I. Adachi (KEK)
The Belle experiment has accumulated an integrated luminosity of more than 240fb-1 so far, and a daily logged luminosity has exceeded 800pb-1. This requires more efficient and reliable way of event processing. To meet this requirement, new offline processing scheme has been constructed, based upon technique employed for the Belle online reconstruction farm. Event processing is performed at PC farms, which consists of 60 quad(0.7GHz) and 225 dual(1.3GHz or 3.2GHz) CPU PC nodes. Raw event data are read from a Solaris tape server connected to a DTF2 tape drive, and they are distributed over all PC nodes. Reconstructed events are recorded onto 8 file servers, which are newly installed last year. To maximize processing capabilities, various optimizations such as PC clustering, job control, output data management and so on have been done. As a result, processing power with this scheme has been more than doubled, which corresponds to that more than 3 fb-1 of beam data per day can be processed. In this talk, stable operation of our new system, together with a description of the Belle offline computing model, will be demonstrated by showing computing performance obtained from experience in processing beam data.