With stacked series ("Graph theses queries as a; b") or grouped queries ("avg by host"), you'll have several metric lines on the same graph and you may occasionally see some graph lines dropping back to 0:
You can see from the graph legend "N/A" (or by graphing the serie alone in a graph) that there is actually no data at these times.
Instead of displaying nothing, our system displays 0s and this really improves the visualization for:
- graphs using the bars visualization.
- series that only have 1 value within the timeframe of the graph (a single value is not visible at all) (2. on the graph above).
- detecting when a serie stops reporting data when there are many series on the same graph (1. on the graph above).
This feature might be changed in the future. For now, if you find it confusing you may use the following solutions to reduce its visual impact (short data gaps only):