Author:
Borga A.,Blair R.,Crone G.J.,Green B.,Kugel A.,Joos M.,Love J.,Panduro Vazquez J.G.,Schumacher J.,Teixeira-Dias P.,Tremblet L.,Vandelli W.,Vermeulen J.C.,Rifki O.,Werner P.,Wickens F.J.
Abstract
Abstract
The ReadOut System (ROS) is a central part of the data
acquisition (DAQ) system of the ATLAS Experiment at the CERN Large
Hadron Collider (LHC). The system is responsible for receiving and
buffering event data from all detector subsystems and serving these
to the High Level Trigger (HLT) system via a 10 GbE network,
discarding or transporting data onward once the trigger has
completed its selection process. The ATLAS ROS was completely
replaced during the 2013–2014 experimental shutdown in order to
meet the demanding conditions expected during LHC Run 2 and Run 3
(2015–2025). The ROS consists of roughly one hundred Linux-based
2U-high rack-mounted servers equipped with PCIe I/O cards and
10 GbE interfaces. This paper documents the system requirements
for LHC Runs 2 and 3 and the design choices taken to meet them. The
results of performance measurements and the re-use of ROS technology
for the development of data sources, test platforms for other
systems, and another ATLAS DAQ system component, namely the Region
of Interest Builder (RoIB), are also discussed. Finally performance
results for Run 2 operations are presented before looking at the
upgrade for Run 3.
Subject
Mathematical Physics,Instrumentation