1# Changelog
   2
   3All notable changes to this project will be documented in this file.
   4
   5The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
   6
   7This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   8
   9## [Unreleased]
  10
  11<!-- Released section -->
  12<!-- Don't change this section unless doing release -->
  13
  14## [1.35.0/0.57.0/0.11.0] 2025-03-05
  15
  16This release is the last to support [Go 1.22].
  17The next release will require at least [Go 1.23].
  18
  19### Added
  20
  21- Add `ValueFromAttribute` and `KeyValueFromAttribute` in `go.opentelemetry.io/otel/log`. (#6180)
  22- Add `EventName` and `SetEventName` to `Record` in `go.opentelemetry.io/otel/log`. (#6187)
  23- Add `EventName` to `RecordFactory` in `go.opentelemetry.io/otel/log/logtest`. (#6187)
  24- `AssertRecordEqual` in `go.opentelemetry.io/otel/log/logtest` checks `Record.EventName`. (#6187)
  25- Add `EventName` and `SetEventName` to `Record` in `go.opentelemetry.io/otel/sdk/log`. (#6193)
  26- Add `EventName` to `RecordFactory` in `go.opentelemetry.io/otel/sdk/log/logtest`. (#6193)
  27- Emit `Record.EventName` field in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc`. (#6211)
  28- Emit `Record.EventName` field in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`. (#6211)
  29- Emit `Record.EventName` field in `go.opentelemetry.io/otel/exporters/stdout/stdoutlog` (#6210)
  30- The `go.opentelemetry.io/otel/semconv/v1.28.0` package.
  31  The package contains semantic conventions from the `v1.28.0` version of the OpenTelemetry Semantic Conventions.
  32  See the [migration documentation](./semconv/v1.28.0/MIGRATION.md) for information on how to upgrade from `go.opentelemetry.io/otel/semconv/v1.27.0`(#6236)
  33- The `go.opentelemetry.io/otel/semconv/v1.30.0` package.
  34  The package contains semantic conventions from the `v1.30.0` version of the OpenTelemetry Semantic Conventions.
  35  See the [migration documentation](./semconv/v1.30.0/MIGRATION.md) for information on how to upgrade from `go.opentelemetry.io/otel/semconv/v1.28.0`(#6240)
  36- Document the pitfalls of using `Resource` as a comparable type.
  37  `Resource.Equal` and `Resource.Equivalent` should be used instead. (#6272)
  38- Support [Go 1.24]. (#6304)
  39- Add `FilterProcessor` and `EnabledParameters` in `go.opentelemetry.io/otel/sdk/log`.
  40  It replaces `go.opentelemetry.io/otel/sdk/log/internal/x.FilterProcessor`.
  41  Compared to previous version it additionally gives the possibility to filter by resource and instrumentation scope. (#6317)
  42
  43### Changed
  44
  45- Update `github.com/prometheus/common` to `v0.62.0`, which changes the `NameValidationScheme` to `NoEscaping`.
  46  This allows metrics names to keep original delimiters (e.g. `.`), rather than replacing with underscores.
  47  This is controlled by the `Content-Type` header, or can be reverted by setting `NameValidationScheme` to `LegacyValidation` in `github.com/prometheus/common/model`. (#6198)
  48
  49### Fixes
  50
  51- Eliminate goroutine leak for the processor returned by `NewSimpleSpanProcessor` in `go.opentelemetry.io/otel/sdk/trace` when `Shutdown` is called and the passed `ctx` is canceled and `SpanExporter.Shutdown` has not returned. (#6368)
  52- Eliminate goroutine leak for the processor returned by `NewBatchSpanProcessor` in `go.opentelemetry.io/otel/sdk/trace` when `ForceFlush` is called and the passed `ctx` is canceled and `SpanExporter.Export` has not returned. (#6369)
  53
  54## [1.34.0/0.56.0/0.10.0] 2025-01-17
  55
  56### Changed
  57
  58- Remove the notices from `Logger` to make the whole Logs API user-facing in `go.opentelemetry.io/otel/log`. (#6167)
  59
  60### Fixed
  61
  62- Relax minimum Go version to 1.22.0 in various modules. (#6073)
  63- The `Type` name logged for the `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` client is corrected from `otlphttpgrpc` to `otlptracegrpc`. (#6143)
  64- The `Type` name logged for the `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlphttpgrpc` client is corrected from `otlphttphttp` to `otlptracehttp`. (#6143)
  65
  66## [1.33.0/0.55.0/0.9.0/0.0.12] 2024-12-12
  67
  68### Added
  69
  70- Add `Reset` method to `SpanRecorder` in `go.opentelemetry.io/otel/sdk/trace/tracetest`. (#5994)
  71- Add `EnabledInstrument` interface in `go.opentelemetry.io/otel/sdk/metric/internal/x`.
  72  This is an experimental interface that is implemented by synchronous instruments provided by `go.opentelemetry.io/otel/sdk/metric`.
  73  Users can use it to avoid performing computationally expensive operations when recording measurements.
  74  It does not fall within the scope of the OpenTelemetry Go versioning and stability [policy](./VERSIONING.md) and it may be changed in backwards incompatible ways or removed in feature releases. (#6016)
  75
  76### Changed
  77
  78- The default global API now supports full auto-instrumentation from the `go.opentelemetry.io/auto` package.
  79  See that package for more information. (#5920)
  80- Propagate non-retryable error messages to client in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`. (#5929)
  81- Propagate non-retryable error messages to client in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#5929)
  82- Propagate non-retryable error messages to client in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#5929)
  83- Performance improvements for attribute value `AsStringSlice`, `AsFloat64Slice`, `AsInt64Slice`, `AsBoolSlice`. (#6011)
  84- Change `EnabledParameters` to have a `Severity` field instead of a getter and setter in `go.opentelemetry.io/otel/log`. (#6009)
  85
  86### Fixed
  87
  88- Fix inconsistent request body closing in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`. (#5954)
  89- Fix inconsistent request body closing in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#5954)
  90- Fix inconsistent request body closing in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#5954)
  91- Fix invalid exemplar keys in `go.opentelemetry.io/otel/exporters/prometheus`. (#5995)
  92- Fix attribute value truncation in `go.opentelemetry.io/otel/sdk/trace`. (#5997)
  93- Fix attribute value truncation in `go.opentelemetry.io/otel/sdk/log`. (#6032)
  94
  95## [1.32.0/0.54.0/0.8.0/0.0.11] 2024-11-08
  96
  97### Added
  98
  99- Add `go.opentelemetry.io/otel/sdk/metric/exemplar.AlwaysOffFilter`, which can be used to disable exemplar recording. (#5850)
 100- Add `go.opentelemetry.io/otel/sdk/metric.WithExemplarFilter`, which can be used to configure the exemplar filter used by the metrics SDK. (#5850)
 101- Add `ExemplarReservoirProviderSelector` and `DefaultExemplarReservoirProviderSelector` to `go.opentelemetry.io/otel/sdk/metric`, which defines the exemplar reservoir to use based on the aggregation of the metric. (#5861)
 102- Add `ExemplarReservoirProviderSelector` to `go.opentelemetry.io/otel/sdk/metric.Stream` to allow using views to configure the exemplar reservoir to use for a metric. (#5861)
 103- Add `ReservoirProvider`, `HistogramReservoirProvider` and `FixedSizeReservoirProvider` to `go.opentelemetry.io/otel/sdk/metric/exemplar` to make it convenient to use providers of Reservoirs. (#5861)
 104- The `go.opentelemetry.io/otel/semconv/v1.27.0` package.
 105  The package contains semantic conventions from the `v1.27.0` version of the OpenTelemetry Semantic Conventions. (#5894)
 106- Add `Attributes attribute.Set` field to `Scope` in `go.opentelemetry.io/otel/sdk/instrumentation`. (#5903)
 107- Add `Attributes attribute.Set` field to `ScopeRecords` in `go.opentelemetry.io/otel/log/logtest`. (#5927)
 108- `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` adds instrumentation scope attributes. (#5934)
 109- `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp` adds instrumentation scope attributes. (#5934)
 110- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` adds instrumentation scope attributes. (#5935)
 111- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` adds instrumentation scope attributes. (#5935)
 112- `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc` adds instrumentation scope attributes. (#5933)
 113- `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp` adds instrumentation scope attributes. (#5933)
 114- `go.opentelemetry.io/otel/exporters/prometheus` adds instrumentation scope attributes in `otel_scope_info` metric as labels. (#5932)
 115
 116### Changed
 117
 118- Support scope attributes and make them as identifying for `Tracer` in `go.opentelemetry.io/otel` and `go.opentelemetry.io/otel/sdk/trace`. (#5924)
 119- Support scope attributes and make them as identifying for `Meter` in `go.opentelemetry.io/otel` and `go.opentelemetry.io/otel/sdk/metric`. (#5926)
 120- Support scope attributes and make them as identifying for `Logger` in `go.opentelemetry.io/otel` and `go.opentelemetry.io/otel/sdk/log`. (#5925)
 121- Make schema URL and scope attributes as identifying for `Tracer` in `go.opentelemetry.io/otel/bridge/opentracing`. (#5931)
 122- Clear unneeded slice elements to allow GC to collect the objects in `go.opentelemetry.io/otel/sdk/metric` and `go.opentelemetry.io/otel/sdk/trace`. (#5804)
 123
 124### Fixed
 125
 126- Global MeterProvider registration unwraps global instrument Observers, the undocumented Unwrap() methods are now private. (#5881)
 127- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` now keeps the metadata already present in the context when `WithHeaders` is used. (#5892)
 128- `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc` now keeps the metadata already present in the context when `WithHeaders` is used. (#5911)
 129- `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` now keeps the metadata already present in the context when `WithHeaders` is used. (#5915)
 130- Fix `go.opentelemetry.io/otel/exporters/prometheus` trying to add exemplars to Gauge metrics, which is unsupported. (#5912)
 131- Fix `WithEndpointURL` to always use a secure connection when an https URL is passed in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#5944)
 132- Fix `WithEndpointURL` to always use a secure connection when an https URL is passed in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#5944)
 133- Fix `WithEndpointURL` to always use a secure connection when an https URL is passed in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`. (#5944)
 134- Fix `WithEndpointURL` to always use a secure connection when an https URL is passed in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#5944)
 135- Fix incorrect metrics generated from callbacks when multiple readers are used in `go.opentelemetry.io/otel/sdk/metric`. (#5900)
 136
 137### Removed
 138
 139- Remove all examples under `go.opentelemetry.io/otel/example` as they are moved to [Contrib repository](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/examples). (#5930)
 140
 141## [1.31.0/0.53.0/0.7.0/0.0.10] 2024-10-11
 142
 143### Added
 144
 145- Add `go.opentelemetry.io/otel/sdk/metric/exemplar` package which includes `Exemplar`, `Filter`, `TraceBasedFilter`, `AlwaysOnFilter`, `HistogramReservoir`, `FixedSizeReservoir`, `Reservoir`, `Value` and `ValueType` types. These will be used for configuring the exemplar reservoir for the metrics sdk. (#5747, #5862)
 146- Add `WithExportBufferSize` option to log batch processor.(#5877)
 147
 148### Changed
 149
 150- Enable exemplars by default in `go.opentelemetry.io/otel/sdk/metric`. Exemplars can be disabled by setting `OTEL_METRICS_EXEMPLAR_FILTER=always_off` (#5778)
 151- `Logger.Enabled` in `go.opentelemetry.io/otel/log` now accepts a newly introduced `EnabledParameters` type instead of `Record`. (#5791)
 152- `FilterProcessor.Enabled` in `go.opentelemetry.io/otel/sdk/log/internal/x` now accepts `EnabledParameters` instead of `Record`. (#5791)
 153- The `Record` type in `go.opentelemetry.io/otel/log` is no longer comparable. (#5847)
 154- Performance improvements for the trace SDK `SetAttributes` method in `Span`. (#5864)
 155- Reduce memory allocations for the `Event` and `Link` lists in `Span`. (#5858)
 156- Performance improvements for the trace SDK `AddEvent`, `AddLink`, `RecordError` and `End` methods in `Span`. (#5874)
 157
 158### Deprecated
 159
 160- Deprecate all examples under `go.opentelemetry.io/otel/example` as they are moved to [Contrib repository](https://github.com/open-telemetry/opentelemetry-go-contrib/tree/main/examples). (#5854)
 161
 162### Fixed
 163
 164- The race condition for multiple `FixedSize` exemplar reservoirs identified in #5814 is resolved. (#5819)
 165- Fix log records duplication in case of heterogeneous resource attributes by correctly mapping each log record to it's resource and scope. (#5803)
 166- Fix timer channel drain to avoid hanging on Go 1.23. (#5868)
 167- Fix delegation for global meter providers, and panic when calling otel.SetMeterProvider. (#5827)
 168- Change the `reflect.TypeOf` to use a nil pointer to not allocate on the heap unless necessary. (#5827)
 169
 170## [1.30.0/0.52.0/0.6.0/0.0.9] 2024-09-09
 171
 172### Added
 173
 174- Support `OTEL_EXPORTER_OTLP_LOGS_INSECURE` and `OTEL_EXPORTER_OTLP_INSECURE` environments in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc`. (#5739)
 175- The `WithResource` option for `NewMeterProvider` now merges the provided resources with the ones from environment variables. (#5773)
 176- The `WithResource` option for `NewLoggerProvider` now merges the provided resources with the ones from environment variables. (#5773)
 177- Add UTF-8 support to `go.opentelemetry.io/otel/exporters/prometheus`. (#5755)
 178
 179### Fixed
 180
 181- Fix memory leak in the global `MeterProvider` when identical instruments are repeatedly created. (#5754)
 182- Fix panic on instruments creation when setting meter provider. (#5758)
 183- Fix an issue where `SetMeterProvider` in `go.opentelemetry.io/otel` might miss the delegation for instruments and registries. (#5780)
 184
 185### Removed
 186
 187- Drop support for [Go 1.21]. (#5736, #5740, #5800)
 188
 189## [1.29.0/0.51.0/0.5.0] 2024-08-23
 190
 191This release is the last to support [Go 1.21].
 192The next release will require at least [Go 1.22].
 193
 194### Added
 195
 196- Add MacOS ARM64 platform to the compatibility testing suite. (#5577)
 197- Add `InstrumentationScope` field to `SpanStub` in `go.opentelemetry.io/otel/sdk/trace/tracetest`, as a replacement for the deprecated `InstrumentationLibrary`. (#5627)
 198- Make the initial release of `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc`.
 199  This new module contains an OTLP exporter that transmits log telemetry using gRPC.
 200  This module is unstable and breaking changes may be introduced.
 201  See our [versioning policy](VERSIONING.md) for more information about these stability guarantees. (#5629)
 202- Add `Walk` function to `TraceState` in `go.opentelemetry.io/otel/trace` to iterate all the key-value pairs. (#5651)
 203- Bridge the trace state in `go.opentelemetry.io/otel/bridge/opencensus`. (#5651)
 204- Zero value of `SimpleProcessor` in `go.opentelemetry.io/otel/sdk/log` no longer panics. (#5665)
 205- The `FilterProcessor` interface type is added in `go.opentelemetry.io/otel/sdk/log/internal/x`.
 206  This is an optional and experimental interface that log `Processor`s can implement to instruct the `Logger` if a `Record` will be processed or not.
 207  It replaces the existing `Enabled` method that is removed from the `Processor` interface itself.
 208  It does not fall within the scope of the OpenTelemetry Go versioning and stability [policy](./VERSIONING.md) and it may be changed in backwards incompatible ways or removed in feature releases. (#5692)
 209- Support [Go 1.23]. (#5720)
 210
 211### Changed
 212
 213- `NewMemberRaw`, `NewKeyProperty` and `NewKeyValuePropertyRaw` in `go.opentelemetry.io/otel/baggage` allow UTF-8 string in key. (#5132)
 214- `Processor.OnEmit` in `go.opentelemetry.io/otel/sdk/log` now accepts a pointer to `Record` instead of a value so that the record modifications done in a processor are propagated to subsequent registered processors. (#5636)
 215- `SimpleProcessor.Enabled` in `go.opentelemetry.io/otel/sdk/log` now returns `false` if the exporter is `nil`. (#5665)
 216- Update the concurrency requirements of `Exporter` in `go.opentelemetry.io/otel/sdk/log`. (#5666)
 217- `SimpleProcessor` in `go.opentelemetry.io/otel/sdk/log` synchronizes `OnEmit` calls. (#5666)
 218- The `Processor` interface in `go.opentelemetry.io/otel/sdk/log` no longer includes the `Enabled` method.
 219  See the `FilterProcessor` interface type added in `go.opentelemetry.io/otel/sdk/log/internal/x` to continue providing this functionality. (#5692)
 220- The `SimpleProcessor` type in `go.opentelemetry.io/otel/sdk/log` is no longer comparable. (#5693)
 221- The `BatchProcessor` type in `go.opentelemetry.io/otel/sdk/log` is no longer comparable. (#5693)
 222
 223### Fixed
 224
 225- Correct comments for the priority of the `WithEndpoint` and `WithEndpointURL` options and their corresponding environment variables in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#5584)
 226- Pass the underlying error rather than a generic retry-able failure in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`, `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp` and `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#5541)
 227- Correct the `Tracer`, `Meter`, and `Logger` names used in `go.opentelemetry.io/otel/example/dice`. (#5612)
 228- Correct the `Tracer` names used in `go.opentelemetry.io/otel/example/namedtracer`. (#5612)
 229- Correct the `Tracer` name used in `go.opentelemetry.io/otel/example/opencensus`. (#5612)
 230- Correct the `Tracer` and `Meter` names used in `go.opentelemetry.io/otel/example/otel-collector`. (#5612)
 231- Correct the `Tracer` names used in `go.opentelemetry.io/otel/example/passthrough`. (#5612)
 232- Correct the `Meter` name used in `go.opentelemetry.io/otel/example/prometheus`. (#5612)
 233- Correct the `Tracer` names used in `go.opentelemetry.io/otel/example/zipkin`. (#5612)
 234- Correct comments for the priority of the `WithEndpoint` and `WithEndpointURL` options and their corresponding environment variables in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#5641)
 235- Correct comments for the priority of the `WithEndpoint` and `WithEndpointURL` options and their corresponding environment variables in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`. (#5650)
 236- Stop percent encoding header environment variables in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`, `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`, `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` (#5705)
 237- Remove invalid environment variable header keys in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`, `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`, `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` (#5705)
 238
 239### Removed
 240
 241- The `Enabled` method of the `SimpleProcessor` in `go.opentelemetry.io/otel/sdk/log` is removed. (#5692)
 242- The `Enabled` method of the `BatchProcessor` in `go.opentelemetry.io/otel/sdk/log` is removed. (#5692)
 243
 244## [1.28.0/0.50.0/0.4.0] 2024-07-02
 245
 246### Added
 247
 248- The `IsEmpty` method is added to the `Instrument` type in `go.opentelemetry.io/otel/sdk/metric`.
 249  This method is used to check if an `Instrument` instance is a zero-value. (#5431)
 250- Store and provide the emitted `context.Context` in `ScopeRecords` of `go.opentelemetry.io/otel/sdk/log/logtest`. (#5468)
 251- The `go.opentelemetry.io/otel/semconv/v1.26.0` package.
 252  The package contains semantic conventions from the `v1.26.0` version of the OpenTelemetry Semantic Conventions. (#5476)
 253- The `AssertRecordEqual` method to `go.opentelemetry.io/otel/log/logtest` to allow comparison of two log records in tests. (#5499)
 254- The `WithHeaders` option to `go.opentelemetry.io/otel/exporters/zipkin` to allow configuring custom http headers while exporting spans. (#5530)
 255
 256### Changed
 257
 258- `Tracer.Start` in `go.opentelemetry.io/otel/trace/noop` no longer allocates a span for empty span context. (#5457)
 259- Upgrade `go.opentelemetry.io/otel/semconv/v1.25.0` to `go.opentelemetry.io/otel/semconv/v1.26.0` in `go.opentelemetry.io/otel/example/otel-collector`. (#5490)
 260- Upgrade `go.opentelemetry.io/otel/semconv/v1.25.0` to `go.opentelemetry.io/otel/semconv/v1.26.0` in `go.opentelemetry.io/otel/example/zipkin`. (#5490)
 261- Upgrade `go.opentelemetry.io/otel/semconv/v1.25.0` to `go.opentelemetry.io/otel/semconv/v1.26.0` in `go.opentelemetry.io/otel/exporters/zipkin`. (#5490)
 262  - The exporter no longer exports the deprecated "otel.library.name" or "otel.library.version" attributes.
 263- Upgrade `go.opentelemetry.io/otel/semconv/v1.25.0` to `go.opentelemetry.io/otel/semconv/v1.26.0` in `go.opentelemetry.io/otel/sdk/resource`. (#5490)
 264- Upgrade `go.opentelemetry.io/otel/semconv/v1.25.0` to `go.opentelemetry.io/otel/semconv/v1.26.0` in `go.opentelemetry.io/otel/sdk/trace`. (#5490)
 265- `SimpleProcessor.OnEmit` in `go.opentelemetry.io/otel/sdk/log` no longer allocates a slice which makes it possible to have a zero-allocation log processing using `SimpleProcessor`. (#5493)
 266- Use non-generic functions in the `Start` method of `"go.opentelemetry.io/otel/sdk/trace".Trace` to reduce memory allocation. (#5497)
 267- `service.instance.id` is populated for a `Resource` created with `"go.opentelemetry.io/otel/sdk/resource".Default` with a default value when `OTEL_GO_X_RESOURCE` is set. (#5520)
 268- Improve performance of metric instruments in `go.opentelemetry.io/otel/sdk/metric` by removing unnecessary calls to `time.Now`. (#5545)
 269
 270### Fixed
 271
 272- Log a warning to the OpenTelemetry internal logger when a `Record` in `go.opentelemetry.io/otel/sdk/log` drops an attribute due to a limit being reached. (#5376)
 273- Identify the `Tracer` returned from the global `TracerProvider` in `go.opentelemetry.io/otel/global` with its schema URL. (#5426)
 274- Identify the `Meter` returned from the global `MeterProvider` in `go.opentelemetry.io/otel/global` with its schema URL. (#5426)
 275- Log a warning to the OpenTelemetry internal logger when a `Span` in `go.opentelemetry.io/otel/sdk/trace` drops an attribute, event, or link due to a limit being reached. (#5434)
 276- Document instrument name requirements in `go.opentelemetry.io/otel/metric`. (#5435)
 277- Prevent random number generation data-race for experimental rand exemplars in `go.opentelemetry.io/otel/sdk/metric`. (#5456)
 278- Fix counting number of dropped attributes of `Record` in `go.opentelemetry.io/otel/sdk/log`. (#5464)
 279- Fix panic in baggage creation when a member contains `0x80` char in key or value. (#5494)
 280- Correct comments for the priority of the `WithEndpoint` and `WithEndpointURL` options and their corresponding environment variables in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`. (#5508)
 281- Retry trace and span ID generation if it generated an invalid one in `go.opentelemetry.io/otel/sdk/trace`. (#5514)
 282- Fix stale timestamps reported by the last-value aggregation. (#5517)
 283- Indicate the `Exporter` in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp` must be created by the `New` method. (#5521)
 284- Improved performance in all `{Bool,Int64,Float64,String}SliceValue` functions of `go.opentelemetry.io/attributes` by reducing the number of allocations. (#5549)
 285- Replace invalid percent-encoded octet sequences with replacement char in `go.opentelemetry.io/otel/baggage`. (#5528)
 286
 287## [1.27.0/0.49.0/0.3.0] 2024-05-21
 288
 289### Added
 290
 291- Add example for `go.opentelemetry.io/otel/exporters/stdout/stdoutlog`. (#5242)
 292- Add `RecordFactory` in `go.opentelemetry.io/otel/sdk/log/logtest` to facilitate testing exporter and processor implementations. (#5258)
 293- Add `RecordFactory` in `go.opentelemetry.io/otel/log/logtest` to facilitate testing bridge implementations. (#5263)
 294- The count of dropped records from the `BatchProcessor` in `go.opentelemetry.io/otel/sdk/log` is logged. (#5276)
 295- Add metrics in the `otel-collector` example. (#5283)
 296- Add the synchronous gauge instrument to `go.opentelemetry.io/otel/metric`. (#5304)
 297  - An `int64` or `float64` synchronous gauge instrument can now be created from a `Meter`.
 298  - All implementations of the API (`go.opentelemetry.io/otel/metric/noop`, `go.opentelemetry.io/otel/sdk/metric`) are updated to support this instrument.
 299- Add logs to `go.opentelemetry.io/otel/example/dice`. (#5349)
 300
 301### Changed
 302
 303- The `Shutdown` method of `Exporter` in `go.opentelemetry.io/otel/exporters/stdout/stdouttrace` ignores the context cancellation and always returns `nil`. (#5189)
 304- The `ForceFlush` and `Shutdown` methods of the exporter returned by `New` in `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` ignore the context cancellation and always return `nil`. (#5189)
 305- Apply the value length limits to `Record` attributes in `go.opentelemetry.io/otel/sdk/log`. (#5230)
 306- De-duplicate map attributes added to a `Record` in `go.opentelemetry.io/otel/sdk/log`. (#5230)
 307- `go.opentelemetry.io/otel/exporters/stdout/stdoutlog` won't print timestamps when `WithoutTimestamps` option is set. (#5241)
 308- The `go.opentelemetry.io/otel/exporters/stdout/stdoutlog` exporter won't print `AttributeValueLengthLimit` and `AttributeCountLimit` fields now, instead it prints the `DroppedAttributes` field. (#5272)
 309- Improved performance in the `Stringer` implementation of `go.opentelemetry.io/otel/baggage.Member` by reducing the number of allocations. (#5286)
 310- Set the start time for last-value aggregates in `go.opentelemetry.io/otel/sdk/metric`. (#5305)
 311- The `Span` in `go.opentelemetry.io/otel/sdk/trace` will record links without span context if either non-empty `TraceState` or attributes are provided. (#5315)
 312- Upgrade all dependencies of `go.opentelemetry.io/otel/semconv/v1.24.0` to `go.opentelemetry.io/otel/semconv/v1.25.0`. (#5374)
 313
 314### Fixed
 315
 316- Comparison of unordered maps for `go.opentelemetry.io/otel/log.KeyValue` and `go.opentelemetry.io/otel/log.Value`. (#5306)
 317- Fix the empty output of `go.opentelemetry.io/otel/log.Value` in `go.opentelemetry.io/otel/exporters/stdout/stdoutlog`. (#5311)
 318- Split the behavior of `Recorder` in `go.opentelemetry.io/otel/log/logtest` so it behaves as a `LoggerProvider` only. (#5365)
 319- Fix wrong package name of the error message when parsing endpoint URL in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`. (#5371)
 320- Identify the `Logger` returned from the global `LoggerProvider` in `go.opentelemetry.io/otel/log/global` with its schema URL. (#5375)
 321
 322## [1.26.0/0.48.0/0.2.0-alpha] 2024-04-24
 323
 324### Added
 325
 326- Add `Recorder` in `go.opentelemetry.io/otel/log/logtest` to facilitate testing the log bridge implementations. (#5134)
 327- Add span flags to OTLP spans and links exported by `go.opentelemetry.io/otel/exporters/otlp/otlptrace`. (#5194)
 328- Make the initial alpha release of `go.opentelemetry.io/otel/sdk/log`.
 329  This new module contains the Go implementation of the OpenTelemetry Logs SDK.
 330  This module is unstable and breaking changes may be introduced.
 331  See our [versioning policy](VERSIONING.md) for more information about these stability guarantees. (#5240)
 332- Make the initial alpha release of `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp`.
 333  This new module contains an OTLP exporter that transmits log telemetry using HTTP.
 334  This module is unstable and breaking changes may be introduced.
 335  See our [versioning policy](VERSIONING.md) for more information about these stability guarantees. (#5240)
 336- Make the initial alpha release of `go.opentelemetry.io/otel/exporters/stdout/stdoutlog`.
 337  This new module contains an exporter prints log records to STDOUT.
 338  This module is unstable and breaking changes may be introduced.
 339  See our [versioning policy](VERSIONING.md) for more information about these stability guarantees. (#5240)
 340- The `go.opentelemetry.io/otel/semconv/v1.25.0` package.
 341  The package contains semantic conventions from the `v1.25.0` version of the OpenTelemetry Semantic Conventions. (#5254)
 342
 343### Changed
 344
 345- Update `go.opentelemetry.io/proto/otlp` from v1.1.0 to v1.2.0. (#5177)
 346- Improve performance of baggage member character validation in `go.opentelemetry.io/otel/baggage`. (#5214)
 347- The `otel-collector` example now uses docker compose to bring up services instead of kubernetes. (#5244)
 348
 349### Fixed
 350
 351- Slice attribute values in `go.opentelemetry.io/otel/attribute` are now emitted as their JSON representation. (#5159)
 352
 353## [1.25.0/0.47.0/0.0.8/0.1.0-alpha] 2024-04-05
 354
 355### Added
 356
 357- Add `WithProxy` option in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4906)
 358- Add `WithProxy` option in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlptracehttp`. (#4906)
 359- Add `AddLink` method to the `Span` interface in `go.opentelemetry.io/otel/trace`. (#5032)
 360- The `Enabled` method is added to the `Logger` interface in `go.opentelemetry.io/otel/log`.
 361  This method is used to notify users if a log record will be emitted or not. (#5071)
 362- Add `SeverityUndefined` `const` to `go.opentelemetry.io/otel/log`.
 363  This value represents an unset severity level. (#5072)
 364- Add `Empty` function in `go.opentelemetry.io/otel/log` to return a `KeyValue` for an empty value. (#5076)
 365- Add `go.opentelemetry.io/otel/log/global` to manage the global `LoggerProvider`.
 366  This package is provided with the anticipation that all functionality will be migrate to `go.opentelemetry.io/otel` when `go.opentelemetry.io/otel/log` stabilizes.
 367  At which point, users will be required to migrage their code, and this package will be deprecated then removed. (#5085)
 368- Add support for `Summary` metrics in the `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` exporters. (#5100)
 369- Add `otel.scope.name` and `otel.scope.version` tags to spans exported by `go.opentelemetry.io/otel/exporters/zipkin`. (#5108)
 370- Add support for `AddLink` to `go.opentelemetry.io/otel/bridge/opencensus`. (#5116)
 371- Add `String` method to `Value` and `KeyValue` in `go.opentelemetry.io/otel/log`. (#5117)
 372- Add Exemplar support to `go.opentelemetry.io/otel/exporters/prometheus`. (#5111)
 373- Add metric semantic conventions to `go.opentelemetry.io/otel/semconv/v1.24.0`. Future `semconv` packages will include metric semantic conventions as well. (#4528)
 374
 375### Changed
 376
 377- `SpanFromContext` and `SpanContextFromContext` in `go.opentelemetry.io/otel/trace` no longer make a heap allocation when the passed context has no span. (#5049)
 378- `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` now create a gRPC client in idle mode and with "dns" as the default resolver using [`grpc.NewClient`](https://pkg.go.dev/google.golang.org/grpc#NewClient). (#5151)
 379  Because of that `WithDialOption` ignores [`grpc.WithBlock`](https://pkg.go.dev/google.golang.org/grpc#WithBlock), [`grpc.WithTimeout`](https://pkg.go.dev/google.golang.org/grpc#WithTimeout), and [`grpc.WithReturnConnectionError`](https://pkg.go.dev/google.golang.org/grpc#WithReturnConnectionError).
 380  Notice that [`grpc.DialContext`](https://pkg.go.dev/google.golang.org/grpc#DialContext) which was used before is now deprecated.
 381
 382### Fixed
 383
 384- Clarify the documentation about equivalence guarantees for the `Set` and `Distinct` types in `go.opentelemetry.io/otel/attribute`. (#5027)
 385- Prevent default `ErrorHandler` self-delegation. (#5137)
 386- Update all dependencies to address [GO-2024-2687]. (#5139)
 387
 388### Removed
 389
 390- Drop support for [Go 1.20]. (#4967)
 391
 392### Deprecated
 393
 394- Deprecate `go.opentelemetry.io/otel/attribute.Sortable` type. (#4734)
 395- Deprecate `go.opentelemetry.io/otel/attribute.NewSetWithSortable` function. (#4734)
 396- Deprecate `go.opentelemetry.io/otel/attribute.NewSetWithSortableFiltered` function. (#4734)
 397
 398## [1.24.0/0.46.0/0.0.1-alpha] 2024-02-23
 399
 400This release is the last to support [Go 1.20].
 401The next release will require at least [Go 1.21].
 402
 403### Added
 404
 405- Support [Go 1.22]. (#4890)
 406- Add exemplar support to `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4900)
 407- Add exemplar support to `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4900)
 408- The `go.opentelemetry.io/otel/log` module is added.
 409  This module includes OpenTelemetry Go's implementation of the Logs Bridge API.
 410  This module is in an alpha state, it is subject to breaking changes.
 411  See our [versioning policy](./VERSIONING.md) for more info. (#4961)
 412- Add ARM64 platform to the compatibility testing suite. (#4994)
 413
 414### Fixed
 415
 416- Fix registration of multiple callbacks when using the global meter provider from `go.opentelemetry.io/otel`. (#4945)
 417- Fix negative buckets in output of exponential histograms. (#4956)
 418
 419## [1.23.1] 2024-02-07
 420
 421### Fixed
 422
 423- Register all callbacks passed during observable instrument creation instead of just the last one multiple times in `go.opentelemetry.io/otel/sdk/metric`. (#4888)
 424
 425## [1.23.0] 2024-02-06
 426
 427This release contains the first stable, `v1`, release of the following modules:
 428
 429- `go.opentelemetry.io/otel/bridge/opencensus`
 430- `go.opentelemetry.io/otel/bridge/opencensus/test`
 431- `go.opentelemetry.io/otel/example/opencensus`
 432- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`
 433- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`
 434- `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric`
 435
 436See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 437
 438### Added
 439
 440- Add `WithEndpointURL` option to the `exporters/otlp/otlpmetric/otlpmetricgrpc`, `exporters/otlp/otlpmetric/otlpmetrichttp`, `exporters/otlp/otlptrace/otlptracegrpc` and `exporters/otlp/otlptrace/otlptracehttp` packages. (#4808)
 441- Experimental exemplar exporting is added to the metric SDK.
 442  See [metric documentation](./sdk/metric/internal/x/README.md#exemplars) for more information about this feature and how to enable it. (#4871)
 443- `ErrSchemaURLConflict` is added to `go.opentelemetry.io/otel/sdk/resource`.
 444  This error is returned when a merge of two `Resource`s with different (non-empty) schema URL is attempted. (#4876)
 445
 446### Changed
 447
 448- The `Merge` and `New` functions in `go.opentelemetry.io/otel/sdk/resource` now returns a partial result if there is a schema URL merge conflict.
 449  Instead of returning `nil` when two `Resource`s with different (non-empty) schema URLs are merged the merged `Resource`, along with the new `ErrSchemaURLConflict` error, is returned.
 450  It is up to the user to decide if they want to use the returned `Resource` or not.
 451  It may have desired attributes overwritten or include stale semantic conventions. (#4876)
 452
 453### Fixed
 454
 455- Fix `ContainerID` resource detection on systemd when cgroup path has a colon. (#4449)
 456- Fix `go.opentelemetry.io/otel/sdk/metric` to cache instruments to avoid leaking memory when the same instrument is created multiple times. (#4820)
 457- Fix missing `Mix` and `Max` values for `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` by introducing `MarshalText` and `MarshalJSON` for the `Extrema` type in `go.opentelemetry.io/sdk/metric/metricdata`. (#4827)
 458
 459## [1.23.0-rc.1] 2024-01-18
 460
 461This is a release candidate for the v1.23.0 release.
 462That release is expected to include the `v1` release of the following modules:
 463
 464- `go.opentelemetry.io/otel/bridge/opencensus`
 465- `go.opentelemetry.io/otel/bridge/opencensus/test`
 466- `go.opentelemetry.io/otel/example/opencensus`
 467- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`
 468- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`
 469- `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric`
 470
 471See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 472
 473## [1.22.0/0.45.0] 2024-01-17
 474
 475### Added
 476
 477- The `go.opentelemetry.io/otel/semconv/v1.22.0` package.
 478  The package contains semantic conventions from the `v1.22.0` version of the OpenTelemetry Semantic Conventions. (#4735)
 479- The `go.opentelemetry.io/otel/semconv/v1.23.0` package.
 480  The package contains semantic conventions from the `v1.23.0` version of the OpenTelemetry Semantic Conventions. (#4746)
 481- The `go.opentelemetry.io/otel/semconv/v1.23.1` package.
 482  The package contains semantic conventions from the `v1.23.1` version of the OpenTelemetry Semantic Conventions. (#4749)
 483- The `go.opentelemetry.io/otel/semconv/v1.24.0` package.
 484  The package contains semantic conventions from the `v1.24.0` version of the OpenTelemetry Semantic Conventions. (#4770)
 485- Add `WithResourceAsConstantLabels` option to apply resource attributes for every metric emitted by the Prometheus exporter. (#4733)
 486- Experimental cardinality limiting is added to the metric SDK.
 487  See [metric documentation](./sdk/metric/internal/x/README.md#cardinality-limit) for more information about this feature and how to enable it. (#4457)
 488- Add `NewMemberRaw` and `NewKeyValuePropertyRaw` in `go.opentelemetry.io/otel/baggage`. (#4804)
 489
 490### Changed
 491
 492- Upgrade all use of `go.opentelemetry.io/otel/semconv` to use `v1.24.0`. (#4754)
 493- Update transformations in `go.opentelemetry.io/otel/exporters/zipkin` to follow `v1.24.0` version of the OpenTelemetry specification. (#4754)
 494- Record synchronous measurements when the passed context is canceled instead of dropping in `go.opentelemetry.io/otel/sdk/metric`.
 495  If you do not want to make a measurement when the context is cancelled, you need to handle it yourself (e.g  `if ctx.Err() != nil`). (#4671)
 496- Improve `go.opentelemetry.io/otel/trace.TraceState`'s performance. (#4722)
 497- Improve `go.opentelemetry.io/otel/propagation.TraceContext`'s performance. (#4721)
 498- Improve `go.opentelemetry.io/otel/baggage` performance. (#4743)
 499- Improve performance of the `(*Set).Filter` method in `go.opentelemetry.io/otel/attribute` when the passed filter does not filter out any attributes from the set. (#4774)
 500- `Member.String` in `go.opentelemetry.io/otel/baggage` percent-encodes only when necessary. (#4775)
 501- Improve `go.opentelemetry.io/otel/trace.Span`'s performance when adding multiple attributes. (#4818)
 502- `Property.Value` in `go.opentelemetry.io/otel/baggage` now returns a raw string instead of a percent-encoded value. (#4804)
 503
 504### Fixed
 505
 506- Fix `Parse` in `go.opentelemetry.io/otel/baggage` to validate member value before percent-decoding. (#4755)
 507- Fix whitespace encoding of `Member.String` in `go.opentelemetry.io/otel/baggage`. (#4756)
 508- Fix observable not registered error when the asynchronous instrument has a drop aggregation in `go.opentelemetry.io/otel/sdk/metric`. (#4772)
 509- Fix baggage item key so that it is not canonicalized in `go.opentelemetry.io/otel/bridge/opentracing`. (#4776)
 510- Fix `go.opentelemetry.io/otel/bridge/opentracing` to properly handle baggage values that requires escaping during propagation. (#4804)
 511- Fix a bug where using multiple readers resulted in incorrect asynchronous counter values in `go.opentelemetry.io/otel/sdk/metric`. (#4742)
 512
 513## [1.21.0/0.44.0] 2023-11-16
 514
 515### Removed
 516
 517- Remove the deprecated `go.opentelemetry.io/otel/bridge/opencensus.NewTracer`. (#4706)
 518- Remove the deprecated `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` module. (#4707)
 519- Remove the deprecated `go.opentelemetry.io/otel/example/view` module. (#4708)
 520- Remove the deprecated `go.opentelemetry.io/otel/example/fib` module. (#4723)
 521
 522### Fixed
 523
 524- Do not parse non-protobuf responses in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4719)
 525- Do not parse non-protobuf responses in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#4719)
 526
 527## [1.20.0/0.43.0] 2023-11-10
 528
 529This release brings a breaking change for custom trace API implementations. Some interfaces (`TracerProvider`, `Tracer`, `Span`) now embed the `go.opentelemetry.io/otel/trace/embedded` types. Implementers need to update their implementations based on what they want the default behavior to be. See the "API Implementations" section of the [trace API] package documentation for more information about how to accomplish this.
 530
 531### Added
 532
 533- Add `go.opentelemetry.io/otel/bridge/opencensus.InstallTraceBridge`, which installs the OpenCensus trace bridge, and replaces `opencensus.NewTracer`. (#4567)
 534- Add scope version to trace and metric bridges in `go.opentelemetry.io/otel/bridge/opencensus`. (#4584)
 535- Add the `go.opentelemetry.io/otel/trace/embedded` package to be embedded in the exported trace API interfaces. (#4620)
 536- Add the `go.opentelemetry.io/otel/trace/noop` package as a default no-op implementation of the trace API. (#4620)
 537- Add context propagation in `go.opentelemetry.io/otel/example/dice`. (#4644)
 538- Add view configuration to `go.opentelemetry.io/otel/example/prometheus`. (#4649)
 539- Add `go.opentelemetry.io/otel/metric.WithExplicitBucketBoundaries`, which allows defining default explicit bucket boundaries when creating histogram instruments. (#4603)
 540- Add `Version` function in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4660)
 541- Add `Version` function in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4660)
 542- Add Summary, SummaryDataPoint, and QuantileValue to `go.opentelemetry.io/sdk/metric/metricdata`. (#4622)
 543- `go.opentelemetry.io/otel/bridge/opencensus.NewMetricProducer` now supports exemplars from OpenCensus. (#4585)
 544- Add support for `WithExplicitBucketBoundaries` in `go.opentelemetry.io/otel/sdk/metric`. (#4605)
 545- Add support for Summary metrics in `go.opentelemetry.io/otel/bridge/opencensus`. (#4668)
 546
 547### Deprecated
 548
 549- Deprecate `go.opentelemetry.io/otel/bridge/opencensus.NewTracer` in favor of `opencensus.InstallTraceBridge`. (#4567)
 550- Deprecate `go.opentelemetry.io/otel/example/fib` package is in favor of `go.opentelemetry.io/otel/example/dice`. (#4618)
 551- Deprecate `go.opentelemetry.io/otel/trace.NewNoopTracerProvider`.
 552  Use the added `NewTracerProvider` function in `go.opentelemetry.io/otel/trace/noop` instead. (#4620)
 553- Deprecate `go.opentelemetry.io/otel/example/view` package in favor of `go.opentelemetry.io/otel/example/prometheus`. (#4649)
 554- Deprecate `go.opentelemetry.io/otel/exporters/otlp/otlpmetric`. (#4693)
 555
 556### Changed
 557
 558- `go.opentelemetry.io/otel/bridge/opencensus.NewMetricProducer` returns a `*MetricProducer` struct instead of the metric.Producer interface. (#4583)
 559- The `TracerProvider` in `go.opentelemetry.io/otel/trace` now embeds the `go.opentelemetry.io/otel/trace/embedded.TracerProvider` type.
 560  This extends the `TracerProvider` interface and is is a breaking change for any existing implementation.
 561  Implementers need to update their implementations based on what they want the default behavior of the interface to be.
 562  See the "API Implementations" section of the `go.opentelemetry.io/otel/trace` package documentation for more information about how to accomplish this. (#4620)
 563- The `Tracer` in `go.opentelemetry.io/otel/trace` now embeds the `go.opentelemetry.io/otel/trace/embedded.Tracer` type.
 564  This extends the `Tracer` interface and is is a breaking change for any existing implementation.
 565  Implementers need to update their implementations based on what they want the default behavior of the interface to be.
 566  See the "API Implementations" section of the `go.opentelemetry.io/otel/trace` package documentation for more information about how to accomplish this. (#4620)
 567- The `Span` in `go.opentelemetry.io/otel/trace` now embeds the `go.opentelemetry.io/otel/trace/embedded.Span` type.
 568  This extends the `Span` interface and is is a breaking change for any existing implementation.
 569  Implementers need to update their implementations based on what they want the default behavior of the interface to be.
 570  See the "API Implementations" section of the `go.opentelemetry.io/otel/trace` package documentation for more information about how to accomplish this. (#4620)
 571- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` does no longer depend on `go.opentelemetry.io/otel/exporters/otlp/otlpmetric`. (#4660)
 572- `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` does no longer depend on `go.opentelemetry.io/otel/exporters/otlp/otlpmetric`. (#4660)
 573- Retry for `502 Bad Gateway` and `504 Gateway Timeout` HTTP statuses in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4670)
 574- Retry for `502 Bad Gateway` and `504 Gateway Timeout` HTTP statuses in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#4670)
 575- Retry for `RESOURCE_EXHAUSTED` only if RetryInfo is returned in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4669)
 576- Retry for `RESOURCE_EXHAUSTED` only if RetryInfo is returned in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`. (#4669)
 577- Retry temporary HTTP request failures in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4679)
 578- Retry temporary HTTP request failures in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#4679)
 579
 580### Fixed
 581
 582- Fix improper parsing of characters such us `+`, `/` by `Parse` in `go.opentelemetry.io/otel/baggage` as they were rendered as a whitespace. (#4667)
 583- Fix improper parsing of characters such us `+`, `/` passed via `OTEL_RESOURCE_ATTRIBUTES` in `go.opentelemetry.io/otel/sdk/resource` as they were rendered as a whitespace. (#4699)
 584- Fix improper parsing of characters such us `+`, `/` passed via `OTEL_EXPORTER_OTLP_HEADERS` and `OTEL_EXPORTER_OTLP_METRICS_HEADERS` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` as they were rendered as a whitespace. (#4699)
 585- Fix improper parsing of characters such us `+`, `/` passed via `OTEL_EXPORTER_OTLP_HEADERS` and `OTEL_EXPORTER_OTLP_METRICS_HEADERS` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` as they were rendered as a whitespace. (#4699)
 586- Fix improper parsing of characters such us `+`, `/` passed via `OTEL_EXPORTER_OTLP_HEADERS` and `OTEL_EXPORTER_OTLP_TRACES_HEADERS` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlptracegrpc` as they were rendered as a whitespace. (#4699)
 587- Fix improper parsing of characters such us `+`, `/` passed via `OTEL_EXPORTER_OTLP_HEADERS` and `OTEL_EXPORTER_OTLP_TRACES_HEADERS` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlptracehttp` as they were rendered as a whitespace. (#4699)
 588- In `go.opentelemetry.op/otel/exporters/prometheus`, the exporter no longer `Collect`s metrics after `Shutdown` is invoked. (#4648)
 589- Fix documentation for `WithCompressor` in `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc`. (#4695)
 590- Fix documentation for `WithCompressor` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4695)
 591
 592## [1.19.0/0.42.0/0.0.7] 2023-09-28
 593
 594This release contains the first stable release of the OpenTelemetry Go [metric SDK].
 595Our project stability guarantees now apply to the `go.opentelemetry.io/otel/sdk/metric` package.
 596See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 597
 598### Added
 599
 600- Add the "Roll the dice" getting started application example in `go.opentelemetry.io/otel/example/dice`. (#4539)
 601- The `WithWriter` and `WithPrettyPrint` options to `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` to set a custom `io.Writer`, and allow displaying the output in human-readable JSON. (#4507)
 602
 603### Changed
 604
 605- Allow '/' characters in metric instrument names. (#4501)
 606- The exporter in `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` does not prettify its output by default anymore. (#4507)
 607- Upgrade `gopkg.io/yaml` from `v2` to `v3` in `go.opentelemetry.io/otel/schema`. (#4535)
 608
 609### Fixed
 610
 611- In `go.opentelemetry.op/otel/exporters/prometheus`, don't try to create the Prometheus metric on every `Collect` if we know the scope is invalid. (#4499)
 612
 613### Removed
 614
 615- Remove `"go.opentelemetry.io/otel/bridge/opencensus".NewMetricExporter`, which is replaced by `NewMetricProducer`. (#4566)
 616
 617## [1.19.0-rc.1/0.42.0-rc.1] 2023-09-14
 618
 619This is a release candidate for the v1.19.0/v0.42.0 release.
 620That release is expected to include the `v1` release of the OpenTelemetry Go metric SDK and will provide stability guarantees of that SDK.
 621See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 622
 623### Changed
 624
 625- Allow '/' characters in metric instrument names. (#4501)
 626
 627### Fixed
 628
 629- In `go.opentelemetry.op/otel/exporters/prometheus`, don't try to create the prometheus metric on every `Collect` if we know the scope is invalid. (#4499)
 630
 631## [1.18.0/0.41.0/0.0.6] 2023-09-12
 632
 633This release drops the compatibility guarantee of [Go 1.19].
 634
 635### Added
 636
 637- Add `WithProducer` option in `go.opentelemetry.op/otel/exporters/prometheus` to restore the ability to register producers on the prometheus exporter's manual reader. (#4473)
 638- Add `IgnoreValue` option in `go.opentelemetry.io/otel/sdk/metric/metricdata/metricdatatest` to allow ignoring values when comparing metrics. (#4447)
 639
 640### Changed
 641
 642- Use a `TestingT` interface instead of `*testing.T` struct in `go.opentelemetry.io/otel/sdk/metric/metricdata/metricdatatest`. (#4483)
 643
 644### Deprecated
 645
 646- The `NewMetricExporter` in `go.opentelemetry.io/otel/bridge/opencensus` was deprecated in `v0.35.0` (#3541).
 647  The deprecation notice format for the function has been corrected to trigger Go documentation and build tooling. (#4470)
 648
 649### Removed
 650
 651- Removed the deprecated `go.opentelemetry.io/otel/exporters/jaeger` package. (#4467)
 652- Removed the deprecated `go.opentelemetry.io/otel/example/jaeger` package. (#4467)
 653- Removed the deprecated `go.opentelemetry.io/otel/sdk/metric/aggregation` package. (#4468)
 654- Removed the deprecated internal packages in `go.opentelemetry.io/otel/exporters/otlp` and its sub-packages. (#4469)
 655- Dropped guaranteed support for versions of Go less than 1.20. (#4481)
 656
 657## [1.17.0/0.40.0/0.0.5] 2023-08-28
 658
 659### Added
 660
 661- Export the `ManualReader` struct in `go.opentelemetry.io/otel/sdk/metric`. (#4244)
 662- Export the `PeriodicReader` struct in `go.opentelemetry.io/otel/sdk/metric`. (#4244)
 663- Add support for exponential histogram aggregations.
 664  A histogram can be configured as an exponential histogram using a view with `"go.opentelemetry.io/otel/sdk/metric".ExponentialHistogram` as the aggregation. (#4245)
 665- Export the `Exporter` struct in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc`. (#4272)
 666- Export the `Exporter` struct in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#4272)
 667- The exporters in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` now support the `OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE` environment variable. (#4287)
 668- Add `WithoutCounterSuffixes` option in `go.opentelemetry.io/otel/exporters/prometheus` to disable addition of `_total` suffixes. (#4306)
 669- Add info and debug logging to the metric SDK in `go.opentelemetry.io/otel/sdk/metric`. (#4315)
 670- The `go.opentelemetry.io/otel/semconv/v1.21.0` package.
 671  The package contains semantic conventions from the `v1.21.0` version of the OpenTelemetry Semantic Conventions. (#4362)
 672- Accept 201 to 299 HTTP status as success in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` and `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#4365)
 673- Document the `Temporality` and `Aggregation` methods of the `"go.opentelemetry.io/otel/sdk/metric".Exporter"` need to be concurrent safe. (#4381)
 674- Expand the set of units supported by the Prometheus exporter, and don't add unit suffixes if they are already present in `go.opentelemetry.op/otel/exporters/prometheus` (#4374)
 675- Move the `Aggregation` interface and its implementations from `go.opentelemetry.io/otel/sdk/metric/aggregation` to `go.opentelemetry.io/otel/sdk/metric`. (#4435)
 676- The exporters in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` now support the `OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION` environment variable. (#4437)
 677- Add the `NewAllowKeysFilter` and `NewDenyKeysFilter` functions to `go.opentelemetry.io/otel/attribute` to allow convenient creation of allow-keys and deny-keys filters. (#4444)
 678- Support Go 1.21. (#4463)
 679
 680### Changed
 681
 682- Starting from `v1.21.0` of semantic conventions, `go.opentelemetry.io/otel/semconv/{version}/httpconv` and `go.opentelemetry.io/otel/semconv/{version}/netconv` packages will no longer be published. (#4145)
 683- Log duplicate instrument conflict at a warning level instead of info in `go.opentelemetry.io/otel/sdk/metric`. (#4202)
 684- Return an error on the creation of new instruments in `go.opentelemetry.io/otel/sdk/metric` if their name doesn't pass regexp validation. (#4210)
 685- `NewManualReader` in `go.opentelemetry.io/otel/sdk/metric` returns `*ManualReader` instead of `Reader`. (#4244)
 686- `NewPeriodicReader` in `go.opentelemetry.io/otel/sdk/metric` returns `*PeriodicReader` instead of `Reader`. (#4244)
 687- Count the Collect time in the `PeriodicReader` timeout in `go.opentelemetry.io/otel/sdk/metric`. (#4221)
 688- The function `New` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` returns `*Exporter` instead of `"go.opentelemetry.io/otel/sdk/metric".Exporter`. (#4272)
 689- The function `New` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` returns `*Exporter` instead of `"go.opentelemetry.io/otel/sdk/metric".Exporter`. (#4272)
 690- If an attribute set is omitted from an async callback, the previous value will no longer be exported in `go.opentelemetry.io/otel/sdk/metric`. (#4290)
 691- If an attribute set is observed multiple times in an async callback in `go.opentelemetry.io/otel/sdk/metric`, the values will be summed instead of the last observation winning. (#4289)
 692- Allow the explicit bucket histogram aggregation to be used for the up-down counter, observable counter, observable up-down counter, and observable gauge in the `go.opentelemetry.io/otel/sdk/metric` package. (#4332)
 693- Restrict `Meter`s in `go.opentelemetry.io/otel/sdk/metric` to only register and collect instruments it created. (#4333)
 694- `PeriodicReader.Shutdown` and `PeriodicReader.ForceFlush` in `go.opentelemetry.io/otel/sdk/metric` now apply the periodic reader's timeout to the operation if the user provided context does not contain a deadline. (#4356, #4377)
 695- Upgrade all use of `go.opentelemetry.io/otel/semconv` to use `v1.21.0`. (#4408)
 696- Increase instrument name maximum length from 63 to 255 characters in `go.opentelemetry.io/otel/sdk/metric`. (#4434)
 697- Add `go.opentelemetry.op/otel/sdk/metric.WithProducer` as an `Option` for `"go.opentelemetry.io/otel/sdk/metric".NewManualReader` and `"go.opentelemetry.io/otel/sdk/metric".NewPeriodicReader`. (#4346)
 698
 699### Removed
 700
 701- Remove `Reader.RegisterProducer` in `go.opentelemetry.io/otel/metric`.
 702  Use the added `WithProducer` option instead. (#4346)
 703- Remove `Reader.ForceFlush` in `go.opentelemetry.io/otel/metric`.
 704  Notice that `PeriodicReader.ForceFlush` is still available. (#4375)
 705
 706### Fixed
 707
 708- Correctly format log messages from the `go.opentelemetry.io/otel/exporters/zipkin` exporter. (#4143)
 709- Log an error for calls to `NewView` in `go.opentelemetry.io/otel/sdk/metric` that have empty criteria. (#4307)
 710- Fix `"go.opentelemetry.io/otel/sdk/resource".WithHostID()` to not set an empty `host.id`. (#4317)
 711- Use the instrument identifying fields to cache aggregators and determine duplicate instrument registrations in `go.opentelemetry.io/otel/sdk/metric`. (#4337)
 712- Detect duplicate instruments for case-insensitive names in `go.opentelemetry.io/otel/sdk/metric`. (#4338)
 713- The `ManualReader` will not panic if `AggregationSelector` returns `nil` in `go.opentelemetry.io/otel/sdk/metric`. (#4350)
 714- If a `Reader`'s `AggregationSelector` returns `nil` or `DefaultAggregation` the pipeline will use the default aggregation. (#4350)
 715- Log a suggested view that fixes instrument conflicts in `go.opentelemetry.io/otel/sdk/metric`. (#4349)
 716- Fix possible panic, deadlock and race condition in batch span processor in `go.opentelemetry.io/otel/sdk/trace`. (#4353)
 717- Improve context cancellation handling in batch span processor's `ForceFlush` in  `go.opentelemetry.io/otel/sdk/trace`. (#4369)
 718- Decouple `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal` from `go.opentelemetry.io/otel/exporters/otlp/internal` using gotmpl. (#4397, #3846)
 719- Decouple `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal` from `go.opentelemetry.io/otel/exporters/otlp/internal` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal` using gotmpl. (#4404, #3846)
 720- Decouple `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp/internal` from `go.opentelemetry.io/otel/exporters/otlp/internal` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal` using gotmpl. (#4407, #3846)
 721- Decouple `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc/internal` from `go.opentelemetry.io/otel/exporters/otlp/internal` and `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal` using gotmpl. (#4400, #3846)
 722- Decouple `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp/internal` from `go.opentelemetry.io/otel/exporters/otlp/internal` and `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal` using gotmpl. (#4401, #3846)
 723- Do not block the metric SDK when OTLP metric exports are blocked in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp`. (#3925, #4395)
 724- Do not append `_total` if the counter already has that suffix for the Prometheus exproter in `go.opentelemetry.io/otel/exporter/prometheus`. (#4373)
 725- Fix resource detection data race in `go.opentelemetry.io/otel/sdk/resource`. (#4409)
 726- Use the first-seen instrument name during instrument name conflicts in `go.opentelemetry.io/otel/sdk/metric`. (#4428)
 727
 728### Deprecated
 729
 730- The `go.opentelemetry.io/otel/exporters/jaeger` package is deprecated.
 731  OpenTelemetry dropped support for Jaeger exporter in July 2023.
 732  Use `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`
 733  or `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` instead. (#4423)
 734- The `go.opentelemetry.io/otel/example/jaeger` package is deprecated. (#4423)
 735- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal` package is deprecated. (#4420)
 736- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/oconf` package is deprecated. (#4420)
 737- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/otest` package is deprecated. (#4420)
 738- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/transform` package is deprecated. (#4420)
 739- The `go.opentelemetry.io/otel/exporters/otlp/internal` package is deprecated. (#4421)
 740- The `go.opentelemetry.io/otel/exporters/otlp/internal/envconfig` package is deprecated. (#4421)
 741- The `go.opentelemetry.io/otel/exporters/otlp/internal/retry` package is deprecated. (#4421)
 742- The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal` package is deprecated. (#4425)
 743- The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/envconfig` package is deprecated. (#4425)
 744- The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/otlpconfig` package is deprecated. (#4425)
 745- The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/otlptracetest` package is deprecated. (#4425)
 746- The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/retry` package is deprecated. (#4425)
 747- The `go.opentelemetry.io/otel/sdk/metric/aggregation` package is deprecated.
 748  Use the aggregation types added to `go.opentelemetry.io/otel/sdk/metric` instead. (#4435)
 749
 750## [1.16.0/0.39.0] 2023-05-18
 751
 752This release contains the first stable release of the OpenTelemetry Go [metric API].
 753Our project stability guarantees now apply to the `go.opentelemetry.io/otel/metric` package.
 754See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 755
 756### Added
 757
 758- The `go.opentelemetry.io/otel/semconv/v1.19.0` package.
 759  The package contains semantic conventions from the `v1.19.0` version of the OpenTelemetry specification. (#3848)
 760- The `go.opentelemetry.io/otel/semconv/v1.20.0` package.
 761  The package contains semantic conventions from the `v1.20.0` version of the OpenTelemetry specification. (#4078)
 762- The Exponential Histogram data types in `go.opentelemetry.io/otel/sdk/metric/metricdata`. (#4165)
 763- OTLP metrics exporter now supports the Exponential Histogram Data Type. (#4222)
 764- Fix serialization of `time.Time` zero values in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` packages. (#4271)
 765
 766### Changed
 767
 768- Use `strings.Cut()` instead of `string.SplitN()` for better readability and memory use. (#4049)
 769- `MeterProvider` returns noop meters once it has been shutdown. (#4154)
 770
 771### Removed
 772
 773- The deprecated `go.opentelemetry.io/otel/metric/instrument` package is removed.
 774  Use `go.opentelemetry.io/otel/metric` instead. (#4055)
 775
 776### Fixed
 777
 778- Fix build for BSD based systems in `go.opentelemetry.io/otel/sdk/resource`. (#4077)
 779
 780## [1.16.0-rc.1/0.39.0-rc.1] 2023-05-03
 781
 782This is a release candidate for the v1.16.0/v0.39.0 release.
 783That release is expected to include the `v1` release of the OpenTelemetry Go metric API and will provide stability guarantees of that API.
 784See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 785
 786### Added
 787
 788- Support global `MeterProvider` in `go.opentelemetry.io/otel`. (#4039)
 789  - Use `Meter` for a `metric.Meter` from the global `metric.MeterProvider`.
 790  - Use `GetMeterProivder` for a global `metric.MeterProvider`.
 791  - Use `SetMeterProivder` to set the global `metric.MeterProvider`.
 792
 793### Changed
 794
 795- Move the `go.opentelemetry.io/otel/metric` module to the `stable-v1` module set.
 796  This stages the metric API to be released as a stable module. (#4038)
 797
 798### Removed
 799
 800- The `go.opentelemetry.io/otel/metric/global` package is removed.
 801  Use `go.opentelemetry.io/otel` instead. (#4039)
 802
 803## [1.15.1/0.38.1] 2023-05-02
 804
 805### Fixed
 806
 807- Remove unused imports from `sdk/resource/host_id_bsd.go` which caused build failures. (#4040, #4041)
 808
 809## [1.15.0/0.38.0] 2023-04-27
 810
 811### Added
 812
 813- The `go.opentelemetry.io/otel/metric/embedded` package. (#3916)
 814- The `Version` function to `go.opentelemetry.io/otel/sdk` to return the SDK version. (#3949)
 815- Add a `WithNamespace` option to `go.opentelemetry.io/otel/exporters/prometheus` to allow users to prefix metrics with a namespace. (#3970)
 816- The following configuration types were added to `go.opentelemetry.io/otel/metric/instrument` to be used in the configuration of measurement methods. (#3971)
 817  - The `AddConfig` used to hold configuration for addition measurements
 818    - `NewAddConfig` used to create a new `AddConfig`
 819    - `AddOption` used to configure an `AddConfig`
 820  - The `RecordConfig` used to hold configuration for recorded measurements
 821    - `NewRecordConfig` used to create a new `RecordConfig`
 822    - `RecordOption` used to configure a `RecordConfig`
 823  - The `ObserveConfig` used to hold configuration for observed measurements
 824    - `NewObserveConfig` used to create a new `ObserveConfig`
 825    - `ObserveOption` used to configure an `ObserveConfig`
 826- `WithAttributeSet` and `WithAttributes` are added to `go.opentelemetry.io/otel/metric/instrument`.
 827  They return an option used during a measurement that defines the attribute Set associated with the measurement. (#3971)
 828- The `Version` function to `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` to return the OTLP metrics client version. (#3956)
 829- The `Version` function to `go.opentelemetry.io/otel/exporters/otlp/otlptrace` to return the OTLP trace client version. (#3956)
 830
 831### Changed
 832
 833- The `Extrema` in `go.opentelemetry.io/otel/sdk/metric/metricdata` is redefined with a generic argument of `[N int64 | float64]`. (#3870)
 834- Update all exported interfaces from `go.opentelemetry.io/otel/metric` to embed their corresponding interface from `go.opentelemetry.io/otel/metric/embedded`.
 835  This adds an implementation requirement to set the interface default behavior for unimplemented methods. (#3916)
 836- Move No-Op implementation from `go.opentelemetry.io/otel/metric` into its own package `go.opentelemetry.io/otel/metric/noop`. (#3941)
 837  - `metric.NewNoopMeterProvider` is replaced with `noop.NewMeterProvider`
 838- Add all the methods from `"go.opentelemetry.io/otel/trace".SpanContext` to `bridgeSpanContext` by embedding `otel.SpanContext` in `bridgeSpanContext`. (#3966)
 839- Wrap `UploadMetrics` error in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/` to improve error message when encountering generic grpc errors. (#3974)
 840- The measurement methods for all instruments in `go.opentelemetry.io/otel/metric/instrument` accept an option instead of the variadic `"go.opentelemetry.io/otel/attribute".KeyValue`. (#3971)
 841  - The `Int64Counter.Add` method now accepts `...AddOption`
 842  - The `Float64Counter.Add` method now accepts `...AddOption`
 843  - The `Int64UpDownCounter.Add` method now accepts `...AddOption`
 844  - The `Float64UpDownCounter.Add` method now accepts `...AddOption`
 845  - The `Int64Histogram.Record` method now accepts `...RecordOption`
 846  - The `Float64Histogram.Record` method now accepts `...RecordOption`
 847  - The `Int64Observer.Observe` method now accepts `...ObserveOption`
 848  - The `Float64Observer.Observe` method now accepts `...ObserveOption`
 849- The `Observer` methods in `go.opentelemetry.io/otel/metric` accept an option instead of the variadic `"go.opentelemetry.io/otel/attribute".KeyValue`. (#3971)
 850  - The `Observer.ObserveInt64` method now accepts `...ObserveOption`
 851  - The `Observer.ObserveFloat64` method now accepts `...ObserveOption`
 852- Move global metric back to `go.opentelemetry.io/otel/metric/global` from `go.opentelemetry.io/otel`. (#3986)
 853
 854### Fixed
 855
 856- `TracerProvider` allows calling `Tracer()` while it's shutting down.
 857  It used to deadlock. (#3924)
 858- Use the SDK version for the Telemetry SDK resource detector in `go.opentelemetry.io/otel/sdk/resource`. (#3949)
 859- Fix a data race in `SpanProcessor` returned by `NewSimpleSpanProcessor` in `go.opentelemetry.io/otel/sdk/trace`. (#3951)
 860- Automatically figure out the default aggregation with `aggregation.Default`. (#3967)
 861
 862### Deprecated
 863
 864- The `go.opentelemetry.io/otel/metric/instrument` package is deprecated.
 865  Use the equivalent types added to `go.opentelemetry.io/otel/metric` instead. (#4018)
 866
 867## [1.15.0-rc.2/0.38.0-rc.2] 2023-03-23
 868
 869This is a release candidate for the v1.15.0/v0.38.0 release.
 870That release will include the `v1` release of the OpenTelemetry Go metric API and will provide stability guarantees of that API.
 871See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 872
 873### Added
 874
 875- The `WithHostID` option to `go.opentelemetry.io/otel/sdk/resource`. (#3812)
 876- The `WithoutTimestamps` option to `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` to sets all timestamps to zero. (#3828)
 877- The new `Exemplar` type is added to `go.opentelemetry.io/otel/sdk/metric/metricdata`.
 878  Both the `DataPoint` and `HistogramDataPoint` types from that package have a new field of `Exemplars` containing the sampled exemplars for their timeseries. (#3849)
 879- Configuration for each metric instrument in `go.opentelemetry.io/otel/sdk/metric/instrument`. (#3895)
 880- The internal logging introduces a warning level verbosity equal to `V(1)`. (#3900)
 881- Added a log message warning about usage of `SimpleSpanProcessor` in production environments. (#3854)
 882
 883### Changed
 884
 885- Optimize memory allocation when creation a new `Set` using `NewSet` or `NewSetWithFiltered` in `go.opentelemetry.io/otel/attribute`. (#3832)
 886- Optimize memory allocation when creation new metric instruments in `go.opentelemetry.io/otel/sdk/metric`. (#3832)
 887- Avoid creating new objects on all calls to `WithDeferredSetup` and `SkipContextSetup` in OpenTracing bridge. (#3833)
 888- The `New` and `Detect` functions from `go.opentelemetry.io/otel/sdk/resource` return errors that wrap underlying errors instead of just containing the underlying error strings. (#3844)
 889- Both the `Histogram` and `HistogramDataPoint` are redefined with a generic argument of `[N int64 | float64]` in `go.opentelemetry.io/otel/sdk/metric/metricdata`. (#3849)
 890- The metric `Export` interface from `go.opentelemetry.io/otel/sdk/metric` accepts a `*ResourceMetrics` instead of `ResourceMetrics`. (#3853)
 891- Rename `Asynchronous` to `Observable` in `go.opentelemetry.io/otel/metric/instrument`. (#3892)
 892- Rename `Int64ObserverOption` to `Int64ObservableOption` in `go.opentelemetry.io/otel/metric/instrument`. (#3895)
 893- Rename `Float64ObserverOption` to `Float64ObservableOption` in `go.opentelemetry.io/otel/metric/instrument`. (#3895)
 894- The internal logging changes the verbosity level of info to `V(4)`, the verbosity level of debug to `V(8)`. (#3900)
 895
 896### Fixed
 897
 898- `TracerProvider` consistently doesn't allow to register a `SpanProcessor` after shutdown. (#3845)
 899
 900### Removed
 901
 902- The deprecated `go.opentelemetry.io/otel/metric/global` package is removed. (#3829)
 903- The unneeded `Synchronous` interface in `go.opentelemetry.io/otel/metric/instrument` was removed. (#3892)
 904- The `Float64ObserverConfig` and `NewFloat64ObserverConfig` in `go.opentelemetry.io/otel/sdk/metric/instrument`.
 905  Use the added `float64` instrument configuration instead. (#3895)
 906- The `Int64ObserverConfig` and `NewInt64ObserverConfig` in `go.opentelemetry.io/otel/sdk/metric/instrument`.
 907  Use the added `int64` instrument configuration instead. (#3895)
 908- The `NewNoopMeter` function in `go.opentelemetry.io/otel/metric`, use `NewMeterProvider().Meter("")` instead. (#3893)
 909
 910## [1.15.0-rc.1/0.38.0-rc.1] 2023-03-01
 911
 912This is a release candidate for the v1.15.0/v0.38.0 release.
 913That release will include the `v1` release of the OpenTelemetry Go metric API and will provide stability guarantees of that API.
 914See our [versioning policy](VERSIONING.md) for more information about these stability guarantees.
 915
 916This release drops the compatibility guarantee of [Go 1.18].
 917
 918### Added
 919
 920- Support global `MeterProvider` in `go.opentelemetry.io/otel`. (#3818)
 921  - Use `Meter` for a `metric.Meter` from the global `metric.MeterProvider`.
 922  - Use `GetMeterProivder` for a global `metric.MeterProvider`.
 923  - Use `SetMeterProivder` to set the global `metric.MeterProvider`.
 924
 925### Changed
 926
 927- Dropped compatibility testing for [Go 1.18].
 928  The project no longer guarantees support for this version of Go. (#3813)
 929
 930### Fixed
 931
 932- Handle empty environment variable as it they were not set. (#3764)
 933- Clarify the `httpconv` and `netconv` packages in `go.opentelemetry.io/otel/semconv/*` provide tracing semantic conventions. (#3823)
 934- Fix race conditions in `go.opentelemetry.io/otel/exporters/metric/prometheus` that could cause a panic. (#3899)
 935- Fix sending nil `scopeInfo` to metrics channel in `go.opentelemetry.io/otel/exporters/metric/prometheus` that could cause a panic in `github.com/prometheus/client_golang/prometheus`. (#3899)
 936
 937### Deprecated
 938
 939- The `go.opentelemetry.io/otel/metric/global` package is deprecated.
 940  Use `go.opentelemetry.io/otel` instead. (#3818)
 941
 942### Removed
 943
 944- The deprecated `go.opentelemetry.io/otel/metric/unit` package is removed. (#3814)
 945
 946## [1.14.0/0.37.0/0.0.4] 2023-02-27
 947
 948This release is the last to support [Go 1.18].
 949The next release will require at least [Go 1.19].
 950
 951### Added
 952
 953- The `event` type semantic conventions are added to `go.opentelemetry.io/otel/semconv/v1.17.0`. (#3697)
 954- Support [Go 1.20]. (#3693)
 955- The `go.opentelemetry.io/otel/semconv/v1.18.0` package.
 956  The package contains semantic conventions from the `v1.18.0` version of the OpenTelemetry specification. (#3719)
 957  - The following `const` renames from `go.opentelemetry.io/otel/semconv/v1.17.0` are included:
 958    - `OtelScopeNameKey` -> `OTelScopeNameKey`
 959    - `OtelScopeVersionKey` -> `OTelScopeVersionKey`
 960    - `OtelLibraryNameKey` -> `OTelLibraryNameKey`
 961    - `OtelLibraryVersionKey` -> `OTelLibraryVersionKey`
 962    - `OtelStatusCodeKey` -> `OTelStatusCodeKey`
 963    - `OtelStatusDescriptionKey` -> `OTelStatusDescriptionKey`
 964    - `OtelStatusCodeOk` -> `OTelStatusCodeOk`
 965    - `OtelStatusCodeError` -> `OTelStatusCodeError`
 966  - The following `func` renames from `go.opentelemetry.io/otel/semconv/v1.17.0` are included:
 967    - `OtelScopeName` -> `OTelScopeName`
 968    - `OtelScopeVersion` -> `OTelScopeVersion`
 969    - `OtelLibraryName` -> `OTelLibraryName`
 970    - `OtelLibraryVersion` -> `OTelLibraryVersion`
 971    - `OtelStatusDescription` -> `OTelStatusDescription`
 972- A `IsSampled` method is added to the `SpanContext` implementation in `go.opentelemetry.io/otel/bridge/opentracing` to expose the span sampled state.
 973  See the [README](./bridge/opentracing/README.md) for more information. (#3570)
 974- The `WithInstrumentationAttributes` option to `go.opentelemetry.io/otel/metric`. (#3738)
 975- The `WithInstrumentationAttributes` option to `go.opentelemetry.io/otel/trace`. (#3739)
 976- The following environment variables are supported by the periodic `Reader` in `go.opentelemetry.io/otel/sdk/metric`. (#3763)
 977  - `OTEL_METRIC_EXPORT_INTERVAL` sets the time between collections and exports.
 978  - `OTEL_METRIC_EXPORT_TIMEOUT` sets the timeout an export is attempted.
 979
 980### Changed
 981
 982- Fall-back to `TextMapCarrier` when it's not `HttpHeader`s in `go.opentelemetry.io/otel/bridge/opentracing`. (#3679)
 983- The `Collect` method of the `"go.opentelemetry.io/otel/sdk/metric".Reader` interface is updated to accept the `metricdata.ResourceMetrics` value the collection will be made into.
 984  This change is made to enable memory reuse by SDK users. (#3732)
 985- The `WithUnit` option in `go.opentelemetry.io/otel/sdk/metric/instrument` is updated to accept a `string` for the unit value. (#3776)
 986
 987### Fixed
 988
 989- Ensure `go.opentelemetry.io/otel` does not use generics. (#3723, #3725)
 990- Multi-reader `MeterProvider`s now export metrics for all readers, instead of just the first reader. (#3720, #3724)
 991- Remove use of deprecated `"math/rand".Seed` in `go.opentelemetry.io/otel/example/prometheus`. (#3733)
 992- Do not silently drop unknown schema data with `Parse` in  `go.opentelemetry.io/otel/schema/v1.1`. (#3743)
 993- Data race issue in OTLP exporter retry mechanism. (#3755, #3756)
 994- Wrapping empty errors when exporting in `go.opentelemetry.io/otel/sdk/metric`. (#3698, #3772)
 995- Incorrect "all" and "resource" definition for schema files in `go.opentelemetry.io/otel/schema/v1.1`. (#3777)
 996
 997### Deprecated
 998
 999- The `go.opentelemetry.io/otel/metric/unit` package is deprecated.
1000  Use the equivalent unit string instead. (#3776)
1001  - Use `"1"` instead of `unit.Dimensionless`
1002  - Use `"By"` instead of `unit.Bytes`
1003  - Use `"ms"` instead of `unit.Milliseconds`
1004
1005## [1.13.0/0.36.0] 2023-02-07
1006
1007### Added
1008
1009- Attribute `KeyValue` creations functions to `go.opentelemetry.io/otel/semconv/v1.17.0` for all non-enum semantic conventions.
1010  These functions ensure semantic convention type correctness. (#3675)
1011
1012### Fixed
1013
1014- Removed the `http.target` attribute from being added by `ServerRequest` in the following packages. (#3687)
1015  - `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`
1016  - `go.opentelemetry.io/otel/semconv/v1.14.0/httpconv`
1017  - `go.opentelemetry.io/otel/semconv/v1.15.0/httpconv`
1018  - `go.opentelemetry.io/otel/semconv/v1.16.0/httpconv`
1019  - `go.opentelemetry.io/otel/semconv/v1.17.0/httpconv`
1020
1021### Removed
1022
1023- The deprecated `go.opentelemetry.io/otel/metric/instrument/asyncfloat64` package is removed. (#3631)
1024- The deprecated `go.opentelemetry.io/otel/metric/instrument/asyncint64` package is removed. (#3631)
1025- The deprecated `go.opentelemetry.io/otel/metric/instrument/syncfloat64` package is removed. (#3631)
1026- The deprecated `go.opentelemetry.io/otel/metric/instrument/syncint64` package is removed. (#3631)
1027
1028## [1.12.0/0.35.0] 2023-01-28
1029
1030### Added
1031
1032- The `WithInt64Callback` option to `go.opentelemetry.io/otel/metric/instrument`.
1033  This options is used to configure `int64` Observer callbacks during their creation. (#3507)
1034- The `WithFloat64Callback` option to `go.opentelemetry.io/otel/metric/instrument`.
1035  This options is used to configure `float64` Observer callbacks during their creation. (#3507)
1036- The `Producer` interface and `Reader.RegisterProducer(Producer)` to `go.opentelemetry.io/otel/sdk/metric`.
1037  These additions are used to enable external metric Producers. (#3524)
1038- The `Callback` function type to `go.opentelemetry.io/otel/metric`.
1039  This new named function type is registered with a `Meter`. (#3564)
1040- The `go.opentelemetry.io/otel/semconv/v1.13.0` package.
1041  The package contains semantic conventions from the `v1.13.0` version of the OpenTelemetry specification. (#3499)
1042  - The `EndUserAttributesFromHTTPRequest` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is merged into `ClientRequest` and `ServerRequest` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1043  - The `HTTPAttributesFromHTTPStatusCode` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is merged into `ClientResponse` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1044  - The `HTTPClientAttributesFromHTTPRequest` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is replaced by `ClientRequest` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1045  - The `HTTPServerAttributesFromHTTPRequest` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is replaced by `ServerRequest` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1046  - The `HTTPServerMetricAttributesFromHTTPRequest` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is replaced by `ServerRequest` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1047  - The `NetAttributesFromHTTPRequest` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is split into `Transport` in `go.opentelemetry.io/otel/semconv/v1.13.0/netconv` and `ClientRequest` or `ServerRequest` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1048  - The `SpanStatusFromHTTPStatusCode` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is replaced by `ClientStatus` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1049  - The `SpanStatusFromHTTPStatusCodeAndSpanKind` function in `go.opentelemetry.io/otel/semconv/v1.12.0` is split into `ClientStatus` and `ServerStatus` in `go.opentelemetry.io/otel/semconv/v1.13.0/httpconv`.
1050  - The `Client` function is included in `go.opentelemetry.io/otel/semconv/v1.13.0/netconv` to generate attributes for a `net.Conn`.
1051  - The `Server` function is included in `go.opentelemetry.io/otel/semconv/v1.13.0/netconv` to generate attributes for a `net.Listener`.
1052- The `go.opentelemetry.io/otel/semconv/v1.14.0` package.
1053  The package contains semantic conventions from the `v1.14.0` version of the OpenTelemetry specification. (#3566)
1054- The `go.opentelemetry.io/otel/semconv/v1.15.0` package.
1055  The package contains semantic conventions from the `v1.15.0` version of the OpenTelemetry specification. (#3578)
1056- The `go.opentelemetry.io/otel/semconv/v1.16.0` package.
1057  The package contains semantic conventions from the `v1.16.0` version of the OpenTelemetry specification. (#3579)
1058- Metric instruments to `go.opentelemetry.io/otel/metric/instrument`.
1059  These instruments are use as replacements of the deprecated `go.opentelemetry.io/otel/metric/instrument/{asyncfloat64,asyncint64,syncfloat64,syncint64}` packages.(#3575, #3586)
1060  - `Float64ObservableCounter` replaces the `asyncfloat64.Counter`
1061  - `Float64ObservableUpDownCounter` replaces the `asyncfloat64.UpDownCounter`
1062  - `Float64ObservableGauge` replaces the `asyncfloat64.Gauge`
1063  - `Int64ObservableCounter` replaces the `asyncint64.Counter`
1064  - `Int64ObservableUpDownCounter` replaces the `asyncint64.UpDownCounter`
1065  - `Int64ObservableGauge` replaces the `asyncint64.Gauge`
1066  - `Float64Counter` replaces the `syncfloat64.Counter`
1067  - `Float64UpDownCounter` replaces the `syncfloat64.UpDownCounter`
1068  - `Float64Histogram` replaces the `syncfloat64.Histogram`
1069  - `Int64Counter` replaces the `syncint64.Counter`
1070  - `Int64UpDownCounter` replaces the `syncint64.UpDownCounter`
1071  - `Int64Histogram` replaces the `syncint64.Histogram`
1072- `NewTracerProvider` to `go.opentelemetry.io/otel/bridge/opentracing`.
1073  This is used to create `WrapperTracer` instances from a `TracerProvider`. (#3116)
1074- The `Extrema` type to `go.opentelemetry.io/otel/sdk/metric/metricdata`.
1075  This type is used to represent min/max values and still be able to distinguish unset and zero values. (#3487)
1076- The `go.opentelemetry.io/otel/semconv/v1.17.0` package.
1077  The package contains semantic conventions from the `v1.17.0` version of the OpenTelemetry specification. (#3599)
1078
1079### Changed
1080
1081- Jaeger and Zipkin exporter use `github.com/go-logr/logr` as the logging interface, and add the `WithLogr` option. (#3497, #3500)
1082- Instrument configuration in `go.opentelemetry.io/otel/metric/instrument` is split into specific options and configuration based on the instrument type. (#3507)
1083  - Use the added `Int64Option` type to configure instruments from `go.opentelemetry.io/otel/metric/instrument/syncint64`.
1084  - Use the added `Float64Option` type to configure instruments from `go.opentelemetry.io/otel/metric/instrument/syncfloat64`.
1085  - Use the added `Int64ObserverOption` type to configure instruments from `go.opentelemetry.io/otel/metric/instrument/asyncint64`.
1086  - Use the added `Float64ObserverOption` type to configure instruments from `go.opentelemetry.io/otel/metric/instrument/asyncfloat64`.
1087- Return a `Registration` from the `RegisterCallback` method of a `Meter` in the `go.opentelemetry.io/otel/metric` package.
1088  This `Registration` can be used to unregister callbacks. (#3522)
1089- Global error handler uses an atomic value instead of a mutex. (#3543)
1090- Add `NewMetricProducer` to `go.opentelemetry.io/otel/bridge/opencensus`, which can be used to pass OpenCensus metrics to an OpenTelemetry Reader. (#3541)
1091- Global logger uses an atomic value instead of a mutex. (#3545)
1092- The `Shutdown` method of the `"go.opentelemetry.io/otel/sdk/trace".TracerProvider` releases all computational resources when called the first time. (#3551)
1093- The `Sampler` returned from `TraceIDRatioBased` `go.opentelemetry.io/otel/sdk/trace` now uses the rightmost bits for sampling decisions.
1094  This fixes random sampling when using ID generators like `xray.IDGenerator` and increasing parity with other language implementations. (#3557)
1095- Errors from `go.opentelemetry.io/otel/exporters/otlp/otlptrace` exporters are wrapped in errors identifying their signal name.
1096  Existing users of the exporters attempting to identify specific errors will need to use `errors.Unwrap()` to get the underlying error. (#3516)
1097- Exporters from `go.opentelemetry.io/otel/exporters/otlp` will print the final retryable error message when attempts to retry time out. (#3514)
1098- The instrument kind names in `go.opentelemetry.io/otel/sdk/metric` are updated to match the API. (#3562)
1099  - `InstrumentKindSyncCounter` is renamed to `InstrumentKindCounter`
1100  - `InstrumentKindSyncUpDownCounter` is renamed to `InstrumentKindUpDownCounter`
1101  - `InstrumentKindSyncHistogram` is renamed to `InstrumentKindHistogram`
1102  - `InstrumentKindAsyncCounter` is renamed to `InstrumentKindObservableCounter`
1103  - `InstrumentKindAsyncUpDownCounter` is renamed to `InstrumentKindObservableUpDownCounter`
1104  - `InstrumentKindAsyncGauge` is renamed to `InstrumentKindObservableGauge`
1105- The `RegisterCallback` method of the `Meter` in `go.opentelemetry.io/otel/metric` changed.
1106  - The named `Callback` replaces the inline function parameter. (#3564)
1107  - `Callback` is required to return an error. (#3576)
1108  - `Callback` accepts the added `Observer` parameter added.
1109    This new parameter is used by `Callback` implementations to observe values for asynchronous instruments instead of calling the `Observe` method of the instrument directly. (#3584)
1110  - The slice of `instrument.Asynchronous` is now passed as a variadic argument. (#3587)
1111- The exporter from `go.opentelemetry.io/otel/exporters/zipkin` is updated to use the `v1.16.0` version of semantic conventions.
1112  This means it no longer uses the removed `net.peer.ip` or `http.host` attributes to determine the remote endpoint.
1113  Instead it uses the `net.sock.peer` attributes. (#3581)
1114- The `Min` and `Max` fields of the `HistogramDataPoint` in `go.opentelemetry.io/otel/sdk/metric/metricdata` are now defined with the added `Extrema` type instead of a `*float64`. (#3487)
1115
1116### Fixed
1117
1118- Asynchronous instruments that use sum aggregators and attribute filters correctly add values from equivalent attribute sets that have been filtered. (#3439, #3549)
1119- The `RegisterCallback` method of the `Meter` from `go.opentelemetry.io/otel/sdk/metric` only registers a callback for instruments created by that meter.
1120  Trying to register a callback with instruments from a different meter will result in an error being returned. (#3584)
1121
1122### Deprecated
1123
1124- The `NewMetricExporter` in `go.opentelemetry.io/otel/bridge/opencensus` is deprecated.
1125  Use `NewMetricProducer` instead. (#3541)
1126- The `go.opentelemetry.io/otel/metric/instrument/asyncfloat64` package is deprecated.
1127  Use the instruments from `go.opentelemetry.io/otel/metric/instrument` instead. (#3575)
1128- The `go.opentelemetry.io/otel/metric/instrument/asyncint64` package is deprecated.
1129  Use the instruments from `go.opentelemetry.io/otel/metric/instrument` instead. (#3575)
1130- The `go.opentelemetry.io/otel/metric/instrument/syncfloat64` package is deprecated.
1131  Use the instruments from `go.opentelemetry.io/otel/metric/instrument` instead. (#3575)
1132- The `go.opentelemetry.io/otel/metric/instrument/syncint64` package is deprecated.
1133  Use the instruments from `go.opentelemetry.io/otel/metric/instrument` instead. (#3575)
1134- The `NewWrappedTracerProvider` in `go.opentelemetry.io/otel/bridge/opentracing` is now deprecated.
1135  Use `NewTracerProvider` instead. (#3116)
1136
1137### Removed
1138
1139- The deprecated `go.opentelemetry.io/otel/sdk/metric/view` package is removed. (#3520)
1140- The `InstrumentProvider` from `go.opentelemetry.io/otel/sdk/metric/asyncint64` is removed.
1141  Use the new creation methods of the `Meter` in `go.opentelemetry.io/otel/sdk/metric` instead. (#3530)
1142  - The `Counter` method is replaced by `Meter.Int64ObservableCounter`
1143  - The `UpDownCounter` method is replaced by `Meter.Int64ObservableUpDownCounter`
1144  - The `Gauge` method is replaced by `Meter.Int64ObservableGauge`
1145- The `InstrumentProvider` from `go.opentelemetry.io/otel/sdk/metric/asyncfloat64` is removed.
1146  Use the new creation methods of the `Meter` in `go.opentelemetry.io/otel/sdk/metric` instead. (#3530)
1147  - The `Counter` method is replaced by `Meter.Float64ObservableCounter`
1148  - The `UpDownCounter` method is replaced by `Meter.Float64ObservableUpDownCounter`
1149  - The `Gauge` method is replaced by `Meter.Float64ObservableGauge`
1150- The `InstrumentProvider` from `go.opentelemetry.io/otel/sdk/metric/syncint64` is removed.
1151  Use the new creation methods of the `Meter` in `go.opentelemetry.io/otel/sdk/metric` instead. (#3530)
1152  - The `Counter` method is replaced by `Meter.Int64Counter`
1153  - The `UpDownCounter` method is replaced by `Meter.Int64UpDownCounter`
1154  - The `Histogram` method is replaced by `Meter.Int64Histogram`
1155- The `InstrumentProvider` from `go.opentelemetry.io/otel/sdk/metric/syncfloat64` is removed.
1156  Use the new creation methods of the `Meter` in `go.opentelemetry.io/otel/sdk/metric` instead. (#3530)
1157  - The `Counter` method is replaced by `Meter.Float64Counter`
1158  - The `UpDownCounter` method is replaced by `Meter.Float64UpDownCounter`
1159  - The `Histogram` method is replaced by `Meter.Float64Histogram`
1160
1161## [1.11.2/0.34.0] 2022-12-05
1162
1163### Added
1164
1165- The `WithView` `Option` is added to the `go.opentelemetry.io/otel/sdk/metric` package.
1166   This option is used to configure the view(s) a `MeterProvider` will use for all `Reader`s that are registered with it. (#3387)
1167- Add Instrumentation Scope and Version as info metric and label in Prometheus exporter.
1168  This can be disabled using the `WithoutScopeInfo()` option added to that package.(#3273, #3357)
1169- OTLP exporters now recognize: (#3363)
1170  - `OTEL_EXPORTER_OTLP_INSECURE`
1171  - `OTEL_EXPORTER_OTLP_TRACES_INSECURE`
1172  - `OTEL_EXPORTER_OTLP_METRICS_INSECURE`
1173  - `OTEL_EXPORTER_OTLP_CLIENT_KEY`
1174  - `OTEL_EXPORTER_OTLP_TRACES_CLIENT_KEY`
1175  - `OTEL_EXPORTER_OTLP_METRICS_CLIENT_KEY`
1176  - `OTEL_EXPORTER_OTLP_CLIENT_CERTIFICATE`
1177  - `OTEL_EXPORTER_OTLP_TRACES_CLIENT_CERTIFICATE`
1178  - `OTEL_EXPORTER_OTLP_METRICS_CLIENT_CERTIFICATE`
1179- The `View` type and related `NewView` function to create a view according to the OpenTelemetry specification are added to `go.opentelemetry.io/otel/sdk/metric`.
1180  These additions are replacements for the `View` type and `New` function from `go.opentelemetry.io/otel/sdk/metric/view`. (#3459)
1181- The `Instrument` and `InstrumentKind` type are added to `go.opentelemetry.io/otel/sdk/metric`.
1182  These additions are replacements for the `Instrument` and `InstrumentKind` types from `go.opentelemetry.io/otel/sdk/metric/view`. (#3459)
1183- The `Stream` type is added to `go.opentelemetry.io/otel/sdk/metric` to define a metric data stream a view will produce. (#3459)
1184- The `AssertHasAttributes` allows instrument authors to test that datapoints returned have appropriate attributes. (#3487)
1185
1186### Changed
1187
1188- The `"go.opentelemetry.io/otel/sdk/metric".WithReader` option no longer accepts views to associate with the `Reader`.
1189   Instead, views are now registered directly with the `MeterProvider` via the new `WithView` option.
1190   The views registered with the `MeterProvider` apply to all `Reader`s. (#3387)
1191- The `Temporality(view.InstrumentKind) metricdata.Temporality` and `Aggregation(view.InstrumentKind) aggregation.Aggregation` methods are added to the `"go.opentelemetry.io/otel/sdk/metric".Exporter` interface. (#3260)
1192- The `Temporality(view.InstrumentKind) metricdata.Temporality` and `Aggregation(view.InstrumentKind) aggregation.Aggregation` methods are added to the `"go.opentelemetry.io/otel/exporters/otlp/otlpmetric".Client` interface. (#3260)
1193- The `WithTemporalitySelector` and `WithAggregationSelector` `ReaderOption`s have been changed to `ManualReaderOption`s in the `go.opentelemetry.io/otel/sdk/metric` package. (#3260)
1194- The periodic reader in the `go.opentelemetry.io/otel/sdk/metric` package now uses the temporality and aggregation selectors from its configured exporter instead of accepting them as options. (#3260)
1195
1196### Fixed
1197
1198- The `go.opentelemetry.io/otel/exporters/prometheus` exporter fixes duplicated `_total` suffixes. (#3369)
1199- Remove comparable requirement for `Reader`s. (#3387)
1200- Cumulative metrics from the OpenCensus bridge (`go.opentelemetry.io/otel/bridge/opencensus`) are defined as monotonic sums, instead of non-monotonic. (#3389)
1201- Asynchronous counters (`Counter` and `UpDownCounter`) from the metric SDK now produce delta sums when configured with delta temporality. (#3398)
1202- Exported `Status` codes in the `go.opentelemetry.io/otel/exporters/zipkin` exporter are now exported as all upper case values. (#3340)
1203- `Aggregation`s from `go.opentelemetry.io/otel/sdk/metric` with no data are not exported. (#3394, #3436)
1204- Re-enabled Attribute Filters in the Metric SDK. (#3396)
1205- Asynchronous callbacks are only called if they are registered with at least one instrument that does not use drop aggregation. (#3408)
1206- Do not report empty partial-success responses in the `go.opentelemetry.io/otel/exporters/otlp` exporters. (#3438, #3432)
1207- Handle partial success responses in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` exporters. (#3162, #3440)
1208- Prevent duplicate Prometheus description, unit, and type. (#3469)
1209- Prevents panic when using incorrect `attribute.Value.As[Type]Slice()`. (#3489)
1210
1211### Removed
1212
1213- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric.Client` interface is removed. (#3486)
1214- The `go.opentelemetry.io/otel/exporters/otlp/otlpmetric.New` function is removed. Use the `otlpmetric[http|grpc].New` directly. (#3486)
1215
1216### Deprecated
1217
1218- The `go.opentelemetry.io/otel/sdk/metric/view` package is deprecated.
1219  Use `Instrument`, `InstrumentKind`, `View`, and `NewView` in `go.opentelemetry.io/otel/sdk/metric` instead. (#3476)
1220
1221## [1.11.1/0.33.0] 2022-10-19
1222
1223### Added
1224
1225- The Prometheus exporter in `go.opentelemetry.io/otel/exporters/prometheus` registers with a Prometheus registerer on creation.
1226   By default, it will register with the default Prometheus registerer.
1227   A non-default registerer can be used by passing the `WithRegisterer` option. (#3239)
1228- Added the `WithAggregationSelector` option to the `go.opentelemetry.io/otel/exporters/prometheus` package to change the default `AggregationSelector` used. (#3341)
1229- The Prometheus exporter in `go.opentelemetry.io/otel/exporters/prometheus` converts the `Resource` associated with metric exports into a `target_info` metric. (#3285)
1230
1231### Changed
1232
1233- The `"go.opentelemetry.io/otel/exporters/prometheus".New` function is updated to return an error.
1234   It will return an error if the exporter fails to register with Prometheus. (#3239)
1235
1236### Fixed
1237
1238- The URL-encoded values from the `OTEL_RESOURCE_ATTRIBUTES` environment variable are decoded. (#2963)
1239- The `baggage.NewMember` function decodes the `value` parameter instead of directly using it.
1240   This fixes the implementation to be compliant with the W3C specification. (#3226)
1241- Slice attributes of the `attribute` package are now comparable based on their value, not instance. (#3108 #3252)
1242- The `Shutdown` and `ForceFlush` methods of the `"go.opentelemetry.io/otel/sdk/trace".TraceProvider` no longer return an error when no processor is registered. (#3268)
1243- The Prometheus exporter in `go.opentelemetry.io/otel/exporters/prometheus` cumulatively sums histogram buckets. (#3281)
1244- The sum of each histogram data point is now uniquely exported by the `go.opentelemetry.io/otel/exporters/otlpmetric` exporters. (#3284, #3293)
1245- Recorded values for asynchronous counters (`Counter` and `UpDownCounter`) are interpreted as exact, not incremental, sum values by the metric SDK. (#3350, #3278)
1246- `UpDownCounters` are now correctly output as Prometheus gauges in the `go.opentelemetry.io/otel/exporters/prometheus` exporter. (#3358)
1247- The Prometheus exporter in `go.opentelemetry.io/otel/exporters/prometheus` no longer describes the metrics it will send to Prometheus on startup.
1248   Instead the exporter is defined as an "unchecked" collector for Prometheus.
1249   This fixes the `reader is not registered` warning currently emitted on startup. (#3291 #3342)
1250- The `go.opentelemetry.io/otel/exporters/prometheus` exporter now correctly adds `_total` suffixes to counter metrics. (#3360)
1251- The `go.opentelemetry.io/otel/exporters/prometheus` exporter now adds a unit suffix to metric names.
1252   This can be disabled using the `WithoutUnits()` option added to that package. (#3352)
1253
1254## [1.11.0/0.32.3] 2022-10-12
1255
1256### Added
1257
1258- Add default User-Agent header to OTLP exporter requests (`go.opentelemetry.io/otel/exporters/otlptrace/otlptracegrpc` and `go.opentelemetry.io/otel/exporters/otlptrace/otlptracehttp`). (#3261)
1259
1260### Changed
1261
1262- `span.SetStatus` has been updated such that calls that lower the status are now no-ops. (#3214)
1263- Upgrade `golang.org/x/sys/unix` from `v0.0.0-20210423185535-09eb48e85fd7` to `v0.0.0-20220919091848-fb04ddd9f9c8`.
1264  This addresses [GO-2022-0493](https://pkg.go.dev/vuln/GO-2022-0493). (#3235)
1265
1266## [0.32.2] Metric SDK (Alpha) - 2022-10-11
1267
1268### Added
1269
1270- Added an example of using metric views to customize instruments. (#3177)
1271- Add default User-Agent header to OTLP exporter requests (`go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlpmetric/otlpmetrichttp`). (#3261)
1272
1273### Changed
1274
1275- Flush pending measurements with the `PeriodicReader` in the `go.opentelemetry.io/otel/sdk/metric` when `ForceFlush` or `Shutdown` are called. (#3220)
1276- Update histogram default bounds to match the requirements of the latest specification. (#3222)
1277- Encode the HTTP status code in the OpenTracing bridge (`go.opentelemetry.io/otel/bridge/opentracing`) as an integer.  (#3265)
1278
1279### Fixed
1280
1281- Use default view if instrument does not match any registered view of a reader. (#3224, #3237)
1282- Return the same instrument every time a user makes the exact same instrument creation call. (#3229, #3251)
1283- Return the existing instrument when a view transforms a creation call to match an existing instrument. (#3240, #3251)
1284- Log a warning when a conflicting instrument (e.g. description, unit, data-type) is created instead of returning an error. (#3251)
1285- The OpenCensus bridge no longer sends empty batches of metrics. (#3263)
1286
1287## [0.32.1] Metric SDK (Alpha) - 2022-09-22
1288
1289### Changed
1290
1291- The Prometheus exporter sanitizes OpenTelemetry instrument names when exporting.
1292   Invalid characters are replaced with `_`. (#3212)
1293
1294### Added
1295
1296- The metric portion of the OpenCensus bridge (`go.opentelemetry.io/otel/bridge/opencensus`) has been reintroduced. (#3192)
1297- The OpenCensus bridge example (`go.opentelemetry.io/otel/example/opencensus`) has been reintroduced. (#3206)
1298
1299### Fixed
1300
1301- Updated go.mods to point to valid versions of the sdk. (#3216)
1302- Set the `MeterProvider` resource on all exported metric data. (#3218)
1303
1304## [0.32.0] Revised Metric SDK (Alpha) - 2022-09-18
1305
1306### Changed
1307
1308- The metric SDK in `go.opentelemetry.io/otel/sdk/metric` is completely refactored to comply with the OpenTelemetry specification.
1309  Please see the package documentation for how the new SDK is initialized and configured. (#3175)
1310- Update the minimum supported go version to go1.18. Removes support for go1.17 (#3179)
1311
1312### Removed
1313
1314- The metric portion of the OpenCensus bridge (`go.opentelemetry.io/otel/bridge/opencensus`) has been removed.
1315  A new bridge compliant with the revised metric SDK will be added back in a future release. (#3175)
1316- The `go.opentelemetry.io/otel/sdk/metric/aggregator/aggregatortest` package is removed, see the new metric SDK. (#3175)
1317- The `go.opentelemetry.io/otel/sdk/metric/aggregator/histogram` package is removed, see the new metric SDK. (#3175)
1318- The `go.opentelemetry.io/otel/sdk/metric/aggregator/lastvalue` package is removed, see the new metric SDK. (#3175)
1319- The `go.opentelemetry.io/otel/sdk/metric/aggregator/sum` package is removed, see the new metric SDK. (#3175)
1320- The `go.opentelemetry.io/otel/sdk/metric/aggregator` package is removed, see the new metric SDK. (#3175)
1321- The `go.opentelemetry.io/otel/sdk/metric/controller/basic` package is removed, see the new metric SDK. (#3175)
1322- The `go.opentelemetry.io/otel/sdk/metric/controller/controllertest` package is removed, see the new metric SDK. (#3175)
1323- The `go.opentelemetry.io/otel/sdk/metric/controller/time` package is removed, see the new metric SDK. (#3175)
1324- The `go.opentelemetry.io/otel/sdk/metric/export/aggregation` package is removed, see the new metric SDK. (#3175)
1325- The `go.opentelemetry.io/otel/sdk/metric/export` package is removed, see the new metric SDK. (#3175)
1326- The `go.opentelemetry.io/otel/sdk/metric/metrictest` package is removed.
1327  A replacement package that supports the new metric SDK will be added back in a future release. (#3175)
1328- The `go.opentelemetry.io/otel/sdk/metric/number` package is removed, see the new metric SDK. (#3175)
1329- The `go.opentelemetry.io/otel/sdk/metric/processor/basic` package is removed, see the new metric SDK. (#3175)
1330- The `go.opentelemetry.io/otel/sdk/metric/processor/processortest` package is removed, see the new metric SDK. (#3175)
1331- The `go.opentelemetry.io/otel/sdk/metric/processor/reducer` package is removed, see the new metric SDK. (#3175)
1332- The `go.opentelemetry.io/otel/sdk/metric/registry` package is removed, see the new metric SDK. (#3175)
1333- The `go.opentelemetry.io/otel/sdk/metric/sdkapi` package is removed, see the new metric SDK. (#3175)
1334- The `go.opentelemetry.io/otel/sdk/metric/selector/simple` package is removed, see the new metric SDK. (#3175)
1335- The `"go.opentelemetry.io/otel/sdk/metric".ErrUninitializedInstrument` variable was removed. (#3175)
1336- The `"go.opentelemetry.io/otel/sdk/metric".ErrBadInstrument` variable was removed. (#3175)
1337- The `"go.opentelemetry.io/otel/sdk/metric".Accumulator` type was removed, see the `MeterProvider`in the new metric SDK. (#3175)
1338- The `"go.opentelemetry.io/otel/sdk/metric".NewAccumulator` function was removed, see `NewMeterProvider`in the new metric SDK. (#3175)
1339- The deprecated `"go.opentelemetry.io/otel/sdk/metric".AtomicFieldOffsets` function was removed. (#3175)
1340
1341## [1.10.0] - 2022-09-09
1342
1343### Added
1344
1345- Support Go 1.19. (#3077)
1346  Include compatibility testing and document support. (#3077)
1347- Support the OTLP ExportTracePartialSuccess response; these are passed to the registered error handler. (#3106)
1348- Upgrade go.opentelemetry.io/proto/otlp from v0.18.0 to v0.19.0 (#3107)
1349
1350### Changed
1351
1352- Fix misidentification of OpenTelemetry `SpanKind` in OpenTracing bridge (`go.opentelemetry.io/otel/bridge/opentracing`).  (#3096)
1353- Attempting to start a span with a nil `context` will no longer cause a panic. (#3110)
1354- All exporters will be shutdown even if one reports an error (#3091)
1355- Ensure valid UTF-8 when truncating over-length attribute values. (#3156)
1356
1357## [1.9.0/0.0.3] - 2022-08-01
1358
1359### Added
1360
1361- Add support for Schema Files format 1.1.x (metric "split" transform) with the new `go.opentelemetry.io/otel/schema/v1.1` package. (#2999)
1362- Add the `go.opentelemetry.io/otel/semconv/v1.11.0` package.
1363  The package contains semantic conventions from the `v1.11.0` version of the OpenTelemetry specification. (#3009)
1364- Add the `go.opentelemetry.io/otel/semconv/v1.12.0` package.
1365  The package contains semantic conventions from the `v1.12.0` version of the OpenTelemetry specification. (#3010)
1366- Add the `http.method` attribute to HTTP server metric from all `go.opentelemetry.io/otel/semconv/*` packages. (#3018)
1367
1368### Fixed
1369
1370- Invalid warning for context setup being deferred in `go.opentelemetry.io/otel/bridge/opentracing` package. (#3029)
1371
1372## [1.8.0/0.31.0] - 2022-07-08
1373
1374### Added
1375
1376- Add support for `opentracing.TextMap` format in the `Inject` and `Extract` methods
1377of the `"go.opentelemetry.io/otel/bridge/opentracing".BridgeTracer` type. (#2911)
1378
1379### Changed
1380
1381- The `crosslink` make target has been updated to use the `go.opentelemetry.io/build-tools/crosslink` package. (#2886)
1382- In the `go.opentelemetry.io/otel/sdk/instrumentation` package rename `Library` to `Scope` and alias `Library` as `Scope` (#2976)
1383- Move metric no-op implementation form `nonrecording` to `metric` package. (#2866)
1384
1385### Removed
1386
1387- Support for go1.16. Support is now only for go1.17 and go1.18 (#2917)
1388
1389### Deprecated
1390
1391- The `Library` struct in the `go.opentelemetry.io/otel/sdk/instrumentation` package is deprecated.
1392  Use the equivalent `Scope` struct instead. (#2977)
1393- The `ReadOnlySpan.InstrumentationLibrary` method from the `go.opentelemetry.io/otel/sdk/trace` package is deprecated.
1394  Use the equivalent `ReadOnlySpan.InstrumentationScope` method instead. (#2977)
1395
1396## [1.7.0/0.30.0] - 2022-04-28
1397
1398### Added
1399
1400- Add the `go.opentelemetry.io/otel/semconv/v1.8.0` package.
1401  The package contains semantic conventions from the `v1.8.0` version of the OpenTelemetry specification. (#2763)
1402- Add the `go.opentelemetry.io/otel/semconv/v1.9.0` package.
1403  The package contains semantic conventions from the `v1.9.0` version of the OpenTelemetry specification. (#2792)
1404- Add the `go.opentelemetry.io/otel/semconv/v1.10.0` package.
1405  The package contains semantic conventions from the `v1.10.0` version of the OpenTelemetry specification. (#2842)
1406- Added an in-memory exporter to metrictest to aid testing with a full SDK. (#2776)
1407
1408### Fixed
1409
1410- Globally delegated instruments are unwrapped before delegating asynchronous callbacks. (#2784)
1411- Remove import of `testing` package in non-tests builds of the `go.opentelemetry.io/otel` package. (#2786)
1412
1413### Changed
1414
1415- The `WithLabelEncoder` option from the `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` package is renamed to `WithAttributeEncoder`. (#2790)
1416- The `LabelFilterSelector` interface from `go.opentelemetry.io/otel/sdk/metric/processor/reducer` is renamed to `AttributeFilterSelector`.
1417  The method included in the renamed interface also changed from `LabelFilterFor` to `AttributeFilterFor`. (#2790)
1418- The `Metadata.Labels` method from the `go.opentelemetry.io/otel/sdk/metric/export` package is renamed to `Metadata.Attributes`.
1419  Consequentially, the `Record` type from the same package also has had the embedded method renamed. (#2790)
1420
1421### Deprecated
1422
1423- The `Iterator.Label` method in the `go.opentelemetry.io/otel/attribute` package is deprecated.
1424  Use the equivalent `Iterator.Attribute` method instead. (#2790)
1425- The `Iterator.IndexedLabel` method in the `go.opentelemetry.io/otel/attribute` package is deprecated.
1426  Use the equivalent `Iterator.IndexedAttribute` method instead. (#2790)
1427- The `MergeIterator.Label` method in the `go.opentelemetry.io/otel/attribute` package is deprecated.
1428  Use the equivalent `MergeIterator.Attribute` method instead. (#2790)
1429
1430### Removed
1431
1432- Removed the `Batch` type from the `go.opentelemetry.io/otel/sdk/metric/metrictest` package. (#2864)
1433- Removed the `Measurement` type from the `go.opentelemetry.io/otel/sdk/metric/metrictest` package. (#2864)
1434
1435## [0.29.0] - 2022-04-11
1436
1437### Added
1438
1439- The metrics global package was added back into several test files. (#2764)
1440- The `Meter` function is added back to the `go.opentelemetry.io/otel/metric/global` package.
1441  This function is a convenience function equivalent to calling `global.MeterProvider().Meter(...)`. (#2750)
1442
1443### Removed
1444
1445- Removed module the `go.opentelemetry.io/otel/sdk/export/metric`.
1446  Use the `go.opentelemetry.io/otel/sdk/metric` module instead. (#2720)
1447
1448### Changed
1449
1450- Don't panic anymore when setting a global MeterProvider to itself. (#2749)
1451- Upgrade `go.opentelemetry.io/proto/otlp` in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` from `v0.12.1` to `v0.15.0`.
1452  This replaces the use of the now deprecated `InstrumentationLibrary` and `InstrumentationLibraryMetrics` types and fields in the proto library with the equivalent `InstrumentationScope` and `ScopeMetrics`. (#2748)
1453
1454## [1.6.3] - 2022-04-07
1455
1456### Fixed
1457
1458- Allow non-comparable global `MeterProvider`, `TracerProvider`, and `TextMapPropagator` types to be set. (#2772, #2773)
1459
1460## [1.6.2] - 2022-04-06
1461
1462### Changed
1463
1464- Don't panic anymore when setting a global TracerProvider or TextMapPropagator to itself. (#2749)
1465- Upgrade `go.opentelemetry.io/proto/otlp` in `go.opentelemetry.io/otel/exporters/otlp/otlptrace` from `v0.12.1` to `v0.15.0`.
1466  This replaces the use of the now deprecated `InstrumentationLibrary` and `InstrumentationLibrarySpans` types and fields in the proto library with the equivalent `InstrumentationScope` and `ScopeSpans`. (#2748)
1467
1468## [1.6.1] - 2022-03-28
1469
1470### Fixed
1471
1472- The `go.opentelemetry.io/otel/schema/*` packages now use the correct schema URL for their `SchemaURL` constant.
1473  Instead of using `"https://opentelemetry.io/schemas/v<version>"` they now use the correct URL without a `v` prefix, `"https://opentelemetry.io/schemas/<version>"`. (#2743, #2744)
1474
1475### Security
1476
1477- Upgrade `go.opentelemetry.io/proto/otlp` from `v0.12.0` to `v0.12.1`.
1478  This includes an indirect upgrade of `github.com/grpc-ecosystem/grpc-gateway` which resolves [a vulnerability](https://nvd.nist.gov/vuln/detail/CVE-2019-11254) from `gopkg.in/yaml.v2` in version `v2.2.3`. (#2724, #2728)
1479
1480## [1.6.0/0.28.0] - 2022-03-23
1481
1482### ⚠️ Notice ⚠️
1483
1484This update is a breaking change of the unstable Metrics API.
1485Code instrumented with the `go.opentelemetry.io/otel/metric` will need to be modified.
1486
1487### Added
1488
1489- Add metrics exponential histogram support.
1490  New mapping functions have been made available in `sdk/metric/aggregator/exponential/mapping` for other OpenTelemetry projects to take dependencies on. (#2502)
1491- Add Go 1.18 to our compatibility tests. (#2679)
1492- Allow configuring the Sampler with the `OTEL_TRACES_SAMPLER` and `OTEL_TRACES_SAMPLER_ARG` environment variables. (#2305, #2517)
1493- Add the `metric/global` for obtaining and setting the global `MeterProvider`. (#2660)
1494
1495### Changed
1496
1497- The metrics API has been significantly changed to match the revised OpenTelemetry specification.
1498  High-level changes include:
1499
1500  - Synchronous and asynchronous instruments are now handled by independent `InstrumentProvider`s.
1501    These `InstrumentProvider`s are managed with a `Meter`.
1502  - Synchronous and asynchronous instruments are grouped into their own packages based on value types.
1503  - Asynchronous callbacks can now be registered with a `Meter`.
1504
1505  Be sure to check out the metric module documentation for more information on how to use the revised API. (#2587, #2660)
1506
1507### Fixed
1508
1509- Fallback to general attribute limits when span specific ones are not set in the environment. (#2675, #2677)
1510
1511## [1.5.0] - 2022-03-16
1512
1513### Added
1514
1515- Log the Exporters configuration in the TracerProviders message. (#2578)
1516- Added support to configure the span limits with environment variables.
1517  The following environment variables are supported. (#2606, #2637)
1518  - `OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT`
1519  - `OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT`
1520  - `OTEL_SPAN_EVENT_COUNT_LIMIT`
1521  - `OTEL_EVENT_ATTRIBUTE_COUNT_LIMIT`
1522  - `OTEL_SPAN_LINK_COUNT_LIMIT`
1523  - `OTEL_LINK_ATTRIBUTE_COUNT_LIMIT`
1524
1525  If the provided environment variables are invalid (negative), the default values would be used.
1526- Rename the `gc` runtime name to `go` (#2560)
1527- Add resource container ID detection. (#2418)
1528- Add span attribute value length limit.
1529  The new `AttributeValueLengthLimit` field is added to the `"go.opentelemetry.io/otel/sdk/trace".SpanLimits` type to configure this limit for a `TracerProvider`.
1530  The default limit for this resource is "unlimited". (#2637)
1531- Add the `WithRawSpanLimits` option to `go.opentelemetry.io/otel/sdk/trace`.
1532  This option replaces the `WithSpanLimits` option.
1533  Zero or negative values will not be changed to the default value like `WithSpanLimits` does.
1534  Setting a limit to zero will effectively disable the related resource it limits and setting to a negative value will mean that resource is unlimited.
1535  Consequentially, limits should be constructed using `NewSpanLimits` and updated accordingly. (#2637)
1536
1537### Changed
1538
1539- Drop oldest tracestate `Member` when capacity is reached. (#2592)
1540- Add event and link drop counts to the exported data from the `oltptrace` exporter. (#2601)
1541- Unify path cleaning functionally in the `otlpmetric` and `otlptrace` configuration. (#2639)
1542- Change the debug message from the `sdk/trace.BatchSpanProcessor` to reflect the count is cumulative. (#2640)
1543- Introduce new internal `envconfig` package for OTLP exporters. (#2608)
1544- If `http.Request.Host` is empty, fall back to use `URL.Host` when populating `http.host` in the `semconv` packages. (#2661)
1545
1546### Fixed
1547
1548- Remove the OTLP trace exporter limit of SpanEvents when exporting. (#2616)
1549- Default to port `4318` instead of `4317` for the `otlpmetrichttp` and `otlptracehttp` client. (#2614, #2625)
1550- Unlimited span limits are now supported (negative values). (#2636, #2637)
1551
1552### Deprecated
1553
1554- Deprecated `"go.opentelemetry.io/otel/sdk/trace".WithSpanLimits`.
1555  Use `WithRawSpanLimits` instead.
1556  That option allows setting unlimited and zero limits, this option does not.
1557  This option will be kept until the next major version incremented release. (#2637)
1558
1559## [1.4.1] - 2022-02-16
1560
1561### Fixed
1562
1563- Fix race condition in reading the dropped spans number for the `BatchSpanProcessor`. (#2615)
1564
1565## [1.4.0] - 2022-02-11
1566
1567### Added
1568
1569- Use `OTEL_EXPORTER_ZIPKIN_ENDPOINT` environment variable to specify zipkin collector endpoint. (#2490)
1570- Log the configuration of `TracerProvider`s, and `Tracer`s for debugging.
1571  To enable use a logger with Verbosity (V level) `>=1`. (#2500)
1572- Added support to configure the batch span-processor with environment variables.
1573  The following environment variables are used. (#2515)
1574  - `OTEL_BSP_SCHEDULE_DELAY`
1575  - `OTEL_BSP_EXPORT_TIMEOUT`
1576  - `OTEL_BSP_MAX_QUEUE_SIZE`.
1577  - `OTEL_BSP_MAX_EXPORT_BATCH_SIZE`
1578
1579### Changed
1580
1581- Zipkin exporter exports `Resource` attributes in the `Tags` field. (#2589)
1582
1583### Deprecated
1584
1585- Deprecate module the `go.opentelemetry.io/otel/sdk/export/metric`.
1586  Use the `go.opentelemetry.io/otel/sdk/metric` module instead. (#2382)
1587- Deprecate `"go.opentelemetry.io/otel/sdk/metric".AtomicFieldOffsets`. (#2445)
1588
1589### Fixed
1590
1591- Fixed the instrument kind for noop async instruments to correctly report an implementation. (#2461)
1592- Fix UDP packets overflowing with Jaeger payloads. (#2489, #2512)
1593- Change the `otlpmetric.Client` interface's `UploadMetrics` method to accept a single `ResourceMetrics` instead of a slice of them. (#2491)
1594- Specify explicit buckets in Prometheus example, fixing issue where example only has `+inf` bucket. (#2419, #2493)
1595- W3C baggage will now decode urlescaped values. (#2529)
1596- Baggage members are now only validated once, when calling `NewMember` and not also when adding it to the baggage itself. (#2522)
1597- The order attributes are dropped from spans in the `go.opentelemetry.io/otel/sdk/trace` package when capacity is reached is fixed to be in compliance with the OpenTelemetry specification.
1598  Instead of dropping the least-recently-used attribute, the last added attribute is dropped.
1599  This drop order still only applies to attributes with unique keys not already contained in the span.
1600  If an attribute is added with a key already contained in the span, that attribute is updated to the new value being added. (#2576)
1601
1602### Removed
1603
1604- Updated `go.opentelemetry.io/proto/otlp` from `v0.11.0` to `v0.12.0`. This version removes a number of deprecated methods. (#2546)
1605  - [`Metric.GetIntGauge()`](https://pkg.go.dev/go.opentelemetry.io/proto/otlp@v0.11.0/metrics/v1#Metric.GetIntGauge)
1606  - [`Metric.GetIntHistogram()`](https://pkg.go.dev/go.opentelemetry.io/proto/otlp@v0.11.0/metrics/v1#Metric.GetIntHistogram)
1607  - [`Metric.GetIntSum()`](https://pkg.go.dev/go.opentelemetry.io/proto/otlp@v0.11.0/metrics/v1#Metric.GetIntSum)
1608
1609## [1.3.0] - 2021-12-10
1610
1611### ⚠️ Notice ⚠️
1612
1613We have updated the project minimum supported Go version to 1.16
1614
1615### Added
1616
1617- Added an internal Logger.
1618  This can be used by the SDK and API to provide users with feedback of the internal state.
1619  To enable verbose logs configure the logger which will print V(1) logs. For debugging information configure to print V(5) logs. (#2343)
1620- Add the `WithRetry` `Option` and the `RetryConfig` type to the `go.opentelemetry.io/otel/exporter/otel/otlpmetric/otlpmetrichttp` package to specify retry behavior consistently. (#2425)
1621- Add `SpanStatusFromHTTPStatusCodeAndSpanKind` to all `semconv` packages to return a span status code similar to `SpanStatusFromHTTPStatusCode`, but exclude `4XX` HTTP errors as span errors if the span is of server kind. (#2296)
1622
1623### Changed
1624
1625- The `"go.opentelemetry.io/otel/exporter/otel/otlptrace/otlptracegrpc".Client` now uses the underlying gRPC `ClientConn` to handle name resolution, TCP connection establishment (with retries and backoff) and TLS handshakes, and handling errors on established connections by re-resolving the name and reconnecting. (#2329)
1626- The `"go.opentelemetry.io/otel/exporter/otel/otlpmetric/otlpmetricgrpc".Client` now uses the underlying gRPC `ClientConn` to handle name resolution, TCP connection establishment (with retries and backoff) and TLS handshakes, and handling errors on established connections by re-resolving the name and reconnecting. (#2425)
1627- The `"go.opentelemetry.io/otel/exporter/otel/otlpmetric/otlpmetricgrpc".RetrySettings` type is renamed to `RetryConfig`. (#2425)
1628- The `go.opentelemetry.io/otel/exporter/otel/*` gRPC exporters now default to using the host's root CA set if none are provided by the user and `WithInsecure` is not specified. (#2432)
1629- Change `resource.Default` to be evaluated the first time it is called, rather than on import. This allows the caller the option to update `OTEL_RESOURCE_ATTRIBUTES` first, such as with `os.Setenv`. (#2371)
1630
1631### Fixed
1632
1633- The `go.opentelemetry.io/otel/exporter/otel/*` exporters are updated to handle per-signal and universal endpoints according to the OpenTelemetry specification.
1634  Any per-signal endpoint set via an `OTEL_EXPORTER_OTLP_<signal>_ENDPOINT` environment variable is now used without modification of the path.
1635  When `OTEL_EXPORTER_OTLP_ENDPOINT` is set, if it contains a path, that path is used as a base path which per-signal paths are appended to. (#2433)
1636- Basic metric controller updated to use sync.Map to avoid blocking calls (#2381)
1637- The `go.opentelemetry.io/otel/exporter/jaeger` correctly sets the `otel.status_code` value to be a string of `ERROR` or `OK` instead of an integer code. (#2439, #2440)
1638
1639### Deprecated
1640
1641- Deprecated the `"go.opentelemetry.io/otel/exporter/otel/otlpmetric/otlpmetrichttp".WithMaxAttempts` `Option`, use the new `WithRetry` `Option` instead. (#2425)
1642- Deprecated the `"go.opentelemetry.io/otel/exporter/otel/otlpmetric/otlpmetrichttp".WithBackoff` `Option`, use the new `WithRetry` `Option` instead. (#2425)
1643
1644### Removed
1645
1646- Remove the metric Processor's ability to convert cumulative to delta aggregation temporality. (#2350)
1647- Remove the metric Bound Instruments interface and implementations. (#2399)
1648- Remove the metric MinMaxSumCount kind aggregation and the corresponding OTLP export path. (#2423)
1649- Metric SDK removes the "exact" aggregator for histogram instruments, as it performed a non-standard aggregation for OTLP export (creating repeated Gauge points) and worked its way into a number of confusing examples. (#2348)
1650
1651## [1.2.0] - 2021-11-12
1652
1653### Changed
1654
1655- Metric SDK `export.ExportKind`, `export.ExportKindSelector` types have been renamed to `aggregation.Temporality` and `aggregation.TemporalitySelector` respectively to keep in line with current specification and protocol along with built-in selectors (e.g., `aggregation.CumulativeTemporalitySelector`, ...). (#2274)
1656- The Metric `Exporter` interface now requires a `TemporalitySelector` method instead of an `ExportKindSelector`. (#2274)
1657- Metrics API cleanup. The `metric/sdkapi` package has been created to relocate the API-to-SDK interface:
1658  - The following interface types simply moved from `metric` to `metric/sdkapi`: `Descriptor`, `MeterImpl`, `InstrumentImpl`, `SyncImpl`, `BoundSyncImpl`, `AsyncImpl`, `AsyncRunner`, `AsyncSingleRunner`, and `AsyncBatchRunner`
1659  - The following struct types moved and are replaced with type aliases, since they are exposed to the user: `Observation`, `Measurement`.
1660  - The No-op implementations of sync and async instruments are no longer exported, new functions `sdkapi.NewNoopAsyncInstrument()` and `sdkapi.NewNoopSyncInstrument()` are provided instead. (#2271)
1661- Update the SDK `BatchSpanProcessor` to export all queued spans when `ForceFlush` is called. (#2080, #2335)
1662
1663### Added
1664
1665- Add the `"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc".WithGRPCConn` option so the exporter can reuse an existing gRPC connection. (#2002)
1666- Added a new `schema` module to help parse Schema Files in OTEP 0152 format. (#2267)
1667- Added a new `MapCarrier` to the `go.opentelemetry.io/otel/propagation` package to hold propagated cross-cutting concerns as a `map[string]string` held in memory. (#2334)
1668
1669## [1.1.0] - 2021-10-27
1670
1671### Added
1672
1673- Add the `"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc".WithGRPCConn` option so the exporter can reuse an existing gRPC connection. (#2002)
1674- Add the `go.opentelemetry.io/otel/semconv/v1.7.0` package.
1675  The package contains semantic conventions from the `v1.7.0` version of the OpenTelemetry specification. (#2320)
1676- Add the `go.opentelemetry.io/otel/semconv/v1.6.1` package.
1677  The package contains semantic conventions from the `v1.6.1` version of the OpenTelemetry specification. (#2321)
1678- Add the `go.opentelemetry.io/otel/semconv/v1.5.0` package.
1679  The package contains semantic conventions from the `v1.5.0` version of the OpenTelemetry specification. (#2322)
1680  - When upgrading from the `semconv/v1.4.0` package note the following name changes:
1681    - `K8SReplicasetUIDKey` -> `K8SReplicaSetUIDKey`
1682    - `K8SReplicasetNameKey` -> `K8SReplicaSetNameKey`
1683    - `K8SStatefulsetUIDKey` -> `K8SStatefulSetUIDKey`
1684    - `k8SStatefulsetNameKey` -> `K8SStatefulSetNameKey`
1685    - `K8SDaemonsetUIDKey` -> `K8SDaemonSetUIDKey`
1686    - `K8SDaemonsetNameKey` -> `K8SDaemonSetNameKey`
1687
1688### Changed
1689
1690- Links added to a span will be dropped by the SDK if they contain an invalid span context (#2275).
1691
1692### Fixed
1693
1694- The `"go.opentelemetry.io/otel/semconv/v1.4.0".HTTPServerAttributesFromHTTPRequest` now correctly only sets the HTTP client IP attribute even if the connection was routed with proxies and there are multiple addresses in the `X-Forwarded-For` header. (#2282, #2284)
1695- The `"go.opentelemetry.io/otel/semconv/v1.4.0".NetAttributesFromHTTPRequest` function correctly handles IPv6 addresses as IP addresses and sets the correct net peer IP instead of the net peer hostname attribute. (#2283, #2285)
1696- The simple span processor shutdown method deterministically returns the exporter error status if it simultaneously finishes when the deadline is reached. (#2290, #2289)
1697
1698## [1.0.1] - 2021-10-01
1699
1700### Fixed
1701
1702- json stdout exporter no longer crashes due to concurrency bug. (#2265)
1703
1704## [Metrics 0.24.0] - 2021-10-01
1705
1706### Changed
1707
1708- NoopMeterProvider is now private and NewNoopMeterProvider must be used to obtain a noopMeterProvider. (#2237)
1709- The Metric SDK `Export()` function takes a new two-level reader interface for iterating over results one instrumentation library at a time. (#2197)
1710  - The former `"go.opentelemetry.io/otel/sdk/export/metric".CheckpointSet` is renamed `Reader`.
1711  - The new interface is named `"go.opentelemetry.io/otel/sdk/export/metric".InstrumentationLibraryReader`.
1712
1713## [1.0.0] - 2021-09-20
1714
1715This is the first stable release for the project.
1716This release includes an API and SDK for the tracing signal that will comply with the stability guarantees defined by the projects [versioning policy](./VERSIONING.md).
1717
1718### Added
1719
1720- OTLP trace exporter now sets the `SchemaURL` field in the exported telemetry if the Tracer has `WithSchemaURL` option. (#2242)
1721
1722### Fixed
1723
1724- Slice-valued attributes can correctly be used as map keys. (#2223)
1725
1726### Removed
1727
1728- Removed the `"go.opentelemetry.io/otel/exporters/zipkin".WithSDKOptions` function. (#2248)
1729- Removed the deprecated package `go.opentelemetry.io/otel/oteltest`. (#2234)
1730- Removed the deprecated package `go.opentelemetry.io/otel/bridge/opencensus/utils`. (#2233)
1731- Removed deprecated functions, types, and methods from `go.opentelemetry.io/otel/attribute` package.
1732  Use the typed functions and methods added to the package instead. (#2235)
1733  - The `Key.Array` method is removed.
1734  - The `Array` function is removed.
1735  - The `Any` function is removed.
1736  - The `ArrayValue` function is removed.
1737  - The `AsArray` function is removed.
1738
1739## [1.0.0-RC3] - 2021-09-02
1740
1741### Added
1742
1743- Added `ErrorHandlerFunc` to use a function as an `"go.opentelemetry.io/otel".ErrorHandler`. (#2149)
1744- Added `"go.opentelemetry.io/otel/trace".WithStackTrace` option to add a stack trace when using `span.RecordError` or when panic is handled in `span.End`. (#2163)
1745- Added typed slice attribute types and functionality to the `go.opentelemetry.io/otel/attribute` package to replace the existing array type and functions. (#2162)
1746  - `BoolSlice`, `IntSlice`, `Int64Slice`, `Float64Slice`, and `StringSlice` replace the use of the `Array` function in the package.
1747- Added the `go.opentelemetry.io/otel/example/fib` example package.
1748  Included is an example application that computes Fibonacci numbers. (#2203)
1749
1750### Changed
1751
1752- Metric instruments have been renamed to match the (feature-frozen) metric API specification:
1753  - ValueRecorder becomes Histogram
1754  - ValueObserver becomes Gauge
1755  - SumObserver becomes CounterObserver
1756  - UpDownSumObserver becomes UpDownCounterObserver
1757  The API exported from this project is still considered experimental. (#2202)
1758- Metric SDK/API implementation type `InstrumentKind` moves into `sdkapi` sub-package. (#2091)
1759- The Metrics SDK export record no longer contains a Resource pointer, the SDK `"go.opentelemetry.io/otel/sdk/trace/export/metric".Exporter.Export()` function for push-based exporters now takes a single Resource argument, pull-based exporters use `"go.opentelemetry.io/otel/sdk/metric/controller/basic".Controller.Resource()`. (#2120)
1760- The JSON output of the `go.opentelemetry.io/otel/exporters/stdout/stdouttrace` is harmonized now such that the output is "plain" JSON objects after each other of the form `{ ... } { ... } { ... }`. Earlier the JSON objects describing a span were wrapped in a slice for each `Exporter.ExportSpans` call, like `[ { ... } ][ { ... } { ... } ]`. Outputting JSON object directly after each other is consistent with JSON loggers, and a bit easier to parse and read. (#2196)
1761- Update the `NewTracerConfig`, `NewSpanStartConfig`, `NewSpanEndConfig`, and `NewEventConfig` function in the `go.opentelemetry.io/otel/trace` package to return their respective configurations as structs instead of pointers to the struct. (#2212)
1762
1763### Deprecated
1764
1765- The `go.opentelemetry.io/otel/bridge/opencensus/utils` package is deprecated.
1766  All functionality from this package now exists in the `go.opentelemetry.io/otel/bridge/opencensus` package.
1767  The functions from that package should be used instead. (#2166)
1768- The `"go.opentelemetry.io/otel/attribute".Array` function and the related `ARRAY` value type is deprecated.
1769  Use the typed `*Slice` functions and types added to the package instead. (#2162)
1770- The `"go.opentelemetry.io/otel/attribute".Any` function is deprecated.
1771  Use the typed functions instead. (#2181)
1772- The `go.opentelemetry.io/otel/oteltest` package is deprecated.
1773  The `"go.opentelemetry.io/otel/sdk/trace/tracetest".SpanRecorder` can be registered with the default SDK (`go.opentelemetry.io/otel/sdk/trace`) as a `SpanProcessor` and used as a replacement for this deprecated package. (#2188)
1774
1775### Removed
1776
1777- Removed metrics test package `go.opentelemetry.io/otel/sdk/export/metric/metrictest`. (#2105)
1778
1779### Fixed
1780
1781- The `fromEnv` detector no longer throws an error when `OTEL_RESOURCE_ATTRIBUTES` environment variable is not set or empty. (#2138)
1782- Setting the global `ErrorHandler` with `"go.opentelemetry.io/otel".SetErrorHandler` multiple times is now supported. (#2160, #2140)
1783- The `"go.opentelemetry.io/otel/attribute".Any` function now supports `int32` values. (#2169)
1784- Multiple calls to `"go.opentelemetry.io/otel/sdk/metric/controller/basic".WithResource()` are handled correctly, and when no resources are provided `"go.opentelemetry.io/otel/sdk/resource".Default()` is used. (#2120)
1785- The `WithoutTimestamps` option for the `go.opentelemetry.io/otel/exporters/stdout/stdouttrace` exporter causes the exporter to correctly omit timestamps. (#2195)
1786- Fixed typos in resources.go. (#2201)
1787
1788## [1.0.0-RC2] - 2021-07-26
1789
1790### Added
1791
1792- Added `WithOSDescription` resource configuration option to set OS (Operating System) description resource attribute (`os.description`). (#1840)
1793- Added `WithOS` resource configuration option to set all OS (Operating System) resource attributes at once. (#1840)
1794- Added the `WithRetry` option to the `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp` package.
1795  This option is a replacement for the removed `WithMaxAttempts` and `WithBackoff` options. (#2095)
1796- Added API `LinkFromContext` to return Link which encapsulates SpanContext from provided context and also encapsulates attributes. (#2115)
1797- Added a new `Link` type under the SDK `otel/sdk/trace` package that counts the number of attributes that were dropped for surpassing the `AttributePerLinkCountLimit` configured in the Span's `SpanLimits`.
1798  This new type replaces the equal-named API `Link` type found in the `otel/trace` package for most usages within the SDK.
1799  For example, instances of this type are now returned by the `Links()` function of `ReadOnlySpan`s provided in places like the `OnEnd` function of `SpanProcessor` implementations. (#2118)
1800- Added the `SpanRecorder` type to the `go.opentelemetry.io/otel/skd/trace/tracetest` package.
1801  This type can be used with the default SDK as a `SpanProcessor` during testing. (#2132)
1802
1803### Changed
1804
1805- The `SpanModels` function is now exported from the `go.opentelemetry.io/otel/exporters/zipkin` package to convert OpenTelemetry spans into Zipkin model spans. (#2027)
1806- Rename the `"go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc".RetrySettings` to `RetryConfig`. (#2095)
1807
1808### Deprecated
1809
1810- The `TextMapCarrier` and `TextMapPropagator` from the `go.opentelemetry.io/otel/oteltest` package and their associated creation functions (`TextMapCarrier`, `NewTextMapPropagator`) are deprecated. (#2114)
1811- The `Harness` type from the `go.opentelemetry.io/otel/oteltest` package and its associated creation function, `NewHarness` are deprecated and will be removed in the next release. (#2123)
1812- The `TraceStateFromKeyValues` function from the `go.opentelemetry.io/otel/oteltest` package is deprecated.
1813  Use the `trace.ParseTraceState` function instead. (#2122)
1814
1815### Removed
1816
1817- Removed the deprecated package `go.opentelemetry.io/otel/exporters/trace/jaeger`. (#2020)
1818- Removed the deprecated package `go.opentelemetry.io/otel/exporters/trace/zipkin`. (#2020)
1819- Removed the `"go.opentelemetry.io/otel/sdk/resource".WithBuiltinDetectors` function.
1820  The explicit `With*` options for every built-in detector should be used instead. (#2026 #2097)
1821- Removed the `WithMaxAttempts` and `WithBackoff` options from the `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp` package.
1822  The retry logic of the package has been updated to match the `otlptracegrpc` package and accordingly a `WithRetry` option is added that should be used instead. (#2095)
1823- Removed `DroppedAttributeCount` field from `otel/trace.Link` struct. (#2118)
1824
1825### Fixed
1826
1827- When using WithNewRoot, don't use the parent context for making sampling decisions. (#2032)
1828- `oteltest.Tracer` now creates a valid `SpanContext` when using `WithNewRoot`. (#2073)
1829- OS type detector now sets the correct `dragonflybsd` value for DragonFly BSD. (#2092)
1830- The OTel span status is correctly transformed into the OTLP status in the `go.opentelemetry.io/otel/exporters/otlp/otlptrace` package.
1831  This fix will by default set the status to `Unset` if it is not explicitly set to `Ok` or `Error`. (#2099 #2102)
1832- The `Inject` method for the `"go.opentelemetry.io/otel/propagation".TraceContext` type no longer injects empty `tracestate` values. (#2108)
1833- Use `6831` as default Jaeger agent port instead of `6832`. (#2131)
1834
1835## [Experimental Metrics v0.22.0] - 2021-07-19
1836
1837### Added
1838
1839- Adds HTTP support for OTLP metrics exporter. (#2022)
1840
1841### Removed
1842
1843- Removed the deprecated package `go.opentelemetry.io/otel/exporters/metric/prometheus`. (#2020)
1844
1845## [1.0.0-RC1] / 0.21.0 - 2021-06-18
1846
1847With this release we are introducing a split in module versions.  The tracing API and SDK are entering the `v1.0.0` Release Candidate phase with `v1.0.0-RC1`
1848while the experimental metrics API and SDK continue with `v0.x` releases at `v0.21.0`.  Modules at major version 1 or greater will not depend on modules
1849with major version 0.
1850
1851### Added
1852
1853- Adds `otlpgrpc.WithRetry`option for configuring the retry policy for transient errors on the otlp/gRPC exporter. (#1832)
1854  - The following status codes are defined as transient errors:
1855      | gRPC Status Code | Description |
1856      | ---------------- | ----------- |
1857      | 1  | Cancelled |
1858      | 4  | Deadline Exceeded |
1859      | 8  | Resource Exhausted |
1860      | 10 | Aborted |
1861      | 10 | Out of Range |
1862      | 14 | Unavailable |
1863      | 15 | Data Loss |
1864- Added `Status` type to the `go.opentelemetry.io/otel/sdk/trace` package to represent the status of a span. (#1874)
1865- Added `SpanStub` type and its associated functions to the `go.opentelemetry.io/otel/sdk/trace/tracetest` package.
1866  This type can be used as a testing replacement for the `SpanSnapshot` that was removed from the `go.opentelemetry.io/otel/sdk/trace` package. (#1873)
1867- Adds support for scheme in `OTEL_EXPORTER_OTLP_ENDPOINT` according to the spec. (#1886)
1868- Adds `trace.WithSchemaURL` option for configuring the tracer with a Schema URL. (#1889)
1869- Added an example of using OpenTelemetry Go as a trace context forwarder. (#1912)
1870- `ParseTraceState` is added to the `go.opentelemetry.io/otel/trace` package.
1871  It can be used to decode a `TraceState` from a `tracestate` header string value. (#1937)
1872- Added `Len` method to the `TraceState` type in the `go.opentelemetry.io/otel/trace` package.
1873  This method returns the number of list-members the `TraceState` holds. (#1937)
1874- Creates package `go.opentelemetry.io/otel/exporters/otlp/otlptrace` that defines a trace exporter that uses a `otlptrace.Client` to send data.
1875  Creates package `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc` implementing a gRPC `otlptrace.Client` and offers convenience functions, `NewExportPipeline` and `InstallNewPipeline`, to setup and install a `otlptrace.Exporter` in tracing .(#1922)
1876- Added `Baggage`, `Member`, and `Property` types to the `go.opentelemetry.io/otel/baggage` package along with their related functions. (#1967)
1877- Added `ContextWithBaggage`, `ContextWithoutBaggage`, and `FromContext` functions to the `go.opentelemetry.io/otel/baggage` package.
1878  These functions replace the `Set`, `Value`, `ContextWithValue`, `ContextWithoutValue`, and `ContextWithEmpty` functions from that package and directly work with the new `Baggage` type. (#1967)
1879- The `OTEL_SERVICE_NAME` environment variable is the preferred source for `service.name`, used by the environment resource detector if a service name is present both there and in `OTEL_RESOURCE_ATTRIBUTES`. (#1969)
1880- Creates package `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp` implementing an HTTP `otlptrace.Client` and offers convenience functions, `NewExportPipeline` and `InstallNewPipeline`, to setup and install a `otlptrace.Exporter` in tracing. (#1963)
1881- Changes `go.opentelemetry.io/otel/sdk/resource.NewWithAttributes` to require a schema URL. The old function is still available as `resource.NewSchemaless`. This is a breaking change. (#1938)
1882- Several builtin resource detectors now correctly populate the schema URL. (#1938)
1883- Creates package `go.opentelemetry.io/otel/exporters/otlp/otlpmetric` that defines a metrics exporter that uses a `otlpmetric.Client` to send data.
1884- Creates package `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` implementing a gRPC `otlpmetric.Client` and offers convenience functions, `New` and `NewUnstarted`, to create an `otlpmetric.Exporter`.(#1991)
1885- Added `go.opentelemetry.io/otel/exporters/stdout/stdouttrace` exporter. (#2005)
1886- Added `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` exporter. (#2005)
1887- Added a `TracerProvider()` method to the `"go.opentelemetry.io/otel/trace".Span` interface. This can be used to obtain a `TracerProvider` from a given span that utilizes the same trace processing pipeline.  (#2009)
1888
1889### Changed
1890
1891- Make `NewSplitDriver` from `go.opentelemetry.io/otel/exporters/otlp` take variadic arguments instead of a `SplitConfig` item.
1892  `NewSplitDriver` now automatically implements an internal `noopDriver` for `SplitConfig` fields that are not initialized. (#1798)
1893- `resource.New()` now creates a Resource without builtin detectors. Previous behavior is now achieved by using `WithBuiltinDetectors` Option. (#1810)
1894- Move the `Event` type from the `go.opentelemetry.io/otel` package to the `go.opentelemetry.io/otel/sdk/trace` package. (#1846)
1895- CI builds validate against last two versions of Go, dropping 1.14 and adding 1.16. (#1865)
1896- BatchSpanProcessor now report export failures when calling `ForceFlush()` method. (#1860)
1897- `Set.Encoded(Encoder)` no longer caches the result of an encoding. (#1855)
1898- Renamed `CloudZoneKey` to `CloudAvailabilityZoneKey` in Resource semantic conventions according to spec. (#1871)
1899- The `StatusCode` and `StatusMessage` methods of the `ReadOnlySpan` interface and the `Span` produced by the `go.opentelemetry.io/otel/sdk/trace` package have been replaced with a single `Status` method.
1900  This method returns the status of a span using the new `Status` type. (#1874)
1901- Updated `ExportSpans` method of the`SpanExporter` interface type to accept `ReadOnlySpan`s instead of the removed `SpanSnapshot`.
1902  This brings the export interface into compliance with the specification in that it now accepts an explicitly immutable type instead of just an implied one. (#1873)
1903- Unembed `SpanContext` in `Link`. (#1877)
1904- Generate Semantic conventions from the specification YAML. (#1891)
1905- Spans created by the global `Tracer` obtained from `go.opentelemetry.io/otel`, prior to a functioning `TracerProvider` being set, now propagate the span context from their parent if one exists. (#1901)
1906- The `"go.opentelemetry.io/otel".Tracer` function now accepts tracer options. (#1902)
1907- Move the `go.opentelemetry.io/otel/unit` package to `go.opentelemetry.io/otel/metric/unit`. (#1903)
1908- Changed `go.opentelemetry.io/otel/trace.TracerConfig` to conform to the [Contributing guidelines](CONTRIBUTING.md#config.) (#1921)
1909- Changed `go.opentelemetry.io/otel/trace.SpanConfig` to conform to the [Contributing guidelines](CONTRIBUTING.md#config). (#1921)
1910- Changed `span.End()` now only accepts Options that are allowed at `End()`. (#1921)
1911- Changed `go.opentelemetry.io/otel/metric.InstrumentConfig` to conform to the [Contributing guidelines](CONTRIBUTING.md#config). (#1921)
1912- Changed `go.opentelemetry.io/otel/metric.MeterConfig` to conform to the [Contributing guidelines](CONTRIBUTING.md#config). (#1921)
1913- Refactored option types according to the contribution style guide. (#1882)
1914- Move the `go.opentelemetry.io/otel/trace.TraceStateFromKeyValues` function to the `go.opentelemetry.io/otel/oteltest` package.
1915  This function is preserved for testing purposes where it may be useful to create a `TraceState` from `attribute.KeyValue`s, but it is not intended for production use.
1916  The new `ParseTraceState` function should be used to create a `TraceState`. (#1931)
1917- Updated `MarshalJSON` method of the `go.opentelemetry.io/otel/trace.TraceState` type to marshal the type into the string representation of the `TraceState`. (#1931)
1918- The `TraceState.Delete` method from the `go.opentelemetry.io/otel/trace` package no longer returns an error in addition to a `TraceState`. (#1931)
1919- Updated `Get` method of the `TraceState` type from the `go.opentelemetry.io/otel/trace` package to accept a `string` instead of an `attribute.Key` type. (#1931)
1920- Updated `Insert` method of the `TraceState` type from the `go.opentelemetry.io/otel/trace` package to accept a pair of `string`s instead of an `attribute.KeyValue` type. (#1931)
1921- Updated `Delete` method of the `TraceState` type from the `go.opentelemetry.io/otel/trace` package to accept a `string` instead of an `attribute.Key` type. (#1931)
1922- Renamed `NewExporter` to `New` in the `go.opentelemetry.io/otel/exporters/stdout` package. (#1985)
1923- Renamed `NewExporter` to `New` in the `go.opentelemetry.io/otel/exporters/metric/prometheus` package. (#1985)
1924- Renamed `NewExporter` to `New` in the `go.opentelemetry.io/otel/exporters/trace/jaeger` package. (#1985)
1925- Renamed `NewExporter` to `New` in the `go.opentelemetry.io/otel/exporters/trace/zipkin` package. (#1985)
1926- Renamed `NewExporter` to `New` in the `go.opentelemetry.io/otel/exporters/otlp` package. (#1985)
1927- Renamed `NewUnstartedExporter` to `NewUnstarted` in the `go.opentelemetry.io/otel/exporters/otlp` package. (#1985)
1928- The `go.opentelemetry.io/otel/semconv` package has been moved to `go.opentelemetry.io/otel/semconv/v1.4.0` to allow for multiple [telemetry schema](https://github.com/open-telemetry/oteps/blob/main/text/0152-telemetry-schemas.md) versions to be used concurrently. (#1987)
1929- Metrics test helpers in `go.opentelemetry.io/otel/oteltest` have been moved to `go.opentelemetry.io/otel/metric/metrictest`. (#1988)
1930
1931### Deprecated
1932
1933- The `go.opentelemetry.io/otel/exporters/metric/prometheus` is deprecated, use `go.opentelemetry.io/otel/exporters/prometheus` instead. (#1993)
1934- The `go.opentelemetry.io/otel/exporters/trace/jaeger` is deprecated, use `go.opentelemetry.io/otel/exporters/jaeger` instead. (#1993)
1935- The `go.opentelemetry.io/otel/exporters/trace/zipkin` is deprecated, use `go.opentelemetry.io/otel/exporters/zipkin` instead. (#1993)
1936
1937### Removed
1938
1939- Removed `resource.WithoutBuiltin()`. Use `resource.New()`. (#1810)
1940- Unexported types `resource.FromEnv`, `resource.Host`, and `resource.TelemetrySDK`, Use the corresponding `With*()` to use individually. (#1810)
1941- Removed the `Tracer` and `IsRecording` method from the `ReadOnlySpan` in the `go.opentelemetry.io/otel/sdk/trace`.
1942  The `Tracer` method is not a required to be included in this interface and given the mutable nature of the tracer that is associated with a span, this method is not appropriate.
1943  The `IsRecording` method returns if the span is recording or not.
1944  A read-only span value does not need to know if updates to it will be recorded or not.
1945  By definition, it cannot be updated so there is no point in communicating if an update is recorded. (#1873)
1946- Removed the `SpanSnapshot` type from the `go.opentelemetry.io/otel/sdk/trace` package.
1947  The use of this type has been replaced with the use of the explicitly immutable `ReadOnlySpan` type.
1948  When a concrete representation of a read-only span is needed for testing, the newly added `SpanStub` in the `go.opentelemetry.io/otel/sdk/trace/tracetest` package should be used. (#1873)
1949- Removed the `Tracer` method from the `Span` interface in the `go.opentelemetry.io/otel/trace` package.
1950  Using the same tracer that created a span introduces the error where an instrumentation library's `Tracer` is used by other code instead of their own.
1951  The `"go.opentelemetry.io/otel".Tracer` function or a `TracerProvider` should be used to acquire a library specific `Tracer` instead. (#1900)
1952  - The `TracerProvider()` method on the `Span` interface may also be used to obtain a `TracerProvider` using the same trace processing pipeline. (#2009)
1953- The `http.url` attribute generated by `HTTPClientAttributesFromHTTPRequest` will no longer include username or password information. (#1919)
1954- Removed `IsEmpty` method of the `TraceState` type in the `go.opentelemetry.io/otel/trace` package in favor of using the added `TraceState.Len` method. (#1931)
1955- Removed `Set`, `Value`, `ContextWithValue`, `ContextWithoutValue`, and `ContextWithEmpty` functions in the `go.opentelemetry.io/otel/baggage` package.
1956  Handling of baggage is now done using the added `Baggage` type and related context functions (`ContextWithBaggage`, `ContextWithoutBaggage`, and `FromContext`) in that package. (#1967)
1957- The `InstallNewPipeline` and `NewExportPipeline` creation functions in all the exporters (prometheus, otlp, stdout, jaeger, and zipkin) have been removed.
1958  These functions were deemed premature attempts to provide convenience that did not achieve this aim. (#1985)
1959- The `go.opentelemetry.io/otel/exporters/otlp` exporter has been removed.  Use `go.opentelemetry.io/otel/exporters/otlp/otlptrace` instead. (#1990)
1960- The `go.opentelemetry.io/otel/exporters/stdout` exporter has been removed.  Use `go.opentelemetry.io/otel/exporters/stdout/stdouttrace` or `go.opentelemetry.io/otel/exporters/stdout/stdoutmetric` instead. (#2005)
1961
1962### Fixed
1963
1964- Only report errors from the `"go.opentelemetry.io/otel/sdk/resource".Environment` function when they are not `nil`. (#1850, #1851)
1965- The `Shutdown` method of the simple `SpanProcessor` in the `go.opentelemetry.io/otel/sdk/trace` package now honors the context deadline or cancellation. (#1616, #1856)
1966- BatchSpanProcessor now drops span batches that failed to be exported. (#1860)
1967- Use `http://localhost:14268/api/traces` as default Jaeger collector endpoint instead of `http://localhost:14250`. (#1898)
1968- Allow trailing and leading whitespace in the parsing of a `tracestate` header. (#1931)
1969- Add logic to determine if the channel is closed to fix Jaeger exporter test panic with close closed channel. (#1870, #1973)
1970- Avoid transport security when OTLP endpoint is a Unix socket. (#2001)
1971
1972### Security
1973
1974## [0.20.0] - 2021-04-23
1975
1976### Added
1977
1978- The OTLP exporter now has two new convenience functions, `NewExportPipeline` and `InstallNewPipeline`, setup and install the exporter in tracing and metrics pipelines. (#1373)
1979- Adds semantic conventions for exceptions. (#1492)
1980- Added Jaeger Environment variables: `OTEL_EXPORTER_JAEGER_AGENT_HOST`, `OTEL_EXPORTER_JAEGER_AGENT_PORT`
1981  These environment variables can be used to override Jaeger agent hostname and port (#1752)
1982- Option `ExportTimeout` was added to batch span processor. (#1755)
1983- `trace.TraceFlags` is now a defined type over `byte` and `WithSampled(bool) TraceFlags` and `IsSampled() bool` methods have been added to it. (#1770)
1984- The `Event` and `Link` struct types from the `go.opentelemetry.io/otel` package now include a `DroppedAttributeCount` field to record the number of attributes that were not recorded due to configured limits being reached. (#1771)
1985- The Jaeger exporter now reports dropped attributes for a Span event in the exported log. (#1771)
1986- Adds test to check BatchSpanProcessor ignores `OnEnd` and `ForceFlush` post `Shutdown`. (#1772)
1987- Extract resource attributes from the `OTEL_RESOURCE_ATTRIBUTES` environment variable and merge them with the `resource.Default` resource as well as resources provided to the `TracerProvider` and metric `Controller`. (#1785)
1988- Added `WithOSType` resource configuration option to set OS (Operating System) type resource attribute (`os.type`). (#1788)
1989- Added `WithProcess*` resource configuration options to set Process resource attributes. (#1788)
1990  - `process.pid`
1991  - `process.executable.name`
1992  - `process.executable.path`
1993  - `process.command_args`
1994  - `process.owner`
1995  - `process.runtime.name`
1996  - `process.runtime.version`
1997  - `process.runtime.description`
1998- Adds `k8s.node.name` and `k8s.node.uid` attribute keys to the `semconv` package. (#1789)
1999- Added support for configuring OTLP/HTTP and OTLP/gRPC Endpoints, TLS Certificates, Headers, Compression and Timeout via Environment Variables. (#1758, #1769 and #1811)
2000  - `OTEL_EXPORTER_OTLP_ENDPOINT`
2001  - `OTEL_EXPORTER_OTLP_TRACES_ENDPOINT`
2002  - `OTEL_EXPORTER_OTLP_METRICS_ENDPOINT`
2003  - `OTEL_EXPORTER_OTLP_HEADERS`
2004  - `OTEL_EXPORTER_OTLP_TRACES_HEADERS`
2005  - `OTEL_EXPORTER_OTLP_METRICS_HEADERS`
2006  - `OTEL_EXPORTER_OTLP_COMPRESSION`
2007  - `OTEL_EXPORTER_OTLP_TRACES_COMPRESSION`
2008  - `OTEL_EXPORTER_OTLP_METRICS_COMPRESSION`
2009  - `OTEL_EXPORTER_OTLP_TIMEOUT`
2010  - `OTEL_EXPORTER_OTLP_TRACES_TIMEOUT`
2011  - `OTEL_EXPORTER_OTLP_METRICS_TIMEOUT`
2012  - `OTEL_EXPORTER_OTLP_CERTIFICATE`
2013  - `OTEL_EXPORTER_OTLP_TRACES_CERTIFICATE`
2014  - `OTEL_EXPORTER_OTLP_METRICS_CERTIFICATE`
2015- Adds `otlpgrpc.WithTimeout` option for configuring timeout to the otlp/gRPC exporter. (#1821)
2016- Adds `jaeger.WithMaxPacketSize` option for configuring maximum UDP packet size used when connecting to the Jaeger agent. (#1853)
2017
2018### Fixed
2019
2020- The `Span.IsRecording` implementation from `go.opentelemetry.io/otel/sdk/trace` always returns false when not being sampled. (#1750)
2021- The Jaeger exporter now correctly sets tags for the Span status code and message.
2022  This means it uses the correct tag keys (`"otel.status_code"`, `"otel.status_description"`) and does not set the status message as a tag unless it is set on the span. (#1761)
2023- The Jaeger exporter now correctly records Span event's names using the `"event"` key for a tag.
2024  Additionally, this tag is overridden, as specified in the OTel specification, if the event contains an attribute with that key. (#1768)
2025- Zipkin Exporter: Ensure mapping between OTel and Zipkin span data complies with the specification. (#1688)
2026- Fixed typo for default service name in Jaeger Exporter. (#1797)
2027- Fix flaky OTLP for the reconnnection of the client connection. (#1527, #1814)
2028- Fix Jaeger exporter dropping of span batches that exceed the UDP packet size limit.
2029  Instead, the exporter now splits the batch into smaller sendable batches. (#1828)
2030
2031### Changed
2032
2033- Span `RecordError` now records an `exception` event to comply with the semantic convention specification. (#1492)
2034- Jaeger exporter was updated to use thrift v0.14.1. (#1712)
2035- Migrate from using internally built and maintained version of the OTLP to the one hosted at `go.opentelemetry.io/proto/otlp`. (#1713)
2036- Migrate from using `github.com/gogo/protobuf` to `google.golang.org/protobuf` to match `go.opentelemetry.io/proto/otlp`. (#1713)
2037- The storage of a local or remote Span in a `context.Context` using its SpanContext is unified to store just the current Span.
2038  The Span's SpanContext can now self-identify as being remote or not.
2039  This means that `"go.opentelemetry.io/otel/trace".ContextWithRemoteSpanContext` will now overwrite any existing current Span, not just existing remote Spans, and make it the current Span in a `context.Context`. (#1731)
2040- Improve OTLP/gRPC exporter connection errors. (#1737)
2041- Information about a parent span context in a `"go.opentelemetry.io/otel/export/trace".SpanSnapshot` is unified in a new `Parent` field.
2042  The existing `ParentSpanID` and `HasRemoteParent` fields are removed in favor of this. (#1748)
2043- The `ParentContext` field of the `"go.opentelemetry.io/otel/sdk/trace".SamplingParameters` is updated to hold a `context.Context` containing the parent span.
2044  This changes it to make `SamplingParameters` conform with the OpenTelemetry specification. (#1749)
2045- Updated Jaeger Environment Variables: `JAEGER_ENDPOINT`, `JAEGER_USER`, `JAEGER_PASSWORD`
2046  to `OTEL_EXPORTER_JAEGER_ENDPOINT`, `OTEL_EXPORTER_JAEGER_USER`, `OTEL_EXPORTER_JAEGER_PASSWORD` in compliance with OTel specification. (#1752)
2047- Modify `BatchSpanProcessor.ForceFlush` to abort after timeout/cancellation. (#1757)
2048- The `DroppedAttributeCount` field of the `Span` in the `go.opentelemetry.io/otel` package now only represents the number of attributes dropped for the span itself.
2049  It no longer is a conglomerate of itself, events, and link attributes that have been dropped. (#1771)
2050- Make `ExportSpans` in Jaeger Exporter honor context deadline. (#1773)
2051- Modify Zipkin Exporter default service name, use default resource's serviceName instead of empty. (#1777)
2052- The `go.opentelemetry.io/otel/sdk/export/trace` package is merged into the `go.opentelemetry.io/otel/sdk/trace` package. (#1778)
2053- The prometheus.InstallNewPipeline example is moved from comment to example test (#1796)
2054- The convenience functions for the stdout exporter have been updated to return the `TracerProvider` implementation and enable the shutdown of the exporter. (#1800)
2055- Replace the flush function returned from the Jaeger exporter's convenience creation functions (`InstallNewPipeline` and `NewExportPipeline`) with the `TracerProvider` implementation they create.
2056  This enables the caller to shutdown and flush using the related `TracerProvider` methods. (#1822)
2057- Updated the Jaeger exporter to have a default endpoint, `http://localhost:14250`, for the collector. (#1824)
2058- Changed the function `WithCollectorEndpoint` in the Jaeger exporter to no longer accept an endpoint as an argument.
2059  The endpoint can be passed with the `CollectorEndpointOption` using the `WithEndpoint` function or by setting the `OTEL_EXPORTER_JAEGER_ENDPOINT` environment variable value appropriately. (#1824)
2060- The Jaeger exporter no longer batches exported spans itself, instead it relies on the SDK's `BatchSpanProcessor` for this functionality. (#1830)
2061- The Jaeger exporter creation functions (`NewRawExporter`, `NewExportPipeline`, and `InstallNewPipeline`) no longer accept the removed `Option` type as a variadic argument. (#1830)
2062
2063### Removed
2064
2065- Removed Jaeger Environment variables: `JAEGER_SERVICE_NAME`, `JAEGER_DISABLED`, `JAEGER_TAGS`
2066  These environment variables will no longer be used to override values of the Jaeger exporter (#1752)
2067- No longer set the links for a `Span` in `go.opentelemetry.io/otel/sdk/trace` that is configured to be a new root.
2068  This is unspecified behavior that the OpenTelemetry community plans to standardize in the future.
2069  To prevent backwards incompatible changes when it is specified, these links are removed. (#1726)
2070- Setting error status while recording error with Span from oteltest package. (#1729)
2071- The concept of a remote and local Span stored in a context is unified to just the current Span.
2072  Because of this `"go.opentelemetry.io/otel/trace".RemoteSpanContextFromContext` is removed as it is no longer needed.
2073  Instead, `"go.opentelemetry.io/otel/trace".SpanContextFromContext` can be used to return the current Span.
2074  If needed, that Span's `SpanContext.IsRemote()` can then be used to determine if it is remote or not. (#1731)
2075- The `HasRemoteParent` field of the `"go.opentelemetry.io/otel/sdk/trace".SamplingParameters` is removed.
2076  This field is redundant to the information returned from the `Remote` method of the `SpanContext` held in the `ParentContext` field. (#1749)
2077- The `trace.FlagsDebug` and `trace.FlagsDeferred` constants have been removed and will be localized to the B3 propagator. (#1770)
2078- Remove `Process` configuration, `WithProcessFromEnv` and `ProcessFromEnv`, and type from the Jaeger exporter package.
2079  The information that could be configured in the `Process` struct should be configured in a `Resource` instead. (#1776, #1804)
2080- Remove the `WithDisabled` option from the Jaeger exporter.
2081  To disable the exporter unregister it from the `TracerProvider` or use a no-operation `TracerProvider`. (#1806)
2082- Removed the functions `CollectorEndpointFromEnv` and `WithCollectorEndpointOptionFromEnv` from the Jaeger exporter.
2083  These functions for retrieving specific environment variable values are redundant of other internal functions and
2084  are not intended for end user use. (#1824)
2085- Removed the Jaeger exporter `WithSDKOptions` `Option`.
2086  This option was used to set SDK options for the exporter creation convenience functions.
2087  These functions are provided as a way to easily setup or install the exporter with what are deemed reasonable SDK settings for common use cases.
2088  If the SDK needs to be configured differently, the `NewRawExporter` function and direct setup of the SDK with the desired settings should be used. (#1825)
2089- The `WithBufferMaxCount` and `WithBatchMaxCount` `Option`s from the Jaeger exporter are removed.
2090  The exporter no longer batches exports, instead relying on the SDK's `BatchSpanProcessor` for this functionality. (#1830)
2091- The Jaeger exporter `Option` type is removed.
2092  The type is no longer used by the exporter to configure anything.
2093  All the previous configurations these options provided were duplicates of SDK configuration.
2094  They have been removed in favor of using the SDK configuration and focuses the exporter configuration to be only about the endpoints it will send telemetry to. (#1830)
2095
2096## [0.19.0] - 2021-03-18
2097
2098### Added
2099
2100- Added `Marshaler` config option to `otlphttp` to enable otlp over json or protobufs. (#1586)
2101- A `ForceFlush` method to the `"go.opentelemetry.io/otel/sdk/trace".TracerProvider` to flush all registered `SpanProcessor`s. (#1608)
2102- Added `WithSampler` and `WithSpanLimits` to tracer provider. (#1633, #1702)
2103- `"go.opentelemetry.io/otel/trace".SpanContext` now has a `remote` property, and `IsRemote()` predicate, that is true when the `SpanContext` has been extracted from remote context data. (#1701)
2104- A `Valid` method to the `"go.opentelemetry.io/otel/attribute".KeyValue` type. (#1703)
2105
2106### Changed
2107
2108- `trace.SpanContext` is now immutable and has no exported fields. (#1573)
2109  - `trace.NewSpanContext()` can be used in conjunction with the `trace.SpanContextConfig` struct to initialize a new `SpanContext` where all values are known.
2110- Update the `ForceFlush` method signature to the `"go.opentelemetry.io/otel/sdk/trace".SpanProcessor` to accept a `context.Context` and return an error. (#1608)
2111- Update the `Shutdown` method to the `"go.opentelemetry.io/otel/sdk/trace".TracerProvider` return an error on shutdown failure. (#1608)
2112- The SimpleSpanProcessor will now shut down the enclosed `SpanExporter` and gracefully ignore subsequent calls to `OnEnd` after `Shutdown` is called. (#1612)
2113- `"go.opentelemetry.io/sdk/metric/controller.basic".WithPusher` is replaced with `WithExporter` to provide consistent naming across project. (#1656)
2114- Added non-empty string check for trace `Attribute` keys. (#1659)
2115- Add `description` to SpanStatus only when `StatusCode` is set to error. (#1662)
2116- Jaeger exporter falls back to `resource.Default`'s `service.name` if the exported Span does not have one. (#1673)
2117- Jaeger exporter populates Jaeger's Span Process from Resource. (#1673)
2118- Renamed the `LabelSet` method of `"go.opentelemetry.io/otel/sdk/resource".Resource` to `Set`. (#1692)
2119- Changed `WithSDK` to `WithSDKOptions` to accept variadic arguments of `TracerProviderOption` type in `go.opentelemetry.io/otel/exporters/trace/jaeger` package. (#1693)
2120- Changed `WithSDK` to `WithSDKOptions` to accept variadic arguments of `TracerProviderOption` type in `go.opentelemetry.io/otel/exporters/trace/zipkin` package. (#1693)
2121
2122### Removed
2123
2124- Removed `serviceName` parameter from Zipkin exporter and uses resource instead. (#1549)
2125- Removed `WithConfig` from tracer provider to avoid overriding configuration. (#1633)
2126- Removed the exported `SimpleSpanProcessor` and `BatchSpanProcessor` structs.
2127   These are now returned as a SpanProcessor interface from their respective constructors. (#1638)
2128- Removed `WithRecord()` from `trace.SpanOption` when creating a span. (#1660)
2129- Removed setting status to `Error` while recording an error as a span event in `RecordError`. (#1663)
2130- Removed `jaeger.WithProcess` configuration option. (#1673)
2131- Removed `ApplyConfig` method from `"go.opentelemetry.io/otel/sdk/trace".TracerProvider` and the now unneeded `Config` struct. (#1693)
2132
2133### Fixed
2134
2135- Jaeger Exporter: Ensure mapping between OTEL and Jaeger span data complies with the specification. (#1626)
2136- `SamplingResult.TraceState` is correctly propagated to a newly created span's `SpanContext`. (#1655)
2137- The `otel-collector` example now correctly flushes metric events prior to shutting down the exporter. (#1678)
2138- Do not set span status message in `SpanStatusFromHTTPStatusCode` if it can be inferred from `http.status_code`. (#1681)
2139- Synchronization issues in global trace delegate implementation. (#1686)
2140- Reduced excess memory usage by global `TracerProvider`. (#1687)
2141
2142## [0.18.0] - 2021-03-03
2143
2144### Added
2145
2146- Added `resource.Default()` for use with meter and tracer providers. (#1507)
2147- `AttributePerEventCountLimit` and `AttributePerLinkCountLimit` for `SpanLimits`. (#1535)
2148- Added `Keys()` method to `propagation.TextMapCarrier` and `propagation.HeaderCarrier` to adapt `http.Header` to this interface. (#1544)
2149- Added `code` attributes to `go.opentelemetry.io/otel/semconv` package. (#1558)
2150- Compatibility testing suite in the CI system for the following systems. (#1567)
2151   | OS      | Go Version | Architecture |
2152   | ------- | ---------- | ------------ |
2153   | Ubuntu  | 1.15       | amd64        |
2154   | Ubuntu  | 1.14       | amd64        |
2155   | Ubuntu  | 1.15       | 386          |
2156   | Ubuntu  | 1.14       | 386          |
2157   | MacOS   | 1.15       | amd64        |
2158   | MacOS   | 1.14       | amd64        |
2159   | Windows | 1.15       | amd64        |
2160   | Windows | 1.14       | amd64        |
2161   | Windows | 1.15       | 386          |
2162   | Windows | 1.14       | 386          |
2163
2164### Changed
2165
2166- Replaced interface `oteltest.SpanRecorder` with its existing implementation
2167  `StandardSpanRecorder`. (#1542)
2168- Default span limit values to 128. (#1535)
2169- Rename `MaxEventsPerSpan`, `MaxAttributesPerSpan` and `MaxLinksPerSpan` to `EventCountLimit`, `AttributeCountLimit` and `LinkCountLimit`, and move these fields into `SpanLimits`. (#1535)
2170- Renamed the `otel/label` package to `otel/attribute`. (#1541)
2171- Vendor the Jaeger exporter's dependency on Apache Thrift. (#1551)
2172- Parallelize the CI linting and testing. (#1567)
2173- Stagger timestamps in exact aggregator tests. (#1569)
2174- Changed all examples to use `WithBatchTimeout(5 * time.Second)` rather than `WithBatchTimeout(5)`. (#1621)
2175- Prevent end-users from implementing some interfaces (#1575)
2176
2177  ```
2178      "otel/exporters/otlp/otlphttp".Option
2179      "otel/exporters/stdout".Option
2180      "otel/oteltest".Option
2181      "otel/trace".TracerOption
2182      "otel/trace".SpanOption
2183      "otel/trace".EventOption
2184      "otel/trace".LifeCycleOption
2185      "otel/trace".InstrumentationOption
2186      "otel/sdk/resource".Option
2187      "otel/sdk/trace".ParentBasedSamplerOption
2188      "otel/sdk/trace".ReadOnlySpan
2189      "otel/sdk/trace".ReadWriteSpan
2190  ```
2191
2192### Removed
2193
2194- Removed attempt to resample spans upon changing the span name with `span.SetName()`. (#1545)
2195- The `test-benchmark` is no longer a dependency of the `precommit` make target. (#1567)
2196- Removed the `test-386` make target.
2197   This was replaced with a full compatibility testing suite (i.e. multi OS/arch) in the CI system. (#1567)
2198
2199### Fixed
2200
2201- The sequential timing check of timestamps in the stdout exporter are now setup explicitly to be sequential (#1571). (#1572)
2202- Windows build of Jaeger tests now compiles with OS specific functions (#1576). (#1577)
2203- The sequential timing check of timestamps of go.opentelemetry.io/otel/sdk/metric/aggregator/lastvalue are now setup explicitly to be sequential (#1578). (#1579)
2204- Validate tracestate header keys with vendors according to the W3C TraceContext specification (#1475). (#1581)
2205- The OTLP exporter includes related labels for translations of a GaugeArray (#1563). (#1570)
2206
2207## [0.17.0] - 2021-02-12
2208
2209### Changed
2210
2211- Rename project default branch from `master` to `main`. (#1505)
2212- Reverse order in which `Resource` attributes are merged, per change in spec. (#1501)
2213- Add tooling to maintain "replace" directives in go.mod files automatically. (#1528)
2214- Create new modules: otel/metric, otel/trace, otel/oteltest, otel/sdk/export/metric, otel/sdk/metric (#1528)
2215- Move metric-related public global APIs from otel to otel/metric/global. (#1528)
2216
2217## Fixed
2218
2219- Fixed otlpgrpc reconnection issue.
2220- The example code in the README.md of `go.opentelemetry.io/otel/exporters/otlp` is moved to a compiled example test and used the new `WithAddress` instead of `WithEndpoint`. (#1513)
2221- The otel-collector example now uses the default OTLP receiver port of the collector.
2222
2223## [0.16.0] - 2021-01-13
2224
2225### Added
2226
2227- Add the `ReadOnlySpan` and `ReadWriteSpan` interfaces to provide better control for accessing span data. (#1360)
2228- `NewGRPCDriver` function returns a `ProtocolDriver` that maintains a single gRPC connection to the collector. (#1369)
2229- Added documentation about the project's versioning policy. (#1388)
2230- Added `NewSplitDriver` for OTLP exporter that allows sending traces and metrics to different endpoints. (#1418)
2231- Added codeql workflow to GitHub Actions (#1428)
2232- Added Gosec workflow to GitHub Actions (#1429)
2233- Add new HTTP driver for OTLP exporter in `exporters/otlp/otlphttp`. Currently it only supports the binary protobuf payloads. (#1420)
2234- Add an OpenCensus exporter bridge. (#1444)
2235
2236### Changed
2237
2238- Rename `internal/testing` to `internal/internaltest`. (#1449)
2239- Rename `export.SpanData` to `export.SpanSnapshot` and use it only for exporting spans. (#1360)
2240- Store the parent's full `SpanContext` rather than just its span ID in the `span` struct. (#1360)
2241- Improve span duration accuracy. (#1360)
2242- Migrated CI/CD from CircleCI to GitHub Actions (#1382)
2243- Remove duplicate checkout from GitHub Actions workflow (#1407)
2244- Metric `array` aggregator renamed `exact` to match its `aggregation.Kind` (#1412)
2245- Metric `exact` aggregator includes per-point timestamps (#1412)
2246- Metric stdout exporter uses MinMaxSumCount aggregator for ValueRecorder instruments (#1412)
2247- `NewExporter` from `exporters/otlp` now takes a `ProtocolDriver` as a parameter. (#1369)
2248- Many OTLP Exporter options became gRPC ProtocolDriver options. (#1369)
2249- Unify endpoint API that related to OTel exporter. (#1401)
2250- Optimize metric histogram aggregator to reuse its slice of buckets. (#1435)
2251- Metric aggregator Count() and histogram Bucket.Counts are consistently `uint64`. (1430)
2252- Histogram aggregator accepts functional options, uses default boundaries if none given. (#1434)
2253- `SamplingResult` now passed a `Tracestate` from the parent `SpanContext` (#1432)
2254- Moved gRPC driver for OTLP exporter to `exporters/otlp/otlpgrpc`. (#1420)
2255- The `TraceContext` propagator now correctly propagates `TraceState` through the `SpanContext`. (#1447)
2256- Metric Push and Pull Controller components are combined into a single "basic" Controller:
2257  - `WithExporter()` and `Start()` to configure Push behavior
2258  - `Start()` is optional; use `Collect()` and `ForEach()` for Pull behavior
2259  - `Start()` and `Stop()` accept Context. (#1378)
2260- The `Event` type is moved from the `otel/sdk/export/trace` package to the `otel/trace` API package. (#1452)
2261
2262### Removed
2263
2264- Remove `errUninitializedSpan` as its only usage is now obsolete. (#1360)
2265- Remove Metric export functionality related to quantiles and summary data points: this is not specified (#1412)
2266- Remove DDSketch metric aggregator; our intention is to re-introduce this as an option of the histogram aggregator after [new OTLP histogram data types](https://github.com/open-telemetry/opentelemetry-proto/pull/226) are released (#1412)
2267
2268### Fixed
2269
2270- `BatchSpanProcessor.Shutdown()` will now shutdown underlying `export.SpanExporter`. (#1443)
2271
2272## [0.15.0] - 2020-12-10
2273
2274### Added
2275
2276- The `WithIDGenerator` `TracerProviderOption` is added to the `go.opentelemetry.io/otel/trace` package to configure an `IDGenerator` for the `TracerProvider`. (#1363)
2277
2278### Changed
2279
2280- The Zipkin exporter now uses the Span status code to determine. (#1328)
2281- `NewExporter` and `Start` functions in `go.opentelemetry.io/otel/exporters/otlp` now receive `context.Context` as a first parameter. (#1357)
2282- Move the OpenCensus example into `example` directory. (#1359)
2283- Moved the SDK's `internal.IDGenerator` interface in to the `sdk/trace` package to enable support for externally-defined ID generators. (#1363)
2284- Bump `github.com/google/go-cmp` from 0.5.3 to 0.5.4 (#1374)
2285- Bump `github.com/golangci/golangci-lint` in `/internal/tools` (#1375)
2286
2287### Fixed
2288
2289- Metric SDK `SumObserver` and `UpDownSumObserver` instruments correctness fixes. (#1381)
2290
2291## [0.14.0] - 2020-11-19
2292
2293### Added
2294
2295- An `EventOption` and the related `NewEventConfig` function are added to the `go.opentelemetry.io/otel` package to configure Span events. (#1254)
2296- A `TextMapPropagator` and associated `TextMapCarrier` are added to the `go.opentelemetry.io/otel/oteltest` package to test `TextMap` type propagators and their use. (#1259)
2297- `SpanContextFromContext` returns `SpanContext` from context. (#1255)
2298- `TraceState` has been added to `SpanContext`. (#1340)
2299- `DeploymentEnvironmentKey` added to `go.opentelemetry.io/otel/semconv` package. (#1323)
2300- Add an OpenCensus to OpenTelemetry tracing bridge. (#1305)
2301- Add a parent context argument to `SpanProcessor.OnStart` to follow the specification. (#1333)
2302- Add missing tests for `sdk/trace/attributes_map.go`. (#1337)
2303
2304### Changed
2305
2306- Move the `go.opentelemetry.io/otel/api/trace` package into `go.opentelemetry.io/otel/trace` with the following changes. (#1229) (#1307)
2307  - `ID` has been renamed to `TraceID`.
2308  - `IDFromHex` has been renamed to `TraceIDFromHex`.
2309  - `EmptySpanContext` is removed.
2310- Move the `go.opentelemetry.io/otel/api/trace/tracetest` package into `go.opentelemetry.io/otel/oteltest`. (#1229)
2311- OTLP Exporter updates:
2312  - supports OTLP v0.6.0 (#1230, #1354)
2313  - supports configurable aggregation temporality (default: Cumulative, optional: Stateless). (#1296)
2314- The Sampler is now called on local child spans. (#1233)
2315- The `Kind` type from the `go.opentelemetry.io/otel/api/metric` package was renamed to `InstrumentKind` to more specifically describe what it is and avoid semantic ambiguity. (#1240)
2316- The `MetricKind` method of the `Descriptor` type in the `go.opentelemetry.io/otel/api/metric` package was renamed to `Descriptor.InstrumentKind`.
2317   This matches the returned type and fixes misuse of the term metric. (#1240)
2318- Move test harness from the `go.opentelemetry.io/otel/api/apitest` package into `go.opentelemetry.io/otel/oteltest`. (#1241)
2319- Move the `go.opentelemetry.io/otel/api/metric/metrictest` package into `go.opentelemetry.io/oteltest` as part of #964. (#1252)
2320- Move the `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric` as part of #1303. (#1321)
2321- Move the `go.opentelemetry.io/otel/api/metric/registry` package into `go.opentelemetry.io/otel/metric/registry` as a part of #1303. (#1316)
2322- Move the `Number` type (together with related functions) from `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric/number` as a part of #1303. (#1316)
2323- The function signature of the Span `AddEvent` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required name and a variable number of `EventOption`s. (#1254)
2324- The function signature of the Span `RecordError` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required error value and a variable number of `EventOption`s. (#1254)
2325- Move the `go.opentelemetry.io/otel/api/global` package to `go.opentelemetry.io/otel`. (#1262) (#1330)
2326- Move the `Version` function from `go.opentelemetry.io/otel/sdk` to `go.opentelemetry.io/otel`. (#1330)
2327- Rename correlation context header from `"otcorrelations"` to `"baggage"` to match the OpenTelemetry specification. (#1267)
2328- Fix `Code.UnmarshalJSON` to work with valid JSON only. (#1276)
2329- The `resource.New()` method changes signature to support builtin attributes and functional options, including `telemetry.sdk.*` and
2330  `host.name` semantic conventions; the former method is renamed `resource.NewWithAttributes`. (#1235)
2331- The Prometheus exporter now exports non-monotonic counters (i.e. `UpDownCounter`s) as gauges. (#1210)
2332- Correct the `Span.End` method documentation in the `otel` API to state updates are not allowed on a span after it has ended. (#1310)
2333- Updated span collection limits for attribute, event and link counts to 1000 (#1318)
2334- Renamed `semconv.HTTPUrlKey` to `semconv.HTTPURLKey`. (#1338)
2335
2336### Removed
2337
2338- The `ErrInvalidHexID`, `ErrInvalidTraceIDLength`, `ErrInvalidSpanIDLength`, `ErrInvalidSpanIDLength`, or `ErrNilSpanID` from the `go.opentelemetry.io/otel` package are unexported now. (#1243)
2339- The `AddEventWithTimestamp` method on the `Span` interface in `go.opentelemetry.io/otel` is removed due to its redundancy.
2340   It is replaced by using the `AddEvent` method with a `WithTimestamp` option. (#1254)
2341- The `MockSpan` and `MockTracer` types are removed from `go.opentelemetry.io/otel/oteltest`.
2342   `Tracer` and `Span` from the same module should be used in their place instead. (#1306)
2343- `WorkerCount` option is removed from `go.opentelemetry.io/otel/exporters/otlp`. (#1350)
2344- Remove the following labels types: INT32, UINT32, UINT64 and FLOAT32. (#1314)
2345
2346### Fixed
2347
2348- Rename `MergeItererator` to `MergeIterator` in the `go.opentelemetry.io/otel/label` package. (#1244)
2349- The `go.opentelemetry.io/otel/api/global` packages global TextMapPropagator now delegates functionality to a globally set delegate for all previously returned propagators. (#1258)
2350- Fix condition in `label.Any`. (#1299)
2351- Fix global `TracerProvider` to pass options to its configured provider. (#1329)
2352- Fix missing handler for `ExactKind` aggregator in OTLP metrics transformer (#1309)
2353
2354## [0.13.0] - 2020-10-08
2355
2356### Added
2357
2358- OTLP Metric exporter supports Histogram aggregation. (#1209)
2359- The `Code` struct from the `go.opentelemetry.io/otel/codes` package now supports JSON marshaling and unmarshaling as well as implements the `Stringer` interface. (#1214)
2360- A Baggage API to implement the OpenTelemetry specification. (#1217)
2361- Add Shutdown method to sdk/trace/provider, shutdown processors in the order they were registered. (#1227)
2362
2363### Changed
2364
2365- Set default propagator to no-op propagator. (#1184)
2366- The `HTTPSupplier`, `HTTPExtractor`, `HTTPInjector`, and `HTTPPropagator` from the `go.opentelemetry.io/otel/api/propagation` package were replaced with unified `TextMapCarrier` and `TextMapPropagator` in the `go.opentelemetry.io/otel/propagation` package. (#1212) (#1325)
2367- The `New` function from the `go.opentelemetry.io/otel/api/propagation` package was replaced with `NewCompositeTextMapPropagator` in the `go.opentelemetry.io/otel` package. (#1212)
2368- The status codes of the `go.opentelemetry.io/otel/codes` package have been updated to match the latest OpenTelemetry specification.
2369   They now are `Unset`, `Error`, and `Ok`.
2370   They no longer track the gRPC codes. (#1214)
2371- The `StatusCode` field of the `SpanData` struct in the `go.opentelemetry.io/otel/sdk/export/trace` package now uses the codes package from this package instead of the gRPC project. (#1214)
2372- Move the `go.opentelemetry.io/otel/api/baggage` package into `go.opentelemetry.io/otel/baggage`. (#1217) (#1325)
2373- A `Shutdown` method of `SpanProcessor` and all its implementations receives a context and returns an error. (#1264)
2374
2375### Fixed
2376
2377- Copies of data from arrays and slices passed to `go.opentelemetry.io/otel/label.ArrayValue()` are now used in the returned `Value` instead of using the mutable data itself. (#1226)
2378
2379### Removed
2380
2381- The `ExtractHTTP` and `InjectHTTP` functions from the `go.opentelemetry.io/otel/api/propagation` package were removed. (#1212)
2382- The `Propagators` interface from the `go.opentelemetry.io/otel/api/propagation` package was removed to conform to the OpenTelemetry specification.
2383   The explicit `TextMapPropagator` type can be used in its place as this is the `Propagator` type the specification defines. (#1212)
2384- The `SetAttribute` method of the `Span` from the `go.opentelemetry.io/otel/api/trace` package was removed given its redundancy with the `SetAttributes` method. (#1216)
2385- The internal implementation of Baggage storage is removed in favor of using the new Baggage API functionality. (#1217)
2386- Remove duplicate hostname key `HostHostNameKey` in Resource semantic conventions. (#1219)
2387- Nested array/slice support has been removed. (#1226)
2388
2389## [0.12.0] - 2020-09-24
2390
2391### Added
2392
2393- A `SpanConfigure` function in `go.opentelemetry.io/otel/api/trace` to create a new `SpanConfig` from `SpanOption`s. (#1108)
2394- In the `go.opentelemetry.io/otel/api/trace` package, `NewTracerConfig` was added to construct new `TracerConfig`s.
2395   This addition was made to conform with our project option conventions. (#1155)
2396- Instrumentation library information was added to the Zipkin exporter. (#1119)
2397- The `SpanProcessor` interface now has a `ForceFlush()` method. (#1166)
2398- More semantic conventions for k8s as resource attributes. (#1167)
2399
2400### Changed
2401
2402- Add reconnecting udp connection type to Jaeger exporter.
2403   This change adds a new optional implementation of the udp conn interface used to detect changes to an agent's host dns record.
2404   It then adopts the new destination address to ensure the exporter doesn't get stuck. This change was ported from jaegertracing/jaeger-client-go#520. (#1063)
2405- Replace `StartOption` and `EndOption` in `go.opentelemetry.io/otel/api/trace` with `SpanOption`.
2406   This change is matched by replacing the `StartConfig` and `EndConfig` with a unified `SpanConfig`. (#1108)
2407- Replace the `LinkedTo` span option in `go.opentelemetry.io/otel/api/trace` with `WithLinks`.
2408   This is be more consistent with our other option patterns, i.e. passing the item to be configured directly instead of its component parts, and provides a cleaner function signature. (#1108)
2409- The `go.opentelemetry.io/otel/api/trace` `TracerOption` was changed to an interface to conform to project option conventions. (#1109)
2410- Move the `B3` and `TraceContext` from within the `go.opentelemetry.io/otel/api/trace` package to their own `go.opentelemetry.io/otel/propagators` package.
2411    This removal of the propagators is reflective of the OpenTelemetry specification for these propagators as well as cleans up the `go.opentelemetry.io/otel/api/trace` API. (#1118)
2412- Rename Jaeger tags used for instrumentation library information to reflect changes in OpenTelemetry specification. (#1119)
2413- Rename `ProbabilitySampler` to `TraceIDRatioBased` and change semantics to ignore parent span sampling status. (#1115)
2414- Move `tools` package under `internal`. (#1141)
2415- Move `go.opentelemetry.io/otel/api/correlation` package to `go.opentelemetry.io/otel/api/baggage`. (#1142)
2416   The `correlation.CorrelationContext` propagator has been renamed `baggage.Baggage`.  Other exported functions and types are unchanged.
2417- Rename `ParentOrElse` sampler to `ParentBased` and allow setting samplers depending on parent span. (#1153)
2418- In the `go.opentelemetry.io/otel/api/trace` package, `SpanConfigure` was renamed to `NewSpanConfig`. (#1155)
2419- Change `dependabot.yml` to add a `Skip Changelog` label to dependabot-sourced PRs. (#1161)
2420- The [configuration style guide](https://github.com/open-telemetry/opentelemetry-go/blob/master/CONTRIBUTING.md#config) has been updated to
2421   recommend the use of `newConfig()` instead of `configure()`. (#1163)
2422- The `otlp.Config` type has been unexported and changed to `otlp.config`, along with its initializer. (#1163)
2423- Ensure exported interface types include parameter names and update the
2424   Style Guide to reflect this styling rule. (#1172)
2425- Don't consider unset environment variable for resource detection to be an error. (#1170)
2426- Rename `go.opentelemetry.io/otel/api/metric.ConfigureInstrument` to `NewInstrumentConfig` and
2427  `go.opentelemetry.io/otel/api/metric.ConfigureMeter` to `NewMeterConfig`.
2428- ValueObserver instruments use LastValue aggregator by default. (#1165)
2429- OTLP Metric exporter supports LastValue aggregation. (#1165)
2430- Move the `go.opentelemetry.io/otel/api/unit` package to `go.opentelemetry.io/otel/unit`. (#1185)
2431- Rename `Provider` to `MeterProvider` in the `go.opentelemetry.io/otel/api/metric` package. (#1190)
2432- Rename `NoopProvider` to `NoopMeterProvider` in the `go.opentelemetry.io/otel/api/metric` package. (#1190)
2433- Rename `NewProvider` to `NewMeterProvider` in the `go.opentelemetry.io/otel/api/metric/metrictest` package. (#1190)
2434- Rename `Provider` to `MeterProvider` in the `go.opentelemetry.io/otel/api/metric/registry` package. (#1190)
2435- Rename `NewProvider` to `NewMeterProvider` in the `go.opentelemetry.io/otel/api/metri/registryc` package. (#1190)
2436- Rename `Provider` to `TracerProvider` in the `go.opentelemetry.io/otel/api/trace` package. (#1190)
2437- Rename `NoopProvider` to `NoopTracerProvider` in the `go.opentelemetry.io/otel/api/trace` package. (#1190)
2438- Rename `Provider` to `TracerProvider` in the `go.opentelemetry.io/otel/api/trace/tracetest` package. (#1190)
2439- Rename `NewProvider` to `NewTracerProvider` in the `go.opentelemetry.io/otel/api/trace/tracetest` package. (#1190)
2440- Rename `WrapperProvider` to `WrapperTracerProvider` in the `go.opentelemetry.io/otel/bridge/opentracing` package. (#1190)
2441- Rename `NewWrapperProvider` to `NewWrapperTracerProvider` in the `go.opentelemetry.io/otel/bridge/opentracing` package. (#1190)
2442- Rename `Provider` method of the pull controller to `MeterProvider` in the `go.opentelemetry.io/otel/sdk/metric/controller/pull` package. (#1190)
2443- Rename `Provider` method of the push controller to `MeterProvider` in the `go.opentelemetry.io/otel/sdk/metric/controller/push` package. (#1190)
2444- Rename `ProviderOptions` to `TracerProviderConfig` in the `go.opentelemetry.io/otel/sdk/trace` package. (#1190)
2445- Rename `ProviderOption` to `TracerProviderOption` in the `go.opentelemetry.io/otel/sdk/trace` package. (#1190)
2446- Rename `Provider` to `TracerProvider` in the `go.opentelemetry.io/otel/sdk/trace` package. (#1190)
2447- Rename `NewProvider` to `NewTracerProvider` in the `go.opentelemetry.io/otel/sdk/trace` package. (#1190)
2448- Renamed `SamplingDecision` values to comply with OpenTelemetry specification change. (#1192)
2449- Renamed Zipkin attribute names from `ot.status_code & ot.status_description` to `otel.status_code & otel.status_description`. (#1201)
2450- The default SDK now invokes registered `SpanProcessor`s in the order they were registered with the `TracerProvider`. (#1195)
2451- Add test of spans being processed by the `SpanProcessor`s in the order they were registered. (#1203)
2452
2453### Removed
2454
2455- Remove the B3 propagator from `go.opentelemetry.io/otel/propagators`. It is now located in the
2456   `go.opentelemetry.io/contrib/propagators/` module. (#1191)
2457- Remove the semantic convention for HTTP status text, `HTTPStatusTextKey` from package `go.opentelemetry.io/otel/semconv`. (#1194)
2458
2459### Fixed
2460
2461- Zipkin example no longer mentions `ParentSampler`, corrected to `ParentBased`. (#1171)
2462- Fix missing shutdown processor in otel-collector example. (#1186)
2463- Fix missing shutdown processor in basic and namedtracer examples. (#1197)
2464
2465## [0.11.0] - 2020-08-24
2466
2467### Added
2468
2469- Support for exporting array-valued attributes via OTLP. (#992)
2470- `Noop` and `InMemory` `SpanBatcher` implementations to help with testing integrations. (#994)
2471- Support for filtering metric label sets. (#1047)
2472- A dimensionality-reducing metric Processor. (#1057)
2473- Integration tests for more OTel Collector Attribute types. (#1062)
2474- A new `WithSpanProcessor` `ProviderOption` is added to the `go.opentelemetry.io/otel/sdk/trace` package to create a `Provider` and automatically register the `SpanProcessor`. (#1078)
2475
2476### Changed
2477
2478- Rename `sdk/metric/processor/test` to `sdk/metric/processor/processortest`. (#1049)
2479- Rename `sdk/metric/controller/test` to `sdk/metric/controller/controllertest`. (#1049)
2480- Rename `api/testharness` to `api/apitest`. (#1049)
2481- Rename `api/trace/testtrace` to `api/trace/tracetest`. (#1049)
2482- Change Metric Processor to merge multiple observations. (#1024)
2483- The `go.opentelemetry.io/otel/bridge/opentracing` bridge package has been made into its own module.
2484   This removes the package dependencies of this bridge from the rest of the OpenTelemetry based project. (#1038)
2485- Renamed `go.opentelemetry.io/otel/api/standard` package to `go.opentelemetry.io/otel/semconv` to avoid the ambiguous and generic name `standard` and better describe the package as containing OpenTelemetry semantic conventions. (#1016)
2486- The environment variable used for resource detection has been changed from `OTEL_RESOURCE_LABELS` to `OTEL_RESOURCE_ATTRIBUTES` (#1042)
2487- Replace `WithSyncer` with `WithBatcher` in examples. (#1044)
2488- Replace the `google.golang.org/grpc/codes` dependency in the API with an equivalent `go.opentelemetry.io/otel/codes` package. (#1046)
2489- Merge the `go.opentelemetry.io/otel/api/label` and `go.opentelemetry.io/otel/api/kv` into the new `go.opentelemetry.io/otel/label` package. (#1060)
2490- Unify Callback Function Naming.
2491   Rename `*Callback` with `*Func`. (#1061)
2492- CI builds validate against last two versions of Go, dropping 1.13 and adding 1.15. (#1064)
2493- The `go.opentelemetry.io/otel/sdk/export/trace` interfaces `SpanSyncer` and `SpanBatcher` have been replaced with a specification compliant `Exporter` interface.
2494   This interface still supports the export of `SpanData`, but only as a slice.
2495   Implementation are also required now to return any error from `ExportSpans` if one occurs as well as implement a `Shutdown` method for exporter clean-up. (#1078)
2496- The `go.opentelemetry.io/otel/sdk/trace` `NewBatchSpanProcessor` function no longer returns an error.
2497   If a `nil` exporter is passed as an argument to this function, instead of it returning an error, it now returns a `BatchSpanProcessor` that handles the export of `SpanData` by not taking any action. (#1078)
2498- The `go.opentelemetry.io/otel/sdk/trace` `NewProvider` function to create a `Provider` no longer returns an error, instead only a `*Provider`.
2499   This change is related to `NewBatchSpanProcessor` not returning an error which was the only error this function would return. (#1078)
2500
2501### Removed
2502
2503- Duplicate, unused API sampler interface. (#999)
2504   Use the [`Sampler` interface](https://github.com/open-telemetry/opentelemetry-go/blob/v0.11.0/sdk/trace/sampling.go) provided by the SDK instead.
2505- The `grpctrace` instrumentation was moved to the `go.opentelemetry.io/contrib` repository and out of this repository.
2506   This move includes moving the `grpc` example to the `go.opentelemetry.io/contrib` as well. (#1027)
2507- The `WithSpan` method of the `Tracer` interface.
2508   The functionality this method provided was limited compared to what a user can provide themselves.
2509   It was removed with the understanding that if there is sufficient user need it can be added back based on actual user usage. (#1043)
2510- The `RegisterSpanProcessor` and `UnregisterSpanProcessor` functions.
2511   These were holdovers from an approach prior to the TracerProvider design. They were not used anymore. (#1077)
2512- The `oterror` package. (#1026)
2513- The `othttp` and `httptrace` instrumentations were moved to `go.opentelemetry.io/contrib`. (#1032)
2514
2515### Fixed
2516
2517- The `semconv.HTTPServerMetricAttributesFromHTTPRequest()` function no longer generates the high-cardinality `http.request.content.length` label. (#1031)
2518- Correct instrumentation version tag in Jaeger exporter. (#1037)
2519- The SDK span will now set an error event if the `End` method is called during a panic (i.e. it was deferred). (#1043)
2520- Move internally generated protobuf code from the `go.opentelemetry.io/otel` to the OTLP exporter to reduce dependency overhead. (#1050)
2521- The `otel-collector` example referenced outdated collector processors. (#1006)
2522
2523## [0.10.0] - 2020-07-29
2524
2525This release migrates the default OpenTelemetry SDK into its own Go module, decoupling the SDK from the API and reducing dependencies for instrumentation packages.
2526
2527### Added
2528
2529- The Zipkin exporter now has `NewExportPipeline` and `InstallNewPipeline` constructor functions to match the common pattern.
2530    These function build a new exporter with default SDK options and register the exporter with the `global` package respectively. (#944)
2531- Add propagator option for gRPC instrumentation. (#986)
2532- The `testtrace` package now tracks the `trace.SpanKind` for each span. (#987)
2533
2534### Changed
2535
2536- Replace the `RegisterGlobal` `Option` in the Jaeger exporter with an `InstallNewPipeline` constructor function.
2537   This matches the other exporter constructor patterns and will register a new exporter after building it with default configuration. (#944)
2538- The trace (`go.opentelemetry.io/otel/exporters/trace/stdout`) and metric (`go.opentelemetry.io/otel/exporters/metric/stdout`) `stdout` exporters are now merged into a single exporter at `go.opentelemetry.io/otel/exporters/stdout`.
2539   This new exporter was made into its own Go module to follow the pattern of all exporters and decouple it from the `go.opentelemetry.io/otel` module. (#956, #963)
2540- Move the `go.opentelemetry.io/otel/exporters/test` test package to `go.opentelemetry.io/otel/sdk/export/metric/metrictest`. (#962)
2541- The `go.opentelemetry.io/otel/api/kv/value` package was merged into the parent `go.opentelemetry.io/otel/api/kv` package. (#968)
2542  - `value.Bool` was replaced with `kv.BoolValue`.
2543  - `value.Int64` was replaced with `kv.Int64Value`.
2544  - `value.Uint64` was replaced with `kv.Uint64Value`.
2545  - `value.Float64` was replaced with `kv.Float64Value`.
2546  - `value.Int32` was replaced with `kv.Int32Value`.
2547  - `value.Uint32` was replaced with `kv.Uint32Value`.
2548  - `value.Float32` was replaced with `kv.Float32Value`.
2549  - `value.String` was replaced with `kv.StringValue`.
2550  - `value.Int` was replaced with `kv.IntValue`.
2551  - `value.Uint` was replaced with `kv.UintValue`.
2552  - `value.Array` was replaced with `kv.ArrayValue`.
2553- Rename `Infer` to `Any` in the `go.opentelemetry.io/otel/api/kv` package. (#972)
2554- Change `othttp` to use the `httpsnoop` package to wrap the `ResponseWriter` so that optional interfaces (`http.Hijacker`, `http.Flusher`, etc.) that are implemented by the original `ResponseWriter`are also implemented by the wrapped `ResponseWriter`. (#979)
2555- Rename `go.opentelemetry.io/otel/sdk/metric/aggregator/test` package to `go.opentelemetry.io/otel/sdk/metric/aggregator/aggregatortest`. (#980)
2556- Make the SDK into its own Go module called `go.opentelemetry.io/otel/sdk`. (#985)
2557- Changed the default trace `Sampler` from `AlwaysOn` to `ParentOrElse(AlwaysOn)`. (#989)
2558
2559### Removed
2560
2561- The `IndexedAttribute` function from the `go.opentelemetry.io/otel/api/label` package was removed in favor of `IndexedLabel` which it was synonymous with. (#970)
2562
2563### Fixed
2564
2565- Bump github.com/golangci/golangci-lint from 1.28.3 to 1.29.0 in /tools. (#953)
2566- Bump github.com/google/go-cmp from 0.5.0 to 0.5.1. (#957)
2567- Use `global.Handle` for span export errors in the OTLP exporter. (#946)
2568- Correct Go language formatting in the README documentation. (#961)
2569- Remove default SDK dependencies from the `go.opentelemetry.io/otel/api` package. (#977)
2570- Remove default SDK dependencies from the `go.opentelemetry.io/otel/instrumentation` package. (#983)
2571- Move documented examples for `go.opentelemetry.io/otel/instrumentation/grpctrace` interceptors into Go example tests. (#984)
2572
2573## [0.9.0] - 2020-07-20
2574
2575### Added
2576
2577- A new Resource Detector interface is included to allow resources to be automatically detected and included. (#939)
2578- A Detector to automatically detect resources from an environment variable. (#939)
2579- Github action to generate protobuf Go bindings locally in `internal/opentelemetry-proto-gen`. (#938)
2580- OTLP .proto files from `open-telemetry/opentelemetry-proto` imported as a git submodule under `internal/opentelemetry-proto`.
2581   References to `github.com/open-telemetry/opentelemetry-proto` changed to `go.opentelemetry.io/otel/internal/opentelemetry-proto-gen`. (#942)
2582
2583### Changed
2584
2585- Non-nil value `struct`s for key-value pairs will be marshalled using JSON rather than `Sprintf`. (#948)
2586
2587### Removed
2588
2589- Removed dependency on `github.com/open-telemetry/opentelemetry-collector`. (#943)
2590
2591## [0.8.0] - 2020-07-09
2592
2593### Added
2594
2595- The `B3Encoding` type to represent the B3 encoding(s) the B3 propagator can inject.
2596   A value for HTTP supported encodings (Multiple Header: `MultipleHeader`, Single Header: `SingleHeader`) are included. (#882)
2597- The `FlagsDeferred` trace flag to indicate if the trace sampling decision has been deferred. (#882)
2598- The `FlagsDebug` trace flag to indicate if the trace is a debug trace. (#882)
2599- Add `peer.service` semantic attribute. (#898)
2600- Add database-specific semantic attributes. (#899)
2601- Add semantic convention for `faas.coldstart` and `container.id`. (#909)
2602- Add http content size semantic conventions. (#905)
2603- Include `http.request_content_length` in HTTP request basic attributes. (#905)
2604- Add semantic conventions for operating system process resource attribute keys. (#919)
2605- The Jaeger exporter now has a `WithBatchMaxCount` option to specify the maximum number of spans sent in a batch. (#931)
2606
2607### Changed
2608
2609- Update `CONTRIBUTING.md` to ask for updates to `CHANGELOG.md` with each pull request. (#879)
2610- Use lowercase header names for B3 Multiple Headers. (#881)
2611- The B3 propagator `SingleHeader` field has been replaced with `InjectEncoding`.
2612   This new field can be set to combinations of the `B3Encoding` bitmasks and will inject trace information in these encodings.
2613   If no encoding is set, the propagator will default to `MultipleHeader` encoding. (#882)
2614- The B3 propagator now extracts from either HTTP encoding of B3 (Single Header or Multiple Header) based on what is contained in the header.
2615   Preference is given to Single Header encoding with Multiple Header being the fallback if Single Header is not found or is invalid.
2616   This behavior change is made to dynamically support all correctly encoded traces received instead of having to guess the expected encoding prior to receiving. (#882)
2617- Extend semantic conventions for RPC. (#900)
2618- To match constant naming conventions in the `api/standard` package, the `FaaS*` key names are appended with a suffix of `Key`. (#920)
2619  - `"api/standard".FaaSName` -> `FaaSNameKey`
2620  - `"api/standard".FaaSID` -> `FaaSIDKey`
2621  - `"api/standard".FaaSVersion` -> `FaaSVersionKey`
2622  - `"api/standard".FaaSInstance` -> `FaaSInstanceKey`
2623
2624### Removed
2625
2626- The `FlagsUnused` trace flag is removed.
2627   The purpose of this flag was to act as the inverse of `FlagsSampled`, the inverse of `FlagsSampled` is used instead. (#882)
2628- The B3 header constants (`B3SingleHeader`, `B3DebugFlagHeader`, `B3TraceIDHeader`, `B3SpanIDHeader`, `B3SampledHeader`, `B3ParentSpanIDHeader`) are removed.
2629   If B3 header keys are needed [the authoritative OpenZipkin package constants](https://pkg.go.dev/github.com/openzipkin/zipkin-go@v0.2.2/propagation/b3?tab=doc#pkg-constants) should be used instead. (#882)
2630
2631### Fixed
2632
2633- The B3 Single Header name is now correctly `b3` instead of the previous `X-B3`. (#881)
2634- The B3 propagator now correctly supports sampling only values (`b3: 0`, `b3: 1`, or `b3: d`) for a Single B3 Header. (#882)
2635- The B3 propagator now propagates the debug flag.
2636   This removes the behavior of changing the debug flag into a set sampling bit.
2637   Instead, this now follow the B3 specification and omits the `X-B3-Sampling` header. (#882)
2638- The B3 propagator now tracks "unset" sampling state (meaning "defer the decision") and does not set the `X-B3-Sampling` header when injecting. (#882)
2639- Bump github.com/itchyny/gojq from 0.10.3 to 0.10.4 in /tools. (#883)
2640- Bump github.com/opentracing/opentracing-go from v1.1.1-0.20190913142402-a7454ce5950e to v1.2.0. (#885)
2641- The tracing time conversion for OTLP spans is now correctly set to `UnixNano`. (#896)
2642- Ensure span status is not set to `Unknown` when no HTTP status code is provided as it is assumed to be `200 OK`. (#908)
2643- Ensure `httptrace.clientTracer` closes `http.headers` span. (#912)
2644- Prometheus exporter will not apply stale updates or forget inactive metrics. (#903)
2645- Add test for api.standard `HTTPClientAttributesFromHTTPRequest`. (#905)
2646- Bump github.com/golangci/golangci-lint from 1.27.0 to 1.28.1 in /tools. (#901, #913)
2647- Update otel-collector example to use the v0.5.0 collector. (#915)
2648- The `grpctrace` instrumentation uses a span name conforming to the OpenTelemetry semantic conventions (does not contain a leading slash (`/`)). (#922)
2649- The `grpctrace` instrumentation includes an `rpc.method` attribute now set to the gRPC method name. (#900, #922)
2650- The `grpctrace` instrumentation `rpc.service` attribute now contains the package name if one exists.
2651   This is in accordance with OpenTelemetry semantic conventions. (#922)
2652- Correlation Context extractor will no longer insert an empty map into the returned context when no valid values are extracted. (#923)
2653- Bump google.golang.org/api from 0.28.0 to 0.29.0 in /exporters/trace/jaeger. (#925)
2654- Bump github.com/itchyny/gojq from 0.10.4 to 0.11.0 in /tools. (#926)
2655- Bump github.com/golangci/golangci-lint from 1.28.1 to 1.28.2 in /tools. (#930)
2656
2657## [0.7.0] - 2020-06-26
2658
2659This release implements the v0.5.0 version of the OpenTelemetry specification.
2660
2661### Added
2662
2663- The othttp instrumentation now includes default metrics. (#861)
2664- This CHANGELOG file to track all changes in the project going forward.
2665- Support for array type attributes. (#798)
2666- Apply transitive dependabot go.mod dependency updates as part of a new automatic Github workflow. (#844)
2667- Timestamps are now passed to exporters for each export. (#835)
2668- Add new `Accumulation` type to metric SDK to transport telemetry from `Accumulator`s to `Processor`s.
2669   This replaces the prior `Record` `struct` use for this purpose. (#835)
2670- New dependabot integration to automate package upgrades. (#814)
2671- `Meter` and `Tracer` implementations accept instrumentation version version as an optional argument.
2672   This instrumentation version is passed on to exporters. (#811) (#805) (#802)
2673- The OTLP exporter includes the instrumentation version in telemetry it exports. (#811)
2674- Environment variables for Jaeger exporter are supported. (#796)
2675- New `aggregation.Kind` in the export metric API. (#808)
2676- New example that uses OTLP and the collector. (#790)
2677- Handle errors in the span `SetName` during span initialization. (#791)
2678- Default service config to enable retries for retry-able failed requests in the OTLP exporter and an option to override this default. (#777)
2679- New `go.opentelemetry.io/otel/api/oterror` package to uniformly support error handling and definitions for the project. (#778)
2680- New `global` default implementation of the `go.opentelemetry.io/otel/api/oterror.Handler` interface to be used to handle errors prior to an user defined `Handler`.
2681   There is also functionality for the user to register their `Handler` as well as a convenience function `Handle` to handle an error with this global `Handler`(#778)
2682- Options to specify propagators for httptrace and grpctrace instrumentation. (#784)
2683- The required `application/json` header for the Zipkin exporter is included in all exports. (#774)
2684- Integrate HTTP semantics helpers from the contrib repository into the `api/standard` package. #769
2685
2686### Changed
2687
2688- Rename `Integrator` to `Processor` in the metric SDK. (#863)
2689- Rename `AggregationSelector` to `AggregatorSelector`. (#859)
2690- Rename `SynchronizedCopy` to `SynchronizedMove`. (#858)
2691- Rename `simple` integrator to `basic` integrator. (#857)
2692- Merge otlp collector examples. (#841)
2693- Change the metric SDK to support cumulative, delta, and pass-through exporters directly.
2694   With these changes, cumulative and delta specific exporters are able to request the correct kind of aggregation from the SDK. (#840)
2695- The `Aggregator.Checkpoint` API is renamed to `SynchronizedCopy` and adds an argument, a different `Aggregator` into which the copy is stored. (#812)
2696- The `export.Aggregator` contract is that `Update()` and `SynchronizedCopy()` are synchronized with each other.
2697   All the aggregation interfaces (`Sum`, `LastValue`, ...) are not meant to be synchronized, as the caller is expected to synchronize aggregators at a higher level after the `Accumulator`.
2698   Some of the `Aggregators` used unnecessary locking and that has been cleaned up. (#812)
2699- Use of `metric.Number` was replaced by `int64` now that we use `sync.Mutex` in the `MinMaxSumCount` and `Histogram` `Aggregators`. (#812)
2700- Replace `AlwaysParentSample` with `ParentSample(fallback)` to match the OpenTelemetry v0.5.0 specification. (#810)
2701- Rename `sdk/export/metric/aggregator` to `sdk/export/metric/aggregation`. #808
2702- Send configured headers with every request in the OTLP exporter, instead of just on connection creation. (#806)
2703- Update error handling for any one off error handlers, replacing, instead, with the `global.Handle` function. (#791)
2704- Rename `plugin` directory to `instrumentation` to match the OpenTelemetry specification. (#779)
2705- Makes the argument order to Histogram and DDSketch `New()` consistent. (#781)
2706
2707### Removed
2708
2709- `Uint64NumberKind` and related functions from the API. (#864)
2710- Context arguments from `Aggregator.Checkpoint` and `Integrator.Process` as they were unused. (#803)
2711- `SpanID` is no longer included in parameters for sampling decision to match the OpenTelemetry specification. (#775)
2712
2713### Fixed
2714
2715- Upgrade OTLP exporter to opentelemetry-proto matching the opentelemetry-collector v0.4.0 release. (#866)
2716- Allow changes to `go.sum` and `go.mod` when running dependabot tidy-up. (#871)
2717- Bump github.com/stretchr/testify from 1.4.0 to 1.6.1. (#824)
2718- Bump github.com/prometheus/client_golang from 1.7.0 to 1.7.1 in /exporters/metric/prometheus. (#867)
2719- Bump google.golang.org/grpc from 1.29.1 to 1.30.0 in /exporters/trace/jaeger. (#853)
2720- Bump google.golang.org/grpc from 1.29.1 to 1.30.0 in /exporters/trace/zipkin. (#854)
2721- Bumps github.com/golang/protobuf from 1.3.2 to 1.4.2 (#848)
2722- Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/otlp (#817)
2723- Bump github.com/golangci/golangci-lint from 1.25.1 to 1.27.0 in /tools (#828)
2724- Bump github.com/prometheus/client_golang from 1.5.0 to 1.7.0 in /exporters/metric/prometheus (#838)
2725- Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/trace/jaeger (#829)
2726- Bump github.com/benbjohnson/clock from 1.0.0 to 1.0.3 (#815)
2727- Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/trace/zipkin (#823)
2728- Bump github.com/itchyny/gojq from 0.10.1 to 0.10.3 in /tools (#830)
2729- Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/metric/prometheus (#822)
2730- Bump google.golang.org/grpc from 1.27.1 to 1.29.1 in /exporters/trace/zipkin (#820)
2731- Bump google.golang.org/grpc from 1.27.1 to 1.29.1 in /exporters/trace/jaeger (#831)
2732- Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 (#836)
2733- Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 in /exporters/trace/jaeger (#837)
2734- Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 in /exporters/otlp (#839)
2735- Bump google.golang.org/api from 0.20.0 to 0.28.0 in /exporters/trace/jaeger (#843)
2736- Set span status from HTTP status code in the othttp instrumentation. (#832)
2737- Fixed typo in push controller comment. (#834)
2738- The `Aggregator` testing has been updated and cleaned. (#812)
2739- `metric.Number(0)` expressions are replaced by `0` where possible. (#812)
2740- Fixed `global` `handler_test.go` test failure. #804
2741- Fixed `BatchSpanProcessor.Shutdown` to wait until all spans are processed. (#766)
2742- Fixed OTLP example's accidental early close of exporter. (#807)
2743- Ensure zipkin exporter reads and closes response body. (#788)
2744- Update instrumentation to use `api/standard` keys instead of custom keys. (#782)
2745- Clean up tools and RELEASING documentation. (#762)
2746
2747## [0.6.0] - 2020-05-21
2748
2749### Added
2750
2751- Support for `Resource`s in the prometheus exporter. (#757)
2752- New pull controller. (#751)
2753- New `UpDownSumObserver` instrument. (#750)
2754- OpenTelemetry collector demo. (#711)
2755- New `SumObserver` instrument. (#747)
2756- New `UpDownCounter` instrument. (#745)
2757- New timeout `Option` and configuration function `WithTimeout` to the push controller. (#742)
2758- New `api/standards` package to implement semantic conventions and standard key-value generation. (#731)
2759
2760### Changed
2761
2762- Rename `Register*` functions in the metric API to `New*` for all `Observer` instruments. (#761)
2763- Use `[]float64` for histogram boundaries, not `[]metric.Number`. (#758)
2764- Change OTLP example to use exporter as a trace `Syncer` instead of as an unneeded `Batcher`. (#756)
2765- Replace `WithResourceAttributes()` with `WithResource()` in the trace SDK. (#754)
2766- The prometheus exporter now uses the new pull controller. (#751)
2767- Rename `ScheduleDelayMillis` to `BatchTimeout` in the trace `BatchSpanProcessor`.(#752)
2768- Support use of synchronous instruments in asynchronous callbacks (#725)
2769- Move `Resource` from the `Export` method parameter into the metric export `Record`. (#739)
2770- Rename `Observer` instrument to `ValueObserver`. (#734)
2771- The push controller now has a method (`Provider()`) to return a `metric.Provider` instead of the old `Meter` method that acted as a `metric.Provider`. (#738)
2772- Replace `Measure` instrument by `ValueRecorder` instrument. (#732)
2773- Rename correlation context header from `"Correlation-Context"` to `"otcorrelations"` to match the OpenTelemetry specification. (#727)
2774
2775### Fixed
2776
2777- Ensure gRPC `ClientStream` override methods do not panic in grpctrace package. (#755)
2778- Disable parts of `BatchSpanProcessor` test until a fix is found. (#743)
2779- Fix `string` case in `kv` `Infer` function. (#746)
2780- Fix panic in grpctrace client interceptors. (#740)
2781- Refactor the `api/metrics` push controller and add `CheckpointSet` synchronization. (#737)
2782- Rewrite span batch process queue batching logic. (#719)
2783- Remove the push controller named Meter map. (#738)
2784- Fix Histogram aggregator initial state (fix #735). (#736)
2785- Ensure golang alpine image is running `golang-1.14` for examples. (#733)
2786- Added test for grpctrace `UnaryInterceptorClient`. (#695)
2787- Rearrange `api/metric` code layout. (#724)
2788
2789## [0.5.0] - 2020-05-13
2790
2791### Added
2792
2793- Batch `Observer` callback support. (#717)
2794- Alias `api` types to root package of project. (#696)
2795- Create basic `othttp.Transport` for simple client instrumentation. (#678)
2796- `SetAttribute(string, interface{})` to the trace API. (#674)
2797- Jaeger exporter option that allows user to specify custom http client. (#671)
2798- `Stringer` and `Infer` methods to `key`s. (#662)
2799
2800### Changed
2801
2802- Rename `NewKey` in the `kv` package to just `Key`. (#721)
2803- Move `core` and `key` to `kv` package. (#720)
2804- Make the metric API `Meter` a `struct` so the abstract `MeterImpl` can be passed and simplify implementation. (#709)
2805- Rename SDK `Batcher` to `Integrator` to match draft OpenTelemetry SDK specification. (#710)
2806- Rename SDK `Ungrouped` integrator to `simple.Integrator` to match draft OpenTelemetry SDK specification. (#710)
2807- Rename SDK `SDK` `struct` to `Accumulator` to match draft OpenTelemetry SDK specification. (#710)
2808- Move `Number` from `core` to `api/metric` package. (#706)
2809- Move `SpanContext` from `core` to `trace` package. (#692)
2810- Change traceparent header from `Traceparent` to `traceparent` to implement the W3C specification. (#681)
2811
2812### Fixed
2813
2814- Update tooling to run generators in all submodules. (#705)
2815- gRPC interceptor regexp to match methods without a service name. (#683)
2816- Use a `const` for padding 64-bit B3 trace IDs. (#701)
2817- Update `mockZipkin` listen address from `:0` to `127.0.0.1:0`. (#700)
2818- Left-pad 64-bit B3 trace IDs with zero. (#698)
2819- Propagate at least the first W3C tracestate header. (#694)
2820- Remove internal `StateLocker` implementation. (#688)
2821- Increase instance size CI system uses. (#690)
2822- Add a `key` benchmark and use reflection in `key.Infer()`. (#679)
2823- Fix internal `global` test by using `global.Meter` with `RecordBatch()`. (#680)
2824- Reimplement histogram using mutex instead of `StateLocker`. (#669)
2825- Switch `MinMaxSumCount` to a mutex lock implementation instead of `StateLocker`. (#667)
2826- Update documentation to not include any references to `WithKeys`. (#672)
2827- Correct misspelling. (#668)
2828- Fix clobbering of the span context if extraction fails. (#656)
2829- Bump `golangci-lint` and work around the corrupting bug. (#666) (#670)
2830
2831## [0.4.3] - 2020-04-24
2832
2833### Added
2834
2835- `Dockerfile` and `docker-compose.yml` to run example code. (#635)
2836- New `grpctrace` package that provides gRPC client and server interceptors for both unary and stream connections. (#621)
2837- New `api/label` package, providing common label set implementation. (#651)
2838- Support for JSON marshaling of `Resources`. (#654)
2839- `TraceID` and `SpanID` implementations for `Stringer` interface. (#642)
2840- `RemoteAddrKey` in the othttp plugin to include the HTTP client address in top-level spans. (#627)
2841- `WithSpanFormatter` option to the othttp plugin. (#617)
2842- Updated README to include section for compatible libraries and include reference to the contrib repository. (#612)
2843- The prometheus exporter now supports exporting histograms. (#601)
2844- A `String` method to the `Resource` to return a hashable identifier for a now unique resource. (#613)
2845- An `Iter` method to the `Resource` to return an array `AttributeIterator`. (#613)
2846- An `Equal` method to the `Resource` test the equivalence of resources. (#613)
2847- An iterable structure (`AttributeIterator`) for `Resource` attributes.
2848
2849### Changed
2850
2851- zipkin export's `NewExporter` now requires a `serviceName` argument to ensure this needed values is provided. (#644)
2852- Pass `Resources` through the metrics export pipeline. (#659)
2853
2854### Removed
2855
2856- `WithKeys` option from the metric API. (#639)
2857
2858### Fixed
2859
2860- Use the `label.Set.Equivalent` value instead of an encoding in the batcher. (#658)
2861- Correct typo `trace.Exporter` to `trace.SpanSyncer` in comments. (#653)
2862- Use type names for return values in jaeger exporter. (#648)
2863- Increase the visibility of the `api/key` package by updating comments and fixing usages locally. (#650)
2864- `Checkpoint` only after `Update`; Keep records in the `sync.Map` longer. (#647)
2865- Do not cache `reflect.ValueOf()` in metric Labels. (#649)
2866- Batch metrics exported from the OTLP exporter based on `Resource` and labels. (#626)
2867- Add error wrapping to the prometheus exporter. (#631)
2868- Update the OTLP exporter batching of traces to use a unique `string` representation of an associated `Resource` as the batching key. (#623)
2869- Update OTLP `SpanData` transform to only include the `ParentSpanID` if one exists. (#614)
2870- Update `Resource` internal representation to uniquely and reliably identify resources. (#613)
2871- Check return value from `CheckpointSet.ForEach` in prometheus exporter. (#622)
2872- Ensure spans created by httptrace client tracer reflect operation structure. (#618)
2873- Create a new recorder rather than reuse when multiple observations in same epoch for asynchronous instruments. #610
2874- The default port the OTLP exporter uses to connect to the OpenTelemetry collector is updated to match the one the collector listens on by default. (#611)
2875
2876## [0.4.2] - 2020-03-31
2877
2878### Fixed
2879
2880- Fix `pre_release.sh` to update version in `sdk/opentelemetry.go`. (#607)
2881- Fix time conversion from internal to OTLP in OTLP exporter. (#606)
2882
2883## [0.4.1] - 2020-03-31
2884
2885### Fixed
2886
2887- Update `tag.sh` to create signed tags. (#604)
2888
2889## [0.4.0] - 2020-03-30
2890
2891### Added
2892
2893- New API package `api/metric/registry` that exposes a `MeterImpl` wrapper for use by SDKs to generate unique instruments. (#580)
2894- Script to verify examples after a new release. (#579)
2895
2896### Removed
2897
2898- The dogstatsd exporter due to lack of support.
2899   This additionally removes support for statsd. (#591)
2900- `LabelSet` from the metric API.
2901   This is replaced by a `[]core.KeyValue` slice. (#595)
2902- `Labels` from the metric API's `Meter` interface. (#595)
2903
2904### Changed
2905
2906- The metric `export.Labels` became an interface which the SDK implements and the `export` package provides a simple, immutable implementation of this interface intended for testing purposes. (#574)
2907- Renamed `internal/metric.Meter` to `MeterImpl`. (#580)
2908- Renamed `api/global/internal.obsImpl` to `asyncImpl`. (#580)
2909
2910### Fixed
2911
2912- Corrected missing return in mock span. (#582)
2913- Update License header for all source files to match CNCF guidelines and include a test to ensure it is present. (#586) (#596)
2914- Update to v0.3.0 of the OTLP in the OTLP exporter. (#588)
2915- Update pre-release script to be compatible between GNU and BSD based systems. (#592)
2916- Add a `RecordBatch` benchmark. (#594)
2917- Moved span transforms of the OTLP exporter to the internal package. (#593)
2918- Build both go-1.13 and go-1.14 in circleci to test for all supported versions of Go. (#569)
2919- Removed unneeded allocation on empty labels in OLTP exporter. (#597)
2920- Update `BatchedSpanProcessor` to process the queue until no data but respect max batch size. (#599)
2921- Update project documentation godoc.org links to pkg.go.dev. (#602)
2922
2923## [0.3.0] - 2020-03-21
2924
2925This is a first official beta release, which provides almost fully complete metrics, tracing, and context propagation functionality.
2926There is still a possibility of breaking changes.
2927
2928### Added
2929
2930- Add `Observer` metric instrument. (#474)
2931- Add global `Propagators` functionality to enable deferred initialization for propagators registered before the first Meter SDK is installed. (#494)
2932- Simplified export setup pipeline for the jaeger exporter to match other exporters. (#459)
2933- The zipkin trace exporter. (#495)
2934- The OTLP exporter to export metric and trace telemetry to the OpenTelemetry collector. (#497) (#544) (#545)
2935- Add `StatusMessage` field to the trace `Span`. (#524)
2936- Context propagation in OpenTracing bridge in terms of OpenTelemetry context propagation. (#525)
2937- The `Resource` type was added to the SDK. (#528)
2938- The global API now supports a `Tracer` and `Meter` function as shortcuts to getting a global `*Provider` and calling these methods directly. (#538)
2939- The metric API now defines a generic `MeterImpl` interface to support general purpose `Meter` construction.
2940   Additionally, `SyncImpl` and `AsyncImpl` are added to support general purpose instrument construction. (#560)
2941- A metric `Kind` is added to represent the `MeasureKind`, `ObserverKind`, and `CounterKind`. (#560)
2942- Scripts to better automate the release process. (#576)
2943
2944### Changed
2945
2946- Default to to use `AlwaysSampler` instead of `ProbabilitySampler` to match OpenTelemetry specification. (#506)
2947- Renamed `AlwaysSampleSampler` to `AlwaysOnSampler` in the trace API. (#511)
2948- Renamed `NeverSampleSampler` to `AlwaysOffSampler` in the trace API. (#511)
2949- The `Status` field of the `Span` was changed to `StatusCode` to disambiguate with the added `StatusMessage`. (#524)
2950- Updated the trace `Sampler` interface conform to the OpenTelemetry specification. (#531)
2951- Rename metric API `Options` to `Config`. (#541)
2952- Rename metric `Counter` aggregator to be `Sum`. (#541)
2953- Unify metric options into `Option` from instrument specific options. (#541)
2954- The trace API's `TraceProvider` now support `Resource`s. (#545)
2955- Correct error in zipkin module name. (#548)
2956- The jaeger trace exporter now supports `Resource`s. (#551)
2957- Metric SDK now supports `Resource`s.
2958   The `WithResource` option was added to configure a `Resource` on creation and the `Resource` method was added to the metric `Descriptor` to return the associated `Resource`. (#552)
2959- Replace `ErrNoLastValue` and `ErrEmptyDataSet` by `ErrNoData` in the metric SDK. (#557)
2960- The stdout trace exporter now supports `Resource`s. (#558)
2961- The metric `Descriptor` is now included at the API instead of the SDK. (#560)
2962- Replace `Ordered` with an iterator in `export.Labels`. (#567)
2963
2964### Removed
2965
2966- The vendor specific Stackdriver. It is now hosted on 3rd party vendor infrastructure. (#452)
2967- The `Unregister` method for metric observers as it is not in the OpenTelemetry specification. (#560)
2968- `GetDescriptor` from the metric SDK. (#575)
2969- The `Gauge` instrument from the metric API. (#537)
2970
2971### Fixed
2972
2973- Make histogram aggregator checkpoint consistent. (#438)
2974- Update README with import instructions and how to build and test. (#505)
2975- The default label encoding was updated to be unique. (#508)
2976- Use `NewRoot` in the othttp plugin for public endpoints. (#513)
2977- Fix data race in `BatchedSpanProcessor`. (#518)
2978- Skip test-386 for Mac OS 10.15.x (Catalina and upwards). #521
2979- Use a variable-size array to represent ordered labels in maps. (#523)
2980- Update the OTLP protobuf and update changed import path. (#532)
2981- Use `StateLocker` implementation in `MinMaxSumCount`. (#546)
2982- Eliminate goroutine leak in histogram stress test. (#547)
2983- Update OTLP exporter with latest protobuf. (#550)
2984- Add filters to the othttp plugin. (#556)
2985- Provide an implementation of the `Header*` filters that do not depend on Go 1.14. (#565)
2986- Encode labels once during checkpoint.
2987   The checkpoint function is executed in a single thread so we can do the encoding lazily before passing the encoded version of labels to the exporter.
2988   This is a cheap and quick way to avoid encoding the labels on every collection interval. (#572)
2989- Run coverage over all packages in `COVERAGE_MOD_DIR`. (#573)
2990
2991## [0.2.3] - 2020-03-04
2992
2993### Added
2994
2995- `RecordError` method on `Span`s in the trace API to Simplify adding error events to spans. (#473)
2996- Configurable push frequency for exporters setup pipeline. (#504)
2997
2998### Changed
2999
3000- Rename the `exporter` directory to `exporters`.
3001   The `go.opentelemetry.io/otel/exporter/trace/jaeger` package was mistakenly released with a `v1.0.0` tag instead of `v0.1.0`.
3002   This resulted in all subsequent releases not becoming the default latest.
3003   A consequence of this was that all `go get`s pulled in the incompatible `v0.1.0` release of that package when pulling in more recent packages from other otel packages.
3004   Renaming the `exporter` directory to `exporters` fixes this issue by renaming the package and therefore clearing any existing dependency tags.
3005   Consequentially, this action also renames *all* exporter packages. (#502)
3006
3007### Removed
3008
3009- The `CorrelationContextHeader` constant in the `correlation` package is no longer exported. (#503)
3010
3011## [0.2.2] - 2020-02-27
3012
3013### Added
3014
3015- `HTTPSupplier` interface in the propagation API to specify methods to retrieve and store a single value for a key to be associated with a carrier. (#467)
3016- `HTTPExtractor` interface in the propagation API to extract information from an `HTTPSupplier` into a context. (#467)
3017- `HTTPInjector` interface in the propagation API to inject information into an `HTTPSupplier.` (#467)
3018- `Config` and configuring `Option` to the propagator API. (#467)
3019- `Propagators` interface in the propagation API to contain the set of injectors and extractors for all supported carrier formats. (#467)
3020- `HTTPPropagator` interface in the propagation API to inject and extract from an `HTTPSupplier.` (#467)
3021- `WithInjectors` and `WithExtractors` functions to the propagator API to configure injectors and extractors to use. (#467)
3022- `ExtractHTTP` and `InjectHTTP` functions to apply configured HTTP extractors and injectors to a passed context. (#467)
3023- Histogram aggregator. (#433)
3024- `DefaultPropagator` function and have it return `trace.TraceContext` as the default context propagator. (#456)
3025- `AlwaysParentSample` sampler to the trace API. (#455)
3026- `WithNewRoot` option function to the trace API to specify the created span should be considered a root span. (#451)
3027
3028### Changed
3029
3030- Renamed `WithMap` to `ContextWithMap` in the correlation package. (#481)
3031- Renamed `FromContext` to `MapFromContext` in the correlation package. (#481)
3032- Move correlation context propagation to correlation package. (#479)
3033- Do not default to putting remote span context into links. (#480)
3034- `Tracer.WithSpan` updated to accept `StartOptions`. (#472)
3035- Renamed `MetricKind` to `Kind` to not stutter in the type usage. (#432)
3036- Renamed the `export` package to `metric` to match directory structure. (#432)
3037- Rename the `api/distributedcontext` package to `api/correlation`. (#444)
3038- Rename the `api/propagators` package to `api/propagation`. (#444)
3039- Move the propagators from the `propagators` package into the `trace` API package. (#444)
3040- Update `Float64Gauge`, `Int64Gauge`, `Float64Counter`, `Int64Counter`, `Float64Measure`, and `Int64Measure` metric methods to use value receivers instead of pointers. (#462)
3041- Moved all dependencies of tools package to a tools directory. (#466)
3042
3043### Removed
3044
3045- Binary propagators. (#467)
3046- NOOP propagator. (#467)
3047
3048### Fixed
3049
3050- Upgraded `github.com/golangci/golangci-lint` from `v1.21.0` to `v1.23.6` in `tools/`. (#492)
3051- Fix a possible nil-dereference crash (#478)
3052- Correct comments for `InstallNewPipeline` in the stdout exporter. (#483)
3053- Correct comments for `InstallNewPipeline` in the dogstatsd exporter. (#484)
3054- Correct comments for `InstallNewPipeline` in the prometheus exporter. (#482)
3055- Initialize `onError` based on `Config` in prometheus exporter. (#486)
3056- Correct module name in prometheus exporter README. (#475)
3057- Removed tracer name prefix from span names. (#430)
3058- Fix `aggregator_test.go` import package comment. (#431)
3059- Improved detail in stdout exporter. (#436)
3060- Fix a dependency issue (generate target should depend on stringer, not lint target) in Makefile. (#442)
3061- Reorders the Makefile targets within `precommit` target so we generate files and build the code before doing linting, so we can get much nicer errors about syntax errors from the compiler. (#442)
3062- Reword function documentation in gRPC plugin. (#446)
3063- Send the `span.kind` tag to Jaeger from the jaeger exporter. (#441)
3064- Fix `metadataSupplier` in the jaeger exporter to overwrite the header if existing instead of appending to it. (#441)
3065- Upgraded to Go 1.13 in CI. (#465)
3066- Correct opentelemetry.io URL in trace SDK documentation. (#464)
3067- Refactored reference counting logic in SDK determination of stale records. (#468)
3068- Add call to `runtime.Gosched` in instrument `acquireHandle` logic to not block the collector. (#469)
3069
3070## [0.2.1.1] - 2020-01-13
3071
3072### Fixed
3073
3074- Use stateful batcher on Prometheus exporter fixing regression introduced in #395. (#428)
3075
3076## [0.2.1] - 2020-01-08
3077
3078### Added
3079
3080- Global meter forwarding implementation.
3081   This enables deferred initialization for metric instruments registered before the first Meter SDK is installed. (#392)
3082- Global trace forwarding implementation.
3083   This enables deferred initialization for tracers registered before the first Trace SDK is installed. (#406)
3084- Standardize export pipeline creation in all exporters. (#395)
3085- A testing, organization, and comments for 64-bit field alignment. (#418)
3086- Script to tag all modules in the project. (#414)
3087
3088### Changed
3089
3090- Renamed `propagation` package to `propagators`. (#362)
3091- Renamed `B3Propagator` propagator to `B3`. (#362)
3092- Renamed `TextFormatPropagator` propagator to `TextFormat`. (#362)
3093- Renamed `BinaryPropagator` propagator to `Binary`. (#362)
3094- Renamed `BinaryFormatPropagator` propagator to `BinaryFormat`. (#362)
3095- Renamed `NoopTextFormatPropagator` propagator to `NoopTextFormat`. (#362)
3096- Renamed `TraceContextPropagator` propagator to `TraceContext`. (#362)
3097- Renamed `SpanOption` to `StartOption` in the trace API. (#369)
3098- Renamed `StartOptions` to `StartConfig` in the trace API. (#369)
3099- Renamed `EndOptions` to `EndConfig` in the trace API. (#369)
3100- `Number` now has a pointer receiver for its methods. (#375)
3101- Renamed `CurrentSpan` to `SpanFromContext` in the trace API. (#379)
3102- Renamed `SetCurrentSpan` to `ContextWithSpan` in the trace API. (#379)
3103- Renamed `Message` in Event to `Name` in the trace API. (#389)
3104- Prometheus exporter no longer aggregates metrics, instead it only exports them. (#385)
3105- Renamed `HandleImpl` to `BoundInstrumentImpl` in the metric API. (#400)
3106- Renamed `Float64CounterHandle` to `Float64CounterBoundInstrument` in the metric API. (#400)
3107- Renamed `Int64CounterHandle` to `Int64CounterBoundInstrument` in the metric API. (#400)
3108- Renamed `Float64GaugeHandle` to `Float64GaugeBoundInstrument` in the metric API. (#400)
3109- Renamed `Int64GaugeHandle` to `Int64GaugeBoundInstrument` in the metric API. (#400)
3110- Renamed `Float64MeasureHandle` to `Float64MeasureBoundInstrument` in the metric API. (#400)
3111- Renamed `Int64MeasureHandle` to `Int64MeasureBoundInstrument` in the metric API. (#400)
3112- Renamed `Release` method for bound instruments in the metric API to `Unbind`. (#400)
3113- Renamed `AcquireHandle` method for bound instruments in the metric API to `Bind`. (#400)
3114- Renamed the `File` option in the stdout exporter to `Writer`. (#404)
3115- Renamed all `Options` to `Config` for all metric exports where this wasn't already the case.
3116
3117### Fixed
3118
3119- Aggregator import path corrected. (#421)
3120- Correct links in README. (#368)
3121- The README was updated to match latest code changes in its examples. (#374)
3122- Don't capitalize error statements. (#375)
3123- Fix ignored errors. (#375)
3124- Fix ambiguous variable naming. (#375)
3125- Removed unnecessary type casting. (#375)
3126- Use named parameters. (#375)
3127- Updated release schedule. (#378)
3128- Correct http-stackdriver example module name. (#394)
3129- Removed the `http.request` span in `httptrace` package. (#397)
3130- Add comments in the metrics SDK (#399)
3131- Initialize checkpoint when creating ddsketch aggregator to prevent panic when merging into a empty one. (#402) (#403)
3132- Add documentation of compatible exporters in the README. (#405)
3133- Typo fix. (#408)
3134- Simplify span check logic in SDK tracer implementation. (#419)
3135
3136## [0.2.0] - 2019-12-03
3137
3138### Added
3139
3140- Unary gRPC tracing example. (#351)
3141- Prometheus exporter. (#334)
3142- Dogstatsd metrics exporter. (#326)
3143
3144### Changed
3145
3146- Rename `MaxSumCount` aggregation to `MinMaxSumCount` and add the `Min` interface for this aggregation. (#352)
3147- Rename `GetMeter` to `Meter`. (#357)
3148- Rename `HTTPTraceContextPropagator` to `TraceContextPropagator`. (#355)
3149- Rename `HTTPB3Propagator` to `B3Propagator`. (#355)
3150- Rename `HTTPTraceContextPropagator` to `TraceContextPropagator`. (#355)
3151- Move `/global` package to `/api/global`. (#356)
3152- Rename `GetTracer` to `Tracer`. (#347)
3153
3154### Removed
3155
3156- `SetAttribute` from the `Span` interface in the trace API. (#361)
3157- `AddLink` from the `Span` interface in the trace API. (#349)
3158- `Link` from the `Span` interface in the trace API. (#349)
3159
3160### Fixed
3161
3162- Exclude example directories from coverage report. (#365)
3163- Lint make target now implements automatic fixes with `golangci-lint` before a second run to report the remaining issues. (#360)
3164- Drop `GO111MODULE` environment variable in Makefile as Go 1.13 is the project specified minimum version and this is environment variable is not needed for that version of Go. (#359)
3165- Run the race checker for all test. (#354)
3166- Redundant commands in the Makefile are removed. (#354)
3167- Split the `generate` and `lint` targets of the Makefile. (#354)
3168- Renames `circle-ci` target to more generic `ci` in Makefile. (#354)
3169- Add example Prometheus binary to gitignore. (#358)
3170- Support negative numbers with the `MaxSumCount`. (#335)
3171- Resolve race conditions in `push_test.go` identified in #339. (#340)
3172- Use `/usr/bin/env bash` as a shebang in scripts rather than `/bin/bash`. (#336)
3173- Trace benchmark now tests both `AlwaysSample` and `NeverSample`.
3174   Previously it was testing `AlwaysSample` twice. (#325)
3175- Trace benchmark now uses a `[]byte` for `TraceID` to fix failing test. (#325)
3176- Added a trace benchmark to test variadic functions in `setAttribute` vs `setAttributes` (#325)
3177- The `defaultkeys` batcher was only using the encoded label set as its map key while building a checkpoint.
3178   This allowed distinct label sets through, but any metrics sharing a label set could be overwritten or merged incorrectly.
3179   This was corrected. (#333)
3180
3181## [0.1.2] - 2019-11-18
3182
3183### Fixed
3184
3185- Optimized the `simplelru` map for attributes to reduce the number of allocations. (#328)
3186- Removed unnecessary unslicing of parameters that are already a slice. (#324)
3187
3188## [0.1.1] - 2019-11-18
3189
3190This release contains a Metrics SDK with stdout exporter and supports basic aggregations such as counter, gauges, array, maxsumcount, and ddsketch.
3191
3192### Added
3193
3194- Metrics stdout export pipeline. (#265)
3195- Array aggregation for raw measure metrics. (#282)
3196- The core.Value now have a `MarshalJSON` method. (#281)
3197
3198### Removed
3199
3200- `WithService`, `WithResources`, and `WithComponent` methods of tracers. (#314)
3201- Prefix slash in `Tracer.Start()` for the Jaeger example. (#292)
3202
3203### Changed
3204
3205- Allocation in LabelSet construction to reduce GC overhead. (#318)
3206- `trace.WithAttributes` to append values instead of replacing (#315)
3207- Use a formula for tolerance in sampling tests. (#298)
3208- Move export types into trace and metric-specific sub-directories. (#289)
3209- `SpanKind` back to being based on an `int` type. (#288)
3210
3211### Fixed
3212
3213- URL to OpenTelemetry website in README. (#323)
3214- Name of othttp default tracer. (#321)
3215- `ExportSpans` for the stackdriver exporter now handles `nil` context. (#294)
3216- CI modules cache to correctly restore/save from/to the cache. (#316)
3217- Fix metric SDK race condition between `LoadOrStore` and the assignment `rec.recorder = i.meter.exporter.AggregatorFor(rec)`. (#293)
3218- README now reflects the new code structure introduced with these changes. (#291)
3219- Make the basic example work. (#279)
3220
3221## [0.1.0] - 2019-11-04
3222
3223This is the first release of open-telemetry go library.
3224It contains api and sdk for trace and meter.
3225
3226### Added
3227
3228- Initial OpenTelemetry trace and metric API prototypes.
3229- Initial OpenTelemetry trace, metric, and export SDK packages.
3230- A wireframe bridge to support compatibility with OpenTracing.
3231- Example code for a basic, http-stackdriver, http, jaeger, and named tracer setup.
3232- Exporters for Jaeger, Stackdriver, and stdout.
3233- Propagators for binary, B3, and trace-context protocols.
3234- Project information and guidelines in the form of a README and CONTRIBUTING.
3235- Tools to build the project and a Makefile to automate the process.
3236- Apache-2.0 license.
3237- CircleCI build CI manifest files.
3238- CODEOWNERS file to track owners of this project.
3239
3240[Unreleased]: https://github.com/open-telemetry/opentelemetry-go/compare/v1.35.0...HEAD
3241[1.35.0/0.57.0/0.11.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.35.0
3242[1.34.0/0.56.0/0.10.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.34.0
3243[1.33.0/0.55.0/0.9.0/0.0.12]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.33.0
3244[1.32.0/0.54.0/0.8.0/0.0.11]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.32.0
3245[1.31.0/0.53.0/0.7.0/0.0.10]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.31.0
3246[1.30.0/0.52.0/0.6.0/0.0.9]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.30.0
3247[1.29.0/0.51.0/0.5.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.29.0
3248[1.28.0/0.50.0/0.4.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.28.0
3249[1.27.0/0.49.0/0.3.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.27.0
3250[1.26.0/0.48.0/0.2.0-alpha]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.26.0
3251[1.25.0/0.47.0/0.0.8/0.1.0-alpha]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.25.0
3252[1.24.0/0.46.0/0.0.1-alpha]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.24.0
3253[1.23.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.23.1
3254[1.23.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.23.0
3255[1.23.0-rc.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.23.0-rc.1
3256[1.22.0/0.45.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.22.0
3257[1.21.0/0.44.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.21.0
3258[1.20.0/0.43.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.20.0
3259[1.19.0/0.42.0/0.0.7]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.19.0
3260[1.19.0-rc.1/0.42.0-rc.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.19.0-rc.1
3261[1.18.0/0.41.0/0.0.6]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.18.0
3262[1.17.0/0.40.0/0.0.5]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.17.0
3263[1.16.0/0.39.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.16.0
3264[1.16.0-rc.1/0.39.0-rc.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.16.0-rc.1
3265[1.15.1/0.38.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.15.1
3266[1.15.0/0.38.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.15.0
3267[1.15.0-rc.2/0.38.0-rc.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.15.0-rc.2
3268[1.15.0-rc.1/0.38.0-rc.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.15.0-rc.1
3269[1.14.0/0.37.0/0.0.4]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.14.0
3270[1.13.0/0.36.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.13.0
3271[1.12.0/0.35.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.12.0
3272[1.11.2/0.34.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.11.2
3273[1.11.1/0.33.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.11.1
3274[1.11.0/0.32.3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.11.0
3275[0.32.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/sdk/metric/v0.32.2
3276[0.32.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/sdk/metric/v0.32.1
3277[0.32.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/sdk/metric/v0.32.0
3278[1.10.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.10.0
3279[1.9.0/0.0.3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.9.0
3280[1.8.0/0.31.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.8.0
3281[1.7.0/0.30.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.7.0
3282[0.29.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/metric/v0.29.0
3283[1.6.3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.6.3
3284[1.6.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.6.2
3285[1.6.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.6.1
3286[1.6.0/0.28.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.6.0
3287[1.5.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.5.0
3288[1.4.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.4.1
3289[1.4.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.4.0
3290[1.3.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.3.0
3291[1.2.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.2.0
3292[1.1.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.1.0
3293[1.0.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.0.1
3294[Metrics 0.24.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/metric/v0.24.0
3295[1.0.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.0.0
3296[1.0.0-RC3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.0.0-RC3
3297[1.0.0-RC2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.0.0-RC2
3298[Experimental Metrics v0.22.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/metric/v0.22.0
3299[1.0.0-RC1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v1.0.0-RC1
3300[0.20.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.20.0
3301[0.19.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.19.0
3302[0.18.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.18.0
3303[0.17.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.17.0
3304[0.16.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.16.0
3305[0.15.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.15.0
3306[0.14.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.14.0
3307[0.13.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.13.0
3308[0.12.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.12.0
3309[0.11.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.11.0
3310[0.10.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.10.0
3311[0.9.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.9.0
3312[0.8.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.8.0
3313[0.7.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.7.0
3314[0.6.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.6.0
3315[0.5.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.5.0
3316[0.4.3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.4.3
3317[0.4.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.4.2
3318[0.4.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.4.1
3319[0.4.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.4.0
3320[0.3.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.3.0
3321[0.2.3]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.2.3
3322[0.2.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.2.2
3323[0.2.1.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.2.1.1
3324[0.2.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.2.1
3325[0.2.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.2.0
3326[0.1.2]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.1.2
3327[0.1.1]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.1.1
3328[0.1.0]: https://github.com/open-telemetry/opentelemetry-go/releases/tag/v0.1.0
3329
3330<!-- Released section ended -->
3331
3332[Go 1.24]: https://go.dev/doc/go1.24
3333[Go 1.23]: https://go.dev/doc/go1.23
3334[Go 1.22]: https://go.dev/doc/go1.22
3335[Go 1.21]: https://go.dev/doc/go1.21
3336[Go 1.20]: https://go.dev/doc/go1.20
3337[Go 1.19]: https://go.dev/doc/go1.19
3338[Go 1.18]: https://go.dev/doc/go1.18
3339
3340[metric API]:https://pkg.go.dev/go.opentelemetry.io/otel/metric
3341[metric SDK]:https://pkg.go.dev/go.opentelemetry.io/otel/sdk/metric
3342[trace API]:https://pkg.go.dev/go.opentelemetry.io/otel/trace
3343
3344[GO-2024-2687]: https://pkg.go.dev/vuln/GO-2024-2687