S. Dal Pra (INFN-CNAF)

Starting from summer 2013, the amount of computational activity of the INFN-T1 centre reported by the official accounting web portal of the EGI community accounting.egi.eu, was found to be much lower than the real value. Deep investigation on the accounting system pointed out a number of subtle concurrent causes, whose effects dated back from May and were responsible for a loss of collected data records over a period of about 130 days. The ordinary recovery method would have required about one hundred days. A different solution had thus to be designed and implemented. Applying it on the involved set of raw log files (records, for an average production rate of jobs/day) required less than 4 hours to reconstruct the Grid accounting records. The propagation of these records through the usual dataflow up to the EGI portal was then a matter of a few days. This report describes the work done at INFN–T1 to achieve the aforementioned result. The procedure was then adopted to solve a similar problem affecting another site, INFN–PISA. This solution suggests a possible alternative accounting model and provided us with a deep insight on the most subtle aspects of this delicate subject.