How to Use Paraview in Client-Server Mode Oliver Yang February 11, 2014

How to Use Paraview in Client-Server Mode
Oliver Yang∗
School of Engineering and Centre for Scientific Computing
February 11, 2014
In this tutorial, I will demonstrate how to use Paraview in client-server mode on
Minerva system at University of Warwick. This is an extremely useful feature for Paraview when you want to visualized very large data set. First, I’d like to thank Mr Olav
Smørholm for kindly making Paraview work on Minerva cluster and the useful discussion
about Paraview and VisIt softwares with Professor Tony Arber and Dr Keith Bennett.
If you are interesting at the problem we had about Paraview on Minerva, please refer
to this bug on CSC bugzilla: https://bugzilla.csc.warwick.ac.uk/bugzilla/show_
bug.cgi?id=8553.
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Launch Paraview-3.14.1 Client
Currently, there are two Paraview versions installed on Minerva, i.e., Paraview-3.14.1 and
Paraview-4.1.0. According to my experience, Paraview-3.14.1 tends to work more robust
than Paraview-4.1.0, thus I will do the demonstration base on Paraview-3.14.1. To be
noticed that, when you use Client-Server mode of Paraview, the Client and Server must
use the same Paraview version, otherwise you will end with a connection failure.
For the client end, we will use our local desktop. If you have a good video card
available on your desktop, that would be perfect! To make Paraview-3.14.1 available on
the desktop, the simplest way is to go to the Paraview official webpage and download the
binary package for Paraview-3.14.1, http://www.paraview.org/paraview/resources/
∗
University of Warwick, Coventry, CV4 7AL, U.K.
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software.php.
Figure 1: Download Paraview-3.14.1 for your platform.
Extract the file, and enter ParaView-3.14.1-Linux-64bit/bin/ folder, you should
be able to see the executable file paraview. Type ./paraview on your terminal window
to launch Paraview on your desktop.
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Launch Paraview-3.14.1 Server
We don’t have a specific server for Paraview on Minerva, but we can request some resource
from some queue on Minerva, just like a normal job. You need to do the following
commands to launch Paraview-3.14.1 server.
1) Connect to Minerva using ssh:
[email protected]:$ ssh minerva.csc.warwick.ac.uk
2) Clear all the modules you have loaded by default:
[email protected]:$ module purge
3) There are two module sections on Minerva, one is called oldmodules, which is the
default, and the other is called minerva-2.0. Paraview-3.14.1 is installed in minerva2.0, thus we need to swap the two module sections:
[email protected]:$ module swap oldmodules minerva-2.0
4) Load Paraview-3.14.1. To be noticed, it should be the server part, not the client
part.
[email protected]:$ module load goolf/1.6.10/ParaView/3.14.1-server
5) Request sources from a queue. This includes how many processors and how much
memory you want to use for the Paraview-3.14.1 server. Below is an example .pbs file.
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Here, we are requesting 4 processors and each processor has 1900 MB memory in develop
queue. mpirun pvserver will launch the Paraview server in parallel using the resource
requested. The paraview server will be listening to Port 11111 once the job starts to
run. Submit the .pbs file by
[email protected]:$ msub server.pbs
**********server.pbs**********
#!/bin/bash
#PBS -N pvserver
#PBS -q devel
#PBS -l nodes=4:ppn=1,pvmem=1900mb,walltime=01:00:00
#PBS -V
cd $PBS_O_WORKDIR
mpirun pvserver --use-offscreen-rendering --server-port=11111
> pvserver.log 2>&1
exit
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Connect Client and Server
Once the request resource is available, check the log file for the job pvserver.log to see
which node you are using for the Paraview server. Below is an example for the content
of pvserver.log.
Waiting for client...
Connection URL: cs://node6:11111
Accepting connection(s): node6:11111
A tunnel between our local desktop and Minerva need to be established. This can be
done by typing the following command in a new terminal window.
[email protected]:$ ssh -L 11111:node6:11111 minerva.csc.warwick.ac.uk
You can check the established port on your local computer by running:
[email protected]:$ netstat -lnt
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And you should see a new port address 127.0.0.1:11111. Keep the terminal window
for the tunnel alive all the time while you are running Paraview.
Now you can connect to Paraview server by click the connect button (
) on
the client.
Following the steps to establish the server.
1) Click add server. Then configure the server as shown. You can give any name for
the server you like.
Figure 2: Configure Paraview server.
2) Set startup as manual, then save it. You can also click Save Servers to save
the current configuration, so that you can Load Servers directly, rather than configure
the server again when you use it next time.
Figure 3: Set startup as manual and save it.
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3) Click Connect. If the connection is successful, you will get the message from both
sides. In the client, you can observer
. And in the
pvserver.log file, you can see
Client connected.
Congratulation! you are now using the client-server mode of Paraview-3.14.1. For
every button you click on the client, the calculation will be down on the Paraview server,
but only the rendering is done on your local desktop. To be noticed that, when using
client-server mode, your input files are on Minerva side, while your output files are on
your local desktop side. Below is an example visualized in this way. The surface is
coloured by the processor ID, so that you can see how the job is distributed among the
processors.
Figure 4: Near wall turbulent structure in a channel flow, colored by the processor ID.
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Run scripts on batch mode
Even though client-server mode is a very powerful way to use paraview, it is still not wise
to run Paraview interactively for a very big data set. Because you may waste lots of time
waiting in front of your client. In this situation, pvbatch can be very helpful.
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First, you need to record a script file in Paraview by using a smaller data set. To
start recording the script file, go to Tools → Start Trace. A message will shown at the
. You can then use
left bottom of Paraview, saying
the mouse to set the snapshot you want. After that, click Tools → Stop Trace, and
you will see the content of the script file written in python language, as shown in figure
5. Save it to somewhere. You can use vim to open the script file, say trace.py, and
change the input path to your large data set.
Figure 5: Script file in python.
You can then run the script file with pvbatch in parallel. The .pbs file should look
like this.
**********trace.pbs**********
#!/bin/bash
#PBS -l nodes=4:ppn=1,pvmem=1900mb,walltime=00:30:00
#PBS -V
cd $PBS_O_WORKDIR
mpirun pvbatch --use-offscreen-rendering trace.py
exit 0
∼ Thank you for your reading! ∼
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