EPJ Web of Conferences (Jan 2020)

CERN Tape Archive: production status, migration from CASTOR and new features

  • Cano Eric,
  • Bahyl Vladimír,
  • Caffy Cédric,
  • Cancio Germán,
  • Davis Michael,
  • Kotlyar Viktor,
  • Leduc Julien,
  • Lin Tao,
  • Murray Steven

DOI
https://doi.org/10.1051/epjconf/202024504013
Journal volume & issue
Vol. 245
p. 04013

Abstract

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During 2019 and 2020, the CERN tape archive (CTA) will receive new data from LHC experiments and import existing data from CASTOR, which will be phased out for LHC experiments before Run 3. This contribution will present the statuses of CTA as a service and of its integration with EOS and FTS and the data flow chains of LHC experiments. The latest enhancements and additions to the software as well as the development outlook will be presented. With the development of the repack function, a necessary behind-the-scenes feature, CTA can now take over custodial data and handle media migration, compaction and failures. Further metadata handling optimisations allowed doubling the maximum file rate performance to 200Hz per queue. New retrieve scheduling options are being developed at the request of experiments, with optional FIFO behaviour to ensure better control of the timing for datasets retrieve, and fair share support for competing activities within the same VO. Support for multiple backend databases (Oracle, PostgreSQL, MySQL) have been developed at CERN and contributed by external institutes. This contribution will also report on the challenges of and solutions for migrating data from the decades old CASTOR to CTA. The practical example of the preparation for the migration of ATLAS data will be presented.