Understanding the evolution of conditions data access through Frontier for the ATLAS Experiment

0522514 - FZÚ 2020 RIV FR eng C - Konferenční příspěvek (zahraniční konf.)
Svatoš, Michal - De Salvo, A. - Dewhurst, A. - Vamvakopoulos, E. - Bahilo Lozano, J. - Ozturk, N. - Sánchez, J. - Dykstra, D.
Understanding the evolution of conditions data access through Frontier for the ATLAS Experiment.
EPJ Web of Conferences. Vol. 214. les Ulis: EDP Sciences, 2019 - (Forti, A.; Betev, L.; Litmaath, M.; Smirnova, O.; Hristov, P.), s. 1-8, č. článku 03020. ISSN 2100-014X.
[International Conference on Computing in High Energy and Nuclear Physics (CHEP 2018) /23./. Sofia (BG), 09.07.2018-13.07.2018]
Grant CEP: GA MŠMT LM2015058; GA MŠMT EF16_013/0001404
Grant ostatní: OP VVV - CERN-C(XE) CZ.02.1.01/0.0/0.0/16_013/0001404
Institucionální podpora: RVO:68378271
Klíčová slova: ATLAS * LHC Run 2 * Squid * experiment
Obor OECD: Automation and control systems

All ATLAS computing sites use Squid web proxies to cache the data, greatly reducing the load on the Frontier servers and the databases. One feature of the Frontier client is that in the event of failure, it retries with different services. While this allows transient errors and scheduled maintenance to happen transparently, it does open the system up to cascading failures if the load is high enough. Throughout LHC Run 2 there has been an ever increasing demand on the Frontier service. There have been multiple incidents where parts of the service failed due to high load. A significant improvement in the monitoring of the Frontier service was required. The monitoring was needed to identify both problematic tasks, which could then be killed or throttled, and to identify failing site services as the consequence of a cascading failure is much higher.
Trvalý link: http://hdl.handle.net/11104/0306994