Validate metric name before removing empty labels #7253
+87
−37
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Signed-off-by: yeya24 <[email protected]>
Signed-off-by: yeya24 <[email protected]>
Signed-off-by: yeya24 <[email protected]>
friedrichg
approved these changes
Feb 11, 2026
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What this PR does:
Extract
ValidateMetricNamefromValidateLabelsand apply its validation before removing empty label (added in #7069).Today, if we send a series with only one empty metric name label
{__name__=""}. It is validated as a 200 because the empty label will be stripped and distributor will continue when there is no label left.However, the expected behavior is that we should return 400 in this case to reject empty metric name value. To do it, the metric name validation should happen before removing empty label values from the series.
This edge case is caught via the Prometheus compliance test suite for remote write. https://github.com/prometheus/compliance/tree/main/remotewrite
Which issue(s) this PR fixes:
Fixes #
Checklist
CHANGELOG.mdupdated - the order of entries should be[CHANGE],[FEATURE],[ENHANCEMENT],[BUGFIX]