Running Interactive Applications
Open OnDemand can launch supported applications on VHPC compute nodes through your browser.
Each interactive application runs as a Slurm job. After you submit the request, the session waits in the queue until Slurm assigns the requested resources.
Available Applications
The Interactive Apps menu currently includes:
Desktops
- VHPC Desktop (NEW)
- GaussView
Servers
- Jupyter
- MATLAB on VHPC
You can also launch these applications from the left side of My Interactive Sessions.
Open an Application Form
From the Open OnDemand navigation bar:
- Open Interactive Apps.
- Select the application you want to use.
Open OnDemand displays a launch form for that application.
The exact options vary, but may include:
- Slurm account
- Partition
- Requested runtime
- Number of CPU cores
- Number of GPUs
- Memory
- Application version
- Jupyter interface or starting directory
- Optional email notification
Only select resources appropriate for the work you plan to perform.
Choose an Account
Select the Slurm account associated with the project or work being performed.
Only accounts available to your VHPC user account should appear.
If you are unsure which account to select, confirm the correct project before submitting the session.
Choose Resources
Runtime
The requested runtime is the maximum duration of the session.
The session ends when that time limit is reached, even if the application is still open in your browser.
Request enough time to complete your work, but avoid requesting substantially more time than needed.
CPU Cores and Memory
Choose enough CPU cores and memory for the application and workload.
More CPU cores do not automatically make an application run faster. The application must be able to use them.
GPUs
Request a GPU only when the application or workload requires one.
GPU requests may wait longer because GPU resources are more limited.
Warning
Resources generally cannot be increased after the session starts. Save your work regularly and submit a new session if a different allocation is required.
Launch the Session
After completing the form, select Launch.
Open OnDemand submits the request to Slurm and displays it under My Interactive Sessions.
The session initially appears as Queued.
Session States
Interactive-session cards commonly appear as:
| State | Meaning |
|---|---|
| Queued | The request is waiting for Slurm to assign resources. |
| Running | The application is ready to connect. |
| Completed | The session has ended. |
| Failed | The session did not start or ended with an error. |
A queued session is not necessarily experiencing a problem. It may be waiting for CPUs, memory, GPUs, scheduler priority, or another requested resource.
Use My Interactive Sessions
Open My Interactive Sessions to view and manage your requested applications.
A running session card may show:
- Application name
- Assigned compute host
- Allocated nodes, CPU cores, and GPUs
- Remaining runtime
- Slurm job ID
- Connection controls
- Cancel button
Completed session cards remain visible temporarily and can be removed with Delete.
Connect to an Application
The connection method depends on the application.
Jupyter
Select Connect to Jupyter.
Jupyter opens automatically in a new browser tab.
Closing the Jupyter tab does not stop the Slurm job. Return to My Interactive Sessions to reconnect or cancel the session.
Using Jupyter’s own shutdown command may stop the Jupyter process and cause the session to complete. Verify the session state afterward.
Using Slurm commands from a notebook
If you need to run Slurm commands such as squeue, sbatch, sacct, or scontrol from within a Jupyter notebook, you may need to initialize the VHPC Slurm environment first.
module load slurm
This provides the Slurm command-line tools and VHPC-specific Slurm configuration needed to communicate with the cluster.
VHPC Desktop, GaussView, and MATLAB
These applications connect through a browser-based remote graphical display.
The session card may include controls for:
- Compression
- Image quality
- Launching the application
- Opening a view-only shareable connection
The application normally opens in the current browser tab.
Tip
Before connecting to a graphical application, consider opening My Interactive Sessions in a separate browser tab. This keeps the session controls available while the application uses the other tab.
Reconnect to a Running Session
Closing an application tab does not normally stop the underlying Slurm job.
To reconnect:
- Return to Open OnDemand.
- Open My Interactive Sessions.
- Locate the running session.
- Select its connection button.
You can reconnect while the session remains active and within its requested runtime.
Browser Notifications
Open OnDemand can use browser notifications to alert you about interactive-session events, such as when a session is nearing the end of its requested runtime.
Your browser must allow notifications from:
ondemand.kennesaw.edu
If notification permission is blocked, use the browser’s site-permission settings to allow it before enabling notifications in Open OnDemand.
Save Your Work
Save important files to persistent VHPC storage, such as:
- Your home directory
- Your Work directory
- Your Staging directory
- An approved project directory
Files saved only in temporary compute-node locations may be removed when the session ends.
Closing a browser tab does not save unsaved work inside the application.
End a Session
When you are finished:
- Save your work.
- Exit the application normally when appropriate.
- Return to My Interactive Sessions.
- Select Cancel for the queued or running session.
- Confirm the action.
After the session ends, its card changes to Completed. Select Delete when you no longer need the retained card.
Warning
Closing only the application tab may leave the Slurm job running and continuing to hold its allocated VHPC resources.
Interactive Sessions and Active Jobs
Interactive applications appear as Slurm jobs under Jobs → Active Jobs.
Use:
- My Interactive Sessions to connect to and manage the application
- Active Jobs to inspect the associated Slurm job
Cancelling the job from Active Jobs also ends the interactive session immediately.
For more information, see Monitoring and Managing Jobs.
Troubleshooting
My session remains queued
The requested resources may not yet be available.
GPU requests, large memory requests, or requests for many CPU cores may take longer to start.
Do not submit duplicate sessions while the original request remains queued.
The session failed
Keep the failed session visible long enough to record:
- The application name
- The requested resources
- The session ID
- The Slurm job ID, when available
- Any visible error message
Deleting the failed card too quickly may remove useful troubleshooting information.
The connection button is missing
Confirm that the session has reached Running.
The connection button is unavailable while the session is still queued or starting.
Refresh the page if the displayed state appears outdated.
I closed the application tab
Return to My Interactive Sessions and reconnect.
Closing the tab does not normally stop the session.
My session ended unexpectedly
The session may have:
- Reached its runtime limit
- Exceeded its memory allocation
- Been cancelled
- Encountered an application error
- Experienced a compute-node or service problem
Review the session card and any application output files.
Next Steps
- Use an interactive desktop
- Manage files through the browser
- Monitor and manage jobs
- Use the web-based shell
Getting Help
If an interactive session repeatedly fails, remains queued unexpectedly, or cannot be opened, contact the Kennesaw State University Service Desk.
| Method | Students | Faculty/Staff |
|---|---|---|
| Web | ServiceNow | ServiceNow |
| studenthelpdesk@kennesaw.edu | service@kennesaw.edu | |
| Phone | 470-578-3555 | 470-578-6999 |
When reporting a problem, include:
- Your NetID
- The application selected
- The approximate date and time of the problem
- The requested resources
- The Slurm job ID, when available
- The interactive session ID, when available
- Any visible error message