[Paraview] HW acceleration in client/server mode

[Sean Ziegeler, Contractor]

Alain,
I'm going to reply to the mailing list too.  This problem appears on the
list from time to time, so it might benefit others.

I see one thing that might be deceiving you.  When you echo environment
variables through rsh, you need to put single quotes around the echo
statement or the env var, or else your shell on your local host will do
the substitution instead of the remote host.  For example,
rsh node# 'echo $DISPLAY'

So, I'd try running #3 and #5 again.

But based on the response from #2 ("Can't open display: "), with nothing
after the colon, I'd say that DISPLAY isn't set.

Apparently, rsh (though not ssh) doesn't source your .bashrc by
default.  You might try creating a .bash_profile that sources your
.bashrc.  If that doesn't work, try the same thing with .profile.  

Finally, there may be a way to configure rshd to source your init files
properly, but I'm not sure about it.  I use ssh, so I haven't had this
sort of problem.

-Sean

On Fri, 2006-07-07 at 05:31, Alain SENOT wrote:
> Hello Sean,
> 
> First, I would like to thank you for answering a question I had on
> Paraview's mailing list
> 
> Unfortunaltely, I did not resolve my problem, but your answer is
> helping.
> 
> I have made some more observations :
> 
> 1) I tried : rsh node# xlogo 
> and got the error : command not found
> 
> 2) I tried the command : rsh node# /usr/X11R6/bin/xlogo
> and got the error : Error: Can't open display:
> 
> 3) I tried : rsh node# echo $PATH 
> and got an answer containing /usr/X11R6/bin
> 
> 4) I tried : rsh node# hostname 
> and I got the answer : node#
> 
> 5) I tried : rsh node# echo $DISPLAY
> and got the answer : :0.0
> 
> 6) I tried : rlogin node# 
> then : xlogo
> and that opened the display on node#
> 
> 7) I tried on the remote machine : xhost +node_client
> and xhost +localhost
> but it didn't change anything for the result of 2)
> 
> Do you have any idea that could explain thiese observations ?
> 
> I have set the DISPLAY variable to :0.0 in myuser/.bashrc on all nodes
> added each IP address in /etc/hosts
> and written the .rhosts on all nodes : 
>         node#complete_name myuser
>         node#complete_name myuser
> and set the access rights by the command : chmod 600 .rhosts
> 
> 
> Thanks again for your help
> 
> Alain Senot
> 
> 
> >Message: 5
> >Date: Thu, 06 Jul 2006 08:54:56 -0500
> >From: "Sean Ziegeler, Contractor" <seanzig.ctr at navo.hpc.mil>
> >Subject: Re: [Paraview] HW acceleration in client/server mode
> >To: paraview at paraview.org
> >Message-ID: <1152194096.16261.127.camel at infinity.navo.hpc.mil>
> >Content-Type: text/plain
> >
> >You should check to be sure that you do indeed have DISPLAY set to
> :0.0
> >on each node and that you have authority for the X-Servers.  It
> sounds
> >like your MPI configuration uses rsh to execute its processes, so to
> >test this for some node, do the following:
> >rsh somenode xlogo
> >
> >If DISPLAY really is :0.0, then the xlogo should appear on the
> display
> >for that node (I'm assuming you have some way of verifying that
> node's
> >video output).  
> >
> >If you get a "Can't open display: " (with no display value after the
> >color) error, then DISPLAY is not actually getting set.  You'll have
> to
> >be sure it is set in the appropriate .login/profile/cshrc/bashrc/etc
> for
> >your shell, or you can pass environment variables on the mpirun
> command
> >line.
> >
> >If you get a "connection to :0.0 refused by server" error, then you
> >don't have authority for the X-Server.  The quick fix is running
> "xhost
> >+" or "xhost +localhost" from the console of each node.  Or you can
> use
> >xauth to gather the X-Authority data from each node (much more
> involved,
> >but also more secure).
> >
> >-Sean