MPE and X-Server

[Stefan Kuhne]

Hello,

i'va a MPE program.
On my head ist works fine, but i will run it on all nodes.
Does i need an X-Server on all nodes?
If yes, then i've on all nodes an windows?
I want to accelerate the window on my head.

Regards,
Stefan Kuhne

[Heiko Bauke]

Hallo Stefan

On Fri, 04 Dec 2009 13:54:53 +0100

Post by Stefan Kuhne
i'va a MPE program.
On my head ist works fine, but i will run it on all nodes.
Does i need an X-Server on all nodes?
If yes, then i've on all nodes an windows?
I want to accelerate the window on my head.

das geht über Portforwarding mit ssh, genaueres findest Du ab Seite 330
im Buch «Ckuster Computing».
http://www.amazon.de/Cluster-Computing-Heiko-Bauke/dp/3540422994


Heiko

[Stefan Kuhne]

Post by Stefan Kuhne
i'va a MPE program.
On my head ist works fine, but i will run it on all nodes.
Does i need an X-Server on all nodes?

The error:

Could not open display
Failed to connect to head:1000.0 from node1

Stefan Kuhne

[Familie Bisseling]

Post by Stefan Kuhne

Post by Stefan Kuhne
i'va a MPE program.
On my head ist works fine, but i will run it on all nodes.
Does i need an X-Server on all nodes?

Could not open display
Failed to connect to head:1000.0 from node1
Stefan Kuhne

Some years have passed since I had a look into MPE but then
you could choose to have all ranks painting into the same
window using the X11 protocol OR you could use MPE (via MPI)
to delegate the painting to rank 0.

The error message seems to indicate that the environment
variable DISPLAY was set by your SSH client to enable X11
forwarding. The fact that this does not work in turn indicates
that your SSH server on head is not configured to allow
X11 forwarding.

Just for testing purposes you may try to hardcode the X11
display into your MPI code to reach the X11 server directly.

Does
node1$ mpiexec xterm
give a window on head?

[Stefan Kuhne]

Post by Familie Bisseling
Just for testing purposes you may try to hardcode the X11
display into your MPI code to reach the X11 server directly.

I've forgot to say, that i let run it on freeNX.
Under real X11 i've an ulimit problem.
How can i set ulimit -l unlimited under X11?

Post by Familie Bisseling
Does
node1$ mpiexec xterm
give a window on head?

I'll try this.

Regards,
Stefan Kuhne

[Stefan Kuhne]

Familie Bisseling schrieb:

Hello,

Post by Familie Bisseling
Does
node1$ mpiexec xterm
give a window on head?

no:
***@Node1:~$ mpiexec xterm
xterm Xt error: Can't open display:
xterm: DISPLAY is not set
***@Node1:~$

How would it work?
I've no experience with X.

Stefan Kuhne

[Georg Bisseling]

Let's assume that the MPI/MPE processes use just the regular network
protocol to talk directly to the X server.

On the computer where you start the MPI job with mpiexec you must
set the environment variable DISPLAY to something like
head.domain:0.0
where the first zero is the display number and the second zero is
the screen number. If you use VNC or ssh to connect to the head then
the display number might be a 10 or a 1000.

It should be possible to start an xterm on head and see the window.

Now you have to instruct mpiexec to export the environment variable.
For MPICH2 you can just use
mpiexec -genvall ...
to exportz the whole environment for a quick shot.

If X11 authentication comes in the way then you can entirely switch
authentication off for testing purposes by typing
xhost +
in an terminal window running on your X server.

Good luck!
Georg Bisseling

[Stefan Kuhne]

Georg Bisseling schrieb:

Hello,

Post by Georg Bisseling
On the computer where you start the MPI job with mpiexec you must
set the environment variable DISPLAY to something like
head.domain:0.0
where the first zero is the display number and the second zero is
the screen number. If you use VNC or ssh to connect to the head then
the display number might be a 10 or a 1000.
It should be possible to start an xterm on head and see the window.

yeah, i can open an Windows on head (X11 and FreeNX) from head.
(DISPLAY=:0.0 / 1000.0)

But not from node with "DISPLAY=host.domain:0.0" i think X11 doesn't
allow it from other Clients.
I search for it ...

Regards,
Stefan Kuhne


PS.: Can we write in german via mail?

[Stefan Kuhne]

Stefan Kuhne schrieb:
Hello,

Post by Stefan Kuhne
yeah, i can open an Windows on head (X11 and FreeNX) from head.
(DISPLAY=:0.0 / 1000.0)

with "DISPLAY=localhost:0:0" i get the error.
I've found that "name:0.0" uses TCP/IP-Sockets and ":0.0" uses Unix-Sockets.

So i've to find out why i can connect with Inix but not with TCP/IP-sckets.

Regards,
Stefan Kuhne

[Stefan Kuhne]

Post by Stefan Kuhne
So i've to find out why i can connect with Inix but not with TCP/IP-sckets.

Because of my X-Server was started with "-nolisten tcp".

Stefan Kuhne

[Georg Bisseling]

Post by Stefan Kuhne

Post by Stefan Kuhne
So i've to find out why i can connect with Inix but not with TCP/IP-sckets.

Because of my X-Server was started with "-nolisten tcp".
Stefan Kuhne

Does it now work?

[Stefan Kuhne]

Hello,

Post by Georg Bisseling

Post by Stefan Kuhne

Post by Stefan Kuhne
So i've to find out why i can connect with Inix but not with
TCP/IP-sckets.

Because of my X-Server was started with "-nolisten tcp".

Does it now work?

yes.

Thanks for your help.

Stefan Kuhne