Fill beginning of graph


I’m new to Grafana. Have created a dashboard and want to adjust how the beginning of the data are presented in the graphs.
I have added fill(previous) to fill the graph at the right hand. Is there a way to fill the lines with data at the left hand. Either last known data (outside the current scope/zoom), or just fill it with the first known value (straight line)…


Is it possible? :slight_smile:

I do not believe it is possible to add a fill for data that is not there. What is your use case for this?

Ah, I understand that. Thought it could be filled in the same way as fill(previous). Maybe fill(next)
Thanks for your support! :slight_smile:

I ran into this topic when searching how to completely show a graph for the complete selected time range of the graph. Last week I first started with Grafana and was positively surprised by how easy I was able to create a Dashboard!

I have the same situation as described by @zamb: last known data is outside the current scope/zoom (= selected time range of the graph)

So lets say I have data points for a specific measurement each 3 hours: 9:00 / 12:00 / 15:00.
I use in the query fill(previous) (or fill(lineair)) to create lines between the data points.

Result for the graph is that it is perfect when the time range is large enough, so for example 2 days. However when I zoom in to some hours the line is not plotted over the complete time range. The data is available, however outside the shown time range.

So if the time range of the graph is 11:00 - 13:00 it will only plot the line from 12:00 onwards. Is there a way to let the grap also draw a line between the 9:00 and 12:00 data point in this case?

I believe this might help you? It’s from the Troubleshooting section of the technical documentation.

Thanks for your help. That page has some good idea’s, but unfortunately none to solve this issue.

The part about “Some applications publish data intermittently” is exactly the case, but I already had set the null value to connected as proposed there.
It does not cover that the first part of a graph is missing because the data point is not within the graph time interval. The graph would be perfect if the line would be drawn to the first datapoint outside the graph time interval but I have no idea if this is possible at all.

Can you manually enter a beginning point?

I’m not sure how you propose to do this? By editing the dataset of by adjusting the query?
What would be a good solution is having a fixed/higher frequency for the datapoints (each hour and with each change in data would be sufficient), but I have no solution for that (yet).

For Grafana there always is a datapoint outside the graph time range, so it should allways be possible to draw a line between the 1st datapoint within the graph time range and the last datapoint outside and before the graph time range. And obviously there are more people wondering how to do this :slight_smile:

These 2 describe the issue in a more technical way:

I’ll try if it also gives me a solution :wink:
However the last item is still open on github

Hello, could you please explain how you added fill(previous) in Grafana?