Limit exemplar label characters to conform to Prometheus limits#8362
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anuq wants to merge 9 commits into
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Limit exemplar label characters to conform to Prometheus limits#8362anuq wants to merge 9 commits into
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Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #8362 +/- ##
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- Coverage 91.15% 90.99% -0.16%
- Complexity 7763 7814 +51
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Files 881 892 +11
Lines 23409 23718 +309
Branches 2331 2364 +33
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+ Hits 21338 21582 +244
- Misses 1376 1416 +40
- Partials 695 720 +25 ☔ View full report in Codecov by Sentry. 🚀 New features to boost your workflow:
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This was referenced May 4, 2026
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psx95
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May 9, 2026
Addressed both suggestions: codePointCount instead of length() — Updated labelSetLength() to use String.codePointCount() so the limit is measured in Unicode code points, consistent with the OpenMetrics exemplar spec. (reference open-telemetry#6791) Parameterized tests — Consolidated the four exemplar label limit tests into a single @ParameterizedTest with @MethodSource, covering all four combinations (with/without span context × within/exceeding limit)
Addressed both suggestions: codePointCount instead of length() — Updated labelSetLength() to use String.codePointCount() so the limit is measured in Unicode code points, consistent with the OpenMetrics exemplar spec. (reference open-telemetry#6791) Parameterized tests — Consolidated the four exemplar label limit tests into a single @ParameterizedTest with @MethodSource, covering all four combinations (with/without span context × within/exceeding limit)
…github.com/anuq/opentelemetry-java into fix/prometheus-exemplar-label-length-limit # Conflicts: # exporters/prometheus/src/test/java/io/opentelemetry/exporter/prometheus/Otel2PrometheusConverterTest.java
psx95
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May 18, 2026
- Refactor exemplarLabelLimit test to use Named arguments and consistent naming - Replace unused String testName parameter with Named.of() for better test display - Rename "short" attribute key to "short_attr" for consistency with "long_attr"
jack-berg
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May 28, 2026
jack-berg
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May 28, 2026
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Just a nit on EXEMPLAR_MAX_LABEL_SET_LENGTH visibility.
Thanks!
…rometheus/Otel2PrometheusConverter.java review comment fix Co-authored-by: Jack Berg <34418638+jack-berg@users.noreply.github.com>
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Fixes #6770
Limits exemplar label characters to Prometheus's 128 UTF-8 character maximum. When labels exceed this limit, filtered attributes are dropped while preserving trace_id and span_id for correlation.
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