Maintenance and outages can occur both at the application level (JupyterHub) and at the infrastructure level (Kubernetes and nodes).

JupyterHub

The open-source project JupyterHub, on which bwJupyter is based, is not "highly available." This means that JupyterHub is briefly offline during updates.

Scheduled maintenance is performed in the evening. JupyterHub will be unavailable for 1–2 minutes, and https://hub.bwjupyter.de will display the “Service Unavailable” error page. Normally, users’ currently running environments are not stopped. Only pages such as profile management are unavailable, and no new environments can be started during this time. Due to the brief outage late in the evening, these maintenance windows are not announced in advance.

If maintenance work takes longer and/or users’ environments need to be stopped, the maintenance work will be communicated via the mailing list.

Infrastructure

Infrastructure maintenance may also be performed during the day. This typically takes several hours. During this time, there will be intermittent service interruptions. Therefore, maintenance will be announced as early as possible.

Especially when it comes to the infrastructure, it is also possible that security patches must be applied immediately. In this case, maintenance work may be carried out on the same day.

Mailing List

Notifications regarding maintenance work and service disruptions are distributed via the mailing list bwjupyter-maintenance∂lists.kit.edu and displayed as a banner on JupyterHub. Users must actively subscribe to this mailing list and can unsubscribe at any time.

Subscribe at: https://www.lists.kit.edu/sympa/subscribe/bwjupyter-maintenance

Unsubscribe at: https://www.lists.kit.edu/sympa/signoff/bwjupyter-maintenance