The ALICE Experiment at the CERN LHC (Large Hadron Collider) is undertaking a major upgrade during LHC Long Shutdown 2 in 2019-2021, both in terms of hardware and software, to prepare for the LHC Run 3 and 4.
ALICE will operate at a peak Pb-Pb collision rate of 50 kHz and the raw data input from the ALICE detectors will then increase by a hundredfold, up to 3.4 TB/s. In order to cope with such a large data rate, a new online-offline computing system, called O² (Online-Offline), has been developed to compress the data synchronously with the data taking on two online farms, FLP (First Level Processor) and EPN (Event Processing Node).
In this seminar, the main points of the ALICE upgrade will be summarized together with the most relevant aspects of the software and computing. The architecture and software optimization studies on CPU and GPU will be presented. The evolution of distributed computing in ALICE over the next few years, the computing infrastructure of the experiment, and its required compute and storage resources will also be discussed.