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[netCDF #KLC-386191]: Quick question about parallel netCDF

Hi Rodney,

> I was wondering if it was possible to use C++ with parallel netCDF. I
> wasn't able to find anything conclusive on your website about the matter.

The version 4.2 of the netCDF-4 C++ library is implemented as a layer
above the netCDF-4 C interface, which supports parallel I/O using
either the underlying HDF5 parallel I/O functionality or the separate
netCDF-3-based parallel netCDF package from Argonne/Northwestern.

However, the netCDF-4 C++ library doesn't expose any of the parallel
functionality provided by the C library, so to make use of parallel
I/O, you would have to make calls to the C library from a C++ program.
This isn't documented and hasn't been tested, so it might require some
additional care to make sure you don't violate invariants or
assumptions made in the C++ implementation.

So a quick answer is "no", parallel I/O isn't explicitly supported in
the C++ library, only the C and Fortran-90 libraries currently.  It
would take some work to understand the C++ implementation and
implement the C++ analogues for nc_create_par() and nc_open_par()
functions that create or open a netCDF file for parallel access.

I'm Cc:ing the netCDF-4 C++ developer, in case he has any other
comments about parallel I/O with netCDF C++ or needs to correct any
mistakes I've made.

--Russ

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



Ticket Details
===================
Ticket ID: KLC-386191
Department: Support netCDF
Priority: Normal
Status: Closed