Speaker
Marco Clemencic
(CERN)
Description
The LHCb Conditions Database (CondDB) project aims to provide the necessary tools to
handle non-event time-varying data. The LCG project COOL provides a generic API to
handle this type of data and an interface to it has been integrated into the LHCb
framework Gaudi. The interface is based on the Persistency Service infrastructure of
Gaudi, allowing the user to load it at run-time only if needed.
Since condition data are varying with time, as the events are processed, condition
objects in memory must be kept synchronized to the values in the database for the
current event time. A specialized service has been developed independently of the
COOL API interface to provide an automated and optimized update of the condition
objects in memory.
The High Level Trigger of LHCb is a specialized version of an LHCb
reconstruction/analysis program and as such it will need conditions, like alignments
and calibrations, from the conditions database. For performance reasons, the HLT
processes running on the Event Filter Farm cannot access the database directly. A
special Online implementation of the CondDB service is thus needed under supervision
of the LHCb Control system.
Primary authors
Juan Palacios
(CERN)
Marco Clemencic
(CERN)
Nicolas Gilardi
(University of Edinburgh, Edinburgh, UK)
