[Users] Chunked checkpoints with unchunked HDF5_3D output?

[Bernard Kelly]

Hi Roland.

Thanks for the suggestion and code snippets. I tried them out on a
small test case with two variants, and they seemed to work OK:

variant 1: I made a new parameter "unchunked3D" so that I could turn
this on and off:

if ((outdim  == 3) && unchunked3D) { // don't split files
  nioprocs = 1;
  ioproc = 0;
  ioproc_every = dist::size();
} else if (outdim  == 3) { // only 3D output splits files
   const ioGH *IO = (ioGH *) CCTK_GHExtension (cctkGH, "IO");
   assert(IO);
   nioprocs = IO->nioprocs;
} else {...

variant 2: To solve the single-file-per-timestep issue, I needed
"cctkGH->cctk_iteration", rather than just "cctk_iteration"

 basefilenamebuf << my_out_slice_dir << "/" << alias << ".it_" <<
cctkGH->cctk_iteration;

The problem is, now my 2D HDF5 output is *also* split by time step,
which I didn't want/need.

Bernard

On 6 January 2016 at 16:24, Roland Haas <rhaas at aei.mpg.de> wrote:
> Hello Bernard,
>
>> I was originally using out3D_vars etc, but the resulting output was
>> always *chunked* and *cumulative* over time. I don't see a parameter
>> that controls this behavior in CarpetIOHDF5/param.ccl.
> Hmm, in that case you will have to modify C++ code. In CarpetIOHDF5's
> OutputSlice.cc near the end of the routine CheckSteerableParameters
> (around line 215 in my checkout) you will see code:
> --8<--
>     // copy ioprocs and ioproc ot
>     if (outdim  == 3) { // only 3D output splits files
>       const ioGH *IO = (ioGH *) CCTK_GHExtension (cctkGH, "IO");
>       assert(IO);
>       nioprocs = IO->nioprocs;
>       ioproc = IO->ioproc;
>       ioproc_every = IO->ioproc_every;
>       //cout << "nioprocs: " << nioprocs << " ioproc: " << ioproc << endl;
>     } else {
>       nioprocs = 1;
>       ioproc = 0;
>       ioproc_every = dist::size();
>     }
> --8<--
> which tells you that out1d and out2d are always unchunked (one file) and
> out3d respects nioprocs which is what "onefile" sets. So in order to get
> unchuncked 3d output you'd have to make the outdim == 3 case look like
> the else case. Note that the current code does what it ought to do: it
> respects your "onefile" choice.
>
> The single file issue is a bug, and needs a fix. The easiest by far will
> be to add ".it_XXX" to basefilenamebuf in OutputVarAs around line 461,
> ie make it look like this:
>
> --8<--
>       ostringstream basefilenamebuf;
>       basefilenamebuf << my_out_slice_dir << "/" << alias << ".it_" <<
> cctk_iteration;
>       const string basefilename = basefilenamebuf.str();
> --8<--
>
> mind you, this is a hack though :-) it really should be controlled by
> the out_timesteps_per_file option.
>
> Yours,
> Roland
>
> --
> My email is as private as my paper mail. I therefore support encrypting
> and signing email messages. Get my PGP key from http://keys.gnupg.net.
>
>
> _______________________________________________
> Users mailing list
> Users at einsteintoolkit.org
> http://lists.einsteintoolkit.org/mailman/listinfo/users
>