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[netCDF #NJG-578265]: Netcdf4 and multi-unlimited dimension

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  • Subject: [netCDF #NJG-578265]: Netcdf4 and multi-unlimited dimension
  • Date: Thu, 10 Jul 2008 08:51:40 -0600
Ludovic,

We don't have a Use Case Diagram for using parallel netCDF, but
it's most useful when you need to write into a single netCDF file
from a program such as a model running on multiple processors, and
more than one processor needs to write to the file at the same time.
This occurs a lot in high-performance computing contexts where, for
example, a model is running on a large supercomputer and needs to
output information at intermediate time steps or for restarting the
model without duplicating a lot of work, in case something goes wrong.

There are currently two implementations of parallel netCDF, one from
an independent project:

  http://trac.mcs.anl.gov/projects/parallel-netcdf

and the other is included in the netCDF-4.0 distribution, implemented
over HDF5's parallel I/O:

  http://www.unidata.ucar.edu/netcdf/docs/netcdf-c.html#parallel-access

There is also a section of our online netCDF workshop for developers and data
providers that covers both types of parallel I/O:

  http://www.unidata.ucar.edu/netcdf/workshops/2007/nc4features/Parallel.html
  http://www.unidata.ucar.edu/netcdf/workshops/2007/pnetcdf/index.html

--Russ


--Russ

Russ Rew                                         UCAR Unidata Program
address@hidden                     http://www.unidata.ucar.edu



Ticket Details
===================
Ticket ID: NJG-578265
Department: Support netCDF
Priority: Normal
Status: Closed