Cluster Grid

Remote Display on FEP / Worker Nodes

Many debugging programs and profile apps require remote display. This becomes an issue in large clusters. There is usually one entry point in this case fep.grid.pub.ro (currently fep-53-3.grid.pub.ro). To achieve this on the NCIT Cluster we have a two stage process:

1. get remote desktop to fep working
2. get the display from the worker node to fep

Step 1:

• install NX client from NoMachine (http://www.nomachine.com/download-client-windows.php) . You should also install all Fonts extenstions. Many programs need this.
• FEP uses at maximum ICEWM desktop manager, but we require users to only open an xterm session.

Step-by-step configuration of NX Client

Start -> NX Connection Wizard -> Next

Session: [NCIT] Fep

Host: fep-53-3.grid.pub.ro

Next

Select Unix - Custom - Settings ...

Run the console

Floating window

Ok -> Next

Show Advanced Configuration dialog -> Finish

Now, select Key ... -> Click Default -> Save -> Save -> Ok

You can now login: username / password is from curs.cs.pub.ro

Step 2:

Now you must forward the display from the cluster machine to fep. Suppose the machine is named quad-wn16. On fep, record the display variable and run xhost + to allow incomming X connections:

[alexandru.herisanu@fep-53-3 ~]$ echo $DISPLAY
:1000.0
[alexandru.herisanu@fep-53-3 ~]$ xhost +
access control disabled, clients can connect from any host
[alexandru.herisanu@fep-53-3 ~]$

Now, from the remote machine (script will be run by means of qsub), you only have to set the DISPLAY variable to fep and you screen like this and run your program:

[alexandru.herisanu@quad-wn16 ~]$ export DISPLAY=fep-53-3.grid.pub.ro:1000.0
[alexandru.herisanu@quad-wn16 ~]$ xclock

Done.