Fill(null) not working as expected

Grafana
1

Hello Everyone.

I’ve got a query/line graph that isn’t behaving as expected. Where there are no points reported, using the “fill(null)” option should just show empty space. This is not the case. I found several issues on the github page about it, but can’t figure out why it’s not working for me.

If I do bars instead of lines, the space shows up, as shown here: 2017-09-19 10_33_16-Grafana - Networking Stats

If I zoom in close enough, it says: “No data points.”

Here’s what my query looks like:

2017_09_19_10_44_53_Grafana_Networking_Stats
2017_09_19_10_44_53_Grafana_Networking_Stats944×339 15.1 KB

Any ideas on getting this to display properly with a line graph?
Thanks,
~B

2

what is your graph display option “null value” set to (find it in the display tab)

3

It is set to null as well.

4

maybe something caused by derivative inflxudb func? what if you remove that function?

5

If I remove the derivative, the gap shows on a line graph, but data is not correct. I’m following this tutorial to gather SNMP data on switches: https://www.dev-eth0.de/blog/2016/12/06/grafana_snmp.html

The value that is returned is an “octet” format, and thus needs to be derived by 1 second to get the bit/sec value.

6

ok, then maybe there is a problem with InfluxDB derivative function and fill(null) that is not working correctly.

7

Is that a bug request I’d need to file with InfluxDB, or grafana?

8

I found this: https://github.com/influxdata/influxdb/issues/7185

9

InfluxDB is doing the derivative calculation (and fill(null)) so InfluxDB. You can double check if you run Grafana v4.5 , click Query Inspector , then you can see raw query sent to influxdb and raw response

1 Like
10

I’ll see what I can find, and post if I find a solution/workaround.