Journal Article/Contribution to a conference proceedings

GSI-2026-00233

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png High-throughput data distribution for online computing in the CBM Experiment

de Cuveland, J. (Corresponding author) ; Hutter, D. ; Lindenstruth, V.GSI*

2025
EDP Sciences Les Ulis

Please use a persistent id in citations: doi:10.1051/epjconf/202533701201  doi:10.15120/GSI-2026-00233

Abstract: (EDP Sciences)The CBM experiment, a fixed-target heavy-ion experiment at the upcoming GSI/FAIR SIS100 facility, aims to investigate QCD at high baryon densities. The CBM First-level Event Selector (FLES) serves as the central event selection system of the experiment. It functions as a high-performance computer cluster tasked with the online analysis of physics data, including full event reconstruction, at an incoming data rate of up to 1 TB/s. The CBM detector systems operate in a free-running and self-triggered manner, delivering time-stamped data streams. Without inherent event separation, timeslice building replaces global event building. The FLES online data distribution integrates data from around 5000 input links into self-contained, overlapping processing intervals and distributes these to the compute nodes. Using a combination of RDMA and zero-copy techniques, timeslices can be built efficiently over a high-throughput InfiniBand network and distributed to available online computing resources for full online event reconstruction and analysis in a heterogeneous HPC cluster system. A new IPC online interface to timeslice data utilizes Posix shared memory governed by a referencecounting item distributor. This design combines maximum performance and flexibility with minimum memory consumption. These developments have been successfully field-tested in production at the CBM predecessor experiment mCBM at the GSI/FAIR SIS18.

Note: This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (https://creativecommons.org/licenses/by/4.0/).

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Contributing Institute(s):

1. CBM (CBM)
2. Collaboration FAIR: CBM (CBM@FAIR)

Research Program(s):

1. 612 - Cosmic Matter in the Laboratory (POF4-612) (POF4-612)
2. 05P21RFFC1 - Verbundprojekt 05P2021 (ErUM-FSP T06) - Aufbau von CBM bei FAIR: Bau des First-Level Event Selectors (FLES) für das CBM-Experiment an FAIR (BMBF-05P21RFFC1) (BMBF-05P21RFFC1)

Experiment(s):

1. External experiment at external facility/ no experiment at GSI (other)

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Database coverage:
; ; ; ; DOAJ Seal ; SCOPUS

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