Speaker
Dr
Amber Boehnlein
(FERMI NATIONAL ACCELERATOR LABORATORY)
Description
High energy physics experiments periodically reprocess data, in order to take
advantage of improved understanding of the detector and the data processing code.
Between February and May 2007, the DZero experiment will reprocess a substantial
fraction of its dataset. This consists of half a billion events, corresponding to
more than 100 TB of data, organized in 300,000 files.
The activity utilizes resources from sites around the world, including a dozen sites
participating to the Open Science Grid consortium (OSG). About 1,500 jobs are run
every day across the OSG, consuming and producing hundreds of Gigabytes of data. OSG
computing and storage resources are coordinated by the SAM-Grid system. This system
organizes job access to a complex topology of data queues and job scheduling to
clusters, using a SAM-Grid to OSG job forwarding infrastructure.
For the first time in the lifetime of the experiment, a data intensive production
activity is managed on a general purpose grid, such as OSG. This paper describes the
implications of using OSG, where all resources are granted following an opportunistic
model, the challenges of operating a data intensive activity over such large
computing infrastructure, and the lesson learned throughout the few months of the
project.
Primary author
Dr
Gabriele Garzoglio
(FERMI NATIONAL ACCELERATOR LABORATORY)
Co-authors
Andreii Baranovski
(FERMI NATIONAL ACCELERATOR LABORATORY)
Dr
Brad Abbot
(University of Oklahoma)
Dr
Mike Diesburg
(FERMI NATIONAL ACCELERATOR LABORATORY)
Parag Mhashilkar
(FERMI NATIONAL ACCELERATOR LABORATORY)
Dr
Tibor Kurca
(IN2P3)
