Currently there are several operations in HDF5 that can issue
metadata reads from the metadata cache, but that take no property list.
It is therefore not possible set a collective requirement individually
for those operations.
The only solution with the HDF5 1.10.0 release is to set the
collective requirement globally on H5Fopen or
H5Fcreate for all metadata operations to be collective.
The following is a list of those functions in the HDF5 Library. This list is integral to the discussion in the H5Pset_all_coll_metadata_ops entry:
Functions with No Access Property List Parameter
that May Generate Metadata Reads
H5Awrite H5Aread H5Arename H5Aiterate2 H5Adelete H5Aexists H5Dget_space_status H5Dget_storage_size H5Dset_extent H5Ddebug H5Dclose H5Dget_get_create_plist H5Dget_space (when dataset is a virtual dataset) H5Gget_create_plist H5Gget_info H5Gclose H5Literate H5Lvisit H5Rcreate H5Rdereference2 (when reference is an object reference) H5Rget_region H5Rget_obj_type2 H5Rget_name H5Ocopy H5Oopen_by_addr H5Oincr_refcount H5Odecr_refcount H5Oget_info H5Oset_comment H5Ovisit H5Fis_hdf5 H5Fflush H5Fclose H5Fget_file_image H5Freopen H5Fget_freespace H5Fget_info2 H5Fget_free_sections H5Fmount H5Funmount H5Iget_name H5Tget_create_plist H5Tclose H5ZunregisterAnd most deprecated functions
The HDF Group may address the above limitation in a future major release, but no decision has been made at this time. Such a change might, for example, include adding new versions of some or all the above functions with an extra property list parameter to allow an individual setting for the collective calling requirement.