Speaker
Mr
Christoph Wissing
(University of Dortmund)
Description
The H1 Experiment at HERA records electron-proton collisions provided by beam
crossings of a frequency of 10 MHz. The detector has about half a million readout
channels and the data acquisition allows to log about 25 events per second with a
typical size of 100kB.
The increased event rates after the upgrade of the HERA accelerator at DESY led to a
more demanding usage of computing and storage resources. The analysis of these data
requires an increased amount of Monte Carlo events. In order to exploit the new
necessary resources, which are becoming available via the Grid, the H1 collaboration
has therefore started to install a mass production system based on LCG. The H1 mass
production system utilizes Perl and Python scripts on top of the LCG tools to steer
and monitor the productions. Jobs and their status are recorded in a MySQL database.
During autonomous production a daemon lunches appropriate scripts while a web
interface can be used for manual intervention. Additional effort has been put into
the sandbox environment in which the executable runs on the worker node. This was
necessary to work around present weaknesses in the LCG tools, especially in the area
of storage management, and to recover automatically from crashes of the executable.
The system has proven to able to track several hundred jobs allowing for production
rates of more than one million events per day. At the end of 2005 ten sites in five
countries are contributing to the production.
Primary author
Mr
Christoph Wissing
(University of Dortmund)
Co-authors
Mr
Maxim Vorobiev
(ITEP Moscow)
Mr
Moritz Karbach
(University of Dortmund)
