Custom chart with option nonzero and data-dimensions set

[t-h-e]

The option nonzero or "NETDATA.options.current.eliminate_zero_dimensions = true;" should remove dimensions that contain only zeros, which works fine if no dimensions are specified.

If data-dimensions is set, then this flag is ignored. https://github.com/firehol/netdata/blob/master/src/rrd2json.c#L630-L636

Doesn't that seem counter-intuitive? If the user wants to show only certain dimensions, but automatically remove nonzero dimensions, that is not possible. But this could actually be done by adding or removing the nonzero flag.

[ktsaou]

You are right.
I'll remove that code to allow it work in that case too.

[ktsaou]

done!
thanks!

[t-h-e]

Sorry for not checking this earlier, but this change on its own, hasn't done the trick for me. The method rrdr_disable_not_selected_dimensions sets all dimensions that are specified by the user to RRDR_NONZERO, regardless of the option nonzero.

The following change fixes that: t-h-e@cf14df5

PS: It seems kind of confusing that in the REST api the option nonzero removes dimensions that are all zeros and internally RRDR_NONZERO marks dimensions with values other than zero. Maybe renaming the nonzero option to eliminate_zero_dimensions like in the javascript case would be more expressive.

[ktsaou]

ok. I don't see any issues.
Can you make a PR?

[t-h-e]

PR #1658

[ktsaou]

well, I found an issue.

if all dimensions are zero and the nonzero option is set, then the charts are shown as empty.

If am adding code, to detect this, and enable all the zero dimensions if none is nonzero (the way it should work).

[t-h-e]

You are right. I never had that case. Thanks.