Open OnDemand

Open OnDemand provides a web-based interface for accessing OSCER's HPC resources without requiring users to work exclusively from the command line. Through Open OnDemand, you can manage files, monitor jobs, submit batch jobs, and launch interactive applications such as MATLAB, VMD, Jupyter Notebook, and other graphical or web-based applications.

OSCER continues to support traditional command-line access through SSH in addition to Open OnDemand.

Table of Contents:

• Available Applications
• Getting Started with Open OnDemand
• Files Menu
• Jobs Menu
• Clusters Menu
• Interactive Apps
• My Interactive Sessions
• Logging out

Available Applications

The applications available through Open OnDemand depend on your OSCER account, research group, and available resources. Some applications may have additional access restrictions due to licensing or research-group-specific configurations.

If an application you need is not listed, or you need additional resources, please contact OSCER Support.

Starting OSCER Open OnDemand

You must have an OSCER account before using Open OnDemand. If you do not have an account, see the OSCER account request instructions.

Once you have an OSCER account, open a web browser and go to: https://ondemand.oscer.ou.edu

Log in using your OSCER username and password.

After logging in, you will see the Open OnDemand Dashboard. The Dashboard contains several menus for accessing files, managing jobs, opening a shell, and launching interactive applications.

Files Menu

The Files menu provides a web-based file manager for your OSCER storage.

From this menu, you can:

• Browse your home and scratch directories
• Upload files from your local computer to OSCER
• Download files from OSCER to your local computer
• Create, edit, move, rename, and delete files and directories
• Navigate your OSCER filesystem using a graphical interface similar to a file manager on Windows or macOS

Jobs Menu

The Jobs menu provides tools for monitoring and submitting SLURM jobs.

Active Jobs allow you to view the status of your jobs, including jobs that are:

• Queued and waiting to run
• Current running
• Recently completed

Click an individual job to view additional information. You can also click column headers to sort the list.

For more information about writing Slurm jobs, see theThe Job Composer provides a graphical interface for creating, editing, and submitting SLURM batch job scripts.

OSCER may provide job-script templates for commonly used workflows and applications. You can use these templates as a starting point and modify the resource requests and commands for your particular job. For more information about writing Slurm jobs, see the OSCER Slurm documentation.

Clusters Menu

The Clusters menu provides access to an interactive shell on the OSCER cluster.

Selecting Schooner Shell Access opens a terminal directly in your web browser. This provides the same type of command-line environment you would have when connecting to OSCER using SSH, PuTTY, PowerShell, or a macOS/Linux terminal.

From the shell, you can:

• Navigate and manage files.
• Edit files.
• Load software modules.
• Compile software.
• Submit Slurm jobs.
• Monitor jobs.
• Run other commands that do not require significant computational resources.

Important: Do Not Run Compute Jobs on Login Nodes

Your Open OnDemand shell runs on a shared login node. These nodes are intended for lightweight tasks such as editing files, compiling software, and submitting jobs.

Do not run computationally intensive applications directly from the shell. Compute-intensive work should be submitted through Slurm to an appropriate compute node.

See the OSCER Slurm documentation for information about submitting jobs.

Interactive Apps

The Interactive Apps menu allows you to launch research applications on compute nodes through a graphical or web-based interface.

Interactive applications are useful when you need to interact directly with an application rather than submitting a non-interactive batch job.

To launch an interactive application:

1. Select Interactive Apps from the Open OnDemand Dashboard.
2. Select the application you want to use.
3. Enter the requested job parameters.
4. Review the requested resources.
5. Click Launch.

Depending on the application, you may be asked to specify resources such as:

• Partition
• Number of CPUs
• Amount of memory
• Number or type of GPUs
• Wall time
• Other application-specific options

If you are unsure what values to use, the default values are generally a reasonable starting point.

Some applications and resource options may have restrictions. These restrictions may change as OSCER expands and updates Open OnDemand.

If you require more resources than are currently available through an interactive application, contact OSCER support.

Important: Interactive applications are still Slurm jobs. The resources you request determine where and how your application runs, and your session is subject to the same scheduling policies as other jobs.

My Interactive Sessions

After launching an interactive application, use My Interactive Sessions to access and manage your running sessions.

From this page, you can:

• Connect to an active interactive application.
• View the status of your session.
• End a session when you are finished.

If an application does not appear immediately, it may still be waiting in the Slurm queue for the requested resources.

When you are finished, terminate your interactive session rather than leaving it running unnecessarily. This releases the allocated compute resources for other users.

Logging Out of Open OnDemand

When you are finished using Open OnDemand, log out using the Logout option at the top-right of the Open OnDemand Dashboard.

Logging out of Open OnDemand does not necessarily terminate running Slurm jobs or interactive sessions. Check My Interactive Sessions and Active Jobs before logging out if you need to verify that your work has ended.

OSCER welcomes requests for additional applications and interactive interfaces.

When requesting an application, it is helpful to provide:

• The name of the software.
• The version you need.
• The research group or project that will use it.
• Whether you need a graphical or interactive interface.
• Any licensing requirements.
• An example of how you intend to use the application.

Applications that are useful to multiple research groups are particularly good candidates for Open OnDemand integration.

For questions, software requests, or assistance using Open OnDemand, contact OSCER Support at support@oscer.ou.edu.