A Comparison of Data-Access Platforms for the Computing of Large Hadron Collider Experiments
Marco Bencivenni, Francesca Bonifazi, A. Carbone, Andrea Chierici, Alessandro Vissarios D’Apice, Donato De Girolamo, Luca dell'Agnello, Massimo Donatelli, Giacinto Donvito, Armando Fella, Fabrizio Furano, Domenico Galli, Antonia Ghiselli, A. Italiano, Giuseppe Lo Re, U. Marconi, Barbara Martelli, Mirco Mazzucato, Michele Onofri, Pierpaolo Ricci · IEEE Transactions on Nuclear Science · 2008
Performance, reliability and scalability in data-access are key issues in the context of the computing Grid and High Energy Physics data processing and analysis applications, in particular considering the large data size and I/O load that a Large Hadron Collider data centre has to support. In this paper we present the technical details and the results of a large scale validation and performance measurement employing different data-access platforms-namely CASTOR, dCache, GPFS and Scalla/Xrootd. The tests have been performed at the CNAF Tier-1, the central computing facility of the Italian National Institute for Nuclear Research (INFN). Our storage back-end was based on Fibre Channel disk-servers organized in a Storage Area Network, being the disk-servers connected to the computing farm via Gigabit LAN. We used 24 disk-servers, 260 TB of raw-disk space and 280 worker nodes as computing clients, able to run concurrently up to about 1100 jobs. The aim of the test was to perform sequential and random read/write accesses to the data, as well as more realistic access patterns, in order to evaluate efficiency, availability, robustness and performance of the various data-access solutions.