Dr Armando Fella (INFN Pisa) Mr Domenico Diacono (INFN Bari) Dr Giacinto Donvito (INFN-Bari) Mr Giovanni Marzulli (GARR) Paolo Franchini (Universita e INFN (IT)) Dr Silvio Pardi (INFN)
In HEP computing context, R&D studies aiming to the definition of the data and workload models were brought forward by the SuperB community beyond the experiment life itself. This work is considered of great interest for a generic mid- and small size VO during its Computing Model definition phase. Data-model R&D work we are presenting, starts with the general design description of the crucial components in terms of typical HEP use cases; a discussion on strategies and motivations for the taken choices in the fields of data access, mass data transfer and meta-data catalog system is provided firstly. In such a context we focused the evaluation, test and development work on storage systems enabled for geographically-distributed data management: data access, data replication, data recovery and backup in WAN scenarios. HadoopFS and GlusterFS distributed file-system have been mainly considered in this analysis. Data availability in a distributed environment is a key point in the definition of the computing model for an HEP experiment. Among all the possible interesting data models, we identify the WAN direct access via reliable and robust protocols such as HTTP/WebDAV and xrootd as a viable option. The development of a dedicated library has been carried on allowing an optimized file access procedure on remote storage resources. The implemented features include read-ahead and data prefetching techniques, caching mechanism and optimized target file localization. The results of performance and efficiency tests will be presented for the treated subjects trying to describe in conclusion the general strategy lines and technologies for the drafting of a concrete data model design report.
Alberto Gianoli (Universita di Ferrara (IT)) Mr Alessio Gianelle (INFN Padova) Andrea Di Simone (Universita e INFN Roma Tor Vergata (IT)) Bruno Santeramo Cristian De Santis (Universita degli Studi di Roma Tor Vergata (IT)) Domenico Del Prete (I.N.F.N.) Eleonora Luppi (Universita di Ferrara (IT)) Dr Elisa Manoni (INFN Perugia) Fabrizio Bianchi Francesco Giacomini (INFN CNAF) Guido Russo (Universita e INFN (IT)) Luca Tomassetti (University of Ferrara and INFN) Luis Alejandro Perez Perez (INFN Sezione di Pisa) Marcin Jakub Chrzaszcz (Polish Academy of Sciences (PL)) Marco Corvo (INFN) Matteo Manzali (Istituto Nazionale Fisica Nucleare (IT)) Matteo Rama Mr Milosz ZDYBAL (Institute of Nuclear Physics, Polish Academy of Science) Rafal Zbigniew Grzymkowski (P) Prof. Roberto Stroili (Università degli Studi di Padova & INFN) Mr Stefano Longo (INFN CNAF) Steffen Luitz (SLAC National Accelerator Laboratory (US)) Dr Vincenzo Ciaschini (Istituto Nazionale Fisica Nucleare (IT))