27 September 2004 to 1 October 2004
Interlaken, Switzerland
Europe/Zurich timezone

Performance of the ATLAS DAQ DataFlow system

27 Sep 2004, 18:10
Jungfrau (Interlaken, Switzerland)


Interlaken, Switzerland

oral presentation Track 1 - Online Computing Online Computing




The ATLAS Trigger and DAQ system is designed to use the Region of Interest (RoI)mechanism to reduce the initial Level 1 trigger rate of 100 kHz down to about 3.3 kHz Event Building rate. The DataFlow component of the ATLAS TDAQ system is responsible for the reading of the detector specific electronics via 1600 point to point readout links, the collection and provision of RoI to the Level 2 trigger, the building of events accepted by the Level 2 trigger and their subsequent input to the Event Filter system where they are subject to further selection criteria. To validate the design and implementation of the DAQ DataFlow system, a prototype setup representing 20% of the final system, has been put together at CERN. Thisbaseline prototype contains 68 PCs running Linux, and exchanging data via a 64-portand a 31-port Gigabit Ethernet switches for Event Building and RoI Collection. The system performance is measured by playing back simulated data through the system andrunning prototype algorithms in the Level 2 trigger. In parallel a full discrete event model of the system has been developed and tuned to the testbed results as an aid to studying the system performance at and beyond the size of the prototype setup. Measurements will be presented on the performance of the prototype setup, showing that the components of the current integrated system implementation can already sustain the their nominal ATLAS requirements using existing hardware and Gigabit network technology: 20 kHz RoI Collection rate per readout link, 3 kHz Event Building rate and 70 Mbyte/s throughput per event building node. The use of these results to calibrate the model will also be presented along with the model predications for the performance of the final DAQ DataFlow system.

Primary authors

A. CORSORADU (CERN, Geneva, Switzerland) A. DOS ANJOS (Universidade Federal do Rio de Janeiro, COPPE/EE, Brazil) A. KACZMARSKA (Polish Academy of Sciences, Cracow, Poland) A. KUGEL (Universitaet Mannheim, Germany) A. LANKFORD (University of California, Irvine, USA) A. MISIEJUK (University of London, Egham, UK) B. DIGIROLAMO (CERN, Geneva, Switzerland) B. GORINI (CERN, Geneva, Switzerland) B. GREEN (University of London, Egham, UK) B. MARTIN (CERN, Geneva, Switzerland) C. HAEBERLI (University of Bern, Switzerland) C. HINKELBEIN (Universitaet Mannheim, Germany) C. MEIROSU (CERN, Geneva, Switzerland) D. BOTTERILL (RAL, Didcot, UK) D. FRANCIS (CERN, Geneva, Switzerland) D. PRIGENT (CERN, Geneva, Switzerland) E. PALENCIA CORTEZON (CERN, Geneva, Switzerland) E. PASQUALUCCI (INFN Roma, Italy) F. WICKENS (RAL, Didcot, UK) G. CRONE (University College London, UK) G. KIEFT (NIKHEF, The Netherlands) G. LEHMANN (CERN, Geneva, Switzerland) G. MORNACCHI (CERN, Geneva, Switzerland) G. unel (UNIVERSITY OF CALIFORNIA AT IRVINE AND CERN) H. ZOBERNIG (University of Wisconcin, USA) H.P. BECK (University of Bern, Switzerland) J. DAWSON (Argonne National Laboratory, USA) J. PETERSEN (CERN, Geneva, Switzerland) J. SCHLERETH (Argonne National Laboratory, USA) J. STRONG (University of London, Egham, UK) J. VERMEULEN (NIKHEF, The Netherlands) J.A. BOGAERTS (CERN, Geneva, Switzerland) K. KORCYL (Polish Academy of Sciences, Cracow, Poland) K. NAKAYOSHI (KEK, Japan) L. MAPELLI (CERN, Geneva, Switzerland) L. TREMBLET (CERN, Geneva, Switzerland) M. ABOLINS (Michigan State University, USA) M. BERETTA (INFN Frascati, Italy) M. CIOBOTARU (CERN, Geneva, Switzerland) M. GRUWE (CERN, Geneva, Switzerland) M. JOOS (CERN, Geneva, Switzerland) M. LE VINE (BNL, USA) M. LOSADA MAIA (Universidade Federal do Rio de Janeiro, COPPE/EE, Brazil) M. MULLER (Universitaet Mannheim, Germany) M. SHIMOJIMA (Nagazaki Institute of Applied Science, Japan) M. YU (Universitaet Mannheim, Germany) M. ZUREK (Polish Academy of Sciences, Cracow, Poland) M.L. FERRER (INFN Fracati, Italy) P. DE MATOS LOPES PINTO (CERN, Geneva, Switzerland) P. GOLONKA (CERN, Geneva, Switzerland) P. WERNER (CERN, Geneva, Switzerland) R. BLAIR (Argonne National Laboratory, USA) R. CRANFIELD (University College London, UK) R. DOBINSON (CERN, Geneva, Switzerland) R. FERRARI (INFN Pavia, Italy) R. HAUSER (Michigan State University, USA) R. Hughes-Jones (THE UNIVERSITY OF MANCHESTER) R. MCLAREN (CERN, Geneva, Switzerland) R. MOMMSEN (University of California, Irvine, USA) R. SPIWOKS (CERN, Geneva, Switzerland) S. GADOMSKI (University of Bern, Switzerland) S. GAMEIRO (CERN, Geneva, Switzerland) S. HAAS (CERN, Geneva, Switzerland) S. STANCU (CERN, Geneva, Switzerland) T. MAENO (CERN, Geneva, Switzerland) V. PEREZ REALE (University of Bern, Switzerland) W. VANDELLI (INFN Pavia, Italy) Y. ERMOLINE (Michigan State University, USA) Y. HASEGAWA (Shinshu University, Japan) Y. NAGASAKA (Hiroshima Institute of Technology, Japan) Y. YASU (KEK, Japan)

Presentation Materials