[Paraview] Bug 0006714: pvbatch requires X server

[Kent Eschenberg]

Hi Utkarsh,

Sorry its taken so long to try this. Summary: nothing changed - it still fails exactly as before.

You might want to take a close look at your environment when you test it. When you log onto a parallel system I think you still provide a way for it to reach an X server. My parallel system also has no X server but it still got back to the X server of my workstation via the ssh connection which sets the environment variable DISPLAY. When I ran the program I would see windows appearing on the screen for a second. However, when I unset the environment variable DISPLAY it crashed.

More importantly, I tried to emulate the situation would would have in a true batch environment such as we have on the XT3. There, jobs are submitted with the qsub command. What is submitted is a script. qsub is not used on the Linux cluster where I am testing this but I can emulate it with the "at" command. Example: "at -f cut.job NOW" submits file cut.job for immediate execution. That file is simple:

mpiexec -np 2 pvbatch --use-offscreen-rendering cut.py >& cut.log

My default environment variables LD_LIBRARY_PATH and PATH select the correct version of pvbatch, i.e., the compiled from CVS with MPI. However, when submitted this way, the environment variable DISPLAY is not set. The above job fails with no output because of the bad X server connection.

I've attached one of the Python scripts I've been using for testing. I might not be setting something in it that is needed.

Cheers,
Kent

Utkarsh Ayachit wrote:
> Hi Kent,
> 
> Attached is patch. With this patch (and OSMesa build) I could do:
> 
> mpirun -np 2 ./bin/pvbatch --use-offscreen-rendering  /tmp/foo.py
> 
> on a machine with no X. I still get the  "bad X server connection." from 
> the OpenGLExtensionManager -- which I guess you fix using Pat's 
> suggestions. However, in spite of the error message, things should work 
> fine.
> 
> Let me know if this patch works, if so, I'll commit it to the CVS.
> 
> Utkarsh
-------------- next part --------------
A non-text attachment was scrubbed...
Name: toffscreen.py
Type: text/x-python
Size: 425 bytes
Desc: not available
URL: <http://www.paraview.org/pipermail/paraview/attachments/20080407/c8fbae4a/attachment.py>