Storage federations using xrootd

Abstract

In this paper, we introduce a local storage system using Xrootd in which the heterogeneous storage types are combined into a single access point that help clients access to the storage system efficiently without knowing complex architecture underneath. This system is expanding into global storage union federating the storage systems of the WLCG. The WLCG, a collaboration of computing centers to deal with large scale of data produced by the detectors using the LHC at CERN, has distributed storage resources with different protocols and management systems. The heterogeneity of the distributed storage resources prevents efficient access to data and transfer activities between computing centers. The demand on federating storage resources into one single access point has been arising within the WLCG. We introduce the current movement to federating storage resources has been started and expanding into the whole WLCG collaboration upon the successful federation and operation carried by the computing centers supporting ALICE experiment.