The Control and Configuration Software of the ATLAS Data Acquisition System: Upgrades for LHC Run 2

The Trigger and Data Acquisition (TDAQ) system of the ATLAS detector at the Large Hadron Collider (LHC) at CERN is composed of a large number of distributed hardware and software components which in a coordinated manner provide the data-taking functionality of the overall system. The Controls and Configuration (CC) software offers services to configure, control and monitor the TDAQ system. It is a framework which provides essentially the glue that holds the various sub-systems together. While the overall architecture, established at the end of the 90’s, has proven to be solid and flexible, many software components (from core services, like the Run Control and the error management system, to end- user tools) have undergone a complete redesign or re-implementation during the LHC’s Long Shutdown I period. The upgrades were driven by the need to fold-in the additional requirements that appeared in the course of LHC’s Run 1, to profit from new technologies and to re-factorize and cleanup the code. This paper describes the approach that was taken to plan, organize and carry out this software upgrade project. It highlights the main technical choices that have guided the overall work, describes the major achievements and outlines how the CC software may be further improved or re-shaped in the future.