII or point local clients to some other instance(s) on the grid. The information system clients query a top level BDII to find the information that they require.