The latest release of Grafana has a new feature that is quite nice for real-world data –
This feature says that if we have no data for 1h, then don’t show a line between these points. This is very handy because you can now look at a graph and easily see sections without data.
The above example also has alerts configured.
In this case, Grafana sent out an alert because there was no data and drew markers on the graph. So there are now several ways Grafana can tell you there is no data.