Published 2020 | Version v1
Journal article

An Information Aggregation and Analytics System for ATLAS Frontier

  • 1. Ecole Nationale Supérieure d'Informatique, Alger Oued Smar 16309 (Algeria)
  • 2. Université Paris-Saclay, CEA/Saclay IRFU, 91191 Gif-sur-Yvette (France)
  • 3. University of Texas at Arlington, Department of Physics, Arlington Texas 76019 (United States)
  • 4. University of Valencia, Instituto de Física Corpuscular, Parque Científico, E-46980 Paterna (Spain)
  • 5. University of Oxford, Denys Wilkinson Bldg, Keble Rd, Oxford OX1 3RH (United Kingdom)

Description

ATLAS event processing requires access to centralized database systems where information about calibrations, detector status and data-taking conditions are stored. This processing is done on more than 150 computing sites on a world-wide computing grid which are able to access the database using the Squid-Frontier system. Some processing workflows have been found which overload the Frontier system due to the Conditions data model currently in use, specifically because some of the Conditions data requests have been found to have a low caching efficiency. The underlying cause is that non-identical requests as far as the caching are actually retrieving a much smaller number of unique payloads. While ATLAS is undertaking an adiabatic transition during the LHC Long Shutdown 2 and Run 3 from the current COOL Conditions data model to a new data model called CREST for Run 4, it is important to identify the problematic Conditions queries with low caching efficiency and work with the detector subsystems to improve the storage of such data within the current data model. For this purpose ATLAS put together an information aggregation and analytics system. The system is based on aggregated data from the Squid-Frontier logs using the Elasticsearch technology. This paper§ describes the components of this analytics system from the server based on Flask/Celery application to the user interface and how we use Spark SQL functionalities to filter data for making plots, storing the caching efficiency results into a Elasticsearch database and finally deploying the package via a Docker container.

Availability note (English)

Available from https://www.epj-conferences.org/articles/epjconf/pdf/2020/21/epjconf_chep2020_04032.pdf; https://doaj.org/article/77436c8643af4972bff2ee22a89e170a

Additional details

Publishing Information

Journal Title
EPJ. Web of Conferences
Journal Volume
245
Journal Page Range
vp.
ISSN
2100-014X

Conference

Title
24. International Conference on Computing in High Energy and Nuclear Physics
Acronym
CHEP 2019
Dates
4-8 Nov 2019
Place
Adelaide (Australia)

INIS

Country of Publication
France
Country of Input or Organization
France
INIS RN
53090907
Subject category
S46: INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY;
Resource subtype / Literary indicator
Conference
Descriptors DEI
AGGLOMERATION; ATLAS DETECTOR; CALIBRATION; CERN LHC; EFFICIENCY; FILTERS
Descriptors DEC
ACCELERATORS; CYCLIC ACCELERATORS; MEASURING INSTRUMENTS; RADIATION DETECTORS; STORAGE RINGS; SYNCHROTRONS