v1.10.0 (2022-04-01)

Context

• No changes.

Traces

• Introduce the concept of Instrumentation Scope to replace/extend Instrumentation
  Library. The Tracer is now associated with Instrumentation Scope
  (#2276).
• Add OTEL_EXPORTER_JAEGER_PROTOCOL environment variable to select the protocol
  used by the Jaeger exporter.
  (#2341)
• Add documentation REQUIREMENT for adding attributes at span creation.
  (#2383).

Metrics

• Initial Prometheus <-> OTLP datamodel specification
  (#2266)
• Introduce the concept of Instrumentation Scope to replace/extend Instrumentation
  Library. The Meter is now associated with Instrumentation Scope
  (#2276).
• Specify the behavior of duplicate instrumentation registration in the API, specify
  duplicate conflicts in the data model, specify how the SDK is meant to report and
  assist the user when these conflicts arise.
  (#2317).
• Clarify that expectations for user callback behavior are documentation REQUIREMENTs.
  (#2361).
• Specify how to handle prometheus exemplar timestamp and attributes
  (#2376)
• Clarify that the periodic metric reader is the default metric reader to be
  paired with push metric exporters (OTLP, stdout, in-memory)
  (#2379).
• Convert OpenMetrics Info and StateSet metrics to non-monotonic sums
  (#2380)
• Clarify that MetricReader has one-to-one mapping to MeterProvider.
  (#2406).
• For prometheus metrics without sums, leave the sum unset
  (#2413)
• Specify default configuration for a periodic metric reader that is associated with
  the stdout metric exporter.
  (#2415).
• Clarify the manner in which aggregation and temporality preferences
  are encoded via MetricReader parameters "on the basis of instrument
  kind". Rename the environment variable
  OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE used to set the
  preference to be used when auto-configuring an OTLP Exporter,
  defaults to CUMULATIVE, with DELTA an option that makes Counter,
  Asynchronous Counter, and Histogram instruments choose Delta
  temporality by default.
  (#2404).
• Clarify that instruments are enabled by default, even when Views are configured.
  Require support for the match-all View expression having name=* to support
  disabling instruments by default.
  (#2417).
• Mark Metrics SDK spec as Mixed, with most components moving to Stable, while
  Exemplar remaining Feature-freeze.
  (#2304)
• Clarify how metric metadata and type suffixes are handled
  (#2440)

Logs

• Add draft logging library SDK specification
  (#2328)
• Add InstrumentationScope/Logger Name to log data model
  (#2359)
• Remove flush method on LogEmitter
  (#2405)
• Declare Log Data Model Stable
  (#2387)

Resource

• No changes.

Semantic Conventions

• Define span structure for HTTP retries and redirects.
  (#2078)
• Changed rpc.system to an enum (allowing custom values), and changed the
  rpc.system value for .NET WCF from wcf to dotnet_wcf.
  (#2377)
• Define JavaScript runtime semantic conventions.
  (#2290)
• Add semantic conventions for CloudEvents.
  (#1978)
• Add process.cpu.utilization metric.
  (#2436)
• Add rpc.system value for Apache Dubbo.
  (#2453)

Compatibility

• Mark the OpenTracing compatibility section as stable.
  (#2327)

OpenTelemetry Protocol

• Add experimental JSON serialization format
  (#2235)
• Parameters for private key and its chain added
  (#2370)

SDK Configuration

• No changes.

Telemetry Schemas

• No changes.

Common

• Describe how to convert non-string primitives for protocols which only support strings
  (#2343)
• Add "Mapping Arbitrary Data to OTLP AnyValue" document.
  (#2385)