Speaker
Dr
Jose Hernandez
(CIEMAT)
Description
CMS undertakes periodic computing challenges of increasing scale and complexity
to test its computing model and Grid computing systems. The computing challenges are
aimed at establishing a working distributed computing system that implements the CMS
computing model based on an underlying multi-flavour grid infrastructure. CMS
dataflows and data processing workflows are exercised during a period of about a
month targeting specific performance and scale goals. Performance values are
measured, problems are identified and feedback into the design, integration and
operation of the computing system is provided.
The CMS computing architecture is based on a tier-organised structure of computing
resources, based on a Tier-0 centre at CERN, 7 Tier-1 centres for organized mass data
processing, and about 30 Tier-2 centres where user physics analysis is performed.
The Tier-0 is in charge of storing the data coming from the detector onto mass
storage, performs a prompt reconstruction of the data and distributes the data among
the Tier-1 centres. The Tier-1 sites archive on mass storage its share of data, run
data reprocessing, organized group physics analysis for data selection and distribute
down the selected data to Tier-2's for user analysis. Tier-1 centres also have the
responsibility of storing Monte Carlo data produced at the Tier-2 sites. The above
mentioned workflows have been exercised during October 2006 at a scale of 25% of what
is needed for operations in 2008, and at a 50% scale during July 2007.
An overview of the data- and workflows conducted at the Spanish Tier-1 and Tier-2
sites during the CMS computing challenges since last CHEP conference is presented.
The focus is on presenting achieved results, operational experience and lessons
learnt during the challenges.
Authors
Mr
Antonio Delgado Peris
(CIEMAT)
Dr
F. Javier Rodriguez Calonge
(CIEMAT)
Dr
Francisco Matorras
(IFCA)
Dr
Gonzalo Merino
(PIC/CIEMAT)
Dr
Iban Cabrillo
(IFCA)
Dr
Isidro Gonzalez Caballero
(IFCA)
Mr
Jose Caballero
(CIEMAT)
Dr
Jose Hernandez
(CIEMAT)
Dr
Josep Flix
(PIC/CIEMAT)
Dr
Nicanor Colino
(CIEMAT)
Dr
Rafael Marco
(IFCA)
