[v10.4.x] Tempo: Better fallbacks for metrics query #83688
Merged
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Backport 036e190 from #83619
What is this feature?
This PR fixes a couple of bugs we were seeing when Tempo returned no labels or labels with empty values for a specific query when using the metrics endpoint.
When there are no labels and the results contains a single series, we fallback to the query string, to mimic the Prometheus datasource.
When the value for a label is an empty string we force the series name to be
""
since this is the actual value of the label. In Tempo the values are typed so we know that""
is the value of empty string instead of the absence of value.Why do we need this feature?
We were seeing errors and undesired behaviours when querying the metrics endpoint of Tempo.
Who is this feature for?
Users of the Tempo datasource.
Which issue(s) does this PR fix?:
Fixes grafana/tempo#3429
Special notes for your reviewer:
Please check that: