v1.9.0 (2022-02-14)

Context

• No changes.

Traces

• Clarify StartSpan returning the parent as a non-recording Span when no SDK is in use
  (#2121)
• Align Jaeger remote sampler endpoint with OTLP endpoint.
  (#2246)
• Add JaegerRemoteSampler spec.
  (#2222)
• Add support for probability sampling in the OpenTelemetry tracestate entry and
  add optional specification for consistent probability sampling.
  (#2047)
• Change description and default value of OTEL_EXPORTER_JAEGER_ENDPOINT env var
  to point to the correct HTTP port and correct description of OTEL_TRACES_EXPORTER
  (#2333).

Metrics

• Rename None aggregation to Drop.
  (#2101)
• Add details to the Prometheus Exporter requirements.
  (#2124)
• Consolidate the aggregation/aggregator term.
  (#2153)
• Remove the concept of supported temporality, keep preferred.
  (#2154)
• Rename extra dimensions to extra attributes.
  (#2162)
• Mark In-memory, OTLP and Stdout exporter specs as Stable.
  (#2175)
• Remove usage of baggage in View from initial SDK specification.
  (#2215)
• Add to the supplemental guidelines for metric SDK authors text about implementing
  attribute-removal Views for asynchronous instruments.
  (#2208)
• Clarify integer count instrument units.
  (#2210)
• Use UCUM units in Metrics Semantic Conventions.
  (#2199)
• Add semantic conventions for process metrics.
  #2032
• Changed default Prometheus Exporter host from 0.0.0.0 to localhost.
  (#2282)
• Clarified wildcard and predicate support in metrics SDK View API.
  (#2325)

Logs

• Fix attributes names in Google Cloud Logging mapping.
  (#2093)
• Add OTEL_LOGS_EXPORTER environment variable.
  (#2196)
• Added ObservedTimestamp to the Log Data Model.
  (#2184)
• Change mapping for log_name of Google Cloud Logging.
  (#2092)
• Drop Log name field
  (#2271)

Resource

• No changes.

Semantic Conventions

• Align runtime metric and resource namespaces
  (#2112)
• Prohibit usage of retired names in semantic conventions.
  (#2191)
• Add device.manufacturer to describe mobile device manufacturers.
  (2100)
• Change golang namespace to 'go', rather than 'gc'
  (#2262)
• Add JVM memory runtime semantic
  conventions. (#2272)
• Add opentracing.ref_type semantic convention.
  (#2297)

Compatibility

• Simplify Baggage handling in the OpenTracing Shim layer.
  (#2194)
• State that ONLY error mapping can happen in the OpenTracing Shim layer.
  (#2148)
• Define the instrumentation library name for the OpenTracing Shim.
  (#2227)
• Add a Start Span section to the OpenTracing Shim.
  (#2228)

OpenTelemetry Protocol

• Rename OTEL_EXPORTER_OTLP_SPAN_INSECURE to OTEL_EXPORTER_OTLP_TRACES_INSECURE and
  OTEL_EXPORTER_OTLP_METRIC_INSECURE to OTEL_EXPORTER_OTLP_METRICS_INSECURE
  so they match the naming of all other OTLP environment variables.
  (#2240)

SDK Configuration

• No changes.

Telemetry Schemas

• No changes.