Running visualization programs

Procedures overview | Using TurboVNC

To run advanced visualization applications remotely on the Geyser and Caldera clusters, use TurboVNC software and the procedures described below.

The documentation applies to running two types of visualization applications.

  1. Applications that use OpenGL to display advanced, 3D graphics on your local machine. These include VAPOR, VisIt*, ParaView*, and Vis5D.
  2. Applications that use X11 forwarding rather than OpenGL.

You can run X11 data analysis packages on the Geyser cluster without using TurboVNC. However, TurboVNC can provide better display performance than the X11 protocol if you are connecting from a site with low bandwidth or high latency.

See Running interactive applications for how to request an interactive session through LSF and start X11 applications.


Procedures overview

To use TurboVNC, you will need to do the following.


Using TurboVNC

To begin, log in to the Yellowstone system using your SSH client.

ssh yellowstone.ucar.edu

Enter your username and YubiKey or CRYPTOCard token response when requested.

Start the TurboVNC server

Start the TurboVNC server by running the vncserver_submit command as shown, using the -P option to specify the project code to charge for your VNC work.

vncserver_submit -P project_code

This submits a batch job to the intviz queue on the Geyser cluster with a wall-clock time of 4 hours. The default screen geometry is 1024x768. You can specify a different queue, wall-clock limit or other job directive by including the appropriate script option, such as -q geyser-W 24:00 or -f +geometry 1600x1200. Use -h to get a list of supported options. 

You can run the same command later to return to a server session that you have left running. You can start an additional server session by adding -s and a session name, as in -s session2.

The output from the vncserver_submit command details three steps to follow.

  1. Run a command in your local terminal to establish SSH tunneling. You can do this in the native SSH client on your desktop or laptop, or copy and paste the information into an SSH client such as PuTTY for Windows. Follow this link for an example of how to do it using PuTTY SSH client in Windows.
  2. Start the TurboVNC client on your local machine as described just below.
  3. Copy and paste a "localhost:nnnn" string into your TurboVNC dialog box.

Start the TurboVNC client

Run the TurboVNC client on your local system, following these examples.

Linux and Mac OS X

Open an X terminal application and run vncviewer on your command line with the "localhost:nnnn" output.

vncviewer localhost:nnnn

Windows

Select TurboVNC Viewer from the Start Menu TurboVNC group on your desktop.

Paste the "localhost:nnnn" string in the dialog box and click Connect.

TurboVNC dialog box   TurboVNC dialog box

Authenticate

Next, you will be asked to enter your username and password. Your username is the same one you use to log in to Yellowstone. For the password, use your YubiKey authentication token or CRYPTOCard keypad.

If TurboVNC reports an inability to connect, make sure that:

  • you correctly entered your username and token response.
  • the VNC host is the one specified by the vncserver_submit script that you ran on Yellowstone; localhost is always the same, but the port may be different.
  • that you did Step 1 (above) correctly to establish the ssh tunnel.
  • that your local firewall is not blocking connections from the local TurboVNC to the local ssh tunnel. Check your firewall instructions or see your system administrator for assistance.

Run your application

Open a terminal within your TurboVNC client window. (Select Applications, then System Tools, then Terminal.)

Load the module for the desired application using the module load command.

module load matlab
  • To run applications that do not require OpenGL, use the regular startup command.
matlab
  • To start an application that requires OpenGL, use the vglrun command and the executable name as in this example:
vglrun glxgears

When you are finished with your application

It is important to close all TurboVNC client windows before closing your local terminal or killing the SSH tunnel. Failure to do so can result in frozen client windows that may be difficult to close.

Follow these steps:

  1. Close your TurboVNC client window.
  2. Close your local X Window terminal session.
  3. Kill the batch job that is running on the Geyser cluster, or let it shut down when the wall-clock limit is reached.

Leave the batch job running if you are simply taking a break and plan to return to the session later on.

* Both ParaView and VisIt have their own built-in remote display capabilities. See each application's web site for details.