A New Event Builder for CMS Run II

14 Apr 2015, 15:00
Village Center (Village Center)

Village Center

Village Center

oral presentation Track1: Online computing Track 1 Session


Remi Mommsen (Fermi National Accelerator Lab. (US))


The data acquisition system (DAQ) of the CMS experiment at the CERN Large Hadron Collider (LHC) assembles events at a rate of 100 kHz, transporting event data at an aggregate throughput of 100 GB/s to the high-level trigger (HLT) farm. The DAQ system has been redesigned during the LHC shutdown in 2013/14. The new DAQ architecture is based on state-of-the-art network technologies for the event building. For the data concentration, 10/40 Gb/s Ethernet technologies are used together with a reduced TCP/IP protocol implemented in FPGA for a reliable transport between custom electronics and commercial computing hardware. A 56 Gb/s Infiniband FDR CLOS network has been chosen for the event builder with a throughput of 4 Tb/s. This paper will discuss the software design, protocols and optimizations for exploiting the hardware capabilities. We will present performance measurements from small-scale prototypes and from the full-scale production system.

Primary author

Remi Mommsen (Fermi National Accelerator Lab. (US))


Andre Georg Holzner (Univ. of California San Diego (US)) Andrea Petrucci (CERN) Andrew Kevin Forrest (University of Kent (GB)) Andronidis Anastasios (CERN) Dr Attila Racz (CERN) Aymeric Arnaud Dupont (CERN) Benjamin Stieger (CERN) Carlos Nunez Barranco Fernandez (CERN) Christian Deldicque (CERN) Christoph Paus (Massachusetts Inst. of Technology (US)) Christoph Schwick (CERN) Christopher Colin Wakefield (Staffordshire University (GB)) Dominique Gigi (CERN) Emilio Meschi (CERN) Frank Glege (CERN) Frans Meijers (CERN) Georgiana Lavinia Darlea (Massachusetts Inst. of Technology (US)) Guillelmo Gomez Ceballos Retuerto (Massachusetts Inst. of Technology (US)) Hannes Sakulin (CERN) James Gordon Branson (Univ. of California San Diego (US)) Mr Jan Veverka (Massachusetts Inst. of Technology (US)) Jean-Marc Olivier Andre (FNAL) Dr Jeroen Hegeman (CERN) Konstanty Sumorok (Massachusetts Inst. of Technology (US)) Lorenzo Masetti (CERN) Luciano Orsini (CERN) Dr Marc Dobson (CERN) Marco Pieri (Univ. of California San Diego (US)) Olivier Chaze (CERN) Petr Zejdl (CERN) Samim Erhan (Univ. of California Los Angeles (US)) Sergio Cittolin (Univ. of California San Diego (US)) Srecko Morovic (CERN) Tomasz Adrian Bawej (University of Wisconsin (US)) Ulf Behrens (Deutsches Elektronen-Synchrotron (DE)) Vivian O'Dell (Fermi National Accelerator Laboratory (FNAL))

Presentation Materials