HDF5 documents and links 
Introduction to HDF5 
HDF5 User’s Guide 
In the HDF5 Reference Manual 
H5DS   H5IM   H5LT   H5PT   H5TB  Optimized 
H5   H5A   H5D   H5E   H5F   H5G   H5I   H5L 
H5O   H5P   H5PL   H5R   H5S   H5T   H5Z 
Tools   Datatypes   Fortran   Compatibility Macros 
Collective Calls in Parallel 

Collective Calling Requirements
in Parallel HDF5 Applications

Introduction

This document addresses two topics of concern in a parallel computing environment:

The term Macro in the “Additional notes” column indicates that the first item in the “Function” column of the same row is a macro that is selectively mapped to one of the two immediately-following functions. For example, H5Acreate is a macro that can be mapped to either H5Acreate1 or H5Acreate2. This mapping is configurable and is explained in “API Compatibility Macros in HDF5.” The macro structure was introduced at HDF5 Release 1.8.0.

Always collective

The following functions must always be called collectively.

API Function All processes:
same datatype
& dataspace
All processes:
same access
properties
All processes:
same creation
properties
Available in
releases since
Additional notes
H5A H5Acreate
H5Acreate1
H5Acreate2
1.8.x Macro
The function H5Acreate was renamed to H5Acreate1 at Release 1.8.0.
  H5Acreate_by_name 1.8.x  
  H5Adelete          
  H5Adelete_by_idx       1.8.x  
  H5Adelete_by_name       1.8.x  
  H5Arename       1.6.x  
  H5Arename_by_name       1.8.x  
  H5Awrite         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.
 
H5D H5Dcreate
H5Dcreate1
H5Dcreate2
1.8.x Macro
The function H5Dcreate was renamed to H5Dcreate1 at Release 1.8.0.
  H5Dcreate_anon 1.8.x  
  H5Dextend         All processes must participate only if the number of chunks in the dataset actually changes.
All processes must use the same dataspace dimensions.
  H5Dset_extent       1.6.x All processes must participate only if the number of chunks in the dataset actually changes.
All processes must use the same dataspace dimensions.
 
H5F H5Fclose         All processes must participate only if this is the last reference to the file identifier.
  H5Fcreate      
  H5Fflush          
  H5Fmount          
  H5Fopen        
  H5Freopen          
  H5Funmount          
 
H5G H5Gcreate
H5Gcreate1
H5Gcreate2
  1.8.x Macro
The function H5Gcreate was renamed to H5Gcreate1 at Release 1.8.0.
  H5Gcreate_anon   1.8.x  
  H5Glink          
  H5Glink2       1.6.x  
  H5Gmove          
  H5Gmove2       1.6.x  
  H5Gset_comment          
  H5Gunlink          
 
H5I H5Idec_ref       1.6.x This function may be called independently if the object identifier does not refer to an object that was collectively opened.
  H5LIinc_ref       1.6.x This function may be called independently if the object identifier does not refer to an object that was collectively opened.
 
H5L H5Lcopy       1.8.x  
  H5Lcreate_external     1.8.x  
  H5Lcreate_hard     1.8.x  
  H5Lcreate_soft     1.8.x  
  H5Lcreate_ud     1.8.x  
  H5Ldelete       1.8.x  
  H5Ldelete_by_idx       1.8.x  
  H5Lmove       1.8.x  
 
H5O H5Ocopy       1.8.x  
  H5Odecr_refcount       1.8.x  
  H5Oincr_refcount       1.8.x  
  H5Olink       1.8.x  
  H5Oset_comment       1.8.x  
  H5Oset_comment_by_name       1.8.x  
 
H5R H5Rcreate          
 
H5T H5Tcommit
H5Tcommit1
H5Tcommit2
  1.8.x Macro
The function H5Tcommit was renamed to H5Tcommit1 at Release 1.8.0.
  H5Tcommit_anon   1.8.x  

Collective, unless target object will not be modified

The following functions must normally be called collectively. If, however, the target object will not be modified, they may be called independently.

API Function All processes:
same datatype
& dataspace
All processes:
same access
properties
All processes:
same creation
properties
Available in
releases since
Additional notes
H5A H5Aclose         All processes must participate only if all file identifiers for a file have been closed and this is the last outstanding object identifier.
  H5Aopen     1.8.x  
  H5Aopen_by_idx     1.8.x  
  H5Aopen_by_name     1.8.x  
  H5Aopen_idx        
  H5Aopen_name        
 
H5D H5Dclose         All processes must participate only if all file identifiers for a file have been closed and this is the last outstanding object identifier.
  H5Dopen
H5Dopen1
H5Dopen2
    1.8.x Macro
The function H5Dopen was renamed to H5Dopen1 at Release 1.8.0.
 
H5G H5Gclose         All processes must participate only if all file identifiers for a file have been closed and this is the last outstanding object identifier.
  H5Gopen
H5Gopen1
H5Gopen2
    1.8.x Macro
The function H5Gopen was renamed to H5Gopen1 at Release 1.8.0.
 
H5I H5Iget_file_id       1.8.x  
 
H5O H5Oclose       1.8.x All processes must participate only if all file identifiers for a file have been closed and this is the last outstanding object identifier.
  H5Oopen     1.8.x  
  H5Oopen_by_addr     1.8.x  
  H5Oopen_by_idx     1.8.x  
 
H5R H5Rdereference          
 
H5T H5Tclose         All processes must participate only if the datatype is for a committed datatype, all the file identifiers for the file have been closed, and this is the last outstanding object identifier.
  H5Topen
H5Topen1
H5Topen2
    1.8.x Macro
The function H5Topen was renamed to H5Topen1 at Release 1.8.0.

Properties

The following properties must be set to the same values for an object or link in all cases where the object or link is accessed in a parallel program.
Function Available in
releases since
Dataset creation properties
H5Pmodify_filter 1.8.x
H5Premove_filter 1.8.x
H5Pset_alloc_time  
H5Pset_chunk  
H5Pset_external  
H5Pset_fill_time  
H5Pset_fill_value  
H5Pset_filter  
H5Pset_fletcher32 1.8.x
H5Pset_layout  
H5Pset_nbit 1.8.x
H5Pset_shuffle  
H5Pset_szip  
 
Dataset transfer properties
H5Pset_btree_ratios  
H5Pset_buffer  
H5Pset_dxpl_mpio  
H5Pset_hyper_cache  
H5Pset_preserve  
 
File access properties
H5Pset_alignment  
H5Pset_cache  
H5Pset_fapl_mpio  
H5Pset_fclose_degree  
H5Pset_gc_references  
H5Pset_latest_format 1.8.x
H5Pset_libver_bounds 1.8.x
H5Pset_mdc_config  
H5Pset_meta_block_size  
H5Pset_small_data_block_size     
H5Pset_sieve_buf_size  
 
Function Available in
releases since
File creation properties
H5Pset_istore_k  
H5Pset_shared_mesg_index 1.8.x
H5Pset_shared_mesg_nindexes 1.8.x
H5Pset_shared_mesg_phase_change 1.8.x
H5Pset_sizes  
H5Pset_sym_k  
H5Pset_userblock  
 
Group creation properties
H5Pset_ext_link_info 1.8.x
H5Pset_link_creation_order 1.8.x
H5Pset_link_phase_change 1.8.x
H5Pset_local_heap_size_hint 1.8.x
 
Link creation properties
H5Pset_char_encoding 1.8.x
H5Pset_create_intermediate_group    1.8.x
 
Object creation properties
H5Pset_attr_phase_change 1.8.x
H5Pset_attr_creation_order 1.8.x
H5Pset_obj_track_times 1.8.x
 
Object copy properties
H5Pset_copy_object 1.8.x

HDF5 documents and links 
Introduction to HDF5 
HDF5 User’s Guide 
In the HDF5 Reference Manual 
H5DS   H5IM   H5LT   H5PT   H5TB  Optimized 
H5   H5A   H5D   H5E   H5F   H5G   H5I   H5L 
H5O   H5P   H5PL   H5R   H5S   H5T   H5Z 
Tools   Datatypes   Fortran   Compatibility Macros 
Collective Calls in Parallel 

The HDF Group Help Desk:
Describes HDF5 Development Trunk, Release 1.11.x.
Highest current public release is HDF5 Release 1.8.x.
  Copyright by The HDF Group