Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog.

This project adheres to Semantic Versioning.

Unreleased

0.13.0 - 2020-10-08

Added

• OTLP Metric exporter supports Histogram aggregation. (#1209)
• 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)
• A Baggage API to implement the OpenTelemetry specification. (#1217)

Changed

• Set default propagator to no-op propagator. (#1184)
• 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 package. (#1212)
• The New function from the go.opentelemetry.io/otel/api/propagation package was replaced with NewCompositeTextMapPropagator in the go.opentelemetry.io/otel package. (#1212)
• The status codes of the go.opentelemetry.io/otel/codes package have been updated to match the latest OpenTelemetry specification. They now are Unset, Error, and Ok. They no longer track the gRPC codes. (#1214)
• 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)
• Move the go.opentelemetry.io/otel/api/baggage package into go.opentelemetry.io/otel/propagators. (#1217)

Fixed

• 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)

Removed

• The ExtractHTTP and InjectHTTP functions from the go.opentelemetry.io/otel/api/propagation package were removed. (#1212)
• The Propagators interface from the go.opentelemetry.io/otel/api/propagation package was removed to conform to the OpenTelemetry specification. The explicit TextMapPropagator type can be used in its place as this is the Propagator type the specification defines. (#1212)
• 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)
• The internal implementation of Baggage storage is removed in favor of using the new Baggage API functionality. (#1217)
• Remove duplicate hostname key HostHostNameKey in Resource semantic conventions. (#1219)
• Nested array/slice support has been removed. (#1226)

0.12.0 - 2020-09-24

Added

• A SpanConfigure function in go.opentelemetry.io/otel/api/trace to create a new SpanConfig from SpanOptions. (#1108)
• In the go.opentelemetry.io/otel/api/trace package, NewTracerConfig was added to construct new TracerConfigs. This addition was made to conform with our project option conventions. (#1155)
• Instrumentation library information was added to the Zipkin exporter. (#1119)
• The SpanProcessor interface now has a ForceFlush() method. (#1166)
• More semantic conventions for k8s as resource attributes. (#1167)

Changed

• Add reconnecting udp connection type to Jaeger exporter. This change adds a new optional implementation of the udp conn interface used to detect changes to an agent's host dns record. 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)
• Replace StartOption and EndOption in go.opentelemetry.io/otel/api/trace with SpanOption. This change is matched by replacing the StartConfig and EndConfig with a unified SpanConfig. (#1108)
• Replace the LinkedTo span option in go.opentelemetry.io/otel/api/trace with WithLinks. 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)
• The go.opentelemetry.io/otel/api/trace TracerOption was changed to an interface to conform to project option conventions. (#1109)
• Move the B3 and TraceContext from within the go.opentelemetry.io/otel/api/trace package to their own go.opentelemetry.io/otel/propagators package. 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)
• Rename Jaeger tags used for instrumentation library information to reflect changes in OpenTelemetry specification. (#1119)
• Rename ProbabilitySampler to TraceIDRatioBased and change semantics to ignore parent span sampling status. (#1115)
• Move tools package under internal. (#1141)
• Move go.opentelemetry.io/otel/api/correlation package to go.opentelemetry.io/otel/api/baggage. (#1142) The correlation.CorrelationContext propagator has been renamed baggage.Baggage. Other exported functions and types are unchanged.
• Rename ParentOrElse sampler to ParentBased and allow setting samplers depending on parent span. (#1153)
• In the go.opentelemetry.io/otel/api/trace package, SpanConfigure was renamed to NewSpanConfig. (#1155)
• Change dependabot.yml to add a Skip Changelog label to dependabot-sourced PRs. (#1161)
• The configuration style guide has been updated to recommend the use of newConfig() instead of configure(). (#1163)
• The otlp.Config type has been unexported and changed to otlp.config, along with its initializer. (#1163)
• Ensure exported interface types include parameter names and update the Style Guide to reflect this styling rule. (#1172)
• Don't consider unset environment variable for resource detection to be an error. (#1170)
• Rename go.opentelemetry.io/otel/api/metric.ConfigureInstrument to NewInstrumentConfig and go.opentelemetry.io/otel/api/metric.ConfigureMeter to NewMeterConfig.
• ValueObserver instruments use LastValue aggregator by default. (#1165)
• OTLP Metric exporter supports LastValue aggregation. (#1165)
• Move the go.opentelemetry.io/otel/api/unit package to go.opentelemetry.io/otel/unit. (#1185)
• Rename Provider to MeterProvider in the go.opentelemetry.io/otel/api/metric package. (#1190)
• Rename NoopProvider to NoopMeterProvider in the go.opentelemetry.io/otel/api/metric package. (#1190)
• Rename NewProvider to NewMeterProvider in the go.opentelemetry.io/otel/api/metric/metrictest package. (#1190)
• Rename Provider to MeterProvider in the go.opentelemetry.io/otel/api/metric/registry package. (#1190)
• Rename NewProvider to NewMeterProvider in the go.opentelemetry.io/otel/api/metri/registryc package. (#1190)
• Rename Provider to TracerProvider in the go.opentelemetry.io/otel/api/trace package. (#1190)
• Rename NoopProvider to NoopTracerProvider in the go.opentelemetry.io/otel/api/trace package. (#1190)
• Rename Provider to TracerProvider in the go.opentelemetry.io/otel/api/trace/tracetest package. (#1190)
• Rename NewProvider to NewTracerProvider in the go.opentelemetry.io/otel/api/trace/tracetest package. (#1190)
• Rename WrapperProvider to WrapperTracerProvider in the go.opentelemetry.io/otel/bridge/opentracing package. (#1190)
• Rename NewWrapperProvider to NewWrapperTracerProvider in the go.opentelemetry.io/otel/bridge/opentracing package. (#1190)
• Rename Provider method of the pull controller to MeterProvider in the go.opentelemetry.io/otel/sdk/metric/controller/pull package. (#1190)
• Rename Provider method of the push controller to MeterProvider in the go.opentelemetry.io/otel/sdk/metric/controller/push package. (#1190)
• Rename ProviderOptions to TracerProviderConfig in the go.opentelemetry.io/otel/sdk/trace package. (#1190)
• Rename ProviderOption to TracerProviderOption in the go.opentelemetry.io/otel/sdk/trace package. (#1190)
• Rename Provider to TracerProvider in the go.opentelemetry.io/otel/sdk/trace package. (#1190)
• Rename NewProvider to NewTracerProvider in the go.opentelemetry.io/otel/sdk/trace package. (#1190)
• Renamed SamplingDecision values to comply with OpenTelemetry specification change. (#1192)
• Renamed Zipkin attribute names from ot.status_code & ot.status_description to otel.status_code & otel.status_description. (#1201)
• The default SDK now invokes registered SpanProcessors in the order they were registered with the TracerProvider. (#1195)
• Add test of spans being processed by the SpanProcessors in the order they were registered. (#1203)

Removed

• Remove the B3 propagator from go.opentelemetry.io/otel/propagators. It is now located in the go.opentelemetry.io/contrib/propagators/ module. (#1191)
• Remove the semantic convention for HTTP status text, HTTPStatusTextKey from package go.opentelemetry.io/otel/semconv. (#1194)

Fixed

• Zipkin example no longer mentions ParentSampler, corrected to ParentBased. (#1171)
• Fix missing shutdown processor in otel-collector example. (#1186)
• Fix missing shutdown processor in basic and namedtracer examples. (#1197)

0.11.0 - 2020-08-24

Added

• Support for exporting array-valued attributes via OTLP. (#992)
• Noop and InMemory SpanBatcher implementations to help with testing integrations. (#994)
• Support for filtering metric label sets. (#1047)
• A dimensionality-reducing metric Processor. (#1057)
• Integration tests for more OTel Collector Attribute types. (#1062)
• 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)

Changed

• Rename sdk/metric/processor/test to sdk/metric/processor/processortest. (#1049)
• Rename sdk/metric/controller/test to sdk/metric/controller/controllertest. (#1049)
• Rename api/testharness to api/apitest. (#1049)
• Rename api/trace/testtrace to api/trace/tracetest. (#1049)
• Change Metric Processor to merge multiple observations. (#1024)
• The go.opentelemetry.io/otel/bridge/opentracing bridge package has been made into its own module. This removes the package dependencies of this bridge from the rest of the OpenTelemetry based project. (#1038)
• 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)
• The environment variable used for resource detection has been changed from OTEL_RESOURCE_LABELS to OTEL_RESOURCE_ATTRIBUTES (#1042)
• Replace WithSyncer with WithBatcher in examples. (#1044)
• Replace the google.golang.org/grpc/codes dependency in the API with an equivalent go.opentelemetry.io/otel/codes package. (#1046)
• 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)
• Unify Callback Function Naming. Rename *Callback with *Func. (#1061)
• CI builds validate against last two versions of Go, dropping 1.13 and adding 1.15. (#1064)
• The go.opentelemetry.io/otel/sdk/export/trace interfaces SpanSyncer and SpanBatcher have been replaced with a specification compliant Exporter interface. This interface still supports the export of SpanData, but only as a slice. 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)
• The go.opentelemetry.io/otel/sdk/trace NewBatchSpanProcessor function no longer returns an error. 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)
• The go.opentelemetry.io/otel/sdk/trace NewProvider function to create a Provider no longer returns an error, instead only a *Provider. This change is related to NewBatchSpanProcessor not returning an error which was the only error this function would return. (#1078)

Removed

• Duplicate, unused API sampler interface. (#999) Use the Sampler interface provided by the SDK instead.
• The grpctrace instrumentation was moved to the go.opentelemetry.io/contrib repository and out of this repository. This move includes moving the grpc example to the go.opentelemetry.io/contrib as well. (#1027)
• The WithSpan method of the Tracer interface. The functionality this method provided was limited compared to what a user can provide themselves. It was removed with the understanding that if there is sufficient user need it can be added back based on actual user usage. (#1043)
• The RegisterSpanProcessor and UnregisterSpanProcessor functions. These were holdovers from an approach prior to the TracerProvider design. They were not used anymore. (#1077)
• The oterror package. (#1026)
• The othttp and httptrace instrumentations were moved to go.opentelemetry.io/contrib. (#1032)

Fixed

• The semconv.HTTPServerMetricAttributesFromHTTPRequest() function no longer generates the high-cardinality http.request.content.length label. (#1031)
• Correct instrumentation version tag in Jaeger exporter. (#1037)
• The SDK span will now set an error event if the End method is called during a panic (i.e. it was deferred). (#1043)
• Move internally generated protobuf code from the go.opentelemetry.io/otel to the OTLP exporter to reduce dependency overhead. (#1050)
• The otel-collector example referenced outdated collector processors. (#1006)

0.10.0 - 2020-07-29

This release migrates the default OpenTelemetry SDK into its own Go module, decoupling the SDK from the API and reducing dependencies for instrumentation packages.

Added

• The Zipkin exporter now has NewExportPipeline and InstallNewPipeline constructor functions to match the common pattern. These function build a new exporter with default SDK options and register the exporter with the global package respectively. (#944)
• Add propagator option for gRPC instrumentation. (#986)
• The testtrace package now tracks the trace.SpanKind for each span. (#987)

Changed

• Replace the RegisterGlobal Option in the Jaeger exporter with an InstallNewPipeline constructor function. This matches the other exporter constructor patterns and will register a new exporter after building it with default configuration. (#944)
• 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. 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)
• Move the go.opentelemetry.io/otel/exporters/test test package to go.opentelemetry.io/otel/sdk/export/metric/metrictest. (#962)
• The go.opentelemetry.io/otel/api/kv/value package was merged into the parent go.opentelemetry.io/otel/api/kv package. (#968)
  • value.Bool was replaced with kv.BoolValue.
  • value.Int64 was replaced with kv.Int64Value.
  • value.Uint64 was replaced with kv.Uint64Value.
  • value.Float64 was replaced with kv.Float64Value.
  • value.Int32 was replaced with kv.Int32Value.
  • value.Uint32 was replaced with kv.Uint32Value.
  • value.Float32 was replaced with kv.Float32Value.
  • value.String was replaced with kv.StringValue.
  • value.Int was replaced with kv.IntValue.
  • value.Uint was replaced with kv.UintValue.
  • value.Array was replaced with kv.ArrayValue.
• Rename Infer to Any in the go.opentelemetry.io/otel/api/kv package. (#972)
• 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 ResponseWriterare also implemented by the wrapped ResponseWriter. (#979)
• Rename go.opentelemetry.io/otel/sdk/metric/aggregator/test package to go.opentelemetry.io/otel/sdk/metric/aggregator/aggregatortest. (#980)
• Make the SDK into its own Go module called go.opentelemetry.io/otel/sdk. (#985)
• Changed the default trace Sampler from AlwaysOn to ParentOrElse(AlwaysOn). (#989)

Removed

• The IndexedAttribute function from the go.opentelemetry.io/otel/api/label package was removed in favor of IndexedLabel which it was synonymous with. (#970)

Fixed

• Bump github.com/golangci/golangci-lint from 1.28.3 to 1.29.0 in /tools. (#953)
• Bump github.com/google/go-cmp from 0.5.0 to 0.5.1. (#957)
• Use global.Handle for span export errors in the OTLP exporter. (#946)
• Correct Go language formatting in the README documentation. (#961)
• Remove default SDK dependencies from the go.opentelemetry.io/otel/api package. (#977)
• Remove default SDK dependencies from the go.opentelemetry.io/otel/instrumentation package. (#983)
• Move documented examples for go.opentelemetry.io/otel/instrumentation/grpctrace interceptors into Go example tests. (#984)

0.9.0 - 2020-07-20

Added

• A new Resource Detector interface is included to allow resources to be automatically detected and included. (#939)
• A Detector to automatically detect resources from an environment variable. (#939)
• Github action to generate protobuf Go bindings locally in internal/opentelemetry-proto-gen. (#938)
• OTLP .proto files from open-telemetry/opentelemetry-proto imported as a git submodule under internal/opentelemetry-proto. References to github.com/open-telemetry/opentelemetry-proto changed to go.opentelemetry.io/otel/internal/opentelemetry-proto-gen. (#942)

Changed

• Non-nil value structs for key-value pairs will be marshalled using JSON rather than Sprintf. (#948)

Removed

• Removed dependency on github.com/open-telemetry/opentelemetry-collector. (#943)

0.8.0 - 2020-07-09

Added

• The B3Encoding type to represent the B3 encoding(s) the B3 propagator can inject. A value for HTTP supported encodings (Multiple Header: MultipleHeader, Single Header: SingleHeader) are included. (#882)
• The FlagsDeferred trace flag to indicate if the trace sampling decision has been deferred. (#882)
• The FlagsDebug trace flag to indicate if the trace is a debug trace. (#882)
• Add peer.service semantic attribute. (#898)
• Add database-specific semantic attributes. (#899)
• Add semantic convention for faas.coldstart and container.id. (#909)
• Add http content size semantic conventions. (#905)
• Include http.request_content_length in HTTP request basic attributes. (#905)
• Add semantic conventions for operating system process resource attribute keys. (#919)
• The Jaeger exporter now has a WithBatchMaxCount option to specify the maximum number of spans sent in a batch. (#931)

Changed

• Update CONTRIBUTING.md to ask for updates to CHANGELOG.md with each pull request. (#879)
• Use lowercase header names for B3 Multiple Headers. (#881)
• The B3 propagator SingleHeader field has been replaced with InjectEncoding. This new field can be set to combinations of the B3Encoding bitmasks and will inject trace information in these encodings. If no encoding is set, the propagator will default to MultipleHeader encoding. (#882)
• The B3 propagator now extracts from either HTTP encoding of B3 (Single Header or Multiple Header) based on what is contained in the header. Preference is given to Single Header encoding with Multiple Header being the fallback if Single Header is not found or is invalid. 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)
• Extend semantic conventions for RPC. (#900)
• To match constant naming conventions in the api/standard package, the FaaS* key names are appended with a suffix of Key. (#920)
  • "api/standard".FaaSName -> FaaSNameKey
  • "api/standard".FaaSID -> FaaSIDKey
  • "api/standard".FaaSVersion -> FaaSVersionKey
  • "api/standard".FaaSInstance -> FaaSInstanceKey

Removed

• The FlagsUnused trace flag is removed. The purpose of this flag was to act as the inverse of FlagsSampled, the inverse of FlagsSampled is used instead. (#882)
• The B3 header constants (B3SingleHeader, B3DebugFlagHeader, B3TraceIDHeader, B3SpanIDHeader, B3SampledHeader, B3ParentSpanIDHeader) are removed. If B3 header keys are needed the authoritative OpenZipkin package constants should be used instead. (#882)

Fixed

• The B3 Single Header name is now correctly b3 instead of the previous X-B3. (#881)
• The B3 propagator now correctly supports sampling only values (b3: 0, b3: 1, or b3: d) for a Single B3 Header. (#882)
• The B3 propagator now propagates the debug flag. This removes the behavior of changing the debug flag into a set sampling bit. Instead, this now follow the B3 specification and omits the X-B3-Sampling header. (#882)
• The B3 propagator now tracks "unset" sampling state (meaning "defer the decision") and does not set the X-B3-Sampling header when injecting. (#882)
• Bump github.com/itchyny/gojq from 0.10.3 to 0.10.4 in /tools. (#883)
• Bump github.com/opentracing/opentracing-go from v1.1.1-0.20190913142402-a7454ce5950e to v1.2.0. (#885)
• The tracing time conversion for OTLP spans is now correctly set to UnixNano. (#896)
• Ensure span status is not set to Unknown when no HTTP status code is provided as it is assumed to be 200 OK. (#908)
• Ensure httptrace.clientTracer closes http.headers span. (#912)
• Prometheus exporter will not apply stale updates or forget inactive metrics. (#903)
• Add test for api.standard HTTPClientAttributesFromHTTPRequest. (#905)
• Bump github.com/golangci/golangci-lint from 1.27.0 to 1.28.1 in /tools. (#901, #913)
• Update otel-colector example to use the v0.5.0 collector. (#915)
• The grpctrace instrumentation uses a span name conforming to the OpenTelemetry semantic conventions (does not contain a leading slash (/)). (#922)
• The grpctrace instrumentation includes an rpc.method attribute now set to the gRPC method name. (#900, #922)
• The grpctrace instrumentation rpc.service attribute now contains the package name if one exists. This is in accordance with OpenTelemetry semantic conventions. (#922)
• Correlation Context extractor will no longer insert an empty map into the returned context when no valid values are extracted. (#923)
• Bump google.golang.org/api from 0.28.0 to 0.29.0 in /exporters/trace/jaeger. (#925)
• Bump github.com/itchyny/gojq from 0.10.4 to 0.11.0 in /tools. (#926)
• Bump github.com/golangci/golangci-lint from 1.28.1 to 1.28.2 in /tools. (#930)

0.7.0 - 2020-06-26

This release implements the v0.5.0 version of the OpenTelemetry specification.

Added

• The othttp instrumentation now includes default metrics. (#861)
• This CHANGELOG file to track all changes in the project going forward.
• Support for array type attributes. (#798)
• Apply transitive dependabot go.mod dependency updates as part of a new automatic Github workflow. (#844)
• Timestamps are now passed to exporters for each export. (#835)
• Add new Accumulation type to metric SDK to transport telemetry from Accumulators to Processors. This replaces the prior Record struct use for this purpose. (#835)
• New dependabot integration to automate package upgrades. (#814)
• Meter and Tracer implementations accept instrumentation version version as an optional argument. This instrumentation version is passed on to exporters. (#811) (#805) (#802)
• The OTLP exporter includes the instrumentation version in telemetry it exports. (#811)
• Environment variables for Jaeger exporter are supported. (#796)
• New aggregation.Kind in the export metric API. (#808)
• New example that uses OTLP and the collector. (#790)
• Handle errors in the span SetName during span initialization. (#791)
• Default service config to enable retries for retry-able failed requests in the OTLP exporter and an option to override this default. (#777)
• New go.opentelemetry.io/otel/api/oterror package to uniformly support error handling and definitions for the project. (#778)
• 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. 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)
• Options to specify propagators for httptrace and grpctrace instrumentation. (#784)
• The required application/json header for the Zipkin exporter is included in all exports. (#774)
• Integrate HTTP semantics helpers from the contrib repository into the api/standard package. #769

Changed

• Rename Integrator to Processor in the metric SDK. (#863)
• Rename AggregationSelector to AggregatorSelector. (#859)
• Rename SynchronizedCopy to SynchronizedMove. (#858)
• Rename simple integrator to basic integrator. (#857)
• Merge otlp collector examples. (#841)
• Change the metric SDK to support cumulative, delta, and pass-through exporters directly. With these changes, cumulative and delta specific exporters are able to request the correct kind of aggregation from the SDK. (#840)
• The Aggregator.Checkpoint API is renamed to SynchronizedCopy and adds an argument, a different Aggregator into which the copy is stored. (#812)
• The export.Aggregator contract is that Update() and SynchronizedCopy() are synchronized with each other. 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. Some of the Aggregators used unnecessary locking and that has been cleaned up. (#812)
• Use of metric.Number was replaced by int64 now that we use sync.Mutex in the MinMaxSumCount and Histogram Aggregators. (#812)
• Replace AlwaysParentSample with ParentSample(fallback) to match the OpenTelemetry v0.5.0 specification. (#810)
• Rename sdk/export/metric/aggregator to sdk/export/metric/aggregation. #808
• Send configured headers with every request in the OTLP exporter, instead of just on connection creation. (#806)
• Update error handling for any one off error handlers, replacing, instead, with the global.Handle function. (#791)
• Rename plugin directory to instrumentation to match the OpenTelemetry specification. (#779)
• Makes the argument order to Histogram and DDSketch New() consistent. (#781)

Removed

• Uint64NumberKind and related functions from the API. (#864)
• Context arguments from Aggregator.Checkpoint and Integrator.Process as they were unused. (#803)
• SpanID is no longer included in parameters for sampling decision to match the OpenTelemetry specification. (#775)

Fixed

• Upgrade OTLP exporter to opentelemetry-proto matching the opentelemetry-collector v0.4.0 release. (#866)
• Allow changes to go.sum and go.mod when running dependabot tidy-up. (#871)
• Bump github.com/stretchr/testify from 1.4.0 to 1.6.1. (#824)
• Bump github.com/prometheus/client_golang from 1.7.0 to 1.7.1 in /exporters/metric/prometheus. (#867)
• Bump google.golang.org/grpc from 1.29.1 to 1.30.0 in /exporters/trace/jaeger. (#853)
• Bump google.golang.org/grpc from 1.29.1 to 1.30.0 in /exporters/trace/zipkin. (#854)
• Bumps github.com/golang/protobuf from 1.3.2 to 1.4.2 (#848)
• Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/otlp (#817)
• Bump github.com/golangci/golangci-lint from 1.25.1 to 1.27.0 in /tools (#828)
• Bump github.com/prometheus/client_golang from 1.5.0 to 1.7.0 in /exporters/metric/prometheus (#838)
• Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/trace/jaeger (#829)
• Bump github.com/benbjohnson/clock from 1.0.0 to 1.0.3 (#815)
• Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/trace/zipkin (#823)
• Bump github.com/itchyny/gojq from 0.10.1 to 0.10.3 in /tools (#830)
• Bump github.com/stretchr/testify from 1.4.0 to 1.6.1 in /exporters/metric/prometheus (#822)
• Bump google.golang.org/grpc from 1.27.1 to 1.29.1 in /exporters/trace/zipkin (#820)
• Bump google.golang.org/grpc from 1.27.1 to 1.29.1 in /exporters/trace/jaeger (#831)
• Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 (#836)
• Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 in /exporters/trace/jaeger (#837)
• Bump github.com/google/go-cmp from 0.4.0 to 0.5.0 in /exporters/otlp (#839)
• Bump google.golang.org/api from 0.20.0 to 0.28.0 in /exporters/trace/jaeger (#843)
• Set span status from HTTP status code in the othttp instrumentation. (#832)
• Fixed typo in push controller comment. (#834)
• The Aggregator testing has been updated and cleaned. (#812)
• metric.Number(0) expressions are replaced by 0 where possible. (#812)
• Fixed global handler_test.go test failure. #804
• Fixed BatchSpanProcessor.Shutdown to wait until all spans are processed. (#766)
• Fixed OTLP example's accidental early close of exporter. (#807)
• Ensure zipkin exporter reads and closes response body. (#788)
• Update instrumentation to use api/standard keys instead of custom keys. (#782)
• Clean up tools and RELEASING documentation. (#762)

0.6.0 - 2020-05-21

Added

• Support for Resources in the prometheus exporter. (#757)
• New pull controller. (#751)
• New UpDownSumObserver instrument. (#750)
• OpenTelemetry collector demo. (#711)
• New SumObserver instrument. (#747)
• New UpDownCounter instrument. (#745)
• New timeout Option and configuration function WithTimeout to the push controller. (#742)
• New api/standards package to implement semantic conventions and standard key-value generation. (#731)

Changed

• Rename Register* functions in the metric API to New* for all Observer instruments. (#761)
• Use []float64 for histogram boundaries, not []metric.Number. (#758)
• Change OTLP example to use exporter as a trace Syncer instead of as an unneeded Batcher. (#756)
• Replace WithResourceAttributes() with WithResource() in the trace SDK. (#754)
• The prometheus exporter now uses the new pull controller. (#751)
• Rename ScheduleDelayMillis to BatchTimeout in the trace BatchSpanProcessor.(#752)
• Support use of synchronous instruments in asynchronous callbacks (#725)
• Move Resource from the Export method parameter into the metric export Record. (#739)
• Rename Observer instrument to ValueObserver. (#734)
• 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)
• Replace Measure instrument by ValueRecorder instrument. (#732)
• Rename correlation context header from "Correlation-Context" to "otcorrelations" to match the OpenTelemetry specification. 727)

Fixed

• Ensure gRPC ClientStream override methods do not panic in grpctrace package. (#755)
• Disable parts of BatchSpanProcessor test until a fix is found. (#743)
• Fix string case in kv Infer function. (#746)
• Fix panic in grpctrace client interceptors. (#740)
• Refactor the api/metrics push controller and add CheckpointSet synchronization. (#737)
• Rewrite span batch process queue batching logic. (#719)
• Remove the push controller named Meter map. (#738)
• Fix Histogram aggregator initial state (fix #735). (#736)
• Ensure golang alpine image is running golang-1.14 for examples. (#733)
• Added test for grpctrace UnaryInterceptorClient. (#695)
• Rearrange api/metric code layout. (#724)

0.5.0 - 2020-05-13

Added

• Batch Observer callback support. (#717)
• Alias api types to root package of project. (#696)
• Create basic othttp.Transport for simple client instrumentation. (#678)
• SetAttribute(string, interface{}) to the trace API. (#674)
• Jaeger exporter option that allows user to specify custom http client. (#671)
• Stringer and Infer methods to keys. (#662)

Changed

• Rename NewKey in the kv package to just Key. (#721)
• Move core and key to kv package. (#720)
• Make the metric API Meter a struct so the abstract MeterImpl can be passed and simplify implementation. (#709)
• Rename SDK Batcher to Integrator to match draft OpenTelemetry SDK specification. (#710)
• Rename SDK Ungrouped integrator to simple.Integrator to match draft OpenTelemetry SDK specification. (#710)
• Rename SDK SDK struct to Accumulator to match draft OpenTelemetry SDK specification. (#710)
• Move Number from core to api/metric package. (#706)
• Move SpanContext from core to trace package. (#692)
• Change traceparent header from Traceparent to traceparent to implement the W3C specification. (#681)

Fixed

• Update tooling to run generators in all submodules. (#705)
• gRPC interceptor regexp to match methods without a service name. (#683)
• Use a const for padding 64-bit B3 trace IDs. (#701)
• Update mockZipkin listen address from :0 to 127.0.0.1:0. (#700)
• Left-pad 64-bit B3 trace IDs with zero. (#698)
• Propagate at least the first W3C tracestate header. (#694)
• Remove internal StateLocker implementation. (#688)
• Increase instance size CI system uses. (#690)
• Add a key benchmark and use reflection in key.Infer(). (#679)
• Fix internal global test by using global.Meter with RecordBatch(). (#680)
• Reimplement histogram using mutex instead of StateLocker. (#669)
• Switch MinMaxSumCount to a mutex lock implementation instead of StateLocker. (#667)
• Update documentation to not include any references to WithKeys. (#672)
• Correct misspelling. (#668)
• Fix clobbering of the span context if extraction fails. (#656)
• Bump golangci-lint and work around the corrupting bug. (#666) (#670)

0.4.3 - 2020-04-24

Added

• Dockerfile and docker-compose.yml to run example code. (#635)
• New grpctrace package that provides gRPC client and server interceptors for both unary and stream connections. (#621)
• New api/label package, providing common label set implementation. (#651)
• Support for JSON marshaling of Resources. (#654)
• TraceID and SpanID implementations for Stringer interface. (#642)
• RemoteAddrKey in the othttp plugin to include the HTTP client address in top-level spans. (#627)
• WithSpanFormatter option to the othttp plugin. (#617)
• Updated README to include section for compatible libraries and include reference to the contrib repository. (#612)
• The prometheus exporter now supports exporting histograms. (#601)
• A String method to the Resource to return a hashable identifier for a now unique resource. (#613)
• An Iter method to the Resource to return an array AttributeIterator. (#613)
• An Equal method to the Resource test the equivalence of resources. (#613)
• An iterable structure (AttributeIterator) for Resource attributes.

Changed

• zipkin export's NewExporter now requires a serviceName argument to ensure this needed values is provided. (#644)
• Pass Resources through the metrics export pipeline. (#659)

Removed

• WithKeys option from the metric API. (#639)

Fixed

• Use the label.Set.Equivalent value instead of an encoding in the batcher. (#658)
• Correct typo trace.Exporter to trace.SpanSyncer in comments. (#653)
• Use type names for return values in jaeger exporter. (#648)
• Increase the visibility of the api/key package by updating comments and fixing usages locally. (#650)
• Checkpoint only after Update; Keep records in the sync.Map longer. (#647)
• Do not cache reflect.ValueOf() in metric Labels. (#649)
• Batch metrics exported from the OTLP exporter based on Resource and labels. (#626)
• Add error wrapping to the prometheus exporter. (#631)
• Update the OTLP exporter batching of traces to use a unique string representation of an associated Resource as the batching key. (#623)
• Update OTLP SpanData transform to only include the ParentSpanID if one exists. (#614)
• Update Resource internal representation to uniquely and reliably identify resources. (#613)
• Check return value from CheckpointSet.ForEach in prometheus exporter. (#622)
• Ensure spans created by httptrace client tracer reflect operation structure. (#618)
• Create a new recorder rather than reuse when multiple observations in same epoch for asynchronous instruments. #610
• 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)

0.4.2 - 2020-03-31

Fixed

• Fix pre_release.sh to update version in sdk/opentelemetry.go. (#607)
• Fix time conversion from internal to OTLP in OTLP exporter. (#606)

0.4.1 - 2020-03-31

Fixed

• Update tag.sh to create signed tags. (#604)

0.4.0 - 2020-03-30

Added

• New API package api/metric/registry that exposes a MeterImpl wrapper for use by SDKs to generate unique instruments. (#580)
• Script to verify examples after a new release. (#579)

Removed

• The dogstatsd exporter due to lack of support. This additionally removes support for statsd. (#591)
• LabelSet from the metric API. This is replaced by a []core.KeyValue slice. (#595)
• Labels from the metric API's Meter interface. (#595)

Changed

• 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)
• Renamed internal/metric.Meter to MeterImpl. (#580)
• Renamed api/global/internal.obsImpl to asyncImpl. (#580)

Fixed

• Corrected missing return in mock span. (#582)
• Update License header for all source files to match CNCF guidelines and include a test to ensure it is present. (#586) (#596)
• Update to v0.3.0 of the OTLP in the OTLP exporter. (#588)
• Update pre-release script to be compatible between GNU and BSD based systems. (#592)
• Add a RecordBatch benchmark. (#594)
• Moved span transforms of the OTLP exporter to the internal package. (#593)
• Build both go-1.13 and go-1.14 in circleci to test for all supported versions of Go. (#569)
• Removed unneeded allocation on empty labels in OLTP exporter. (#597)
• Update BatchedSpanProcessor to process the queue until no data but respect max batch size. (#599)
• Update project documentation godoc.org links to pkg.go.dev. (#602)

0.3.0 - 2020-03-21

This is a first official beta release, which provides almost fully complete metrics, tracing, and context propagation functionality. There is still a possibility of breaking changes.

Added

• Add Observer metric instrument. (#474)
• Add global Propagators functionality to enable deferred initialization for propagators registered before the first Meter SDK is installed. (#494)
• Simplified export setup pipeline for the jaeger exporter to match other exporters. (#459)
• The zipkin trace exporter. (#495)
• The OTLP exporter to export metric and trace telemetry to the OpenTelemetry collector. (#497) (#544) (#545)
• The StatusMessage field was add to the trace Span. (#524)
• Context propagation in OpenTracing bridge in terms of OpenTelemetry context propagation. (#525)
• The Resource type was added to the SDK. (#528)
• The global API now supports a Tracer and Meter function as shortcuts to getting a global *Provider and calling these methods directly. (#538)
• The metric API now defines a generic MeterImpl interface to support general purpose Meter construction. Additionally, SyncImpl and AsyncImpl are added to support general purpose instrument construction. (#560)
• A metric Kind is added to represent the MeasureKind, ObserverKind, and CounterKind. (#560)
• Scripts to better automate the release process. (#576)

Changed

• Default to to use AlwaysSampler instead of ProbabilitySampler to match OpenTelemetry specification. (#506)
• Renamed AlwaysSampleSampler to AlwaysOnSampler in the trace API. (#511)
• Renamed NeverSampleSampler to AlwaysOffSampler in the trace API. (#511)
• The Status field of the Span was changed to StatusCode to disambiguate with the added StatusMessage. (#524)
• Updated the trace Sampler interface conform to the OpenTelemetry specification. (#531)
• Rename metric API Options to Config. (#541)
• Rename metric Counter aggregator to be Sum. (#541)
• Unify metric options into Option from instrument specific options. (#541)
• The trace API's TraceProvider now support Resources. (#545)
• Correct error in zipkin module name. (#548)
• The jaeger trace exporter now supports Resources. (#551)
• Metric SDK now supports Resources. 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)
• Replace ErrNoLastValue and ErrEmptyDataSet by ErrNoData in the metric SDK. (#557)
• The stdout trace exporter now supports Resources. (#558)
• The metric Descriptor is now included at the API instead of the SDK. (#560)
• Replace Ordered with an iterator in export.Labels. (#567)

Removed

• The vendor specific Stackdriver. It is now hosted on 3rd party vendor infrastructure. (#452)
• The Unregister method for metric observers as it is not in the OpenTelemetry specification. (#560)
• GetDescriptor from the metric SDK. (#575)
• The Gauge instrument from the metric API. (#537)

Fixed

• Make histogram aggregator checkpoint consistent. (#438)
• Update README with import instructions and how to build and test. (#505)
• The default label encoding was updated to be unique. (#508)
• Use NewRoot in the othttp plugin for public endpoints. (#513)
• Fix data race in BatchedSpanProcessor. (#518)
• Skip test-386 for Mac OS 10.15.x (Catalina and upwards). #521
• Use a variable-size array to represent ordered labels in maps. (#523)
• Update the OTLP protobuf and update changed import path. (#532)
• Use StateLocker implementation in MinMaxSumCount. (#546)
• Eliminate goroutine leak in histogram stress test. (#547)
• Update OTLP exporter with latest protobuf. (#550)
• Add filters to the othttp plugin. (#556)
• Provide an implementation of the Header* filters that do not depend on Go 1.14. (#565)
• Encode labels once during checkpoint. 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. This is a cheap and quick way to avoid encoding the labels on every collection interval. (#572)
• Run coverage over all packages in COVERAGE_MOD_DIR. (#573)

0.2.3 - 2020-03-04

Added

• RecordError method on Spans in the trace API to Simplify adding error events to spans. (#473)
• Configurable push frequency for exporters setup pipeline. (#504)

Changed

• Rename the exporter directory to exporters. The go.opentelemetry.io/otel/exporter/trace/jaeger package was mistakenly released with a v1.0.0 tag instead of v0.1.0. This resulted in all subsequent releases not becoming the default latest. A consequence of this was that all go gets pulled in the incompatible v0.1.0 release of that package when pulling in more recent packages from other otel packages. Renaming the exporter directory to exporters fixes this issue by renaming the package and therefore clearing any existing dependency tags. Consequentially, this action also renames all exporter packages. (#502)

Removed

• The CorrelationContextHeader constant in the correlation package is no longer exported. (#503)

0.2.2 - 2020-02-27

Added

• 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)
• HTTPExtractor interface in the propagation API to extract information from an HTTPSupplier into a context. (#467)
• HTTPInjector interface in the propagation API to inject information into an HTTPSupplier. (#467)
• Config and configuring Option to the propagator API. (#467)
• Propagators interface in the propagation API to contain the set of injectors and extractors for all supported carrier formats. (#467)
• HTTPPropagator interface in the propagation API to inject and extract from an HTTPSupplier. (#467)
• WithInjectors and WithExtractors functions to the propagator API to configure injectors and extractors to use. (#467)
• ExtractHTTP and InjectHTTP functions to apply configured HTTP extractors and injectors to a passed context. (#467)
• Histogram aggregator. (#433)
• DefaultPropagator function and have it return trace.TraceContext as the default context propagator. (#456)
• AlwaysParentSample sampler to the trace API. (#455)
• WithNewRoot option function to the trace API to specify the created span should be considered a root span. (#451)

Changed

• Renamed WithMap to ContextWithMap in the correlation package. (#481)
• Renamed FromContext to MapFromContext in the correlation package. (#481)
• Move correlation context propagation to correlation package. (#479)
• Do not default to putting remote span context into links. (#480)
• Propagators extrac
• Tracer.WithSpan updated to accept StartOptions. (#472)
• Renamed MetricKind to Kind to not stutter in the type usage. (#432)
• Renamed the export package to metric to match directory structure. (#432)
• Rename the api/distributedcontext package to api/correlation. (#444)
• Rename the api/propagators package to api/propagation. (#444)
• Move the propagators from the propagators package into the trace API package. (#444)
• Update Float64Gauge, Int64Gauge, Float64Counter, Int64Counter, Float64Measure, and Int64Measure metric methods to use value receivers instead of pointers. (#462)
• Moved all dependencies of tools package to a tools directory. (#466)

Removed

• Binary propagators. (#467)
• NOOP propagator. (#467)

Fixed

• Upgraded github.com/golangci/golangci-lint from v1.21.0 to v1.23.6 in tools/. (#492)
• Fix a possible nil-dereference crash (#478)
• Correct comments for InstallNewPipeline in the stdout exporter. (#483)
• Correct comments for InstallNewPipeline in the dogstatsd exporter. (#484)
• Correct comments for InstallNewPipeline in the prometheus exporter. (#482)
• Initialize onError based on Config in prometheus exporter. (#486)
• Correct module name in prometheus exporter README. (#475)
• Removed tracer name prefix from span names. (#430)
• Fix aggregator_test.go import package comment. (#431)
• Improved detail in stdout exporter. (#436)
• Fix a dependency issue (generate target should depend on stringer, not lint target) in Makefile. (#442)
• 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)
• Reword function documentation in gRPC plugin. (#446)
• Send the span.kind tag to Jaeger from the jaeger exporter. (#441)
• Fix metadataSupplier in the jaeger exporter to overwrite the header if existing instead of appending to it. (#441)
• Upgraded to Go 1.13 in CI. (#465)
• Correct opentelemetry.io URL in trace SDK documentation. (#464)
• Refactored reference counting logic in SDK determination of stale records. (#468)
• Add call to runtime.Gosched in instrument acquireHandle logic to not block the collector. (#469)

0.2.1.1 - 2020-01-13

Fixed

• Use stateful batcher on Prometheus exporter fixing regresion introduced in #395. (#428)

0.2.1 - 2020-01-08

Added

• Global meter forwarding implementation. This enables deferred initialization for metric instruments registered before the first Meter SDK is installed. (#392)
• Global trace forwarding implementation. This enables deferred initialization for tracers registered before the first Trace SDK is installed. (#406)
• Standardize export pipeline creation in all exporters. (#395)
• A testing, organization, and comments for 64-bit field alignment. (#418)
• Script to tag all modules in the project. (#414)

Changed

• Renamed propagation package to propagators. (#362)
• Renamed B3Propagator propagator to B3. (#362)
• Renamed TextFormatPropagator propagator to TextFormat. (#362)
• Renamed BinaryPropagator propagator to Binary. (#362)
• Renamed BinaryFormatPropagator propagator to BinaryFormat. (#362)
• Renamed NoopTextFormatPropagator propagator to NoopTextFormat. (#362)
• Renamed TraceContextPropagator propagator to TraceContext. (#362)
• Renamed SpanOption to StartOption in the trace API. (#369)
• Renamed StartOptions to StartConfig in the trace API. (#369)
• Renamed EndOptions to EndConfig in the trace API. (#369)
• Number now has a pointer receiver for its methods. (#375)
• Renamed CurrentSpan to SpanFromContext in the trace API. (#379)
• Renamed SetCurrentSpan to ContextWithSpan in the trace API. (#379)
• Renamed Message in Event to Name in the trace API. (#389)
• Prometheus exporter no longer aggregates metrics, instead it only exports them. (#385)
• Renamed HandleImpl to BoundInstrumentImpl in the metric API. (#400)
• Renamed Float64CounterHandle to Float64CounterBoundInstrument in the metric API. (#400)
• Renamed Int64CounterHandle to Int64CounterBoundInstrument in the metric API. (#400)
• Renamed Float64GaugeHandle to Float64GaugeBoundInstrument in the metric API. (#400)
• Renamed Int64GaugeHandle to Int64GaugeBoundInstrument in the metric API. (#400)
• Renamed Float64MeasureHandle to Float64MeasureBoundInstrument in the metric API. (#400)
• Renamed Int64MeasureHandle to Int64MeasureBoundInstrument in the metric API. (#400)
• Renamed Release method for bound instruments in the metric API to Unbind. (#400)
• Renamed AcquireHandle method for bound instruments in the metric API to Bind. (#400)
• Renamed the File option in the stdout exporter to Writer. (#404)
• Renamed all Options to Config for all metric exports where this wasn't already the case.

Fixed

• Aggregator import path corrected. (#421)
• Correct links in README. (#368)
• The README was updated to match latest code changes in its examples. (#374)
• Don't capitalize error statements. (#375)
• Fix ignored errors. (#375)
• Fix ambiguous variable naming. (#375)
• Removed unnecessary type casting. (#375)
• Use named parameters. (#375)
• Updated release schedule. (#378)
• Correct http-stackdriver example module name. (#394)
• Removed the http.request span in httptrace package. (#397)
• Add comments in the metrics SDK (#399)
• Initialize checkpoint when creating ddsketch aggregator to prevent panic when merging into a empty one. (#402) (#403)
• Add documentation of compatible exporters in the README. (#405)
• Typo fix. (#408)
• Simplify span check logic in SDK tracer implementation. (#419)

0.2.0 - 2019-12-03

Added

• Unary gRPC tracing example. (#351)
• Prometheus exporter. (#334)
• Dogstatsd metrics exporter. (#326)

Changed

• Rename MaxSumCount aggregation to MinMaxSumCount and add the Min interface for this aggregation. (#352)
• Rename GetMeter to Meter. (#357)
• Rename HTTPTraceContextPropagator to TraceContextPropagator. (#355)
• Rename HTTPB3Propagator to B3Propagator. (#355)
• Rename HTTPTraceContextPropagator to TraceContextPropagator. (#355)
• Move /global package to /api/global. (#356)
• Rename GetTracer to Tracer. (#347)

Removed

• SetAttribute from the Span interface in the trace API. (#361)
• AddLink from the Span interface in the trace API. (#349)
• Link from the Span interface in the trace API. (#349)

Fixed

• Exclude example directories from coverage report. (#365)
• Lint make target now implements automatic fixes with golangci-lint before a second run to report the remaining issues. (#360)
• 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)
• Run the race checker for all test. (#354)
• Redundant commands in the Makefile are removed. (#354)
• Split the generate and lint targets of the Makefile. (#354)
• Renames circle-ci target to more generic ci in Makefile. (#354)
• Add example Prometheus binary to gitignore. (#358)
• Support negative numbers with the MaxSumCount. (#335)
• Resolve race conditions in push_test.go identified in #339. (#340)
• Use /usr/bin/env bash as a shebang in scripts rather than /bin/bash. (#336)
• Trace benchmark now tests both AlwaysSample and NeverSample. Previously it was testing AlwaysSample twice. (#325)
• Trace benchmark now uses a []byte for TraceID to fix failing test. (#325)
• Added a trace benchmark to test variadic functions in setAttribute vs setAttributes (#325)
• The defaultkeys batcher was only using the encoded label set as its map key while building a checkpoint. This allowed distinct label sets through, but any metrics sharing a label set could be overwritten or merged incorrectly. This was corrected. (#333)

0.1.2 - 2019-11-18

Fixed

• Optimized the simplelru map for attributes to reduce the number of allocations. (#328)
• Removed unnecessary unslicing of parameters that are already a slice. (#324)

0.1.1 - 2019-11-18

This release contains a Metrics SDK with stdout exporter and supports basic aggregations such as counter, gauges, array, maxsumcount, and ddsketch.

Added

• Metrics stdout export pipeline. (#265)
• Array aggregation for raw measure metrics. (#282)
• The core.Value now have a MarshalJSON method. (#281)

Removed

• WithService, WithResources, and WithComponent methods of tracers. (#314)
• Prefix slash in Tracer.Start() for the Jaeger example. (#292)

Changed

• Allocation in LabelSet construction to reduce GC overhead. (#318)
• trace.WithAttributes to append values instead of replacing (#315)
• Use a formula for tolerance in sampling tests. (#298)
• Move export types into trace and metric-specific sub-directories. (#289)
• SpanKind back to being based on an int type. (#288)

Fixed

• URL to OpenTelemetry website in README. (#323)
• Name of othttp default tracer. (#321)
• ExportSpans for the stackdriver exporter now handles nil context. (#294)
• CI modules cache to correctly restore/save from/to the cache. (#316)
• Fix metric SDK race condition between LoadOrStore and the assignment rec.recorder = i.meter.exporter.AggregatorFor(rec). (#293)
• README now reflects the new code structure introduced with these changes. (#291)
• Make the basic example work. (#279)

0.1.0 - 2019-11-04

This is the first release of open-telemetry go library. It contains api and sdk for trace and meter.

Added

• Initial OpenTelemetry trace and metric API prototypes.
• Initial OpenTelemetry trace, metric, and export SDK packages.
• A wireframe bridge to support compatibility with OpenTracing.
• Example code for a basic, http-stackdriver, http, jaeger, and named tracer setup.
• Exporters for Jaeger, Stackdriver, and stdout.
• Propagators for binary, B3, and trace-context protocols.
• Project information and guidelines in the form of a README and CONTRIBUTING.
• Tools to build the project and a Makefile to automate the process.
• Apache-2.0 license.
• CircleCI build CI manifest files.
• CODEOWNERS file to track owners of this project.