Experience with the Custom-Developed ATLAS Trigger Monitoring and Reprocessing Infrastructure

Powerful and sensitive monitoring is vital for such a complex system as the ATLAS trigger. Any occurring processing failures, misbehaviour of selection algorithms and data defects must be discovered immediately and made known to the relevant experts. Any data not usable for physics analysis must be flagged. A complex system of data quality assessment has been developed which was used very successfully in 2011. This is based on a first processing of a subset of data a few hours after recording, complemented by further monitoring performed during the bulk data processing ~48 hours later. The offline trigger monitoring framework includes also the tools to test new trigger configurations before their online usage and a thorough analysis of those events where no trigger decision could be made during the online selection process.