[Paraview] General X window issue when running paraview server

[Wylie, Brian]

All,

There is a general issue about how X windows get opened when running
pvserver on a PC cluster. Normally X windows will not allow an x window
to be opened if you are not 'logged into the display (console)'. So if I
set my DISPLAY to :0.0 and I run an mpi job that simply launches
'xclock' on 4 different nodes. I will generally get some sort of X error
like... "bad X server connection" or whatever.

This is because the X server is not allowing an X window to be opened
from someone who is not 'on the console'. This is the normal behavior of
an X server. You have to 'bypass' the security feature in order to open
an X window. How you do this is an 'advanced' topic and hopefully you
have a cluster administrator that can help you out with this.

If you do not have an administrator that can do this for you, then let
me know and I can get our cluster guy to give me a list of the
configuration changes made to the X server to allow windows to be opened
by folks not on the console.

Also, do not under any circumstances have your DISPLAY variable set to
anything other than localhost:0.0 (or equiv) when running pvserver. If
you set your DISPLAY variable to any other machine besides localhost you
have completely crippled pvserver. ParaView will have to send X traffic
from one node to another and the whole purpose behind the system design
will be completely bypassed and your performance will probably be 100x
slower.

Brian Wylie - Org 9227
Sandia National Laboratories
MS 0822 - Building 880/A1-J
(505)844-2238 FAX(505)845-0833                       
     ____                  _    __
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   / /_/ / __ `/ ___/ __ `/ | / / / _ \ | /| / /
  / ____/ /_/ / /  / /_/ /| |/ / /  __/ |/ |/ /
 /_/    \__,_/_/   \__,_/ |___/_/\___/|__/|__/

                                    Unleash the Beast
 

> -----Original Message-----
> From: Nancy [mailto:haifang_zhou at 163.com] 
> Sent: Wednesday, May 11, 2005 9:02 PM
> To: Wylie, Brian
> Subject: Re: [Paraview] Is it possible to run the paraview in 
> C/S mode on different OS platform?
> 
> Dear Wylie,
>      Thanks for your help! I have run the paraview in C/S 
> mode on two machines with Windows and Linux OS succesfully.
>      But there are still some questions needing your explaining. 
>     " If your cluster is setup to allow that your done. If 
> not you will need to compile paraview with mesa and then the 
> X window thing is not an issue."  I can not unterstand these 
> two sentences. What is "mesa"? Can you explain this problem 
> for me in detail?
> 
> Best,
> Nancy
> 
> 
> 
> ----- Original Message -----
> From: "Wylie, Brian" <bnwylie at sandia.gov>
> To: "Nancy" <haifang_zhou at 163.com>; <paraview at paraview.org>
> Sent: Wednesday, May 11, 2005 10:14 PM
> Subject: RE: [Paraview] Is it possible to run the paraview in 
> C/S mode on different OS platform?
> 
> 
> Nancy,
> 
> Sure we do it all the time. There are issues sometimes with how the
> connection works. Lots of time when you run on a linux server you do a
> 'qsub' or equivalent and you don't know which nodes you will actually
> get and even when you know which nodes you will get, your 
> client machine
> will not be able to connect 'into' that particular node. 
> 
> BUT, this is all solved by doing -rc (reverse connect) on both the
> server and client. So you launch the client on windows with 
> -rc (you can
> make a shortcut to pvclient and add the -rc arg in the 'properties' of
> the shortcut).
> After the client is running you launch the server with -rc and that
> client machine name as -ch arg.
> 
> Regarding the server not having graphics cards that is also just fine.
> Any machine these days will run openGL even if they don't have a
> graphics card in them. The one wrinkle is that paraview server
> (pvserver) will normally open up an X window to do the parallel
> rendering. If your cluster is setup to allow that your done. 
> If not you
> will need to compile paraview with mesa and then the X window thing is
> not an issue.
> 
> We do not ever use paraview as a data server. We always use just the
> vanilla (pvclient-pvserver) and the servers do both data handling and
> rendering (even on machines with mesa) and then stream images to the
> client desktop. We find this model works really well. I know 
> other folks
> that use data servers and renders servers but they are just weird and
> should receive some sort of medical attention. (Of course I'm being
> silly, but I do have strong opinions about why that mode of 
> operation is
> not a good idea for most use cases).
> 
> Anyway, if you have any questions just let me know.
> 
> Best regards, 
> 
> Brian Wylie - Org 9227
> Sandia National Laboratories
> MS 0822 - Building 880/A1-J
> (505)844-2238 FAX(505)845-0833                       
>      ____                  _    __
>     / __ \____  _________ | |  / (_)__ _      __ 
>    / /_/ / __ `/ ___/ __ `/ | / / / _ \ | /| / /
>   / ____/ /_/ / /  / /_/ /| |/ / /  __/ |/ |/ /
>  /_/    \__,_/_/   \__,_/ |___/_/\___/|__/|__/
> 
>                                     Unleash the Beast
>  
> 
> > -----Original Message-----
> > From: paraview-bounces+bnwylie=sandia.gov at paraview.org 
> > [mailto:paraview-bounces+bnwylie=sandia.gov at paraview.org] On 
> > Behalf Of Nancy
> > Sent: Tuesday, May 10, 2005 6:32 PM
> > To: paraview at paraview.org
> > Subject: [Paraview] Is it possible to run the paraview in C/S 
> > mode on different OS platform?
> > 
> > Hi, all,
> >     Now we have a server machine with multiple processors 
> > that use Linux OS, and we want to use a PC with Windows XP as 
> > the client. Is it possible to run the paraview in C/S mode on 
> > different OS platform?
> >     By the way, if the server machine dose not have graphic 
> > card and display device, can the Render server and Data 
> > server of Paraview run on this machine?
> >     Thanks a lot!
> > 
> > Best,
> > Nancy
> > 
> 
>