Starting an Interactive App

All currently available SCC OnDemand applications can be found under the “Interactive Apps” tab from the navigation bar. Selecting one of the tab items brings up the session configuration page for that application. In addition to the applications listed in the menu, you can also launch other applications by first launching the “Desktop” application and then running the application you are interested in.

Session Configuration

On the session configuration page you are able to set various options for the application session. All applications allow you to set an allocation for the:

  • Number of hours: number of hours for the session to run.
  • Number of cores (gpus): the number of CPU cores/GPUs requested.
  • Project: which project the session’s usage will be applied to (Buy-In nodes that the project has priority access to will be used preferentially).
  • Extra Qsub Options: any additional qsub options you would like to specify (see the page on qsub to see what options are available).

Most applications allow you to select any of the versions available on the SCC. Additional application specific configuration options are explained below.

Launching Your Application

After you have set your desired configuration options, click the blue “Launch” button to start the session. This will redirect you to the “My Interactive Sessions” page where you will see your new job and any other of your queued/running OnDemand jobs displayed. Depending on the resources you requested and how busy the SCC is your job may be queued while it waits for available resources. You are unable to connect to a session while it is queued. It’s current state is displayed in the upper right corner of the session’s panel:

  • Queued: Job is awaiting the requested resources to start.
  • Starting: Job has begun and is initializing.
  • Running: Job has completed startup and is available to be used.

If you have incorrectly specified any parameters or the system is otherwise unable to submit your job request a pink box will appear at the top of the page titled “Failed to submit session with the following error:” listing the error encountered. You will need to fix any issues with your configuration parameters to resolve the error and start your application.

It is important to note that even if you log out of OnDemand or close all tabs, unless you delete your sessions they will continue to run (using up SUs) until the hours you have requested for the session have run out. You can delete active OnDemand sessions from the “My Interactive Sessions” page.

Desktops Versus Servers

Applications listed in the “Interactive Apps” tab are separated into two categories: “Desktops” applications will launch within a desktop environment with your application running. You can freely open terminals within the session or perform other familiar desktop operations. “Servers” applications do not have a desktop environment associated with them and instead provide a native browser interface to the server running on the allocated node.

Application Specific Configuration

Desktop or VirtualGL Desktop

If you have an application that you would like to use that isn’t listed under the “Interactive Apps” tab, you can start it within one of these “Desktop” environments. The process of starting an application can vary, refer to the Module Basics page for more information and to see a list of available software.

  • List of modules to load: You can specify here any modules (as a space separated list) you would like loaded along with the desktop.
  • Initial command to run: This command will run at session startup.

Jupyter Notebook

  • Modules: Python modules that should be loaded at startup.
  • Interface: Choose between a notebook style interface and the lab interface with integrated information panels. For more detail read the JupyterLab overview.
  • Working Directory: Jupyter will start in this directory. Note: It is not possible to navigate to the parent directory (and child directories of the parent); you can only navigate to children of the directory specified here. Therefore you should specify the top level directory that includes all directories you anticipate using. For example: to access notebooks in your project space, type in the path to your project directory.
  • Extra Jupyter Args: Any additional arguments that should be passed at the time of Jupyter notebook startup.

TensorBoard Server

  • Additional modules to load (optional): You can specify here any modules to load (as a space separated list).
  • TensorBoard logdir: The directory for the data that TensorBoard will visualize.
  • Additional TensorBoard arguments (optional): Any additional arguments that should be passed at time of TensorBoard startup.