Re: [h5md-user] Strings again / parallel issue

[Peter Colberg]

On Tue, Feb 04, 2014 at 07:42:19PM +0100, Pierre de Buyl wrote:
> Check the other file, parallel_string_attribute.f90. The call to h5awrite_f is
> done on every rank. And it writes the attribute correctly. The program
> parallel_vl_string_attribute.f90 does not execute properly.

You are right; HDF5 mandates calling H5Awrite from all processes:

http://www.hdfgroup.org/HDF5/doc/RM/CollectiveCalls.html

“Because raw data for an attribute is cached locally, all processes
must participate in order to guarantee that future H5Aread calls
return correct results on all processes.”

I will prepare a test case as well, to better understand this issue.

Regards,
Peter