Afraid I'm not an x-forwarding expert... :-(
Hopefully someone more knowledgeable can chime in.
On Dec 8, 2010, at 12:54 PM, brad baker wrote:
> Ya, I just tested -x as well, and it does indeed set the value of DISPLAY
> correctly for every process, every time I run it. Unfortunately the display
> is still not behaving as desired. Sometimes they open, and sometimes they
> don't.
>
> I'm currently using openmpi-1.4.1 over infiniband on a Rocks cluster. Any
> ideas on how to debug this will be greatly appreciated.
>
> Thanks,
> Brad
>
> On Tue, Dec 7, 2010 at 1:42 PM, Ralph Castain <r...@open-mpi.org> wrote:
> FWIW: I just tested the -x option on a multi-node system and had no problem
> getting the value of DISPLAY to propagate. I was able to define it on the cmd
> line, saw it set correctly on every process, etc.
>
> This was with our devel trunk - not sure what version you are using.
>
>
> On Dec 7, 2010, at 12:12 PM, brad baker wrote:
>
>> Thanks for your responses! I'm at home today so I can't actually do any
>> tests to 'see' if anything works. But I logged in remotely and I did as
>> Ralph suggested and ran env as my app. No process returned a value for
>> DISPLAY. Then I made a small program that calls getenv("DISPLAY") to run
>> with mpi, and each process returns NULL.
>>
>> I did some googling and found in the mpirun man page:
>>
>> "Exported Environment Variables
>> The -x option to mpirun can be used to export specific environment variables
>> to the new processes. While the syntax of the -x option allows the
>> definition of new variables, note that the parser for this option is
>> currently not very sophisticated - it does not even understand quoted
>> values. Users are advised to set variables in the environment and use -x to
>> export them; not to define them."
>> So it looks like I need to manually set them, possible how Jeff suggested.
>> I'll do some more research on this and get back after I've tried a few
>> things in the lab.
>>
>> Thanks again!
>> Brad
>>
>>
>> On Tue, Dec 7, 2010 at 10:26 AM, Jeff Squyres <jsquy...@cisco.com> wrote:
>> Are you using ssh to launch OMPI between your nodes? (i.e., is mpirun using
>> ssh under the covers to launch on remote nodes)
>>
>> If so, you might want to just set OMPI to use "ssh -X", which sets up SSH
>> tunneled X forwarding, and therefore it sets DISPLAY for you properly on all
>> the remote nodes automatically. But it does have the disadvantage of being
>> a bit slow, since it's coming through ssh.
>>
>> Alternatively, you can xhost +<source_host>, where <source_host> is the host
>> where your X app is running. Then set your DISPLAY variable manually to
>> <source_host>:display and it'll just go in an unencrypted fashion. This is
>> normal X forwarding stuff -- you can probably google around for more info on
>> this.
>>
>> NOTE: IIRC, xauth is better than xhost these days. I stopped using X for
>> most things many years ago, so my xhost/xauth information is probably a
>> little dated. Google around for the most recent / best ways to do this
>> stuff.
>>
>>
>> On Dec 6, 2010, at 10:11 PM, Ralph Castain wrote:
>>
>> > BTW: you might check to see if the DISPLAY envar is being correctly set on
>> > all procs. Two ways to do it:
>> >
>> > 1. launch "env" as your app to print out the envars - can be messy on the
>> > output end, though you could use the mpirun options to tag and/or split
>> > the output from the procs
>> >
>> > 2. in your app, just do a getenv and print the display envar
>> >
>> > Would help tell us if there is an OMPI problem, or just a problem in how
>> > you setup X11
>> >
>> >
>> > On Dec 6, 2010, at 9:18 PM, Ralph Castain wrote:
>> >
>> >> Hmmm...yes, the code does seem to handle that '=' being in there. Forgot
>> >> it was there.
>> >>
>> >> Depending on the version you are using, mpirun could just open the
>> >> display for you. There is an mpirun option that tells us to please start
>> >> each app in its own xterm.
>> >>
>> >> You shouldn't need forwarding if you are going to see it on a local
>> >> display (i.e., one physically attached to the node), assuming you are
>> >> logged into those nodes (otherwise you don't own the display).
>> >>
>> >> If you are trying to view it on your own local display, then you do need
>> >> forwarding setup.
>> >>
>> >>
>> >> On Dec 6, 2010, at 8:36 PM, brad baker wrote:
>> >>
>> >>> Without including the -x DISPLAY, glut doesn't know what display to
>> >>> open. For instance, without the -x DISPLAY parameter glut returns an
>> >>> error from each process stating that it could not find display "" (empty
>> >>> string). This strategy is briefly described in the openmpi FAQs for
>> >>> launching gui applications with openmpi.
>> >>>
>> >>> I'm assuming that by setting the DISPLAY envar to :0.0, each process
>> >>> will render to their local display, which is my intention, and as I
>> >>> previously stated works for up to 2 processes. So I believe it to be
>> >>> necessary.
>> >>>
>> >>> But I'm thinking I may have to configure some kind of X11 forwarding.
>> >>> I'm not sure...
>> >>>
>> >>> Thanks for your reply! Any more ideas?
>> >>> Brad
>> >>>
>> >>>
>> >>> On Mon, Dec 6, 2010 at 6:31 PM, Ralph Castain <r...@open-mpi.org> wrote:
>> >>> Guess I'm not entirely sure I understand how this is supposed to work.
>> >>> All the -x does is tell us to pickup an envar of the given name and
>> >>> forward its value to the remote apps. You can't set the envar's value on
>> >>> the cmd line. So you told mpirun to pickup the value of an envar called
>> >>> "DISPLAY=:0.0".
>> >>>
>> >>> So yes - I would expect this would be behaving strangely.
>> >>>
>> >>> If you tell us -x DISPLAY, we'll pickup the local value of DISPLAY and
>> >>> forward it. What that will cause your app to do is, I suppose, up to it.
>> >>>
>> >>>
>> >>> On Dec 6, 2010, at 12:42 PM, brad baker wrote:
>> >>>
>> >>> > Hello,
>> >>> >
>> >>> > I'm working on an mpi application that opens a glut display on each
>> >>> > node of a small cluster for opengl rendering (each node has its own
>> >>> > display). My current implementation scales great with mpich2, but I'd
>> >>> > like to use openmpi infiniband, which is giving me trouble.
>> >>> >
>> >>> > I've had some success with the -x DISPLAY=:0.0 parameter to mpirun,
>> >>> > which will open the display on up to 2 of my nodes... any 2. But when
>> >>> > I attempt to run the application on 4 nodes, the display is
>> >>> > non-deterministic. If any open at all process 0 definately will, and
>> >>> > sometimes process 3 along with that. I haven't observed much behavior
>> >>> > from process 1 or 2.
>> >>> >
>> >>> > My command:
>> >>> >
>> >>> > mpirun -x DISPLAY=:0.0 -np 4 -hostfile ~/openmpi.hosts ./myapp
>> >>> >
>> >>> > I've tried adding the -d option with no success.
>> >>> >
>> >>> > Does anyone have any suggestions or comments? I'll certainly provide
>> >>> > more information if required.
>> >>> >
>> >>> > Thanks,
>> >>> > Brad
>> >>> > _______________________________________________
>> >>> > users mailing list
>> >>> > us...@open-mpi.org
>> >>> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>> >>>
>> >>>
>> >>> _______________________________________________
>> >>> users mailing list
>> >>> us...@open-mpi.org
>> >>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>> >>>
>> >>> _______________________________________________
>> >>> users mailing list
>> >>> us...@open-mpi.org
>> >>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>> >>
>> >
>> > _______________________________________________
>> > users mailing list
>> > us...@open-mpi.org
>> > http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
>>
>> --
>> Jeff Squyres
>> jsquy...@cisco.com
>> For corporate legal information go to:
>> http://www.cisco.com/web/about/doing_business/legal/cri/
>>
>>
>> _______________________________________________
>> users mailing list
>> us...@open-mpi.org
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>>
>> _______________________________________________
>> users mailing list
>> us...@open-mpi.org
>> http://www.open-mpi.org/mailman/listinfo.cgi/users
>
>
> _______________________________________________
> users mailing list
> us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users
>
> _______________________________________________
> users mailing list
> us...@open-mpi.org
> http://www.open-mpi.org/mailman/listinfo.cgi/users
