Arvados

While working on #15407 I encountered an issue when testing against a cluster that didn't published its websocket URL on the cluster config endpoint. The app crash was fixed and a warning message added to the Javascript console.

What would be useful for the user is to add a notification that live updates will be disabled, but adding it as a snackbar message may be too invasive/bothersome, and a notification on the 'bell' notification menu sounds like a better approach.

From a first look, I didn't found any implementation code on this feature, so maybe additional work is required.