The DUNE Collaboration is pursuing an experimental program (named protoDUNE)
which involves a beam test of two large-scale prototypes of the DUNE Far Detector
at CERN in 2018. The volume of data to be collected by the protoDUNE-SP (the single-phase detector) will amount to a few petabytes and the sustained rate of data sent to mass
storage will be in the range of a few hundred MB per second. After collection the data
will be committed to storage at CERN and immediately transmitted to Fermi National
Accelerator Laboratory in the US for processing, analysis and long-term preservation.
The protoDUNE experiment requires substantial Data Quality Monitoring
capabilities in order to ascertain the condition of the detector and its various subsystems.
We present the design of the protoDUNE Prompt Processing System, its deployment at
CERN and its performance during the data challenges conducted in 2017 and 2018.