Release v0.4.1

Fixed

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

Changes since v0.4.0

02b6be1 Pre release v0.4.1 (#605)
af0514b update tag.sh to create signed tags. (#604)

Release v0.4.0

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)

Changes since v0.3.0

f474c34 Script to verify example after new release. (#579)
5d346a4 update godoc.org links to pkg.go.dev (#602)
1e8e72b Process the queue until no data but respect max batch size (#599)
e8546e3 Remove Labelset (#595)
e7a9ba1 Remove unneeded allocation on empty labels (#597)
e458809 Build both go-1.13 and go-1.14 in circleci (#569)
c97b4f7 Update project License headers and checking (#596)
c9dcc1b Move span transforms of the OTLP exporter to internal (#593)
cfe74cf Add a RecordBatch benchmark (#594)
4c69dd3 Remove dogstatsd and statsd support (#591)
06f833e Unique instrument checking (#580)
dff6265 Pre-release script fixes (#592)
d648712 Kick label encoder out of sdk (#574)
6f881b4 update to proto v0.3.0 (#588)
a485d0e Update License header for all source files (#586)
c16f56e Fix missing return in mock span (#582)

Release v0.3.0

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)

Changes since v0.2.3

a1c2439 Prepare for releasing v0.3.0 (#578)
a15e507 Scripts for releasing. (#576)
7623fc5 Remove GetDescriptor (#575)
c95360f Run coverage over all packages beneath COVERAGE_MOD_DIR (#573)
cc756f6 Encode labels once during checkpoint (#572)
f7df68b Add support for Resources in the SDK (#552)
a01f63b Replace Ordered with an iterator in export.Labels. (#567)
d8682c1 Refactor the SDK helpers, create MeterImpl (#560)
e0406dd Provide an implementation of the Header* filters that does not depend on go1.14 (#565)
80b720a update stdout trace with resource. (#558)
435c39a Update OTLP exporter with latest proto (#550)
74a5285 update jaeger exporter to translate resources to tags. (#551)
2ef25ea Add filters for othttp plugin (#556)
217a97d Replace ErrNoLastValue and ErrEmptyDataSet by ErrNoData (#557)
6ada85a (resource_zipkin, go_114) add resource option to Provider. (#545)
638b865 Update Sampler descriptions (#511)
cba1664 Add metrics support to the OTLP exporter (#544)
fcc4aca Fix typo in module name (#548)
8680783 Use StateLocker in MinMaxSumCount (#546)
46ac030 Eliminate goroutine leak in histogram stress test (#547)
2ccddfe Update README with import instructions and how to build / test (#505)
23e65ac Remove metric options; rename "counter" aggregator to "sum" (#541)
d9210f5 Zipkin exporter (#495)
4047c08 Introduce metric constructor errors, MeterMust wrapper (#529)
288821c Make histogram aggregator checkpoint consistent (#438)
ae9033e Use a variable-size array to represent ordered labels in maps (#523)
8575142 add shorter version for global providers (#538)
9674c81 Drop the gauge instrument (#537)
fe0099f [tracing] add simplified export pipeline setup for Jaeger (#459)
8cddf30 Context propagation in opentracing bridge (#525)
7a1cbbc Update Samplers to conform to Spec (#531)
af54288 Update OTLP protos, fix imports (#532)
1ff0f2a add resource type. (#528)
3bf3927 Add status message parameter (#524)
5850278 opentelemetry collector trace exporter (#497)
9459629 Remove the StackDriver trace exporter (#452)
43db6ec Propose putting isobel to emeritus :( (#526)
79de90a fix data race in BatchedSpanProcessor (#518)
161556a Update provider to use AlwaysSampler instead of ProbabilitySampler (#506)
20ecc38 skip test-386 for Mac OS 10.15.x (Catalina and upwards). (#521)
a202f16 Add observer metric (#474)
547d584 Add global propagators (#494)
6769330 use NewRoot() standard code. (#513)
148c9ce Make the default label encoding unique (#508)

Release v0.2.3

Corrects lack of tags on v0.2.2 modules, and updates dependencies to function with go1.14

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)

Release v0.2.2

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)

Changes since v0.2.1.1

8ebc7bb Name context functions consistently (#481)
a6b8058 Update tools (#492)
29cd0c0 Fix a possible nil-dereference crash (#478)
6b97bb0 Move correlation context propagation to correlation package (#479)
bfe569d exporter/metric/stdout: fix incorrect code format comments for InstallNewPipeline (#483)
bd74f31 exporter/metric/dogstatsd: fix incorrect code format comments for InstallNewPipeline (#484)
f9a5484 exporter/metric/prometheus: fix incorrect code format comments for InstallNewPipeline (#482)
84d0a2a prometheus exporter initialize on error based on config (#486)
f99337f Do not always put remote span context into links (#480)
cf7a4d9 Refactor propagators (#467)
c397451 exporter/metric/prometheus: fix wrong module in README.md (#475)
f0c70ff Add StartOptions to Tracer.WithSpan() (#472)
0f1771f Add @MrAlias as an approver (#471)
2584c3e Call Gosched if load an unmapped record (#469)
69df67d Refactor metric records logic (#468)
4818358 Move dependencies of tools package to a tools directory (#466)
cab6b28 Fix URL to opentelemetry.io (#464)
5d6654d Use latest version of golang 1.13 in CI (#465)
493e13f Update metric types to not use pointer receivers (#462)
942713a Replace span relationship with a potentially remote parent context (#451)
574463c Allow dropping items from correlations + docs + cleanups (#454)
6051c81 Add AlwaysParentSample sampler (#455)
32489dd make trace.TraceContext as default context propagator (#456)
8fcdf8b Send span.kind to jaeger and overwrite grpc metadata instead of using append (#441)
405a92a Misc fixes from PR 381 (#443)
6b4acf4 Reorganize propagation code (shrink PR 381) (#444)
437d9af Reword some function documentation in grpc plugin (#446)
7200bb9 finish adding krnowak to approvers (#445)
0278559 Some makefile fixes (#442)
20bb650 Improve detail in stdout exporter (#436)
2c460f0 Adds Histogram Aggregator (#433)
dcd0a10 Rename the sdk/export/metric package name (#432)
3a32a19 fix aggregator.go import package (#431)
2d5ba32 Remove Tracer name prefix for Span names (#430)

v0.2.1.1

Fixed

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

Release v0.2.1

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)

Release v0.2.0

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)

Changes since v0.1.2

d35ea75 go module update for release v0.2.0 (#366)
f0eb35b exclude example dirs from coverage test/report. (#365)
eb9fe13 Drop SetAttribute from Span (#361)
f25c84f Fix lint target (#360)
921ea03 Drop GO111MODULE environment variable (#359)
e6d7256 Simplify Makefile (#354)
77543cd Unary gRPC tracing example (#351)
fef504d Add Min() interface - rename MaxSumCount to MinMaxSumCount (#352)
5ec1f5c Add example prometheus binary to gitignore (#358)
a99f872 Span interface should only allow LinkedTo at creation. (#349)
3d78564 Prometheus exporter (#334)
1b08d82 Rename GetMeter() to Meter() (#357)
5f776db Remove "HTTP" from propagator names (#355)
13cd2ac move /global to /api/global (#356)
9a2484c Implement support for NonAbsolute Measurement MaxSumCount (#335)
0f052af Rename GetTracer to Tracer (#347)
059ca3e Removing pjanotti from owners (#342)
799a418 Fix race conditions in push_test.go (#340)
b9706b2 Dogstatsd metrics exporter (#326)
6b63281 Use /usr/bin/env bash rather than /bin/bash (#336)
2c437c9 fix benchmark error, with always/never sample and add benchmark setAttribute vs setAttributes (#325)
dfae2ac Fix the defaultkeys metrics batcher (#333)

Release v0.1.2

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)

Changes since v0.1.1

9d1a0d5 go module update for release v0.1.2 (#330)
3495d74 specialize simplelru(span's lruMap) for attributes only (#328)
eb3b31e Unslice to simplify (#324)

Release v0.1.1

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)

Changes since v0.1.0

90ba74e Fix url to website in readme (#323)
9878f3b Metrics stdout export pipeline (#265)
c3d5b7b remove empty package (#322)
64eaee8 fix typo in othttp handler (#321)
ee87858 Avoid one memory allocation in LabelSet construction (#318)
9d19d82 Clear NoopTracer implementation and improve Tracer argument names (#314)
1fd93b2 change trace.WithAttributes to append values instead of replacing (#315)
a228baf exporter(stackdriver): fix ExportSpans when ctx is not nil (#294)
f403198 propose additional CODEOWNERS (#313)
b6ada23 Fix CI modules cache (#316)
2950978 Remove myself from CODEOWNERS (#308)
769a03a Use a formula for tolerance in sampling tests (#298)
2546646 Fix metric SDK race condition (#293)
68bd627 Move export types into trace and metric-specific subdirs (#289)
17439d8 [example/jaeger] Remove prefix slash in Tracer.Start() (#292)
2ac5725 update README for v0.1.0 (#291)
1bfa1aa Change SpanKind type an integer type (#288)
9040d82 Add array aggregation for raw measure metrics, improve testing (#282)
6b48fce example/basic: make basic example work (#279)
881e51f Add MarshalJSON for core.Value (#281)