Exceed Virtual Access TurboX (ETX)

Introduction

OpenText Exceed Virtual Access TurboX (ETX) provides web browser-based access to NewRiver’s eight login/interactive nodes. This interface provides faster, more interactive access to graphical user interfaces than standard X11 forwarding (e.g. ssh -X). ETX will automatically load balance users between the eight interactive nodes.

To access it, use a web browser (e.g. Firefox or Safari, not Chrome) to go to

http://newriver.arc.vt.edu

You will be prompted to log in; use your PID and password. Once logged in, you will see a number of profiles that provide access to applications.

Proper Usage (A Warning)

Note: These nodes are not scheduled/reserved – many users may be using each node at a single time – and so are not for production computational work. Rather, these nodes are for

  • Code development and testing
  • Visualization
  • Analysis

Think of ETX as a tool to view the results of computations without having to copy the files back to your personal machine. A typical workflow may be:

  1. Use ETX to develop code and do minor testing.
  2. If more computationally-heavy testing is required, use NewRiver’s dev_q to run them.
  3. Run production computations on NewRiver’s normal_q.
  4. Use ETX to view/visualize the results of the production jobs.

Profiles

ETX profiles provided preconfigured access to software packages. The most basic of these is Xterm, which provides something akin to a normal terminal plus graphical capabilities. ARC also provides a number of profiles to open graphical interfaces for centrally-installed software.

Xterm

The Xterm profile opens an SSH session with X11 forwarding. Any graphical interface can be opened from this command line. For example, once Xterm is opened, a user could view a png by calling ImageMagick’s display functionality:
display myplot.png
or open a software with plotting functionality (e.g. R or Python or Julia) and interactively plot. Here’s an example for Python:

[johndoe@nrlogin7 ~]$ module purge; module load gcc atlas python
[johndoe@nrlogin7 ~]$ python
Python 2.7.10 (default, Jan 13 2016, 16:05:29)
[GCC 5.2.0] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import matplotlib.pyplot as plt
>>> plt.plot([1,2,3,4])
>>> plt.show()
[<matplotlib.lines.Line2D object at 0x7f58981a7790>]

After running plt.show(), you should see a new window open showing the plot.

Other Software

ARC provides profiles to open a number of centrally-installed software packages, including the following:

  • Numerical computing:
    • Matlab: Opens a Matlab graphical interface, which can be used for code development, visualization, or even job submission. Try, for example, making a plot like [X,Y,Z]=peaks(100); figure; surf(X,Y,Z) and then rotating it in Matlab figure interface.
    • RStudio: Opens the Rstudio integrated development environment (IDE) for R.
    • Julia: Opens Julia, installed with PyPlot and Gadfly plotting packages.
  • Visualization:
    • Visit
    • ParaView
  • Ansys: Opens the Ansys Workbench graphical interface
  • Allinea Forge: Opens an Allinea Forge (DDT and MAP) graphical interface.

Tips and Troubleshooting

Some other tips for using ETX or troubleshooting problems accessing ETX:

  • Mouse: X11 applications use a middle mouse click to paste. If you are on a Mac that has a one or two button mouse, you can turn on three button mouse emulation by checking the “Emulate three button mouse” button in XQuartz -> Preferences -> Input. You will then be able to mimic middle button functionality (e.g. Paste) holding the Option key and clicking the left mouse button and mimic right mouse button clicks by holding down the Command key and clicking the mouse button.
  • Colors: You should also ensure that your X11 preferences are set to use all available colors. In XQuartz (Mac), this can be set via XQuartz -> Preferences -> Output and setting the Colors option to “From Display”. We have observed this setting correcting “GLX Extension” errors for visualization software via ETX.
  • Java Permissions: ETX requires Java and needs to be given permission within the browser to run the Java Plug-in in “Unsafe Mode”:
    • Safari: Go to Preferences -> Security. Check “Allow Plug-ins” and then select “Plug-in Settings”. Then select Java on the left-hand side. In the table on the right-hand side, look for the ETX website (newriver.arc.vt.edu) and click the associated combo box (where it may say “allow”) and select “Run in Unsafe Mode”. Click “Done” and retry opening an ETX profile.
  • Matlab: The Matlab command line sometimes loses focus when you switch windows from it. If this happens, click on one of the drop-down menus such as the drop-down to change directories (though you need not change anything) and then click on the command line. You should now be able to type again.

If you run into other issues with ETX, please submit a ticket to the ARC Help Desk.