Resources in term of CEs and SEs are published to the grid to maintain access informations that enable an optimized and well balanced work load according to user's needs.
The grid structure is distributed and CEs/SEs are setup at several different sites beloging to cooperating institutions. When a site sets up a new CE/SE, after the validation step, the site manager informs the grid of the new resource by registering the node and related features, i.e. queue manager and queue types, supported VO, installed software packages, storage size and capability, etc.
The Resource Brocker node gains access to the available Grid informations, like node names, list of resources, etc. through the II (Information Index) service(s) stored at one or more sites in the Grid.
This feature has advantages and drawbacks. The advantage is the capability of collecting global informations at the source II site. The drawback is the limitation of local management that cannot insert/remove selected nodes from the local setup.
Hopefully future releases of grid management software will allow a more flexible and dynamical registration of resources, thus allowing local administrators to reconfigure in a easy way the resources, balancing grid and local requirements of the local computing centre.