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Re: [H5part] FYI: H5Part-1.3.2 has been released

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  • From: John Shalf <jshalf AT>
  • To: Achim Gsell <achim AT>
  • Cc: John Biddiscombe <biddisco AT>, h5part AT
  • Subject: Re: [H5part] FYI: H5Part-1.3.2 has been released
  • Date: Thu, 19 Apr 2007 11:18:56 -0700
  • List-archive: <>
  • List-id: H5Part development and discussion <>

On Apr 19, 2007, at 10:45 AM, Achim Gsell wrote:
On Thursday 19 April 2007 17:53, John Biddiscombe wrote:
2) Added option to use INDEPENDENT_IO instead of
COLLECTIVE_IO, I need this when using it on a system with a
non-parallel file-system, using collective IO causes too large
performance drop on our cluster.

INDEPENDENT_IO vs COLLECTIVE_IO in H5Part, good point. A couple
of weeks ago a college found a bug in H5Part concerning
COLLECTIVE_IO (or we understand something completely wrong): The
H5FD_MPIO_COLLECTIVE property is added to the property list
f->xfer_prop, but this property list is not used in I/O calls.
Thus we are using independent I/O. It's the same in version 1.0!
John (Shalf), any idea/comments about this?

Either it is a mistake or a misunderstanding about the operation of parallelIO with HDF5. I was under the impression that if you open a file with the COLLECTIVE_IO property, that the implicit mode of operation for the files is collective unless you tell it otherwise. If this is not the case, then we should make sure the collective property is added to all of the xfer lists (but I assume it is implicit if the file was opened in collective mode).

Lets do some regression testing with the benchmark (bench.c) to see if there is in fact a difference or not.

6) Added a function to query IsTimeStep Present, so
that I don't overwrite an existing one if redoing the same

For me it is OK to add such a function, but SetStep already
returns an error, if the step exists.

Yes, that was the reason we didn't add that function.

If I update my copy to work with your 1.3.2 (svn head), can I
send you a large patch with all of it in, or would you prefer
smaller patches which address individual issues (much more

Since I want to review the patches, I prefer a set of smaller

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