The second generation of the ATLAS Production System: expertise and future evolution

ATLAS production system called ProdSys2 is used during Run2 to define and to organize workflows and to schedule, submit and execute payloads in a distributed computing infrastructure. We design ProdSys2 to manage all ATLAS workflows: data (re)processing, MC simulation, physics groups analysis objects production, High Level Trigger processing, SW release building and user analysis. It simplifies the life of ATLAS scientists by offering a web-based user interface with rich options, which implements a user-friendly environment for workflow management, such as a simple way of combining different data flows, and real-time monitoring, optimised for use with a huge amount of information to present. We present an overview of the ATLAS Production System technical implementation: job and task definitions, workflow manager and the web-based user interface. We show how it interfaces to different computing resources, for instance, HPC systems and clouds, and how the Production System interacts with the ATLAS data management system. We describe important technical design decisions, work experience acquired during the LHC Run2 and how will the Production System evolve to be used in the heterogeneous computing environment foreseen for Run3 and High-Luminosity LHC.