Quantum computing - Troubleshooting

All steps for starting and working on Quantum Notebooks are described in the Quantum Notebooks - Getting Started guide.

If you are unable to connect to Quantum Notebooks, please ensure the following:

• Your notebook is up and running: To connect to your notebook, it must be in RUNNING or in IN SERVICE status (green color in the OVHcloud Control Panel). If your notebook is starting up, wait a few moments until your data synchronizes and you will be able to connect. Starting time may vary due to some parameters. The more data you synchronize, the more time it will take.
• You have an authorized user or an authorized token: To be able to connect to your notebook, you must have created a user or token. To create a new user, log in to the OVHcloud Control Panel and open your Public Cloud project. In the left menu, click the Quantum computing section. This will allow you to manage and create Quantum users. To simply access Quantum computing, use the Quantum reader role. For more advanced use, including management, select the Quantum operator role.

To follow all the steps in detail, please refer to this documentation.

Quantum Notebooks does not allow the use of apt-get install because you are not root. You can install your various packages using these commands:

1. pip command:

pip install package-name

2. conda command:

conda install package-name

• Install packages in a terminal: First, open a new terminal.

If you have chosen the Jupyterlab editor, open a new terminal: File > New > Terminal. If you have chosen the VScode editor, open a new terminal by clicking the menu icon > Terminal > New Terminal.

You can then execute directly in your terminal one of the two following commands:

pip install package-name

or

conda install package-name

• Install packages directly in a notebook cell: If you want to install a package directly in a notebook cell, do not forget to put an exclamation mark in front of your command. Then, you will be able to install a package with:

!pip install package-name

or

!conda install package-name

It is still advisable to install or uninstall packages in a terminal, particularly for authorizations. You can authorize (or not) the installation or uninstallation of packages with a yes or no. It is impossible to do this in a notebook cell.

Check the compatibility between the framework you have chosen when launching your notebook and the package you have installed.

If your framework is not compatible with the package version:

• You can uninstall the package with a pip uninstall <package_name> or conda remove <package_name> command. Then reinstall the package with a version compatible with your framework.
• Otherwise, you have several versions for some frameworks. Choose the one that best suits your project.

Quantum Notebooks does not allow the use of custom Docker images.

You only pay for the resources you use and, if applicable, the local storage. Check this documentation for detailed examples.

When you create a Quantum Notebook, we copy your data in attached Object Storage containers near your compute resources (CPU and GPU) to increase performance and reduce latency.

If you are unable to see your synchronized data, please ensure that:

• Your notebook is stopped: To see your synchronized data in the Object Storage, your notebook must be stopped beforehand. The status of your notebook must be stopped (red colored). If your notebook is STOPPING, wait a little and you will be able to see your synchronized data.
• Your object container is not empty: If your object container is empty, you may not have saved your data in the right place when using it in your notebook. Check how the volume was mounted when you started your notebook.

Each Quantum Notebooks service comes with a monitoring dashboard, allowing you to closely watch your compute, storage and network consumptions.

To verify your usage metrics, go to the Public Cloud section of the OVHcloud Control Panel and select Quantum Notebooks. All your notebooks will be listed. Click on your notebook to check its information. In Resources, you can then access the monitoring of your resources via the Graph Dashboard.

Please note that each Quantum Notebook is limited to a maximum amount of CPUs and GPUs. You can refer to the Quantum Notebooks Capabilities and Limitations guide.

Slowness can be experienced in two major cases: you are running intensive tasks taking all your resources, or it's an issue on OVHcloud's side.

For the first case, you may refer to the question "I may have reached the resource limits".

For the second case, you can verify on OVHcloud status if a task is affecting our infrastructure.

If it is not the case, contact our support.

Currently, you can choose between three live-code editors to launch and edit your notebook:

• VSCode
• JupyterLab
• JupyterLab Real Time (collaborative environment)

You can get the list of available editors using the ovhai CLI with the following command: ovhai capabilities editor list

You cannot install your own code editor on Quantum Notebooks.

Each notebook has a public URL. By default this URL accesses the port 8080 of the notebook. The default port cannot be changed.

However, you can access other ports by appending them to the URL. For example, the notebook URL (starting with the notebook's ID, filled with 0 here) for accessing the 8501 port is https://00000000-0000-0000-0000-000000000000-8501.job.gra.ai.cloud.ovh.net/

• Check if you have permission to connect to Public Cloud Object Storage (PCS): If you remove the permission to connect to PCS, the data synchronization will fail and so will the notebook.
• Check if you have access to the data of the volume you are trying to connect to your notebook: If you try to connect to a volume (from PCS) and you do not have access rights, your notebook will have the failed status.

To debug it yourself, run the following command in the CLI:

ovhai notebook get <notebook_id>

You will know if the failed status is related to data synchronization and which volume could not be synchronized.

A Quantum notebook runs continuously until manually interrupted by the user, unless it exceeds 7 days of running. It will then be automatically stopped. You can choose to automatically restart it using the auto-restart option (set this parameter to True). The notebook will then restart as is. To increase this 7-day limit, you will have to contact the support to ask for an upgrade of this quota for your Public Cloud project.

While we are doing our best to avoid this situation, as for any given service, outages can happen.

Please open a ticket to our support.

If your notebook has shut down unexpectedly, it may be due to an issue in our backend. Usually, your remote data is safe and will be synchronized in Public Cloud Object Storage.

Your ephemeral local storage will be lost.