P o S ( A C A T 2 0 1 0 ) 0 8 7 Interoperating AliEn and ARC for a distributed Tier 1 in the Nordic countries

To reach its large computing needs, the ALICE experiment at C ERN has developed its own middleware called AliEn, centralized and relying on pilot jobs . One of its strength is the automatic installation of the required packages. The Nordic countries have offered a distributed Tier-1 cent re for the CERN experiments, where the job management should be done with the NorduGrid middlew ar ARC. We have developed an interoperation module to allow unifyin g several computing sites using ARC, and make them look like a single site from the point of vie w of AliEn. A prototype has been completed and tested out of production. This talk will p resent implementation details of the system and its performance in tests.