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H5P_SET_COLL_METADATA_WRITE

Sets metadata write mode to collective or independent (default)

Procedure:

H5P_SET_COLL_METADATA_WRITE ( apl_id, is_collective )

Signature:

herr_t H5Pset_coll_metadata_write(
              hid_t fapl_id,
              hbool_t is_collective
        )
    

Fortran Interface: h5pset_coll_metadata_write_f
 
Signature:
  SUBROUTINE h5pset_coll_metadata_write_f(plist_id, is_collective, hdferr)
    INTEGER(HID_T)  , INTENT(IN)  :: plist_id
    LOGICAL, INTENT(IN)           :: is_collective
    INTEGER, INTENT(OUT)          :: hdferr


Inputs:
  fapl_id        - File access property list identifier.
  is_collective  - Indicates if metadata writes are collective or not.


Outputs:
  hdferr         - Returns 0 if successful and -1 if fails.
        

Parameters:
hid_t fapl_idIN: File access propery list identifier
hbool_t is_collectiveIN: Boolean value indicating whether metadata writes are collective (1) or independent (0)
Default mode: Independent (0)

Description:

H5P_SET_COLL_METADATA_WRITE tells the HDF5 library whether to perform metadata writes collectively (1) or independently (0).

If collective access is selected, then on a flush of the metadata cache, all processes will divide the metadata cache entries to be flushed evenly among themselves and issue a single MPI-IO collective write operation. This is the preferred method when the size of the metadata created by the application is large.

If independent access is selected, the library uses the default method for doing metadata I/O either from process zero or independently from each process.

 

Returns:

Returns a non-negative value if successful; otherwise returns a negative value.

Example:

History:
Release    Change
1.10.0C function and Fortran wrapper introduced with this release.

--- Last Modified: July 22, 2020 | 11:23 AM