What is OnDemand?

Last updated on 2026-08-27 | Edit this page

Estimated time: 20 minutes

Overview

Questions

  • What is OnDemand and why use it?
  • How does OnDemand differ from SSH?
  • What are the benefits for HPC users?

Objectives

  • Understand the purpose and benefits of OnDemand
  • Learn the difference between OnDemand web interface and command-line SSH access
  • Identify use cases where OnDemand is most valuable

Introduction to OnDemand

OnDemand is a web-based interface to access and control Sagehen HPC resources without requiring SSH knowledge or specialized terminal software. It provides a graphical dashboard through which you can manage files, submit jobs, monitor computations, and run interactive applications directly from your web browser.

Why Use OnDemand?

OnDemand provides several advantages over traditional SSH access:

  • No SSH knowledge required: Access HPC resources through a familiar web browser
  • Graphical file manager: Upload, download, and organize files without command-line tools
  • Interactive applications: Run Jupyter notebooks, RStudio, and other interactive apps directly
  • Job monitoring: Visualize job status and monitor resource usage in real time
  • Multiple workspaces: Maintain different computational sessions simultaneously
  • Mobile-friendly: Access resources from tablets and laptops with limited terminal capabilities
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Perfect for Beginners

OnDemand is ideal if you’re new to HPC and prefer graphical interfaces. You can accomplish most common tasks without learning command-line tools. Point, click, and go!

The Interactive Apps dropdown menu open on the OnDemand dashboard. It lists a Desktop entry, then a GUIs group containing Autodock Vina, Comsol, Cryosparc, Gaussian, MATLAB, Mathematica, Qgis, Schrodinger, Stata and Tycho, then a Servers group containing Jupyter Notebook and RStudio Server.
Everything OnDemand can launch, in one menu.

OnDemand vs SSH Access

While SSH remains powerful for advanced users, OnDemand complements it by offering:

Feature OnDemand SSH
Learning curve Low Steep
File management Graphical Command-line
Interactive apps Direct support Manual setup
Job submission Web form Script writing
Device compatibility All browsers Terminal only

Accessing OnDemand

OnDemand at Pomona College is available at:

https://ondemand.hpc.pomona.edu/

Access requires: - Valid Pomona College credentials - DUO Multi-Factor Authentication (MFA) - Active HPC account approved by your PI

What You Can Do in OnDemand

File Management

  • Browse your home directory (/rhome/<myusername>)
  • Manage research data in /bigdata
  • Upload and download files
  • Create new directories
  • Edit text files

Job Submission

  • Submit batch jobs without writing SLURM scripts
  • Monitor job progress
  • View job output in real-time
  • Cancel running jobs

Interactive Applications

  • Launch Jupyter notebooks with GPU support
  • Start RStudio for statistical computing
  • Access web terminals for command-line work
  • Run custom interactive applications

System Resources

  • Check CPU and memory availability
  • Monitor cluster status
  • View node information
  • Track quota usage
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Important: Authentication Required

You’ll need valid Pomona College credentials and DUO Multi-Factor Authentication to access OnDemand. Ensure your HPC account is active before attempting to log in. Contact if you have access issues.

Challenge

Challenge: Explore the Concept

Consider your typical workflow on Sagehen. Which tasks would benefit most from using OnDemand instead of SSH? Think about: 1. File management tasks 2. Data exploration work 3. Interactive development 4. Batch processing

There is no single correct answer, but common answers include: - File management: OnDemand is superior for uploading large datasets or browsing files - Data exploration: Jupyter notebooks through OnDemand are ideal for exploratory analysis - Learning: Beginners benefit from OnDemand’s graphical interface - Multiple tasks: OnDemand allows running several applications simultaneously in separate browser tabs - Mobile/remote: OnDemand works anywhere you have internet and a browser

Next Steps

Now that you understand what OnDemand offers, let’s explore the dashboard and learn to navigate its features.

Key Points
  • OnDemand is a web-based interface for accessing Sagehen HPC resources
  • It requires no SSH knowledge and works in any modern web browser
  • OnDemand is ideal for file management, interactive computing, and job monitoring
  • Pomona’s OnDemand is available at https://ondemand.hpc.pomona.edu/
  • OnDemand complements SSH access rather than replacing it