Speaker
I. Adachi
(KEK)
Description
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.
