HPC Cluster Getting Started

Who Is Eligible for Access to the ELSA HPC Cluster

Use of the ELSA HPC cluster is limited to School of Science faculty and invited faculty from other TCNJ schools; TCNJ students who are required to use the cluster for coursework or mentored research; and collaborators from other institutions who have been sponsored by a TCNJ faculty for access. Those that do not meet the stated criteria may request access by emailing their proposal to hpc@tcnj.edu. TCNJ reserves the right to limit cluster resources (e.g. simultaneous active jobs, CPU core count, GPU usage, storage space, etc.) in order to maintain continued operations.

Your existing TCNJ login and password are used to access the ELSA HPC cluster and activate your cluster account.

How Do I "Activate" My TCNJ Account on the Cluster

Activating your account creates some critical files that are needed before you can use the cluster. This only need to be done once. It establishes your HPC home directory which is a space for you to store your personal files, programs and their configurations. It also creates SSH keys which are used by to encrypt network traffic between computers.

1. To begin, point your web browser to https://ondemand.hpc.tcnj.edu
2. Provide your TCNJ username and password when prompted
3. If you've never logged into the cluster before, you will need to follow the on-screen instructions to setup your home directory.
   1. Click the Open Shell to create home directory link. This will open a new browser tab with a terminal window
   2. Provide your TCNJ password again when prompted. **Note:** there is no feedback (e.g. asterisks) as you type your password. Make sure to press the ENTER or RETURN button on your keyboard after entering your password.
   3. After some text is displayed, type exit and then press the ENTER or RETURN button on your keyboard
   4. Close just the terminal window browser tab
4. Back at the original browser tab, click the Restart Web Server link.
5. After a few seconds you should see the Open OnDemand main dashboard. If you get the Home directory not found page again, wait 30 seconds before clicking the Restart Web Server link again.

Accessing the Cluster via Open OnDemand

Once you have activated your account, you can use the web portal to access common functions on the cluster. This web portal is called Open OnDemand and can be accessed at https://ondemand.hpc.tcnj.edu/ from an on-campus (wired or wireless) computer or from off-campus using the TCNJ VPN. Use your existing TCNJ login and password when prompted. To logout of Open OnDemand, you must fully quit your browser.

Accessing the Cluster via SSH

Sometimes you need to directly access the Linux command-line on the HPC cluster to manage files or submit jobs. In order to do so, use one of the methods below depending on your local operating system.

Open OnDemand

Open OnDemand offers a web-based SSH client that works computers running Windows and Mac operating systems. Firefox or Chrome are the recommended web browsers to use.

To access a Linux terminal using Open OnDemand, follow these steps:

1. Login to Open OnDemand at https://ondemand.hpc.tcnj.edu/ using your TCNJ username (in all lowercase) and TCNJ password
2. Choose Clusters from the menu
3. Select >_ELSA HPC Cluster Shell Access for regular access or >_ELSA HPC Developer Shell Access if you need to do software development or compile code

This will open a new tab or window and drop you at the Linux command-line in your cluster home directory. When done using the terminal, type exit before closing the terminal tab/window.

MacOS

MacOS (aka Mac OS X) already has a built-in SSH capable terminal program. It can be accessed by going to Applications > Utilities > Terminal or by clicking the search icon and typing terminal. If you will be a frequent user of the Terminal application, it is suggested that you add it (i.e. drag it) to your application dock for easy access in the future.

Microsoft Windows

Windows, unfortunately, doesn't seem to include an SSH terminal program with the base operating system. You will need to download one from the Internet. The two applications below are the most popular.

• MobaXterm (recommended) - Download site (use Home Edition) | Installation video
• PuTTY - Download site | Installation video

Launch MobaXterm or PuTTY and connect to the cluster. Use elsa.hpc.tcnj.edu when prompted for a hostname, and use your TCNJ username and password when prompted for credentials. The video below shows you how to use MobaXterm to connect to the HPC cluster.