Hi all,
On Feb 26, 2010, at 3:10 AM, Mark Miller wrote:
> I took a brief look at your reference.
>
> There are a couple bullets there with the word 'concurrent' in them.
> However, its really sketchy for me to determine how that term is being
> used in this context.
>
> Is it concurrent writes? Is it concurrent read with write? Is the
> concurrency totally independent or coordinated?
>
> For what its worth, I am certain that HDF5 supports concurrent writes
> from multiple MPI tasks using the MPI vfds (MPI is used to coordinate
> things). I am also certain you can perform totally independent writes to
> different HDF5 files and then do some simple tricks with links such that
> the collection of files can be treated and viewed by HDF5 applications
> as a single, large HDF5 file. So, you get what amounts to a) concurrent
> writes and b) a single, large, global file. That sounds basically like
> what the bullets describing MDSplus do in the reference.
I took a look through the reference he provides and there's a number of
inaccuracies about HDF5 there (which I don't have the time to detail here). I
agree with you about the lack of detail about what is meant by concurrent
writing, so I'll just provide some additional information to yours about
writing with MPI. Multiple-threaded writing is also provided through the HDF5
library being thread safe. Perhaps these two pieces of information will give
Lana enough information to go back and get more details about what MDPlus means
by concurrent writing.
Quincey
> Mark
>
>
> On Fri, 2010-02-26 at 00:46, lana abadie wrote:
>> Hi all
>> i came across this paper
>> :
>> http://*www-fusion-magnetique.cea.fr/tmiaea2009/website/data/fastaux.html?href=docs/000085.ppt
>> it says that concurrent write access is not supported by HDF5.
>> Any comments?
>> thanks
>> Lana
>>
>> ______________________________________________________________________
>> _______________________________________________
>> Hdf-forum is for HDF software users discussion.
>> Hdf-forum@hdfgroup.org
>> http://*mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
> --
> Mark C. Miller, Lawrence Livermore National Laboratory
> ================!!LLNL BUSINESS ONLY!!================
> mille...@llnl.gov urgent: mille...@pager.llnl.gov
> T:8-6 (925)-423-5901 M/W/Th:7-12,2-7 (530)-753-851
>
>
> _______________________________________________
> Hdf-forum is for HDF software users discussion.
> Hdf-forum@hdfgroup.org
> http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
_______________________________________________
Hdf-forum is for HDF software users discussion.
Hdf-forum@hdfgroup.org
http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
