Speaker
Description
The main reconstruction and simulation software framework of the ATLAS
experiment, Athena, underwent a major change during the LHC Run 3 in the way
the configuration step of its applications is performed. The new configuration
system, called ComponentAcumulator, emphasises modularity and provides a way
for standalone execution of parts of a job, as long as the inputs are
available, which allows unit-testing of individual components or groups of
components, as well as easier debugging.
The switch to the new configuration system of the High-Level Trigger (HLT)
software, which utilises Athena algorithms for object reconstruction and
hypothesis testing, required designing a special approach to prevent disruption
of data taking during the code migration to ComponentAccumulator. An additional
challenge is brought by a large amount of HLT chains, where in many cases
copies of the same algorithm with varying configurations are used, which
significantly increases the number of configured parameters compared to offline
reconstruction jobs.
This report describes migration of the HLT software to ComponentAccumulator
along with further improvements in the data acquisition introduced for Run 3
data taking.
