The ALICE Experiment at CERN LHC (Large Hadron Collider) is under
preparation for a major upgrade that is scheduled to be deployed during Long
Shutdown 2 in 2019-2020 and that includes new computing systems, called O2
To ensure the efficient operation of the upgraded experiment along with its
newly designed computing system, a reliable, high performance and automated
control system will be developed with the goal of managing the lifetime of all
the O2 processes, and of handling the various phases of the data taking activity
by interacting with the detectors, the trigger system and the LHC.
The ALICE O2 control system will be a distributed system based on state
of the art cluster management and microservices which have recently emerged
in the distributed computing ecosystem. Such technologies weren’t available
during the design and development of the original LHC computing systems,
and their use will allow the ALICE collaboration to benefit from a vibrant and
innovating open source community.
This paper illustrates the O2 control system architecture. It evaluates sev-
eral solutions that were considered during an initial prototyping phase and pro-
vides a rationale for the choices made. It also provides an in-depth overview of
the components, features and design elements of the actual system.