Graphical login node

Artemis has a graphical login node accessible via a remote viewer program called “NoMachine”. You can use this node to open programs with graphical user interfaces (GUIs).

Note

Logins to this node last 4 hours maximum. If you’re logged out, log in again to start another 4 hour session.

This platform was designed to:

  • Assist with opening GUI job setup/submission where X11 forwarding via ssh is not working.
  • Perform spot checks on data before continuing processing or moving data off Artemis.

This platform was not designed to:

  • Be your primary method of accessing Artemis. This should be a supplemental tool for opening GUI programs. Please continue using the existing ssh access method as your primary Artemis access method.
  • Perform long-running, graphically intensive, or CPU intensive processing tasks. There is not enough CPU or graphics processing power on this node to support all Artemis users simultaneously performing CPU intensive or graphically intensive processing.

Installation and access

  • You need Access to Artemis before you can use the graphical login node.
  • Download and install the NoMachine Enterprise Client for your operating system.
  • If you’re using MacOS, you need to install XQuartz.
  • Download glogin.nxs to your desktop and double-click it.
  • A NoMachine window should start, asking for a username and password.
  • Replace YOUR_UNIKEY with your UniKey, then enter your UniKey password in the password field, then click OK.
  • Approximately 20-30 seconds later, you should see an Artemis terminal window appear on your workstation.

Important

This login node is shared by all Artemis users and it does not have powerful graphics processing capabilities. Therefore, do not run any long-running GPU or graphically intensive processing here. Use the node for things such as setting up jobs or doing spot checks during calculations.

Use

  • Open programs with GUIs by entering the required command(s) into your Terminal session. For example, to open Matlab, type module load matlab, followed by matlab.
[abcd1234@hpc211 ~]$ module load matlab/R2018a
[abcd1234@hpc211 ~]$ matlab &
  • Sessions are persistent and can continue to run without you being connected to see them.
  • To allow a session to continue, disconnect by closing the NoMachine window.
  • To close a session, close all client processes, including the initial terminal window, and any subsequent application processes you may have started.
  • The session “walltime” is limited to four hours. If you are still connected at the time, a warning will be shown ten minutes before the walltime expires.
  • The session will be shut down after four hours whether or not you are connected. You will not see a warning if you are not connected.
  • To reconnect to an existing session, double-click the glogin.nxs file. If you have a running session, it will be resumed. If not, a new session will be started.

Caveats

  • You will achieve the best performance when using a fast, low latency, wired network connection on the University network. Use of wireless, off-campus, VPN, and home connections may degrade performance beyond usability.
  • We do not support streaming of audio.
  • Many applications have not been tested. Some applications may be incompatible with this system and may not be capable of being made to work with it.
  • The NoMachine product is capable of things other than what we’re using it for, including printer redirection, USB device sharing and other. These have been disabled as they present potential security issues which have not been adequately investigated and are not deemed useful for Artemis.

Known problems and their workarounds

Window contents not rendering correctly on some parts of the workstation desktop

We have observed that on some occasions parts of the remote windows when placed at specific locations on the windows desktop can be rendered as black areas instead of the correct content. This has been observed in conjunction with changes to the Windows screen properties and usually clears after disconnecting and resuming the session.

Lost application preconfiguration

  • On some occasions the preferences in the NXS file disappear after loading it into the NoMachine client. This will appear as a dialog when connecting which asks what type of session to launch.
  • Simply disconnect, re-download the glogin.nxs file to your desktop and reconnect using the fresh file.

Hang during session setup

Sometimes the connection can ‘hang’ during session setup. We are investigating this issue.