General/OOD

Introduction

Viper OnDemand is a web portal that provides a single access point to a full range of ways to make use of Viper. Viper OnDemand provides access to your HPC file storage, allows you to prepare, submit and monitor batch jobs, and also allows you to run a range of interactive graphical applications directly on Viper HPC hardware.

Capabilities

Viper OnDemand provides the following capabilities via the web browser:

• File and data management via a file explorer app
• Full shell access, much like an SSH connection you can have full terminal access
• Job management, including job creation and submission, monitoring and cancellation
• Run web front-end applications such as Jupyter Notebooks and RStudio
• Graphical user interface sessions for applications such as Matlab and Stata
• Remote desktop access, providing full-featured desktop sessions

Requirements

You must have a Viper account before attempting to log in to Viper OnDemand. Currently, Viper OnDemand is only available on the University network, so you must be on campus or connected via VPN. In the future, it is anticipated that it will be made accessible from off campus network with Multi-Factor Authentication (MFA). No additional tools or applications are required, only a standard web browser.

Using Viper OnDemand

Connecting to Viper OnDemand

1. Incognito mode - it is recommended to connect to Viper OnDemand from a private or incognito browser window. This is due to some caching issues making your browser think you are logged in when you are not.
2. https://viperood.hpc.hull.ac.uk
3. Log in using your university credentials - note unlike logging into Viper via SSH, in this situation you need to log in with your University email address.

Menu options

Once logged in you will be directed to the portal front page. Across the top of the page is the main menu which contains the following links:

• Viper OnDemand - Shortcut to the main page of the web portal.
• Apps - Shows all available applications.
• Files - File explorer providing access to your Viper home directory.
• Jobs - View active jobs and create batch jobs.
• Clusters - Provides command line access to Viper along with a link to information about resource availability on Viper
• Interactive Apps - List of interactive apps available through the web portal
• My Interactive Sessions - View your currently running OOD jobs.
• Help - Contact support or view our documentation

Interactive Apps

Launch

When launching interactive apps, you will see a form where you can set things like the resource to be used, how much resource (CPU, memory or exclusive access) or how long the job should run for. Some apps let you can pick a version of the application you would like to launch. Please always pick exclusive for Matlab and R Studio.

Connect

After clicking launch, your job will join the queue, before starting to run. Once running you can adjust the image quality of the connected session by adjusting the sliders for Compression level (lower value for better quality) and Image Quality (higher value for better quality) before launching to connect.

Batch Jobs

Compose Job

You can submit a batch job by using the Job Composer. There are a range of templates available for common apps, or jobs can created from previous jobs.

1. Create a new job from the specified path
2. Enter the path to the directory your submission script is in
3. Give the job a name
4. Enter the name of the submission script - you can change this later under job options
5. Click Save
6. Select the job and click submit

Under the job options, you can change the job title, select a submission script, and add an array specification.

Troubleshooting

If you get a 'Bad Response' error, this normally indicates your connection has expired or the network connection you are using to connect to Viper OnDemand has changed. In this situation, please close your browser window (not just the tab) and try reconnecting. Depending on the particular tasks being run, most OnDemand apps should let you reconnect and resume working.