File-based data flow in the CMS Filter Farm
During the LHC Long Shutdown 1, the CMS Data Acquisition system underwent a partial redesign to replace obsolete network equipment, use more homogeneous switching technologies, and prepare the ground for future upgrades of the detector front-ends. The software and hardware infrastructure to provide...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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IOP Publishing
2017
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| Online Access: | http://hdl.handle.net/1721.1/108302 https://orcid.org/0000-0002-6047-4211 |
| _version_ | 1826193999552053248 |
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| author | Darlea, G.-L. Gomez-Ceballos, Guillelmo Paus, Christoph M. E. Veverka, Jan |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Darlea, G.-L. Gomez-Ceballos, Guillelmo Paus, Christoph M. E. Veverka, Jan |
| author_sort | Darlea, G.-L. |
| collection | MIT |
| description | During the LHC Long Shutdown 1, the CMS Data Acquisition system underwent a partial redesign to replace obsolete network equipment, use more homogeneous switching technologies, and prepare the ground for future upgrades of the detector front-ends. The software and hardware infrastructure to provide input, execute the High Level Trigger (HLT) algorithms and deal with output data transport and storage has also been redesigned to be completely file- based. This approach provides additional decoupling between the HLT algorithms and the input and output data flow. All the metadata needed for bookkeeping of the data flow and the HLT process lifetimes are also generated in the form of small "documents" using the JSON encoding, by either services in the flow of the HLT execution (for rates etc.) or watchdog processes. These "files" can remain memory-resident or be written to disk if they are to be used in another part of the system (e.g. for aggregation of output data). We discuss how this redesign improves the robustness and flexibility of the CMS DAQ and the performance of the system currently being commissioned for the LHC Run 2. |
| first_indexed | 2024-09-23T09:48:40Z |
| format | Article |
| id | mit-1721.1/108302 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T09:48:40Z |
| publishDate | 2017 |
| publisher | IOP Publishing |
| record_format | dspace |
| spelling | mit-1721.1/1083022022-09-26T13:54:46Z File-based data flow in the CMS Filter Farm Darlea, G.-L. Gomez-Ceballos, Guillelmo Paus, Christoph M. E. Veverka, Jan Massachusetts Institute of Technology. Department of Physics Massachusetts Institute of Technology. Laboratory for Nuclear Science Darlea, G.-L. Gomez-Ceballos, Guillelmo Paus, Christoph M. E. Veverka, Jan During the LHC Long Shutdown 1, the CMS Data Acquisition system underwent a partial redesign to replace obsolete network equipment, use more homogeneous switching technologies, and prepare the ground for future upgrades of the detector front-ends. The software and hardware infrastructure to provide input, execute the High Level Trigger (HLT) algorithms and deal with output data transport and storage has also been redesigned to be completely file- based. This approach provides additional decoupling between the HLT algorithms and the input and output data flow. All the metadata needed for bookkeeping of the data flow and the HLT process lifetimes are also generated in the form of small "documents" using the JSON encoding, by either services in the flow of the HLT execution (for rates etc.) or watchdog processes. These "files" can remain memory-resident or be written to disk if they are to be used in another part of the system (e.g. for aggregation of output data). We discuss how this redesign improves the robustness and flexibility of the CMS DAQ and the performance of the system currently being commissioned for the LHC Run 2. National Science Foundation (U.S.) United States. Department of Energy 2017-04-20T17:54:24Z 2017-04-20T17:54:24Z 2015-12 2015-04 Article http://purl.org/eprint/type/ConferencePaper 1742-6588 1742-6596 http://hdl.handle.net/1721.1/108302 Andre, J-M et al. “File-Based Data Flow in the CMS Filter Farm.” Journal of Physics: Conference Series 664.8 (2015): 082033. © 2017 IOP Publishing https://orcid.org/0000-0002-6047-4211 en_US http://dx.doi.org/10.1088/1742-6596/664/8/082033 Journal of Physics: Conference Series Creative Commons Attribution 3.0 Unported license http://creativecommons.org/licenses/by/3.0/ application/pdf IOP Publishing IOP Publishing |
| spellingShingle | Darlea, G.-L. Gomez-Ceballos, Guillelmo Paus, Christoph M. E. Veverka, Jan File-based data flow in the CMS Filter Farm |
| title | File-based data flow in the CMS Filter Farm |
| title_full | File-based data flow in the CMS Filter Farm |
| title_fullStr | File-based data flow in the CMS Filter Farm |
| title_full_unstemmed | File-based data flow in the CMS Filter Farm |
| title_short | File-based data flow in the CMS Filter Farm |
| title_sort | file based data flow in the cms filter farm |
| url | http://hdl.handle.net/1721.1/108302 https://orcid.org/0000-0002-6047-4211 |
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