The CMS Event Builder and Storage System

Conference · Fri Jan 01 04:00:00 EST 2010 · J.Phys.Conf.Ser.

DOI:https://doi.org/10.1088/1742-6596/219/2/022038· OSTI ID:1985074

Bauer, G.

The CMS event builder assembles events accepted by the first level trigger and makes them available to the high-level trigger. The event builder needs to handle a maximum input rate of 100 kHz and an aggregated throughput of 100 GB/s originating f rom approximately 500 sources. This paper presents the chosen hardware and software architecture. The system consists of 2 stages: an initial pre-assembly reducing the number of fragments by one order of magnitude and a final assembly by several independe nt readout builder (RU-builder) slices. The RU-builder is based on 3 separate services: the buffering of event fragments during the assembly, the event assembly, and the data flow manager. A further component is responsible for handling events accepted by the high-level trigger: the storage manager (SM) temporarily stores the events on disk at a peak rate of 2 GB/s until they are permanently archived offline. In addition, events and data-quality histograms are served by the SM to online monitoring clients . We discuss the operational experience from the first months of reading out cosmic ray data with the complete CMS detector.

• Research Organization: Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
• DOE Contract Number: AC02-07CH11359
• OSTI ID: 1985074
• Report Number(s): FERMILAB-CONF-10-778; oai:inspirehep.net:859461
• Conference Information: Journal Name: J.Phys.Conf.Ser. Journal Volume: 219
• Country of Publication: United States
• Language: English

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46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY