Design and Operation of the BES-III Distributed Computing System

The paper summarizes general information, the latest results and development plans of the BES-III distributed computing system. The BES-III experiment at the Institute of High Energy Physics (Beijing, China) is aimed at the precision measurements in e+e- annihilation at the energy range from 2.0 to 4.6 GeV. The world's largest samples of J/psi and psi’ events and unique samples of XYZ data have been already collected. To process the BES-III experiment's data the distributed computing infrastructure based on DIRAC interware has been setup and became operational since 2013. The work was done in order to tune and enhance DIRAC itself for BES-III purposes: monitoring system and data transfer system were developed. Experience of the BES-III development team may be very useful for medium scale HEP experiments aiming to apply distributed data processing in their computing model.