General requirements for BES III offline EF selection

General requirements for BES III offline & EF selection software Weidong Li

Requirements on the framework v v v Framework architecture: flexibility, simplicity and robustness Modular structure and dynamically loading software components at run-time Control of data processing l l v v v Allow to specify a sequence of algorithms Execution of algorithm might depend on the physics signature of each event Capable of specifying the configuration for adjustable parameters e. g. through Job. Option file Framework utilities: histogram service, messaging service, particle property service, timing service, input/output service, etc. Independent of the underlying database or I/O technology. Support multiple languages, Fortran and C++ Support parallel processing at least in event level 17/12/2003 BES III Software Meeting 2

requirements on reconstruction algorithms v v v The algorithm should be designed with the goal of modular structure. Break down a major reconstruction task into a reasonable number of components. Algorithms should remain unchanged whatever is the source of the data they are running on: EF data, offline data, simulation data, test-beam data. Any parameters that an algorithm has should be available by user and should be configurable using a standard method. For Monte-Carlo events, navigation from reconstructed data to Monte-Carlo data should be easy. The correct calibration constants should be automatically picked. 17/12/2003 BES III Software Meeting 3

Requirements for Event Filter Selection Software (EFSSW) v v v Fast rejection to avoid unnecessary processing and to minimize the average decision latency. Be able to change the selection strategy without rebuilding the software. Both seeded and unseeded reconstructions should be supported. Should be possible to specify a prescale factor for certain physics events like Bhabha or dimuon events. Forced to accept a small fraction of events which otherwise would not pass for monitoring purpose. 17/12/2003 BES III Software Meeting 4

Requirements for EFSSW (2) v v EFSSW algorithm should be threadsafed for processing events in parallel threads. The interface between the framework control and EF algorithms is desired to be independent of running environment (offline or online). 17/12/2003 BES III Software Meeting 5

Running EFSSW in the offline environment v v Development, testing and verification of EFSSW components Determination and tuning of the performance in terms of selection efficiency, execution time and event rates based on simulation Validation of the results and performance of the online system Study trigger efficiency, acceptance and biases once real data are available 17/12/2003 BES III Software Meeting 6

Requirements for Physics analysis v v Be able to produce and save persistently histograms and ntuples for later analysis using a separate tool like PAW be able to use any reconstruction routines in the analysis environment Existing legacy FORTRAN code should be supported l Telesis l Particle selection and identification l Secondary vertex finding l d. E/dx correction single event display 17/12/2003 BES III Software Meeting 7

Belle and Gaudi framework (1) v v Gaudi architecture separates date from algorithmic code and provides standard software components for specialization: l Data. Object l Algorithm l Service l Tool l Converter Control of data processing l l Path in Belle: the execution of modules is determined by Path and the conditional branch to another path is also supported. Gaudi supports algorithm sequences, filters and branches 17/12/2003 BES III Software Meeting 8

Diagram for algorithm sequences and branches 17/12/2003 BES III Software Meeting 9

Belle and Gaudi framework (2) v Data management l l v v Integral data management based on Panther (Belle) Belongs to blackboard family (Gaudi) Gaudi supports l Objectivity/DB l Microsoft Access l My. SQL l ORACLE Gaudi supports muti-threaded application 17/12/2003 BES III Software Meeting 10

Conclusions and open issue v v v The current BESF framework is in pretty good shape and should be regarded as the baseline solution for offline software. But there are still difficulties to plug the offline algorithms in the online EF dataflow framework. Shall we keep the choice of underlying framework open and make an effort to evaluate the feasibility of adopting Gaudi? 17/12/2003 BES III Software Meeting 11