Experience with dynamic resource provisioning of the CMS online cluster using a cloud overlay
| Autor: | Valdas Rapsevicius, Samim Erhan, Dominique Gigi, Dainius Simeleviciu, Audrius Mecionis, Sergio Cittolin, Frank Glege, Philipp Brummer, Hannes Sakulin, Christoph Schwick, Olivier Chaze, André Holzner, Christian Wernet, Srecko Morovic, Petr Zejdl, Jean-Marc Andre, Marco Pieri, Cristina Vazquez Velez, Christoph Paus, Zeynep Demiragli, Maciej Gladki, Andrea Petrucci, Frans Meijers, Ioannis Papakrivopoulos, Jeroen Hegeman, Vivian O'Dell, Jonathan Richard Fulcher, Marc Dobson, Christian Deldicque, Dinyar Rabady, Georgiana-Lavinia Darlea, Mantas Stankevicius, James G Branson, Diego Da Silva Gomes, Guillelmo Gomez-Ceballos, Attila Racz, Thomas Reis, Nicolas Doualot, Remigius K. Mommsen, Ulf Behrens, Emilio Meschi, Michael Lettrich, Luciano Orsini |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Large Hadron Collider
010308 nuclear & particles physics business.industry Physics::Instrumentation and Detectors Physics QC1-999 Bandwidth (signal processing) Cloud computing Provisioning computer.software_genre Grid 01 natural sciences Grid computing Virtual machine 0103 physical sciences Operating system Detectors and Experimental Techniques 010306 general physics business computer Compact Muon Solenoid |
| Zdroj: | 23rd International Conference on Computing in High Energy and Nuclear Physics (CHEP 2018), Sofia, Bulgaria, July 09-13, 2018, Les Ulis : EDP Sciences, 2019, art. no. 07017, p. [1-8] EPJ Web of Conferences, Vol 214, p 07017 (2019) |
| Popis: | The primary goal of the online cluster of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) is to build event data from the detector and to select interesting collisions in the High Level Trigger (HLT) farm for offline storage. With more than 1500 nodes and a capacity of about 850 kHEPSpecInt06, the HLT machines represent similar computing capacity of all the CMS Tier1 Grid sites together. Moreover, it is currently connected to the CERN IT datacenter via a dedicated 160 Gbps network connection and hence can access the remote EOS based storage with a high bandwidth. In the last few years, a cloud overlay based on OpenStack has been commissioned to use these resources for the WLCG when they are not needed for data taking. This online cloud facility was designed for parasitic use of the HLT, which must never interfere with its primary function as part of the DAQ system. It also allows to abstract from the different types of machines and their underlying segmented networks. During the LHC technical stop periods, the HLT cloud is set to its static mode of operation where it acts like other grid facilities. The online cloud was also extended to make dynamic use of resources during periods between LHC fills. These periods are a-priori unscheduled and of undetermined length, typically of several hours, once or more a day. For that, it dynamically follows LHC beam states and hibernates Virtual Machines (VM) accordingly. Finally, this work presents the design and implementation of a mechanism to dynamically ramp up VMs when the DAQ load on the HLT reduces towards the end of the fill. |
| Databáze: | OpenAIRE |
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