HiPerGator 2.0 documentation

Upstream Xpra Documentation

Xpra Homepage: https://xpra.org/
Xpra Basic Usage: https://xpra.org/trac/wiki/Usage
Xpra Advanced Usage: http://xpra.org/manual.html

Step 1: Client Installation

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.

Step 2: Start a GUI session on HiPerGator

The simplest way to start a GUI application session on HiPerGator is to use the pre-made launcher script available for approved commonly used applications.

Launch pre-approved application

To launch a pre-approved application for which we prepared a launcher script only two steps are needed: Load the application environment module

module load application

Launch the application

launch_xpra_application

See an example on the RSTudio Help Page.

Launch any application

Use a sample job script as the base of your gui session job. Sample job scripts can be found in the '$HPC_GUI_JOB' directory once the 'gui' environment module is loaded.

Within the job script use the xpra_start wrapper to launch the application within the shell section of the job script.

module load application
xpra_start application

List Xpra Sessions

Once you submit a job wait for it to start. Check the job status with 'squeue -u $USER'. When the job starts 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.

Example

$ module add gui
$ xpra_list_sessions

Output:

Refreshing the session list for jdoe to remove stale sessions

List of active Xpra sessions for jdoe:

Session: i111a-s222.rc.ufl.edu:3713
    Job ID: 123456, Name: RStudio
    Client command:
         xpra attach ssh:jdoe@i111a-s222.rc.ufl.edu:3713
        or (downloaded script):
         ./xpra attach ssh:jdoe@i111a-s222.rc.ufl.edu:3713

See the respective application pages for details and sample job scripts.

Step 3: Connect to Xpra Session from the client computer

Connecting from outside of UF campus via VPN

The nodes in SLURM gui partition are accessible only within the UF campus network. If you are working off campus, you will need to use the VPN to connect to the UF campus network using AnyConnect VPN or similar software. Please see: https://vpn.ufl.edu for additional information.

Linux

Xpra is typically automatically added to your path during installation, so you can connect to your running xpra instance using the following syntax where $USERNAME is your UF GatorLink user-name, $SERVERNAME is the server where your application is running inside xpra, and $PORT is the X11 port you assigned when you started your application.

xpra attach ssh:$USERNAME@$SERVERNAME:$PORT

As an example:

testuser@jr-physics:~$ xpra attach ssh:testuser@i21a-s3.rc.ufl.edu:143 --desktop-scaling=on --dpi=96

The xpra_list_sessions command presents a ready-to-use connection command, but you'll have to add the desktop scaling or dpi arguments manually.

Please note that if you close the application window using the close button in the top right (or left) corner, this will exit your application and terminate your SLURM gui session. If you want to simply detach the session and come back later, please follow the detaching xpra session instructions below

MAC OS

Navigate to the folder that contains the xpra executable:

cd /Applications/Xpra.app/Contents/MacOS

Alternatively, download the following 'xpra' shell script, put it into a directory in your $PATH, make it executable, and run xpra through it with the 'xpra' command instead of going into /Applications... each time:

Download the [{{#fileLink: xpra}} xpra macos script]. {{#fileAnchor: xpra}}

#!/bin/bash
cd /Applications/Xpra.app/Contents/MacOS/
./Xpra "$@"

Make sure to make it executable by running 'chmod 750 xpra' in the terminal in the directory you downloaded the script to.

Second, connect to your running xpra instance using the following syntax where $USERNAME is your GatorLink user-name, $SERVERNAME is the server where your application is running inside xpra, and $PORT is the X11 port you assigned when you started your application.

./Xpra attach ssh:$USERNAME@$SERVERNAME:$PORT

Example:

./Xpra attach ssh:test-user@i21a-s3.rc.ufl.edu:143 --desktop-scaling=on --dpi=96

Please note, if you use the xpra_list_sessions command in the GUI module on HPG2, then it will generate these connection commands for you to be able to copy and paste. In addition, if you close the window using the close button, this will exit your application just like a native application. If you want to simply detach the session and come back later, please follow the detaching xpra session instructions below

Microsoft Windows

First, navigate to the install location of xpra (normally C:\Program Files (x86)\Xpra\).

In MobaXterm

cd "/drives/c/Program\ Files\ \(x86\)/Xpra/"

Alternatively, download the following 'xpra' shell script, put it into a directory in your $PATH, make it executable, and run xpra through it with the 'xpra' command instead of changing into the Program Files directory each time manually.

Download the [{{#fileLink: xpra}} xpra mobaxterm script]. {{#fileAnchor: xpra}}

#!/bin/bash
"/drives/c/Program Files (x86)/Xpra/Xpra.exe" "$@"

Second, connect to your running xpra instance using the following syntax where $USERNAME is your GatorLink user-name, $SERVERNAME is the server where your application is running inside xpra, and $PORT is the X11 port you assigned when you started your application.

xpra attach ssh:$USERNAME@$SERVERNAME:$PORT

or, if the xpra script is not in the $PATH,

sh xpra attach ssh:$USERNAME@$SERVERNAME:$PORT

Example

 ./xpra attach ssh:testuser@i21a-s3.rc.ufl.edu:143 --desktop-scaling=on --dpi=96

MatLab running via Xpra under slurm

Please note, if you use the xpra_list_sessions command in the GUI module on HPG2, then it will generate these connection commands for you to be able to copy and paste.

NOTE: If you close the window using the close button, this will exit your application just like a native application. If you want to simply detach the session and come back later, please follow the detaching xpra session instructions below

Step 4: Detaching Xpra Session

These instructions allow you to detach a running xpra client without closing the application.

Linux and MAC OS

In the original terminal where you activated the client, simply press Control-C to detach the session.

2016-04-06 15:18:17,173 Attached to ssh:testuser@i21a-s3.rc.ufl.edu:143 (press Control-C to detach)
^C
got signal SIGINT, exiting
2016-04-06 15:18:42,513 Connection lost

You can re-attach to the running application using the xpra attach command as described in the instructions above.

Windows

Start a new console and navigate to the xpra directory as shown above.
Run the following command where $USERNAME is your UF GatorLink user-name, $SERVERNAME is the server where your application is running inside xpra, and $PORT is the X11 port you assigned when you started your application.

./xpra detach ssh:$USERNAME@$SERVERNAME:$PORT

Example

cd "C:\Program Files (x86)\Xpra"
./xpra detach ssh:testuser@i21a-s3.rc.ufl.edu:143

Note: If you are using mobaXterm, you can press Control-C in the mobaXterm window to detach, just like using the Linux client.

GUI Programs

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