We have used those notebooks for:
- Incidents, collecting different metrics and showing them next to each other, with comments
- Longer-term reliability debugging. They can form a kind of ad-hoc dashboard. These are usually issues that degrade performance, don't have immediate or wide-spread customer impact, and are things we are not immediately able to detect
- Related, performance tuning. Sometimes, the key metric is unknown. We want to explore it, and then make changes to infra, and then see if that moved the needle
- Sometimes, the ad-hoc widgets are useful enough to export to a dashboard
- I can take any widget anywhere else and import it into a notebook, or start a new notebook out of it.
The notebooks are similar to the dashboard, just that, the layout engine only allows a linear notebook layout instead of a grid. There are already text widgets, though the button to add that is easier to access. Other than the comments, it's basically a dashboard with the UI changed so that it feels like a notebook.
Keep in mind too, all dashboard and notebooks modify timestamps and other states in the browser URL, so it is easy for me to copy-paste those into Slack so that other people can see what I am seeing.