[Paraview] [paraview] using with python, mpi pvserver and scalar opacity (3.7)

[burlen]

*Wait a sec... I am not sure I agree with with you after all. Upon 
closer inspection it looks to me like all of the process do end up with 
a copy of the entire dataset in memory when using legacy readers. At the 
very least in between the read and the automagic PV load balancing you 
pointed out, possibly longer depending on how long the pipeline holds 
the reader output.

It looks as though legacy files are read by PV using vtkPDataSetReader. 
I put a couple print statements that show process Id and the number of 
points read on each process during request data. See the attached patch. 
When I run multiple pvservers all processes output the same response as 
a serial run.

For example, using "CylinderQuadratic.vtk" as a test case i get:

$mpiexec -np 2 bin/pvserver --server-port=22222
Listen on port: 22222
Waiting for client...
Waiting for server...
Client connected.
1 Read 2814
0 Read 2814

while with just the builtin I get:

0 Read 2814

> *Berk Geveci* berk.geveci at kitware.com 
> <mailto:paraview%40paraview.org?Subject=Re%3A%20%5BParaview%5D%20%5Bparaview%5D%20using%20with%20python%2C%0A%09mpi%20pvserver%20and%20scalar%20%09opacity%20%283.7%29&In-Reply-To=%3C45d654b0906161227m74ae70d8n79afb5cb6ef174e9%40mail.gmail.com%3E>
> /Tue Jun 16 15:27:58 EDT 2009/
> ------------------------------------------------------------------------
> You can apply Process Id Scalars and then color by ProcessId or use
> Threshold to extract a piece.
>
> The implementation is in vtkSMOutputPort::InsertExtractPiecesIfNecessary()
>
> -berk
>
> On Tue, Jun 16, 2009 at 3:09 PM, burlen<burlen.loring at gmail.com <http://www.paraview.org/mailman/listinfo/paraview>> wrote:
> >/ I stand corrected. I have heard so many different claims in term so how PV
> />/ treats serial readers, it's hard to keep them all straight.
> />/
> />/ Where in the ParaView does the automatic domain decomposition and load
> />/ balancing occur?  Is there a way to take a look at the decomposition from
> />/ within PV?
> />/
> />/ Berk Geveci wrote:
> />>/
> />>/ This is not correct. The reader is indeed serial. However, ParaView
> />>/ redistributes the data after reading it. So the resulting mesh will be
> />>/ load balanced across processors but there will be an I/O and/or
> />>/ communication overhead.
> />>/
> />>/ Note that for unstructured meshes, the redistribution is not
> />>/ necessarily based on spatial partitioning. If you want a nicely
> />>/ partitioned and load balanced mesh, use D3.
> />>/
> />>/ -berk
> />>/
> />>/ On Fri, Jun 5, 2009 at 11:50 AM, burlen<burlen.loring at gmail.com <http://www.paraview.org/mailman/listinfo/paraview>> wrote:
> />>/
> />>>/
> />>>/ Perhaps unrelated but I see you are using the legacy reader. As far as I
> />>>/ know this reader is not parallel and so if you use it while running in
> />>>/ parallel you'll end up with entire data set loaded in all the processes.
> />>>/ Probably not what you had in mind.
> />>>/
> />>>/ BOUSSOIR Jonathan 167706 wrote:
> />>>/
> />>>>/
> />>>>/ Hi all,
> />>>>/
> />>>>/ I am using Linux and last csv version of Paraview (3.7)
> />>>>/ I have 2 Pyphon script which animate a cylinder either with or without
> />>>>/ scalar opacity.
> />>>>/ When I use "pvserver" on one CPU, both work well.
> />>>>/ If I use "mpirun -np 4 pvserver" to work on four cpu, I saw a color
> />>>>/ problem when I use script with scalar opacity.
> />>>>/ I don't understand why.
> />>>>/
> />>>>/ I link the scipts in my email.
> />>>>/ Thanks in advance for your kind help.
> />>>>/
> />>>>/ Regards, Jona
> />>>>/
> />>>>/
> />>>>/
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*

/
/

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