The ATLAS EventIndex: a BigData catalogue for all ATLAS experiment events

• Main Authors: Barberis, Dario, Aleksandrov, Igor, Alexandrov, Evgeny, Baranowski, Zbigniew, Canali, Luca, Cherepanova, Elizaveta, Dimitrov, Gancho, Favareto, Andrea, Casani, Alvaro Fernandez, Gallas, Elizabeth J., Montoro, Carlos Garcia, de la Hoz, Santiago Gonzalez, Hrivnac, Julius, Iakovlev, Alexander, Kazymov, Andrei, Mineev, Mikhail, Prokoshin, Fedor, Rybkin, Grigori, Salt, Jose, Sanchez, Javier, Sorokoletov, Roman, Toebbicke, Rainer, Vasileva, Petya, Villaplana Perez, Miguel, Yuan, Ruijun
• Other Authors: Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
• Format: Report
• Language: English
• Published: HAL CCSD 2022
• Subjects: particle; interaction; ATLAS; accelerator; CERN Lab; programming; tracks; CERN LHC Coll; [INFO]Computer Science [cs]; [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]; The Pointers
• Online Access: https://hal.science/hal-03877874

International audience The ATLAS EventIndex system comprises the catalogue of all events collected, processed or generated by the ATLAS experiment at the CERN LHC accelerator, and all associated software tools to collect, store and query this information. ATLAS records several billion particle interactions every year of operation, processes them for analysis and generates even larger simulated data samples; a global catalogue is needed to keep track of the location of each event record and be able to search and retrieve specific events for in-depth investigations. Each EventIndex record includes summary information on the event itself and the pointers to the files containing the full event. Most components of the EventIndex system are implemented using BigData open-source tools. This paper describes the architectural choices and their evolution in time, as well as the past, current and foreseen future implementations of all EventIndex components.