feat: implement histogram and gauge histogram support for OpenMetrics 2.0 - #964
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dashpole wants to merge 13 commits into
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feat: implement histogram and gauge histogram support for OpenMetrics 2.0#964dashpole wants to merge 13 commits into
dashpole wants to merge 13 commits into
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Pull request overview
This PR extends the OpenMetrics 2.0 encoder to support serialization and validation of histogram and gauge-histogram metrics, aligning output formatting with the OM2 structure (inline histogram fields plus optional exemplars), and adjusts exemplar emission rules to allow empty-label exemplars when a timestamp is present.
Changes:
- Implemented OpenMetrics 2.0 serialization/validation for classic, native, dual, and gauge histograms (including spans/buckets encoding and created timestamps where applicable).
- Updated exemplar handling to no longer drop exemplars solely due to having an empty label set (still dropped if missing timestamp), emitting
{}for empty labels. - Added comprehensive golden/output and error-case test coverage for histogram variants in OM2.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| expfmt/openmetrics_2_0_create.go | Implements histogram/gaugehistogram encoding + validation and updates exemplar formatting for empty-label exemplars. |
| expfmt/openmetrics_2_0_create_test.go | Adds output and error tests covering classic/native/dual/gauge histogram serialization and validation rules. |
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bwplotka
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Aug 24, 2026
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Looks solid, so far, thanks, some nits
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… 2.0 Implement serialization and strict validation for classic, native, dual, and gauge histograms in OpenMetrics 2.0 format according to the specification and ABNF grammar. Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com> Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
…ncoding Signed-off-by: David Ashpole <dashpole@google.com>
…ram encoding Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
…m encoding Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
… in OM 2.0 Signed-off-by: David Ashpole <dashpole@google.com>
…dBuckets Signed-off-by: David Ashpole <dashpole@google.com>
Signed-off-by: David Ashpole <dashpole@google.com>
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dashpole
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August 26, 2026 14:31
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Part 2 of #893
Implement serialization and strict validation for classic, native, dual, and gauge histograms in OpenMetrics 2.0 format according to the specification and ABNF grammar.