== How to run !ParaView on multiple nodes at the same time (= in parallel)
[[PageOutline]]

"ParaView is designed to work well in client/server mode. In this way, users can have the full advantage of using a shared remote high-performance rendering cluster without leaving their offices." [http://www.paraview.org/Wiki/Setting_up_a_ParaView_Server link]

In the following the instructions are for a cluster at the RWTH Aachen University. It should not be too difficult to adopt these to the JSC clusters. We will change these webpage in the future.

=== load ParaView module ===
Prepare first:
{{{ #!ShellExample
    linuxtdc[1-6]:> module load gcc
    linuxtdc[1-6]:> module load openmpi/1.6.5
    linuxtdc[1-6]:> export PATH=/home/vrsw/Qt/qt-4.8.5/LINUX.X86_64/bin/:${PATH}
}}}

Load !ParaView module (compiled for parallel pvserver)
{{{ #!ShellExample
    linuxtdc[1-6]:> export MODULEPATH=${MODULEPATH}:/home/vrsw/modules/modulefiles
    linuxtdc[1-6]:> module load INSITU
    linuxtdc[1-6]:> module load ParaView
}}}

=== start !ParaView server on linuxtdc[1-6]´s display 0 and render into local framebuffer ===
Check for details here: http://www.paraview.org/Wiki/Setting_up_a_ParaView_Server \\
Communication between client<->server(first node) is by default via socket connection  on port 11111, but only 5600-5609 are open (therefore below we use 5601).

single paraview server:
{{{ #!ShellExample
    linuxtdc[1-6]:> export DISPLAY=:0
    linuxtdc[1-6]:> export XAUTHORITY=/var/run/Xauthority-vr
    linuxtdc[1-6]:> pvserver --server-port=5601
}}}

multiple paraview server: \\
Make sure pvserver was compiled with the MPI you use, or you will end up with: \\
//vtkServerSocket (0xf62390): Socket error in call to bind. Address already in use.//
{{{ #!ShellExample
    linuxtdc[1-6]:> export DISPLAY=:0
    linuxtdc[1-6]:> export XAUTHORITY=/var/run/Xauthority-vr
    linuxtdc[1-6]:> mpiexec --skip -np 4 -x DISPLAY -x XAUTHORITY pvserver --server-port=5601
}}}

=== start ParaView client ===
start !ParaView on your local machine and connect to server on linuxtdc[1-6]:5601
 
-----------------------------------

=== tunnel port to localhost ===
If you are outside of the ITCenter, you have to tunnel the port to your localhost first:
{{{ #!ShellExample
    ssh -f -N -L 5601:linuxtdc[1-6].rz.rwth-aachen.de:5601 <TIM-ID>@cluster.rz.rwth-aachen.de
}}}

Then connect to 'localhost:5601' instead of 'linuxtdc[1-6] from the !ParaView client.


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any feedback welcomed - h.zilken@fz.juelich.de, goebbert@jara.rwth-aachen.de