The ATLAS DDM accounting and Storage Usage Service

The ATLAS Distributed Data Management system is the system developed and used by ATLAS for handling large amounts of data. It encompasses data bookkeeping, managing of largescale production transfers as well as endusers data access requests. The multi-petabyte ATLAS data volume already under management requires an accounting and monitoring service that collects different data usage informations in order to show and compare it from the experiment and application perspective. In this paper we will describe the design and implementation of the DDM Accounting and Storage Usage Service, built to meet the monitoring requirement.