The Advanced Resource Connector for Distributed LHC Computing

The NorduGrid collaboration and its middleware product, ARC (the Advanced Resource Connector), span institutions in Scandinavia and several other countries in Europe and the rest of the world. The innovative nature of the ARC design and flexible, lightweight distribution make it an ideal choice to connect heterogeneous distributed resources for use by HEP and non-HEP applications alike. ARC has been used by scientific projects for many years and through experience it has been hardened and refined to a reliable, efficient software product. In this paper we present the architecture and design of ARC and show how ARC’s simplicity eases application integration and facilitates taking advantage of distributed resources. Example applications are shown along with some results from one particular application, simulation production and analysis for the ATLAS experiment, as an illustration of ARC’s common usage today. These results demonstrate ARC’s ability to handle significant fractions of the computing needs of the LHC experiments today and well into the future.