Release v1.15.0-rc.2/v0.38.0-rc.2

This is a release candidate for the v1.15.0/v0.38.0 release. That release will include the v1 release of the OpenTelemetry Go metric API and will provide stability guarantees of that API. See our versioning policy for more information about these stability guarantees.

Added

• The WithHostID option to go.opentelemetry.io/otel/sdk/resource. (#3812)
• The WithoutTimestamps option to go.opentelemetry.io/otel/exporters/stdout/stdoutmetric to sets all timestamps to zero. (#3828)
• The new Exemplar type is added to go.opentelemetry.io/otel/sdk/metric/metricdata. Both the DataPoint and HistogramDataPoint types from that package have a new field of Exemplars containing the sampled exemplars for their timeseries. (#3849)
• Configuration for each metric instrument in go.opentelemetry.io/otel/sdk/metric/instrument. (#3895)
• The internal logging introduces a warning level verbosity equal to V(1). (#3900)

Changed

• Optimize memory allocation when creation a new Set using NewSet or NewSetWithFiltered in go.opentelemetry.io/otel/attribute. (#3832)
• Optimize memory allocation when creation new metric instruments in go.opentelemetry.io/otel/sdk/metric. (#3832)
• Avoid creating new objects on all calls to WithDeferredSetup and SkipContextSetup in OpenTracing bridge. (#3833)
• The New and Detect functions from go.opentelemetry.io/otel/sdk/resource return errors that wrap underlying errors instead of just containing the underlying error strings. (#3844)
• Both the Histogram and HistogramDataPoint are redefined with a generic argument of [N int64 | float64] in go.opentelemetry.io/otel/sdk/metric/metricdata. (#3849)
• The metric Export interface from go.opentelemetry.io/otel/sdk/metric accepts a *ResourceMetrics instead of ResourceMetrics. (#3853)
• Rename Asynchronous to Observable in go.opentelemetry.io/otel/metric/instrument. (#3892)
• Rename Int64ObserverOption to Int64ObservableOption in go.opentelemetry.io/otel/metric/instrument. (#3895)
• Rename Float64ObserverOption to Float64ObservableOption in go.opentelemetry.io/otel/metric/instrument. (#3895)
• The internal logging changes the verbosity level of info to V(4), the verbosity level of debug to V(8). (#3900)

Fixed

• TracerProvider consistently doesn't allow to register a SpanProcessor after shutdown. (#3845)

Removed

• The deprecated go.opentelemetry.io/otel/metric/global package is removed. (#3829)
• The unneeded Synchronous interface in go.opentelemetry.io/otel/metric/instrument was removed. (#3892)
• The Float64ObserverConfig and NewFloat64ObserverConfig in go.opentelemetry.io/otel/sdk/metric/instrument. Use the added float64 instrument configuration instead. (#3895)
• The Int64ObserverConfig and NewInt64ObserverConfig in go.opentelemetry.io/otel/sdk/metric/instrument. Use the added int64 instrument configuration instead. (#3895)
• The NewNoopMeter function in go.opentelemetry.io/otel/metric, use NewMeterProvider().Meter("") instead. (#3893)