HDF with MPI and CPP

Hdf-forum archives
1

Hi,

I have had compiled the current HDF lib with --enabled-cxx and use the C++ interface. Now I would like to switch HDF with MPI. Can I use Cpp and MPI together?

Thanks for the information

Phil

2

Hi Phil,

Depends on mean with MPI. PHDF5 uses MPI-IO to support
parallel I/O to HDF5 files and it has C and Fortran APIs
but no C++ API. Therefore, if you want to do parallel
access to HDF5 file via C++ calls, it won't work.

If you use MPI for the compute and inter-processes
communication but limit each HDF5 file access to a single
process which in turn gathers and scatters HDF5 file data
with other processes, that would still work.

If you want to use parallel access to the HDF5 files, you
would have to code your C++ application to call the PHDF5
C APIs.

Hope this answers your question.

-Albert

···

At 04:46 AM 7/16/2010, Kraus Philipp wrote:

Hi,

I have had compiled the current HDF lib with --enabled-cxx and use the
C++ interface. Now I would like to switch HDF with MPI. Can I use Cpp
and MPI together?

Thanks for the information

Phil

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

3

Hi Albert,

thanks for the answer. I use only "single I/O access" for reading / writing my data to the HDF. Only my master process is using the file

Phil

···

Am 16.07.2010 um 16:37 schrieb Albert Cheng:

Hi Phil,

Depends on mean with MPI. PHDF5 uses MPI-IO to support
parallel I/O to HDF5 files and it has C and Fortran APIs
but no C++ API. Therefore, if you want to do parallel
access to HDF5 file via C++ calls, it won't work.

If you use MPI for the compute and inter-processes
communication but limit each HDF5 file access to a single
process which in turn gathers and scatters HDF5 file data
with other processes, that would still work.

If you want to use parallel access to the HDF5 files, you
would have to code your C++ application to call the PHDF5
C APIs.

Hope this answers your question.

-Albert

At 04:46 AM 7/16/2010, Kraus Philipp wrote:

Hi,

I have had compiled the current HDF lib with --enabled-cxx and use the
C++ interface. Now I would like to switch HDF with MPI. Can I use Cpp
and MPI together?

Thanks for the information

Phil

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org

_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org