ATLAS and CMS applications on the WorldGrid testbed

TL;DR

This paper describes the successful deployment and operation of the WorldGrid testbed, enabling ATLAS and CMS experiments to run data-intensive simulations across Europe and the US with different Grid implementations, demonstrating interoperability and data management capabilities.

Contribution

It presents the first integration of US and European Grid resources for HEP simulations, showcasing interoperability solutions and data management in a large-scale intercontinental testbed.

Findings

US and European resources operated seamlessly for HEP simulations

Data produced could be retrieved, stored, and registered across the Grid

Successful demonstration of cross-continental Grid job execution and data handling

Abstract

WorldGrid is an intercontinental testbed spanning Europe and the US integrating architecturally different Grid implementations based on the Globus toolkit. It has been developed in the context of the DataTAG and iVDGL projects, and successfully demonstrated during the WorldGrid demos at IST2002 (Copenhagen) and SC2002 (Baltimore). Two HEP experiments, ATLAS and CMS, successful exploited the WorldGrid testbed for executing jobs simulating the response of their detectors to physics eve nts produced by real collisions expected at the LHC accelerator starting from 2007. This data intensive activity has been run since many years on local dedicated computing farms consisting of hundreds of nodes and Terabytes of disk and tape storage. Within the WorldGrid testbed, for the first time HEP simulation jobs were submitted and run indifferently on US and European resources, despite of their underlying different Grid implementations, and produced data which could be retrieved and further analysed on the submitting machine, or simply stored on the remote resources and registered on a Replica Catalogue which made them available to the Grid for further processing. In this contribution we describe the job submission from Europe for both ATLAS and CMS applications, performed through the GENIUS portal operating on top of an EDG User Interface submitting to an EDG Resource Broker, pointing out the chosen interoperability solutions which made US and European resources equivalent from the applications point of view, the data management in the WorldGrid environment, and the CMS specific production tools which were interfaced to the GENIUS portal.