- 1 Install Xpra Software on the Client Computer
- 2 Start a GUI Session on HiPerGator
- 3 List GUI Sessions
- 4 Connect From a Client Computer
You can run GUI Programs on HiPerGator, but running such applications on a remote server within a supercomputer and displaying them on your local client computer as if it were running there and making the interface sufficiently responsive is not as easy as simply running them locally. To accomplish this task we use Xpra software - an open-source multi-platform persistent remote display server and client for forwarding applications and desktop screens. Full information on Xpra can be found in its basic usage documentation and the Xpra manual. Below we show the parts of Xpra documentation relevant to its function of running GUI Programs on HiPerGator.
Install Xpra Software on the Client Computer
Since Xpra is required on both ends of the connection you will have to have it installed on your local computer. Xpra client installation depends on the operating system running on your local machine and may require assistance of a system administrator if you do not have the authority to install new software. Once Xpra is installed on your client computer feel free to skip this step. Installation instructions are specific to the operating system running on your local computer:
Start a GUI Session on HiPerGator
- The launch_gui_session script described in the sections below takes a number of arguments allowing specification of the number of cpu cores, memory, time limit, and more. Please run
module load gui launch_gui_session -h
to see all available arguments.
Single command, no job script
There are two classes of applications that can be started with just one command from the gui environment module and do not require you to provide a job script.
Provided job script
If you need to pass custom arguments to the application, load pre-requisite environment modules or run additional commans, you can provide a simple script (linux format text file) with the required commands as an argument to launch_gui_session.
Make sure to prepend the command that starts the program with xpra_start. For example, a following job script named my_molden.sh will use the molden/5.0 environment module and start molden with a particular model file:
module load molden/5.0 xpra_start 'molden /ufrc/data/tests/molden/boc-iso-1t.gjf'
Now, to launch molden with the above script run:
launch_gui_session -e molden -f my_molden.sh
If you prefer to talk directly to SLURM you can write a full job script complete with resource requirements, job name, output file, etc in the #SBATCH section and submit the script to SLURM manually.
Make sure you use the gui partition:
and wrap your command with xpra_start as shown above.
You can use a job script for one of the application presets found in the '$HPC_GUI_JOB' directory once the 'gui' environment module is loaded as the base of your own job script.
List GUI Sessions
If you performed a manual launch or used the '-w' argument to the automated launcher command you'll have to manually check on your gui job. Check the job status with 'squeue -u $USER'. When the job starts you have to list the available xpra sessions using xpra_list_sessions command in the gui module. This command will refresh the Xpra session list and provide a convenient list of live Xpra sessions as well as client commands that can be copied and pasted into a terminal on the client machine.
$ module load gui $ xpra_list_sessions
Refreshing Xpra session list for jdoe. This could take a while..... List of active Xpra sessions for jdoe: Session: i21a-s33.rc.ufl.edu:9626 for RStudio job 2852284 Client command: xpra attach ssh:firstname.lastname@example.org:9626
See the respective application pages for details and sample job scripts.
Connect From a Client Computer
Servers in the SLURM gui partition are accessible only within the UF campus network.
Connecting from Linux
Connecting from MacOS X
Connecting from Microsoft Windows
Special cases (GUI scaling, font issues, etc)
See the Special Cases page for GUI Programs if you run a program or a local system that requires special care compared to the normal usage. Some examples of special cases include desktop scaling and DPI issues.