NERSCPowering Scientific Discovery Since 1974

Data Management

PDSF and IHEP, in Beijing, China, are the two main computing facitilies for the Daya Bay experiment with PDSF being used primarily by North American collaborators and IHEP by Asian collaborators.  All raw data from the experimental facility is first transferred to IHEP and then transferred to PDSF.  Data transfer rates of 5 to 10 MB/s result in up to about 500GB transferred daily.

The tool used to transfer the data is called SPADE and has also been used at PDSF by the icecube experiment.  SPADE is run on one of the PDSF interactive nodes and uses globus-gridftp-server to configure a GridFTP server.  Files are transferred through the interactive node to one of the dayabay elizas where they are cataloged and processed into .root files.  After each .root file is produced diagnostic plots are put on the web via the Daya Bay Science Gateway.  The .root files are then analyzed on PDSF by Daya Bay collaborators or transferred to their local institutions for processing there. 

HPSS is used by Daya Bay to archive the raw data and the .root files as well as the results of large Monte Carlo productions that are run on PDSF.  Files are stored under the Daya Bay HPSS project directory /nersc/projects/dayabay.