Different collection intervals compatibility in Grafana 7.5.5

[bojankezele]

Describe the bug
With Grafana 7.5.5 version, stacking option with Graph visualization is not working properly with different metric collection intervals.

Screenshot of the issue:

Screenshot of expected behavior

There's a workaround to use groupBy(5m, avg) to group all metrics with 5 minutes interval.

Software versions

Grafana	Zabbix	Grafana-Zabbix Plugin
7.5.5	x.x.x	4.1.4

[alexanderzobnin]

Unfortunately, there's no easy solution for this problem, so moving the next release. The best way top fix it - add interpolation, but it's a bit tricky, and this release contains lots of changes, so dont want to add more complexity right now.

[alexanderzobnin]

Looks like the fix does no cover all possible cases, so I have to find better solution.

[k-korn]

I also have a use case affected by this issue: data is sent to Zabbix by external hardware sensors, at flexible intervals not controllable by Zabbix (but by these sensors).
If sensor value does not change, they send it to Zabbix every 15 minutes. But once the value starts to change, that interval can go down to 5 seconds, or be an arbitrary value in between 5 seconds and 15 minutes. So trying to align all values to some set interval will not work, as there is no common update interval.

[alexanderzobnin]

@k-korn yes, in this case I decided to perform it in a bit different way. I use interpolation (which original stacking algorithm used in Grafana) to find all common points and prepare series for proper stacking. This is an example of how it works:

Original Zabbix data:

Prepared for stacking:

[alexanderzobnin]

Closing this again since it's fixed by fcef21b

[borjasueiro]

The bug still exists at 4.2.4 version.When I try to stack values with different update interval it does not work correctly.
Screenshot of the issue:

Screenshot of expected behavior: