Release 1.56.0

Context

• Align environment variable context propagation name restrictions with POSIX.1-2024
  and define normalization behavior.
  (#4944)
• Decouple the responsibilities of the environment variable propagation carrier.
  (#4961)
• Remove misleading implementation approach the environment variable propagation.
  (#5003)
• Change Environment Variables as Context Propagation Carriers document status to Beta.
  (#5020)

Traces

• Stabilize Tracer enabled operation
  (#4941)
• Stabilize AlwaysRecord sampler.
  (#4934)

Metrics

• Add development maxExportBatchSize parameter to Periodic exporting MetricReader.
  (#4895)

Logs

• Add event to span event bridge.
  (#5006)

Resource

• Clarify that a Resource describes the observed entity, not the component
  that technically emits telemetry.
  (#4905)

Entities

• Define merge algorithm.
  (4768)

Compatibility

• Deprecate OpenTracing compatibility requirements in the specification.
  (#4938)
• Stabilize sections of Prometheus and OpenMetrics Compatibility.
  • Stabilize Prometheus Classic Histogram to OTLP Explicit Histogram transformation.
    (#4874)
  • Stabilize Prometheus Timestamp and Start timestamp transformation.
    (#4953)
  • Clarify Prometheus Native Histogram to OTLP Exponential Histogram conversion,
    add conversion rules for Native Histograms with Custom Buckets (NHCB) to OTLP
    Histogram.
    (#4898)
  • Stabilize Prometheus Dropped Types transformation.
    (#4952)
  • Stabilize OpenTelemetry Attributes to Prometheus labels transformation.
    (#4963)
  • Stabilize Prometheus Exemplar to OpenTelemetry Exemplar transformation.
    (#4962)
  • Stabilize Prometheus Metadata transformation.
    (#4954)
  • Stabilize OpenTelemetry Metric Metadata to Prometheus metric metadata.
    (#4966)
  • Stabilize OpenTelemetry Exemplar to Prometheus Exemplar transformation.
    (#4964)
• Stabilize sections of Prometheus Metrics Exporter.
  • Stabilize host configuration.
    (#5025)

SDK Configuration

• Declarative configuration: add in-development guidance for exposing the
  effective Resource returned by Create.
  (#4949)
• Require spec changes to consider declarative config schema
  (#4916)
• Add strict YAML parsing guidance to configuration supplementary guidelines.
  (#4878)

OTEPs

• Process Context: Sharing Resource Attributes with External Readers.
  (#4719)
• Support multiple Resources within an SDK.
  (#4665)

New Contributors

• @fractalwrench made their first contribution in #4907
• @svencowart made their first contribution in #4905
• @tiffany76 made their first contribution in #4958
• @krajorama made their first contribution in #4898
• @adp2201 made their first contribution in #4938
• @dbarker made their first contribution in #4974
• @johannaojeling made their first contribution in #4969
• @bachp made their first contribution in #4996
• @iblancasa made their first contribution in #4949
• @ivoanjo made their first contribution in #4719

Full Changelog: v1.55.0...v1.56.0

Release 1.55.0

Traces

• Add normative language to the Tracing API/SDK spec concurrency requirements.
  (#4887)

Metrics

• Add additional in-development requirements to metric start timestamps.
  (#4807,
  #4902)

Logs

• Stabilize optional Exception parameter to Logger Emit.
  (#4858)

Compatibility

• Stabilize Prometheus Summary to OTLP Summary transformation.
  (#4872)

SDK Configuration

• Declarative configuration: allow language-specific prefixes in environment
  variable substitution.
  (#4891)
• Mark significant portions of declarative configuration as stable.
  (#4568)

Release 1.54.0

Context

• Deprecate Jaeger propagator and make propagator implementation optional.
  (#4827)
• Deprecate OT Trace propagator and make propagator implementation optional.
  (#4851)

Metrics

• Add normative language to the Metrics API/SDK spec concurrency requirements.
  (#4868)

Logs

• Add optional Exception parameter to Emit LogRecord.
  (#4824)
• Add normative language to the Logging API/SDK spec concurrency requirements.
  (#4885)

Resource

• Refine the handling of OTEL_RESOURCE_ATTRIBUTES.
  (#4856)

Common

• Add string representation guidance for complex attribute value types (byte arrays,
  empty values, arrays, and maps) for non-OTLP protocols.
  (#4848)

Compatibility

• Stabilize Prometheus Counter to OTLP Sum transformation.
  (#4862)
• Stabilize Prometheus Gauge to OTLP Gauge transformation.
  (#4871)

SDK Configuration

• Swap Tracer/Meter/LoggerConfig disabled for enabled to avoid double negatives
  (#4823)
• Declarative configuration: rename ComponentProvider to
  PluginComponentProvider, CreatePlugin to CreateComponent in effort to
  use consistent vocabulary
  (#4806)
• Declarative configuration: Update instrumentation config behavior to return
  empty object when not set
  (#4817)

New Contributors

• @am1r021 made their first contribution in #4857

Full Changelog: v1.53.0...v1.54.0

v1.53.0

What's Changed

Metrics

• Stabilize part of Enabled SDK for synchronous instruments.
  (#4787)

Logs

• Add optional Ergonomic API.
  (#4741)

SDK Configuration

• Declarative configuration: clarify default behavior and validation
  requirements of create and parse.
  (#4780)
• Declarative configuration: add optional programmatic customization to
  create, and add related supplemental guidelines.
  (#4777)
• Declarative configuration: add links between SDK extension plugins and
  corresponding declarative config types.
  (#4802)
• Declarative configuration: clarify Registry ComponentProvider type parameter
  (#4799)

Common

• Stabilize complex AnyValue attribute value types and related attribute limits.
  (#4794)

New Contributors

• @vanshika622 made their first contribution in #4776

Full Changelog: v1.52.0...v1.53.0

Release 1.52.0

Context

• Make the W3C randomness flag required.
  (#4761)

Traces

• Deprecate Zipkin exporter document and make exporter implementation optional.
  (#4715)
• Add spec for AlwaysRecord sampler
  (#4699)

Metrics

• Stabilize Enabled API for synchronous instruments.
  (#4746)
• Allow instrument Enabled implementation to have additional optimizations and features.
  (#4747)

Logs

• Stabilize LogRecordProcessor.Enabled.
  (#4717)

SDK Configuration

• Clarifies that guidance related to boolean environment variables is not applicable
  to other configuration interfaces. (#4723)

New Contributors

• @majanjua-amzn made their first contribution in #4699
• @vitorvasc made their first contribution in #4778
• @BatmanAoD made their first contribution in #4795

Release 1.51.0

Metrics

• AlignedHistogramBucketExemplarReservoir SHOULD use a time-weighted algorithm.
  (#4678)

Profiles

• Document the profiles signal.
  (#4685)

Common

• Extend the set of attribute value types to support more complex data structures.
  (#4651)

New Contributors

• @hectorhdzg made their first contribution in #4724

Release 1.50.0

Traces

• Restore TraceIdRatioBased and give it a deprecation timeline. Update recommended
  warnings based on feedback in issue #4601.
  (#4627)
• Changes of TracerConfig.disabled MUST be eventually visible.
  (#4645)
• Remove text related to the former expermental probability sampling specification.
  (#4673)

Metrics

• Changes of MeterConfig.disabled MUST be eventually visible.
  (#4645)

Logs

• Add minimum_severity and trace_based logger configuration parameters.
  (#4612)
• Changes of LoggerConfig.disabled MUST be eventually visible.
  (#4645)

New Contributors

• @maryliag made their first contribution in #4666

Release 1.49.0

Entities

• Specify entity information via an environment variable.
  (#4594)

Common

• OTLP Exporters may allow devs to prepend a product identifier in User-Agent header.
  (#4560)
• ⚠️ IMPORTANT: Extending the set of standard attribute value types is no longer a breaking change.
  (#4614)

OTEPs

• Clarify in Composite Samplers OTEP the unreliable threshold case.
  (#4569)

New Contributors

• @cheempz made their first contribution in #4632
• @kaylareopelle made their first contribution in #4629
• @Calm-Rock made their first contribution in #4638
• @david-luna made their first contribution in #4560

Release 1.48.0

Logs

• Improve concurrency safety description of LogRecordProcessor.OnEmit. (#4578)
• Clarify that SeverityNumber values are used when comparing severities. (#4552)

Entities

• Mention entity references in the stability guarantees. (#4593)

OpenTelemetry Protocol

• Clarify protocol defaults on specification. (#4585)

Compatibility

• Flexibilie escaping of characters that are discouraged by Prometheus Conventions in Prometheus exporters. (#4533)
• Flexibilize addition of unit/type related suffixes in Prometheus exporters. (#4533)
• Define the configuration option "Translation Strategies" for Prometheus exporters. (#4533)
• Define conversion of Prometheus native histograms to OpenTelemetry exponential histograms. (#4561)
• Clarify what to do when scope attribute conflicts with name, version and schema URL. (#4599)

SDK Configuration

• Enum values provided via environment variables SHOULD be interpreted in a case-insensitive manner. (#4576)

New Contributors

• @gustavo-vargas-leon made their first contribution in #4585
• @thompson-tomo made their first contribution in #4597

Full Changelog: v1.47.0...v1.48.0

Release 1.47.0

Traces

• Define sampling threshold field in OpenTelemetry TraceState; define the behavior
  of TraceIdRatioBased sampler in terms of W3C Trace Context Level 2 randomness.
  (#4166)
• Define CompositeSampler implementation and built-in ComposableSampler interfaces.
  (#4466)
• Define how SDK implements Tracer.Enabled.
  (#4537)

Logs

• Stabilize Event Name parameter of Logger.Enabled.
  (#4534)
• Stabilize SDK and No-Op Logger.Enabled.
  (#4536)
• SeverityNumber=0 MAY be used to represent an unspecified value.
  (#4535)

Compatibility

• Clarify expectations about Prometheus content negotiation for metric names.
  (#4543)

Supplementary Guidelines

• Add Supplementary Guidelines for environment variables as context carrier
  specification.
  (#4548)

OTEPs

• Extend attributes to support complex values.
  (#4485)

Common

• Update spec to comply with OTEP-232.
  (#4529)

New Contributors

• @ArthurSens made their first contribution in #4543