In a way I experience the issue (not sure if it’s an issue in the true sense of the word) described in this FAQ: Why is my graph empty when I zoom in?
However I experience this not exactly as described there. So I created this new topic rather than replying below the FAQ.
Because what differs my problem from the one described there is that:
- I do not zoom in
- I directly open either the dashboard with several Graph panels or just a single Graph panel
- I do not have any null value(s) in the displayed series
So the query is like:
SELECT sum("value") FROM "meas1" WHERE "foo" =~ /abc/ AND $timeFilter GROUP BY time($__interval), "foo" fill(null)
and field Group by time interval is empty, then…
The first (browser level) load doesn’t draw lines in the graph:
a. until I manually refresh (Grafana refresh button - ), then it displays all the lines.
b. until the next automatic refresh period, then it displays all the lines.
But if enabled displaying ‘Points’ (in Display tab) …This is actually mentioned in the FAQ
a. the lines still does NOT display
b. the Points DOES display
In order to draw the lines right after opening the panel, I have to explicitly define the time interval right in the query
GROUP BY time(5m) or in field Group by time interval with conjunction of
GROUP BY time($__interval)
What is interesting are bullets 1) a. and 1) b. above. The FAQ doesn’t mention the fact that the “Grafana level” refresh actually redraws all the lines.
Also if I’m displaying several measurements (meas1, meas2, meas3,…) in one graph AND I hit the criteria of having at least one null value in at least one measurement, it impacts drawing lines of all measurements = no lines drawn for all measurements series even if only meas2 has one null value in the time interval.
Usage of Null value: connected is NOT an option for me.
[root@foo]# grafana-server -v; influx --version
Version 4.2.0 (commit: 349f3eb)
InfluxDB shell version: 1.2.0