derivative() not functioning properly #3
Description
This may be a Graphite or even Grafana specific issue, I'd assume, but I thought I'd ask here...
Using Grafana v4.4.1 (commit: 6a9f8ca) on Ubuntu 16.04
Any ideas as to why derivative() would be causing empty graphs? Graphite is collecting data being pushed by your scripts, but the Grafana graphs which use derivative() are blank. As soon as I remove that from the query it works.
UPDATE:
As I'm writing this, I figured it out...might be able to be considered a bug? If you don't have time, would you accept a pull request (it'd be my first, I'd be happy to contribute the fix)?
I'm able to get results after adding keepLastValue to the query, example below:
aliasByNode(scaleToSeconds(derivative(keepLastValue(ddwrt.perf.cpu.*)), 1), 3) works, whereas the original dashboard aliasByNode(scaleToSeconds(derivative(ddwrt.perf.cpu.*), 1), 3) does not.
This is apparently an issue with derivative() not working with empty data points <source>