Prototype of a File-Based High-Level Trigger in CMS
| Autor: | Olivier Raginel, Christian Deldicque, T. Bawej, Guillelmo Gomez-Ceballos, Ac Spataru, Marc Dobson, J. G. Branson, Christoph Schwick, Olivier Chaze, Sergio Cittolin, Attila Racz, Jan Veverka, Dominique Gigi, J A Coarasa, Benjamin Stieger, Samim Erhan, Emilio Meschi, L. Masetti, Hannes Sakulin, C. Paus, Christian Hartl, G. Bauer, C. C. Wakefiled, C. Nunez-Barranco-Fernandez, Wojciech Ozga, Konstanty Sumorok, Remigius K. Mommsen, Ulf Behrens, André Holzner, Robert Gomez-Reino, Srecko Morovic, Matteo Sani, Frank Glege, Georgiana-Lavinia Darlea, A Dupont, Vivian O'Dell, Frans Meijers, Jeroen Hegeman, Andrea Petrucci, Marco Pieri, Luciano Orsini, Petr Zejdl |
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| Jazyk: | chorvatština |
| Rok vydání: | 2014 |
| Předmět: |
DAQ system
CMS experiment LHC File system History Engineering Data processing High level trigger Large Hadron Collider business.industry Physics computer.software_genre Computer Science Applications Education Data acquisition Operating system Code (cryptography) Detectors and Experimental Techniques business Raw data computer Implementation |
| Zdroj: | Journal of Physics: Conference Series |
| Popis: | The DAQ system of the CMS experiment at the LHC is upgraded during the accelerator shutdown in 2013/14. To reduce the interdependency of the DAQ system and the high-level trigger (HLT), we investigate the feasibility of using a file-system-based HLT. Events of $\sim$1\,MB size are built at the level-1 trigger rate of 100\,kHz. The events are assembled by $\sim$50 builder units (BUs). Each BU writes the raw events at $\sim$2\,GB/s to a local file system shared with $\cal O$(10) filter-unit machines (FUs) running the HLT code. The FUs read the raw data from the file system, select $\cal O$(1\%) of the events, and write the selected events together with monitoring meta-data back to a disk. This data is then aggregated over several steps and made available for offline reconstruction and online monitoring. We present the challenges, technical choices, and performance figures from the prototyping phase. In addition, the steps to the final system implementation will be discussed. |
| Databáze: | OpenAIRE |
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