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Using the HPC-UGent web portal#

The HPC-UGent web portal provides "one stop shop" for the HPC-UGent infrastructure. It is based on Open OnDemand (or OoD for short).

Via this web portal you can upload and download files, create, edit, submit, and monitor jobs, run GUI applications, and connect via SSH, all via a standard web browser like Firefox, Chrome or Safari. You do not need to install or configure any client software, and no SSH key is required to connect to your VSC account via this web portal.\ Please note that we do recommend to use our interactive and debug cluster (see chapter interactive and debug cluster) with OoD.

To connect to the HPC-UGent infrastructure via the web portal, visit https://login.hpc.ugent.be

Note that you may only see a "Submitting..." message appear for a couple of seconds, which is perfectly normal.

Through this web portal, you can:

  • browse through the files & directories in your VSC account, and inspect, manage or change them;

  • consult active jobs (across all HPC-UGent Tier-2 clusters);

  • submit new jobs to the HPC-UGent Tier-2 clusters, either from existing job scripts or from job templates;

  • start an interactive graphical user interface (a desktop environment), either on the login nodes or on a cluster workernode;

  • open a terminal session directly in your web browser;

More detailed information is available below, as well as in the Open OnDemand documentation. A walkthrough video is available on YouTube here.

Pilot access#

Known issues & limitations#

Limited resources#

All web portal sessions are currently served through a single separate login node, so the available resources are relatively limited. We will monitor the resources used by the active web portal sessions throughout the pilot phase to evaluate whether more resources are required.

Login#

When visiting the HPC-UGent web portal you will be automatically logged in via the VSC accountpage (see also Section Applying for the account).

First login#

The first time you visit https://login.hpc.ugent.be permission will be requested to let the web portal access some of your personal information (VSC login ID, account status, login shell and institute name), as shown in this screenshot below:

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Please click "Authorize" here.

This request will only be made once, you should not see this again afterwards.

Start page#

Once logged in, you should see this start page:

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This page includes a menu bar at the top, with buttons on the left providing access to the different features supported by the web portal, as well as a Help menu, your VSC account name, and a Log Out button on the top right, and the familiar HPC-UGent welcome message with a high-level overview of the HPC-UGent Tier-2 clusters.

If your browser window is too narrow, the menu is available at the top right through the "hamburger" icon:

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Features#

We briefly cover the different features provided by the web portal, going from left to right in the menu bar at the top.

File browser#

Via the Files drop-down menu at the top left, you can browse through the files and directories in your VSC account using an intuitive interface that is similar to a local file browser, and manage, inspect or change them.

The drop-down menu provides short-cuts to the different $VSC_* directories and filesystems you have access to. Selecting one of the directories will open a new browser tab with the File Explorer:

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Here you can:

  • Click a directory in the tree view on the left to open it;

  • Use the buttons on the top to:

    • go to a specific subdirectory by typing in the path (via Go To...);

    • open the current directory in a terminal (shell) session (via Open in Terminal);

    • create a new file (via New File) or subdirectory (via New Dir) in the current directory;

    • upload files or directories from your local workstation into your VSC account, in the correct directory (via Upload);

    • show hidden files and directories, of which the name starts with a dot (.) (via Show Dotfiles);

    • show the owner and permissions in the file listing (via Show Owner/Mode);

  • Double-click a directory in the file listing to open that directory;

  • Select one or more files and/or directories in the file listing, and:

    • use the View button to see the contents (use the button at the top right to close the resulting popup window);

    • use the Edit button to open a simple file editor in a new browser tab which you can use to make changes to the selected file and save them;

    • use the Rename/Move button to rename or move the selected files and/or directories to a different location in your VSC account;

    • use the Download button to download the selected files and directories from your VSC account to your local workstation;

    • use the Copy button to copy the selected files and/or directories, and then use the Paste button to paste them in a different location;

    • use the (Un)Select All button to select (or unselect) all files and directories in the current directory;

    • use the Delete button to (permanently!) remove the selected files and directories;

For more information, see also https://www.osc.edu/resources/online_portals/ondemand/file_transfer_and_management.

Job management#

Via the Jobs menu item, you can consult your active jobs or submit new jobs using the Job Composer.

For more information, see the sections below as well as https://www.osc.edu/resources/online_portals/ondemand/job_management.

Active jobs#

To get an overview of all your currently active jobs, use the Active Jobs menu item under Jobs.

A new browser tab will be opened that shows all your current queued and/or running jobs:

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You can control which jobs are shown using the Filter input area, or select a particular cluster from the drop-down menu All Clusters, both at the top right.

Jobs that are still queued or running can be deleted using the red button on the right.

Completed jobs will also be visible in this interface, but only for a short amount of time after they have stopped running.

For each listed job, you can click on the arrow ($>$) symbol to get a detailed overview of that job, and get quick access to the corresponding output directory (via the Open in File Manager and Open in Terminal buttons at the bottom of the detailed overview).

Job composer#

To submit new jobs, you can use the Job Composer menu item under Jobs. This will open a new browser tab providing an interface to create new jobs:

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This extensive interface allows you to create jobs from one of the available templates, or by copying an existing job.

You can carefully prepare your job and the corresponding job script via the Job Options button and by editing the job script (see lower right).

Don't forget to actually submit your job to the system via the green Submit button!

Job templates#

In addition, you can inspect provided job templates, copy them or even create your own templates via the Templates button on the top:

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Shell access#

Through the Shell Access button that is available under the Clusters menu item, you can easily open a terminal (shell) session into your VSC account, straight from your browser!

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Using this interface requires being familiar with a Linux shell environment (see Appendix Useful Linux Commands).

To exit the shell session, type exit followed by Enter and then close the browser tab.

Note that you can not access a shell session after you closed a browser tab, even if you didn't exit the shell session first (unless you use terminal multiplexer tool like screen or tmux).

Interactive applications#

Graphical desktop environment#

To create a graphical desktop environment, use on of the desktop on... node buttons under Interactive Apps menu item. For example:

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You can either start a desktop environment on a login node for some lightweight tasks, or on a workernode of one of the HPC-UGent Tier-2 clusters if more resources are required. Keep in mind that for desktop sessions on a workernode the regular queueing times are applicable dependent on requested resources.

Do keep in mind that desktop environments on a cluster workernode are limited to a maximum of 72 hours, just like regular jobs are.

To access the desktop environment, click the My Interactive Sessions menu item at the top, and then use the Launch desktop on ... node button if the desktop session is Running:

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It is also possible to relaunch a desktop session that has ended by clicking the icon on the top-right of the desktop session box:

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Jupyter notebook#

See dedicated page on Jupyter notebooks

Restarting your web server in case of problems#

In case of problems with the web portal, it could help to restart the web server running in your VSC account.

You can do this via the Restart Web Server button under the Help menu item:

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Of course, this only affects your own web portal session (not those of others).

Enable debug logging for interactive apps#

When investigating an issue with an interactive app (e.g. failure to start), it can be very helpful (or you will be asked to by support) to provide more debugging information in the output log file. To do so, tick Show advanced options button (right above the Launch button), and tick Enable extra debugging code to help debug problems button that right above it.

Once the issue is resolved, you can do the same steps to untick the Enable extra debugging code to help debug problems button again or it will add the additional commands and output with every interactive app you start, and it is not recommended to do this by default.

Custom apps#