9-13 July 2018
Sofia, Bulgaria
Europe/Sofia timezone

Operational experience with the new CMS DAQ expert

9 Jul 2018, 12:00
Hall 3.1 (National Palace of Culture)

Hall 3.1

National Palace of Culture

presentation Track 1 - Online computing T1 - Online computing


Dr Hannes Sakulin (CERN)


The data acquisition (DAQ) system of the Compact Muon Solenoid (CMS) at CERN reads out the detector at the level-1 trigger accept rate of 100 kHz, assembles events with a bandwidth of 200 GB/s, provides these events to the high level-trigger running on a farm of 26000 cores and records the accepted events. Comprising custom-built and cutting edge commercial hardware and several 1000 instances of software applications, the DAQ system is complex in itself and failures cannot be completely excluded. Moreover, problems in the detectors, in the first level trigger system or in the high level trigger may provoke anomalous behaviour of the DAQ system which sometimes cannot easily be differentiated from a problem in the DAQ system itself. In order to achieve high data taking efficiency with operators from the entire collaboration and without relying too heavily on the on-call experts, an expert system, the DAQ Expert, has been developed that can pinpoint the source of most failures and give advice to the shift crew on how to recover in the quickest way. The DAQ Expert constantly analyzes monitoring data from the DAQ system and the high level trigger by making use of logic modules written in Java that encapsulate the expert knowledge about potential operational problems. The results of the reasoning are presented to the operator in a web-based dashboard, may trigger sound alerts in the control room and are archived for post-mortem analysis - presented in a web-based timeline browser. We present the design of the DAQ Expert and report on the operational experience since 2017, when it was first put into production.

Primary authors

Dr Hannes Sakulin (CERN) Jean-Marc Olivier Andre (Fermi National Accelerator Lab. (US)) Ulf Behrens (Deutsches Elektronen-Synchrotron (DE)) James Gordon Branson (Univ. of California San Diego (US)) Philipp Brummer (CERN) Sergio Cittolin (Univ. of California San Diego (US)) Diego Da Silva Gomes (CERN) Georgiana Lavinia Darlea (Massachusetts Inst. of Technology (US)) Christian Deldicque (CERN) Zeynep Demiragli (Massachusetts Inst. of Technology (US)) Marc Dobson (CERN) Nicolas Doualot (Fermi National Accelerator Lab. (US)) Samim Erhan (University of California Los Angeles (US)) Jonathan Fulcher (CERN) Dominique Gigi (CERN) Maciej Szymon Gladki (Ministere des affaires etrangeres et europeennes (FR)) Frank Glege (CERN) Guillelmo Gomez Ceballos Retuerto (Massachusetts Inst. of Technology (US)) Jeroen Hegeman (CERN) Andre Georg Holzner (Univ. of California San Diego (US)) Michael Lettrich (Technische Universität Muenchen (DE)) Audrius Mecionis (Vilnius University (LT)) Frans Meijers (CERN) Emilio Meschi (CERN) Remi Mommsen (Fermi National Accelerator Lab. (US)) Srecko Morovic (Fermi National Accelerator Lab. (US)) Vivian O'Dell Luciano Orsini (CERN) Ioannis Papakrivopoulos (National Technical Univ. of Athens (GR)) Christoph Paus (Massachusetts Inst. of Technology (US)) Andrea Petrucci (Rice University (US)) Marco Pieri (Univ. of California San Diego (US)) Dinyar Rabady (CERN) Attila Racz (CERN) Valdas Rapsevicius (Fermi National Accelerator Lab. (US)) Thomas Reis (CERN) Christoph Schwick (CERN) Dainius Simelevicius (Vilnius University (LT)) Mantas Stankevicius (Fermi National Accelerator Lab. (US)) Cristina Vazquez Velez (CERN) Michail Vougioukas (CERN) Christian Wernet (University of Applied Sciences (DE)) Petr Zejdl (Fermi National Accelerator Lab. (US))

Presentation Materials