Exploiting Big Data solutions for CMS computing operations analytics

Computing operations at the Large Hadron Collider (LHC) at CERN rely on the Worldwide LHC Computing Grid (WLCG) infrastructure, designed to efficiently allow storage, access, and processing of data at the pre-exascale level. A close and detailed study of the exploited computing systems for the LHC physics mission represents an increasingly crucial aspect in the roadmap of High Energy Physics (HEP) towards the exascale regime. In this context, the Compact Muon Solenoid (CMS) experiment has been collecting and storing over the last few years a large set of heterogeneous non-collision data (e.g. meta-data about replicas placement, transfer operations, and actual user access to physics datasets). All this data richness is currently residing on a distributed Hadoop cluster, and it is organized so that running fast and arbitrary queries using the Spark analytics framework is a viable approach for Big Data mining efforts. Using a data-driven approach oriented to the analysis of this meta-data deriving from several CMS computing services, such as DBS (Data Bookkeeping Service) and MCM (Monte Carlo Management system), we started to focus on data storage and data access over the WLCG infrastructure, and we drafted an embryonal software toolkit to investigate recurrent patterns and provide indicators about physics datasets popularity. As a long-term goal, this aims at contributing to the overall design of a predictive/adaptive system that would eventually reduce costs and complexity of the CMS computing operations, while taking into account the stringent requests by the physics analysts communit

Giovanni Virginio Schiaparelli e l'Osservatorio di Arcetri

Nell’autunno 1873 la direzione dell’Osservatorio di Arcetri venne offerta a Giovanni Virginio Schiaparelli, già allora uno fra i più autorevoli astronomi italiani. L’astronomo prima accettò, poi rifiutò, per motivi familiari, l’incarico. Nonostante questo, Schiaparelli rimase legato per alcuni anni all’Osservatorio fiorentino, tentando di indirizzarne i lavori lungo il filone dell’astronomia classica, a lui più congeniale della nascente astrofisica. Numerosi problemi impedirono però lo svolgimento di una regolare attività all’Osservatorio, che rimase senza direzione per ben 20 anni. In questo lavoro ripercorriamo la vicenda con l’aiuto di documenti inediti conservati principalmente nell’Archivio dell’Università degli Studi di Firenze

Il primo Osservatorio Astronomico d’Italia. La nascita dell’Osservatorio di Arcetri (1861-1873)

The article describes the early stages of the project and the birth of the Arcetri Observatory, with the main involvment of the astronomer G. B. Donat