Belle II experiment Requirement of data handling system Belle II Metadata service system Data Cache system at Belle II experiment Summary

1. Belle II experiment Accelerator update ⇒ Super KEKB Circulation: 3km Beam Energy Asymmetric: 7.0(e-) X 4.0(e+) → 10.58 GeV (CM)

1. Belle II experiment Belle II Belle Belle Content Belle II 1999~2010 Time Schedule 2014~ 1 ab-1 Luminosity 50 ab-1 1 Billion BBbar events 50 Billion CP measurement Goal New Physics Belle II Belle

2. Requirement of data handling system @ Belle II experiment We need MC(at least data X 3)/data for an analysis. It takes 20 days for skimming using Belle data (2.4 billion events). We suppose 50 times larger data of Belle II than that of Belle. If we suppose that the technology be improved two times, then we can estimate 500 days for Belle II pre-selection works. We suggest the meta system of the event-level and Data Cache system. If we have the good information at metadata system, then we can reduce the CPU times for pre-selection. ex) Fox-Wolfram momentum, number of tracks and so on

To construct the DH system for Belle II experiment 3. Belle II Metadata service system To construct the DH system for Belle II experiment To improve the scalability and performance To run based on grid farm ⇒ AMGA (Arda Metadata Catalog for Grid Application) Data Cache AMGA

4. Data Cache system at Belle II experiment Every pre-selection data is stored in mDST (mini Data Structure Table) format. However, these files occupy so much disk space. Then, we start suffering from the lack of disk space. Basically, Index file has information of the Run period / Run number / Event number of events which have been passed the selection. So, the size of file can be reduced very much. However, the current system has a demerit because it can be used only at local network, not on Grid. Therefore, we have developed the Data Cache system which works on Grid.

4. Data Cache system at Belle II experiment * SE (Storage Element)

4. Data Cache system at Belle II experiment We make the simple data tool which is not based on database.

4. Data Cache system at Belle II experiment The estimation of Data Cache We select the sample data for the estimation of Data Cache. We obtain the metadata from event-level searching. The results show same between Belle and Belle II. We reduce the size of index file.

4. Data Cache system at Belle II experiment (Byte)

5. Summary Constructed the searching service system Designed and developed the Data Cache system Connected the Data Cache system and searching system Estimated the Data Cache system Found and applied Grid system