Empty metric name in the Grafana dropdowns

[Allineer]

Describe the bug

Related to #599

Did you see an empty dropdown item before the "alertmanager"?

[valyala]

The issue should be fixed in the commit 0b2086b . This commit will be included in the next release. In the mean time the bugfix may be tested by building VictoriaMetrics from the commit according to these docs.

[Allineer]

@valyala seems, it's working for me. Thanks.

But I still can’t understand where they come from. I do not have rules that delete all labels and the name of the metric itself.

Exporters used are almost from the list https://github.com/prometheus/prometheus/wiki/Default-port-allocations and, I hope, do not allow yourself to export an empty metric with only a value.

There are two custom exporters, but all the metrics that they exports are all written to the database, all are available.

[Allineer]

Maybe it makes sense to add to vmagent the logging of metrics that he is trying to write to the database without a name AND labels? Perhaps it will turn out to get at least some additional information and the answer to the question "Who is to blame?" - vmagent, vm-node or exporters?

[valyala]

FYI, the commit that prevents from adding and/or selecting metrics with empty label values has been included in v1.38.0.

[Allineer]

Thanks!