Grid Developments at the H1 Experiment

Christoph WISSING

At the H1 Experiment the increased event rates after the upgrade 
of the HERA accelerator at DESY have led to increased demands for 
computing and storage resources for the production both experimental
and Monte Carlo simulation data. At the same time new computing 
resources are becoming available via the Grid.

To make use of the new resources the H1 collaboration has started to 
install a mass production system based on LCG. The 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 executables.

The system has been proven capable of the tracking of 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.