AliECS: A New Experiment Control System for the ALICE Experiment

Abstract

The ALICE Experiment at CERN’s Large Hadron Collider (LHC) has undergone a major upgrade during LHC Long Shutdown 2 in 2019-2021, which includes a new computing system called O2 (Online-Offline). To ensure the efficient operation of the upgraded experiment and of its newly designed computing system, a reliable, high performance, full-featured experiment control system has also been developed and deployed at LHC Point 2. The ALICE Experiment Control System (AliECS) is a microservices-oriented system based on state-of-the-art cluster management technologies that emerged recently in the distributed and high-performance computing ecosystem. It is designed, developed and maintained as a comprehensive solution and single entry point for control of experiment data acquisition (up to 3.5 TB/s) and processing. This communication describes the AliECS architecture by providing an in-depth overview of the system’s components, interfaces, features, and design elements, as well as its performance. It also reports on the experience with AliECS during the first year of ALICE Run 3 data taking with LHC beam, including integration and operational challenges, and lessons learned from real-world use.