(IKP, Uppsala Universitet)
A Grid is defined as being ``coordinated resource sharing and problem solving in
dynamic, multi-institutional virtual organizations''. Over recent years a number of
grid projects, many of which have a strong regional presence, have emerged to help
coordinate institutions and enable grids. Today, we face a situation where a number
of grid projects exist, most of which have slightly different middleware. Grid
interoperation is trying to bridge these differences and enable virtual organizations
to access resources at the institutions independent of the grid project affiliation.
Grid interoperation is usually a bilateral activity between two grid infrastructures.
Recently within the Open Grid Forum, the Grid Interoperability Now (GIN) Community
Group is trying to build upon these bilateral activities. The GIN group is a focal
point where all the infrastructures can come together to share ideas and experiences
on grid interoperation. It is hoped that each bilateral activity will bring us one
step closer to the overall goal of a uniform grid landscape.
A fundamental aspect of a grid is the information system, which is used to find
available grid services. As different grids use different information systems,
interoperation between these systems is crucial for grid interoperability. This
paper describes the work carried out between a number of grid projects to overcome
these differences. It focuses on the different techniques used and highlights the
important areas for future standardization.
The work carried out between large grid projects (EGEE, NDGF, OSG, Teragrid, PRAGMA,
NAREGI) to reach interoperation between their information systems is described. The
different information systems are presented, techniques used to overcome the
differences between the grid projects are explained and important aspects for future
standardization are identified.