Release v1.38.0

[MrAlias]

This release is the last to support [Go 1.23].
The next release will require at least [Go 1.24].

Added

• Add native histogram exemplar support in go.opentelemetry.io/otel/exporters/prometheus. (Add support for native histogram exemplars #6772)
• Add template attribute functions to the go.opentelmetry.io/otel/semconv/v1.34.0 package. (Render semconv template attributes #6939)
  • ContainerLabel
  • DBOperationParameter
  • DBSystemParameter
  • HTTPRequestHeader
  • HTTPResponseHeader
  • K8SCronJobAnnotation
  • K8SCronJobLabel
  • K8SDaemonSetAnnotation
  • K8SDaemonSetLabel
  • K8SDeploymentAnnotation
  • K8SDeploymentLabel
  • K8SJobAnnotation
  • K8SJobLabel
  • K8SNamespaceAnnotation
  • K8SNamespaceLabel
  • K8SNodeAnnotation
  • K8SNodeLabel
  • K8SPodAnnotation
  • K8SPodLabel
  • K8SReplicaSetAnnotation
  • K8SReplicaSetLabel
  • K8SStatefulSetAnnotation
  • K8SStatefulSetLabel
  • ProcessEnvironmentVariable
  • RPCConnectRPCRequestMetadata
  • RPCConnectRPCResponseMetadata
  • RPCGRPCRequestMetadata
  • RPCGRPCResponseMetadata
• Add ErrorType attribute helper function to the go.opentelmetry.io/otel/semconv/v1.34.0 package. (semconv: add ErrorType attribute function #6962)
• Add WithAllowKeyDuplication in go.opentelemetry.io/otel/sdk/log which can be used to disable deduplication for log records. (sdk/log: Add WithAllowKeyDuplication logger provider option #6968)
• Add WithCardinalityLimit option to configure the cardinality limit in go.opentelemetry.io/otel/sdk/metric. (sdk/metric: Add WithCardinalityLimit option #6996, sdk/metric: do not document default cardinality limit #7065, sdk/metric: Apply Cardinality Limits to Aggregations #7081, sdk/metric: Add Unit Tests for Cardinality Limits #7164, sdk/metric: package example includes Cardinality Limits #7165, sdk/metric: Add Documentation for Cardinality Limits #7179)
• Add Clone method to Record in go.opentelemetry.io/otel/log that returns a copy of the record with no shared state. ( log: Add Record.Clone #7001)
• Add experimental self-observability span and batch span processor metrics in go.opentelemetry.io/otel/sdk/trace. Check the go.opentelemetry.io/otel/sdk/trace/internal/x package documentation for more information. (sdk/trace: self-observability: span metrics #7027, sdk/trace: self-observability: batch span processor metrics #6393, Propagate context to self-observability measurements in sdk/trace #7209)
• The go.opentelemetry.io/otel/semconv/v1.36.0 package. The package contains semantic conventions from the v1.36.0 version of the OpenTelemetry Semantic Conventions. See the migration documentation for information on how to upgrade from go.opentelemetry.io/otel/semconv/v1.34.0.(Generate semconv/v1.36.0 #7032, Change generated semconv sdk queue metrics to observable #7041)
• Add support for configuring Prometheus name translation using WithTranslationStrategy option in go.opentelemetry.io/otel/exporters/prometheus. The current default translation strategy when UTF-8 mode is enabled is NoUTF8EscapingWithSuffixes, but a future release will change the default strategy to UnderscoreEscapingWithSuffixes for compliance with the specification. ( prometheus: Add support for setting Translation Strategy config option #7111)
• Add experimental self-observability log metrics in go.opentelemetry.io/otel/sdk/log. Check the go.opentelemetry.io/otel/sdk/log/internal/x package documentation for more information. (sdk/log: self-observability: log created metric #7121)
• Add experimental self-observability trace exporter metrics in go.opentelemetry.io/otel/exporters/stdout/stdouttrace. Check the go.opentelemetry.io/otel/exporters/stdout/stdouttrace/internal/x package documentation for more information. (feat(stdouttrace): add experimental self-observability metrics #7133)
• Support testing of [Go 1.25]. (Support Go 1.25 #7187)
• The go.opentelemetry.io/otel/semconv/v1.37.0 package. The package contains semantic conventions from the v1.37.0 version of the OpenTelemetry Semantic Conventions. See the migration documentation for information on how to upgrade from go.opentelemetry.io/otel/semconv/v1.36.0.(Generate the semconv/v1.37.0 packages #7254)

Changed

• Optimize TraceIDFromHex and SpanIDFromHex in go.opentelemetry.io/otel/sdk/trace. (trace: optimize id parsing and string functions #6791)
• Change AssertEqual in go.opentelemetry.io/otel/log/logtest to accept TestingT in order to support benchmarks and fuzz tests. (log/logtest: change AssertEqual to accept TestingT for benchmark support #6908)
• Change DefaultExemplarReservoirProviderSelector in go.opentelemetry.io/otel/sdk/metric to use runtime.GOMAXPROCS(0) instead of runtime.NumCPU() for the FixedSizeReservoirProvider default size. (sdk/metric: use runtime.GOMAXPROCS(0) instead of runtime.NumCPU() in DefaultExemplarReservoirProviderSelector for the FixedSizeReservoirProvider default size #7094)

Fixed

• SetBody method of Record in go.opentelemetry.io/otel/sdk/log now deduplicates key-value collections (log.Value of log.KindMap from go.opentelemetry.io/otel/log). (sdk/log: Deduplicate key-value collections in Record.SetBody #7002)
• Fix go.opentelemetry.io/otel/exporters/prometheus to not append a suffix if it's already present in metric name. (fix(deps): update github.com/prometheus/otlptranslator digest to ab8d56d #7088)
• Fix the go.opentelemetry.io/otel/exporters/stdout/stdouttrace self-observability component type and name. (Fix component name for stdouttrace #7195)
• Fix partial export count metric in go.opentelemetry.io/otel/exporters/stdout/stdouttrace. (Handle partial export counts in stdouttrace observability #7199)

Deprecated

• Deprecate WithoutUnits and WithoutCounterSuffixes options, preferring WithTranslationStrategy instead. ( prometheus: Add support for setting Translation Strategy config option #7111)
• Deprecate support for OTEL_GO_X_CARDINALITY_LIMIT environment variable in go.opentelemetry.io/otel/sdk/metric. Use WithCardinalityLimit option instead. (sdk/metric: Deprecate the sdk/metric/x Feature Supporting Cardinality Limits #7166)
  [Go 1.25]: https://go.dev/doc/go1.25
  [Go 1.24]: https://go.dev/doc/go1.24

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 82.9%. Comparing base (18424a4) to head (d9f8764).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #7271   +/-   ##
=====================================
  Coverage   82.9%   82.9%           
=====================================
  Files        265     265           
  Lines      24894   24894           
=====================================
+ Hits       20643   20644    +1     
+ Misses      3876    3875    -1     
  Partials     375     375           

Files with missing lines	Coverage Δ
bridge/opencensus/version.go	100.0% <100.0%> (ø)
exporters/otlp/otlplog/otlploggrpc/version.go	100.0% <100.0%> (ø)
exporters/otlp/otlplog/otlploghttp/version.go	100.0% <100.0%> (ø)
...xporters/otlp/otlpmetric/otlpmetricgrpc/version.go	100.0% <100.0%> (ø)
...xporters/otlp/otlpmetric/otlpmetrichttp/version.go	100.0% <100.0%> (ø)
exporters/otlp/otlptrace/version.go	100.0% <100.0%> (ø)
sdk/metric/version.go	100.0% <100.0%> (ø)
sdk/version.go	100.0% <100.0%> (ø)
version.go	100.0% <100.0%> (ø)

... and 1 file with indirect coverage changes

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