Release v0.15.0

Added

• The WithIDGenerator TracerProviderOption is added to the go.opentelemetry.io/otel/trace package to configure an IDGenerator for the TracerProvider. (#1363)

Changed

• The Zipkin exporter now uses the Span status code to determine. (#1328)
• NewExporter and Start functions in go.opentelemetry.io/otel/exporters/otlp now receive context.Context as a first parameter. (#1357)
• Move the OpenCensus example into example directory. (#1359)
• Moved the SDK's internal.IDGenerator interface in to the sdk/trace package to enable support for externally-defined ID generators. (#1363)
• Bump github.com/google/go-cmp from 0.5.3 to 0.5.4 (#1374)
• Bump github.com/golangci/golangci-lint in /internal/tools (#1375)

Fixed

• Metric SDK SumObserver and UpDownSumObserver instruments correctness fixes. (#1381)

Raw changes made between v0.14.0 and v0.15.0

61e07a0 (HEAD -> master, tag: v0.15.0, tag: sdk/v0.15.0, tag: exporters/trace/zipkin/v0.15.0, tag: exporters/trace/jaeger/v0.15.0, tag: exporters/stdout/v0.15.0, tag: exporters/otlp/v0.15.0, tag: exporters/metric/prometheus/v0.15.0, tag: example/zipkin/v0.15.0, tag: example/prometheus/v0.15.0, tag: example/otel-collector/v0.15.0, tag: example/opencensus/v0.15.0, tag: example/namedtracer/v0.15.0, tag: example/jaeger/v0.15.0, tag: example/basic/v0.15.0, tag: bridge/opentracing/v0.15.0, tag: bridge/opencensus/v0.15.0, upstream/master, origin/master, origin/HEAD) Release v0.15.0 (#1392)
599c080 Fix typo in readme (#1390)
eb28005 Metric Accumulator fix for SumObservers (#1381)
970755b Enable support for externally-defined ID generators (#1363)
0021ab0 Rework proto generation (#1371)
787e3f4 chore(zipkin-exporter): relay on the status code for the request but still read the response body. (#1328)
66db2d8 (johananl/master) Build examples last (#1370)
958041d Bump github.com/golangci/golangci-lint in /internal/tools (#1375)
e1ff2d1 Bump github.com/google/go-cmp from 0.5.3 to 0.5.4 (#1374)
5d0372d Fix typo in comment (#1377)
55ff277 Fix golint issue caused by typo (#1372)
5a728db Another batch of cleanups in otlp exporter (#1357)
e081978 Move opencensus example to the example directory (#1359)

Release v0.14.0

Added

• An EventOption and the related NewEventConfig function are added to the go.opentelemetry.io/otel package to configure Span events. (#1254)
• A TextMapPropagator and associated TextMapCarrier are added to the go.opentelemetry.io/otel/oteltest package to test TextMap type propagators and their use. (#1259)
• SpanContextFromContext returns SpanContext from context. (#1255)
• DeploymentEnvironmentKey added to go.opentelemetry.io/otel/semconv package. (#1323)
• Add an OpenCensus to OpenTelemetry tracing bridge. (#1305)
• Add a parent context argument to SpanProcessor.OnStart to follow the specification. (#1333)
• Add missing tests for sdk/trace/attributes_map.go. (#1337)

Changed

• Move the go.opentelemetry.io/otel/api/trace package into go.opentelemetry.io/otel/trace with the following changes. (#1229) (#1307)
  • ID has been renamed to TraceID.
  • IDFromHex has been renamed to TraceIDFromHex.
  • EmptySpanContext is removed.
• Move the go.opentelemetry.io/otel/api/trace/tracetest package into go.opentelemetry.io/otel/oteltest. (#1229)
• OTLP Exporter updates:
  • supports OTLP v0.6.0 (#1230, #1354)
  • supports configurable aggregation temporality (default: Cumulative, optional: Stateless). (#1296)
• The Sampler is now called on local child spans. (#1233)
• 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)
• The MetricKind method of the Descriptor type in the go.opentelemetry.io/otel/api/metric package was renamed to Descriptor.InstrumentKind.
  This matches the returned type and fixes misuse of the term metric. (#1240)
• Move test harness from the go.opentelemetry.io/otel/api/apitest package into go.opentelemetry.io/otel/oteltest. (#1241)
• Move the go.opentelemetry.io/otel/api/metric/metrictest package into go.opentelemetry.io/oteltest as part of #964. (#1252)
• Move the go.opentelemetry.io/otel/api/metric package into go.opentelemetry.io/otel/metric as part of #1303. (#1321)
• Move the go.opentelemetry.io/otel/api/metric/registry package into go.opentelemetry.io/otel/metric/registry as a part of #1303. (#1316)
• 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)
• 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 EventOptions. (#1254)
• 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 EventOptions. (#1254)
• Move the go.opentelemetry.io/otel/api/global package to go.opentelemetry.io/otel. (#1262) (#1330)
• Move the Version function from go.opentelemetry.io/otel/sdk to go.opentelemetry.io/otel. (#1330)
• Rename correlation context header from "otcorrelations" to "baggage" to match the OpenTelemetry specification. (#1267)
• Fix Code.UnmarshalJSON to work with valid JSON only. (#1276)
• The resource.New() method changes signature to support builtin attributes and functional options, including telemetry.sdk.* and
  host.name semantic conventions; the former method is renamed resource.NewWithAttributes. (#1235)
• The Prometheus exporter now exports non-monotonic counters (i.e. UpDownCounters) as gauges. (#1210)
• Correct the Span.End method documentation in the otel API to state updates are not allowed on a span after it has ended. (#1310)
• Updated span collection limits for attribute, event and link counts to 1000 (#1318)
• Renamed semconv.HTTPUrlKey to semconv.HTTPURLKey. (#1338)

Removed

• The ErrInvalidHexID, ErrInvalidTraceIDLength, ErrInvalidSpanIDLength, ErrInvalidSpanIDLength, or ErrNilSpanID from the go.opentelemetry.io/otel package are unexported now. (#1243)
• The AddEventWithTimestamp method on the Span interface in go.opentelemetry.io/otel is removed due to its redundancy.
  It is replaced by using the AddEvent method with a WithTimestamp option. (#1254)
• The MockSpan and MockTracer types are removed from go.opentelemetry.io/otel/oteltest.
  Tracer and Span from the same module should be used in their place instead. (#1306)
• WorkerCount option is removed from go.opentelemetry.io/otel/exporters/otlp. (#1350)

Fixed

• Rename MergeItererator to MergeIterator in the go.opentelemetry.io/otel/label package. (#1244)
• The go.opentelemetry.io/otel/api/global packages global TextMapPropagator now delegates functionality to a globally set delegate for all previously returned propagators. (#1258)
• Fix condition in label.Any. (#1299)
• Fix global TracerProvider to pass options to its configured provider. (#1329)
• Fix missing handler for ExactKind aggregator in OTLP metrics transformer (#1309)

Raw changes made between v0.13.0 and v0.14.0

575df22 (HEAD -> master, tag: v0.14.0, tag: sdk/v0.14.0, tag: exporters/trace/zipkin/v0.14.0, tag: exporters/trace/jaeger/v0.14.0, tag: exporters/stdout/v0.14.0, tag: exporters/otlp/v0.14.0, tag: exporters/metric/prometheus/v0.14.0, tag: example/zipkin/v0.14.0, tag: example/prometheus/v0.14.0, tag: example/otel-collector/v0.14.0, tag: example/namedtracer/v0.14.0, tag: example/jaeger/v0.14.0, tag: example/basic/v0.14.0, tag: bridge/opentracing/v0.14.0, tag: bridge/opencensus/v0.14.0, tag: bridge/opencensus/examples/bridge/v0.14.0, upstream/master, origin/master, origin/HEAD) Release v0.14.0 (#1355)
34aa681 revert part of #1334. Move binary propagation to contrib (#1353)
6eb6801 Some cleanups in otlp exporter (#1350)
5b5b4ab Update OTLP to v0.6.0 (#1354)
4619c06 Add opencensus bridge example and readme (#1348)
2c2f985 Add missing tests for attributesMap (#1337)
fd3c82b support exact kind in OTLP metrics exporter (#1309)
c857a3d Pass options to configured TracerProvider (#1329)
7022c12 Update the package docs for the new API layout (#1346)
bbc9465 Add opencensus binary propagation to bridge (#1334)
73a0539 chore(semconv): Add PR number to changelog (#1323)
3207770 Set telemetry.sdk.name resource attribute to "opentelemetry" (#1332)
380d945 s/HTTPUrlKey/HTTPURLKey/ in semconv (#1338)
3d6e8b5 Move Version function and code from global to toplevel (#1330)
20c78fe Bump github.com/google/go-cmp from 0.5.2 to 0.5.3 (#1339)
070b657 Add parent context to SpanProcessor.OnStart (#1333)
63a1114 Move baggage and propagation to separate packages (#1325)
f6df5df add opencensus tracing bridge (#1305)
27aa1f6 update go documentation badge image (#1322)
75d4911 Move metric code to a separate package (#1321)
386331a Prepare to move metrics code to separate subpackage (#1316)
f9984f2 Support configurable AggregationTemporality in exporters; add OTLP missing sum point temporality/monotonic fields (#1296)
3a06b39 Update span collection limits to 1000 (#1318)
b7508da Export non monotonic counters as gauge values from the prometheus exporter (#1269)
757030d Update Span End method documentation (#1310)
a354c02 Clean up SDK span field docs (#1312)
1041ada Bump github.com/golangci/golangci-lint in /internal/tools (#1315)
3268501 Move tracing code to trace package (#1307)
9ac3a08 Remove MockSpan and MockTracer (#1306)
c9ae670 Fix zipkin example module name (#1308)
e22a48d chore: adds vanity import for files that don't have it. (#1297)
911d7be Check marshalled value instead of iface (#1299)
238d2c0 Bump github.com/golangci/golangci-lint in /internal/tools (#1301)
187adeb Change resource.New() to use functional options; add builtin attributes for (host., telemetry.sdk.) (#1235)
0341956 Update README and documentation to better communicate pre-GA state (#1281)
23e32b1 Minor readability fixes to the Jeager example (#1282)
d98ad10 Fix Code.UnmarshalJSON to work with valid json only (#1276)
a6b31e0 Update SpanProcessor Shutdown with context and error (#1264)
412ee70 Fix typo in example (#1278)
da3f60a Bump github.com/golangci/golangci-lint in /internal/tools (#1274)
d75ccbb Add a Shutdown method to sdk TraceProvider (#1227)
230bdd1 Add SpanContextFromContext() (#1255)
c9bc90b Renaming otcorrelations header to baggage (#1267)
d6dd84f...

Release v0.13.0

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)

Raw changes made between v0.12.0 and v0.13.0

9ebca88 Pre release v0.13.0 (#1231)
5660b0b Update label.ArrayValue to store copies of 1D arrays (#1226)
577b217 Update codes to match specification (#1214)
e9c80e6 Bump github.com/openzipkin/zipkin-go from 0.2.4 to 0.2.5 in /exporters/trace/zipkin (#1224)
b0fd424 Bump github.com/itchyny/gojq from 0.11.1 to 0.11.2 in /internal/tools (#1225)
5e66340 Add Baggage API and move Baggage propagator (#1217)
de50711 feat(span): remove SetAttribute method (#1216)
6e184cd Update propagation to conform with OpenTelemetry specification (#1212)
dc79f7f Remove duplicate hostname in Resource (#1219)
423c891 Set default propagator to no-op propagator (#1204)
04297f4 Enable exporting Histogram aggregation to OTLP metric (#1209)
a69f8fb Add integration tests for span processor ordering (#1208)
3a9f5fe Test benchmarks in precommit (#1207)

Release v0.12.0

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)

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)

Raw changes made between v0.11.0 and v0.12.0

0b348c3 (HEAD -> master, tag: v0.12.0, tag: sdk/v0.12.0, tag: exporters/trace/zipkin/v0.12.0, tag: exporters/trace/jaeger/v0.12.0, tag: exporters/stdout/v0.12.0, tag: exporters/otlp/v0.12.0, tag: exporters/metric/prometheus/v0.12.0, tag: exa
mple/zipkin/v0.12.0, tag: example/prometheus/v0.12.0, tag: example/otel-collector/v0.12.0, tag: example/namedtracer/v0.12.0, tag: example/jaeger/v0.12.0, tag: example/basic/v0.12.0, tag: bridge/opentracing/v0.12.0, origin/master, origin/HEAD) Prepare v0.12.0 release (#1205)
8c3cc43 Use LastValue by default for ValueObserver instruments (#1165)
304d4cd ensure batch span processors are shutdown in examples (#1199)
1e72b51 Add example test for a custom SpanProcessor (#1196)
b97533a Register/unregister in the fixed order (#1198)
559fecd Update the attribute names for the OTel attributes for the zipkin exporter (#1201)
7d71867 Rename *Provider names (#1190)
5dd2962 Remove semantic convention for http status text (#1194)
038f505 Remove B3 propagator from otel repo (#1191)
e7e1dce Update sampling decision names (#1192)
b9357d7 Remove flaky BatchSpanProcessor.ForceFlush() test (#1189)
fa74147 Bump google.golang.org/api from 0.31.0 to 0.32.0 in /exporters/trace/jaeger (#1188)
4b46365 Move api/unit to top level (#1185)
930b4d0 Fix missing shutdown of the batch processor (#1186)
995be31 Add ForceFlush() method to SpanProcessor interface (#1166)
a12224a Ensure exported interfaces have named method parameters (#1172)
2621bd4 Convert XConfigure into constructor for metrics (#1175)
3de7a07 Merge otel into one file and add package doc (#1176)
1f7c220 Don't consider unset env var to be an error during resource detection (#1170)
77de199 Minor change: ParentSampler -> ParentBased in Zipkin example description (#1171)
6f048eb Add more semantic conventions for k8s as resource attributes (#1167)
d91de43 Recommend use of initializers for config structs (#1163)
c9726ef Allow up to 0.5% coverage change before failing build (#1162)
0041e2d Rename ParentOrElse sampler to ParentBased and enhance it according to the spec (#1153)
34c02d1 Add Skip Changelog label to Dependabot-sourced PRs (#1161)
9f45258 Convert XConfigure into constructors (#1155)
a787f09 Update CONTRIBUTING.md to reflect PR process-as-applied (#1159)
36c323f Add the missing vanity import ...

Release v0.11.0

Added

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

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)

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)

Release v0.10.0

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)
• 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)

---

Raw changes made between v0.9.0 and v0.10.0

fd61d2e (HEAD -> master, tag: v0.10.0, tag: sdk/v0.10.0, tag: exporters/trace/zipkin/v0.10.0, tag: exporters/trace/jaeger/v0.10.0, tag: exporters/stdout/v0.10.0, tag: exporters/otlp/v0.10.0, tag: exporters/metric/prometheus/v0.10.0, tag: example/zipkin/v0.10.0, tag: example/prometheus/v0.10.0, tag: example/otel-collector/v0.10.0, tag: example/namedtracer/v0.10.0, tag: example/jaeger/v0.10.0, tag: example/http/v0.10.0, tag: example/grpc/v0.10.0, tag: example/basic/v0.10.0, upstream/master, origin/master, origin/HEAD) Release v0.10.0 (#990)
1299210 Change default Sampler to ParentOrElse(AlwaysOn) (#989)
fa883d4 testtrace.Span tracks and returns its SpanKind. (#987)
26e85e1 Add propagator option for gRPC instrumentation (#986)
8fbaa9d Make the SDK into its own Go module (#985)
d6bf2fb Decouple instrumentation from SDK (#983)
42c2a86 Move grpctrace examples from comment to code (#984)
e06c9da Rename aggregator/test to aggregatortest (#980)
67a2c23 Update Changelog (#982)
2833212 Decouple API from SDK (#977)
7f1dc4a Update Contributing style guide section (#971)
6917167 Rename kv.Infer to kv.Any (#969) (#972)
c9c8137 Remove IndexedAttribute from api/label (#970)
3b01a85 Make the stdout exporter a package (#963)
c6611f4 Move export test package to SDK (#962)
d99ac09 Remove sub-package value from kv (#968)
fd54b6c paivagustavo to emeritus for now (#960)
7918070 README: fixup spaces on code example (#961)
452256c Unify trace and metric stdout exporters (#956)
f31d8ec Unify trace and metric exporter helpers (#944)
c5d77d2 Bump github.com/google/go-cmp from 0.5.0 to 0.5.1 (#957)
c8b657e use global handler for span export err in otlp (#946)
f6b51df Bump github.com/golangci/golangci-lint from 1.28.3 to 1.29.0 in /tools (#953)

Release v0.9.0

This release includes a new Resource auto-detector interface and a generation of the OTLP locally.

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)

---

Raw changes made between v0.8.0 and v0.9.0

58e50e2 (HEAD -> master, tag: v0.9.0, tag: exporters/trace/zipkin/v0.9.0, tag: exporters/trace/jaeger/v0.9.0, tag: exporters/otlp/v0.9.0, tag: exporters/metric/prometheus/v0.9.0, tag: example/zipkin/v0.9.0, tag: example/prometheus/v0.9.0, tag: example/otel-collector/v0.9.0, tag: example/namedtracer/v0.9.0, tag: example/jaeger/v0.9.0, tag: example/http/v0.9.0, tag: example/grpc/v0.9.0, tag: example/basic/v0.9.0, upstream/master, origin/master, origin/HEAD) Release v0.9.0 (#952)
e6537c6 Fix typo in comment (#951)
99c2998 OT resource detector (#939)
b2b23e1 supports marshaling values as json (#948)
d6ad4d4 [jaeger] Stop ignoring uints (#945)
4f3fab3 Remove github.com/open-telemetry/opentelemetry-collector dependency (#943)
166c703 Import open-telemetry/opentelemetry-proto submodule and generate protobuf bindings locally (#942)
dd79483 Create protobuf generation GitHub action (#938)
31dd06a Bump github.com/golangci/golangci-lint from 1.28.2 to 1.28.3 in /tools (#936)
9edcad3 Backport tag script from contrib repo (#934)

Release v0.8.0

This release includes additions and changes to implements the v0.6.0 OpenTelemetry specification and other fixes.

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)

---

Commits since previous tag v0.7.0

aff7a80 (HEAD -> master, tag: v0.8.0, tag: exporters/trace/zipkin/v0.8.0, tag: exporters/trace/jaeger/v0.8.0, tag: exporters/otlp/v0.8.0, tag: exporters/metric/prometheus/v0.8.0, tag: example/zipkin/v0.8.0, tag: example/prometheus/v0.8.0, tag: example/otel-collector/v0.8.0, tag: example/namedtracer/v0.8.0, tag: example/jaeger/v0.8.0, tag: example/http/v0.8.0, tag: example/grpc/v0.8.0, tag: example/basic/v0.8.0, upstream/master, origin/master, origin/HEAD) Release v0.8.0 (#929)
9e99b44 Bump github.com/golangci/golangci-lint from 1.28.1 to 1.28.2 in /tools (#930)
4dec0ad [jaeger] Added WithBatchMaxCount as an option (#931)
d979977 Add semantic conventions for OS process as resource attributes (#919)
54fffd6 Update grpctrace instrumentation span names (#922)
d2913b7 Bump google.golang.org/api from 0.28.0 to 0.29.0 in /exporters/trace/jaeger (#925)
c719588 Avoid replacing existing correlation map data in context when correlation context extractor does not find any valid data (#923)
fab431e Fix api/standard constant names and documentation (#920)
cf6462c Bump github.com/itchyny/gojq from 0.10.4 to 0.11.0 in /tools (#926)
03cd779 Add http content size semantic conventions (#905)
1c9aab6 Extend semantic convetions for RPC (#900)
918c654 Update Changelog with omitted changes (#921)
c506e99 Fix B3 propagator and add tests (#882)
3475d55 Fix incorrect aggregation; Prometheus exporter behavior (#903)
808345c Bump CircleCI instance size (#917)
c219029 Update otel-collector example to use collector v0.5.0 (#915)
1c6ca87 Ensure clientTracer closes http.headers span (#912)
463c458 Add more database-specific semantic attributes (#899)
5a4b68c Add semantic convention for faas.coldstart and container.id (#909)
eaa94e9 Avoid setting span status to Unknown when no HTTP status is provided; stdlib assumes it to be 200 OK (#908)
9342eb2 Bump github.com/golangci/golangci-lint from 1.28.0 to 1.28.1 in /tools (#913)
27e892a Remove -v from Go tests (#904)
bd1e174 Add "peer.service" semantic to standard attributes (#898)
8d1f448 Bump github.com/golangci/golangci-lint from 1.27.0 to 1.28.0 in /tools (#901)
550d365 fix trace event time conversion from internal to otlp (#896)
f1e3536 Update opentracing dependency (#885)
f4b1568 Bump github.com/itchyny/gojq from 0.10.3 to 0.10.4 in /tools (#883)
8205b0b Update B3 header names (#881)
2635f96 Ask for changelog updates with PRs (#879)

Release v0.7.0

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)

Release v0.6.0

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)