CWG13 Meeting, 11/04/2014 11:00 301-R-007
 
Present: Andrei, Barth, Charis, Peter, Predrag, Raffaele, Ruben, Sylvain, Vasco
Remote: Ken, Matthias, Mohammad, people from GSI
 
Data model (Andrei) + discussion during the presentation:

• There is no implementation of the model for the moment;
• The shared memory representation restricts the data model to C structures, eventually inside a C++ class;
• The data are both raw and results of processing, very similar to what we have now in HLT;
• It is not granted that we will have event (interaction) building in O2, we may need offline processing to attach the tracks and clusters to primary vertex and to define the interaction. Only after this step is completed we can do analysis;
• The compressed time frame will not be modified, the new information will be added;
• The multiple data header adds description about the new types of information and permits fast navigation;
• The EPN waits for HBE summary. Since the reconstruction on each EPN is much slower, the latency is not important;
• The permanent extensions contain i.e. check sums;
• Why do we send time frames before they are complete?
  • This correspond to different steps of processing;
  • We may need intermediate checks inside the time frame.
• The calibration is associated with the time frame, but the algorithm may take longer, so we probably need more than one data stream from FLP to EPN;
  • Publish the calibration information in a separate stream, correlated/linked, but not integrated within the time frame;
• EPNs will need the full history for the space charge corrections;
• A possible data structure of the CWG13 repository:
  • Base: contains i.e. the descriptions of the data structures, base classes, etc.;
  • Common: common algorithms;
  • FLP specific code;
  • EPN specific code.

 
Action list:

• Common meeting with CWG3 on the calibration data flow (16/04/2014);
• Start the development of the data model headers.