Release v1.40.0

[MrAlias]

Added

• Add Enabled method to all synchronous instrument interfaces (Float64Counter, Float64UpDownCounter, Float64Histogram, Float64Gauge, Int64Counter, Int64UpDownCounter, Int64Histogram, Int64Gauge,) in go.opentelemetry.io/otel/metric. This stabilizes the synchronous instrument enabled feature, allowing users to check if an instrument will process measurements before performing computationally expensive operations. (metric: add Enabled method to synchronous instruments #7763)
• Add AlwaysRecord sampler in go.opentelemetry.io/otel/sdk/trace. (sdk/trace: Add AlwaysRecord sampler #7724)
• Add go.opentelemetry.io/otel/semconv/v1.39.0 package. The package contains semantic conventions from the v1.39.0 version of the OpenTelemetry Semantic Conventions. See the migration documentation for information on how to upgrade from go.opentelemetry.io/otel/semconv/v1.38.0. (Generate semconv/v1.39.0 #7783, Bump semconv from v1.37.0 to v1.39.0 #7789)

Changed

• Exporter in go.opentelemetry.io/otel/exporter/prometheus ignores metrics with the scope go.opentelemetry.io/contrib/bridges/prometheus. This prevents scrape failures when the Prometheus exporter is misconfigured to get data from the Prometheus bridge. (prometheus exporter ignores metrics from the Prometheus bridge #7688)
• Improve performance of concurrent histogram measurements in go.opentelemetry.io/otel/sdk/metric. (Use sync.Map and atomics for fixed bucket histograms #7474)
• Add experimental observability metrics in go.opentelemetry.io/otel/exporters/stdout/stdoutmetric. (stdoutmetric exporter observability #7492)
• Improve the concurrent performance of HistogramReservoir in go.opentelemetry.io/otel/sdk/metric/exemplar by 4x. (Optimize histogram reservoir #7443)
• Improve performance of concurrent synchronous gauge measurements in go.opentelemetry.io/otel/sdk/metric. (Use sync.Map and atomics for lastvalue aggregations #7478)
• Improve performance of concurrent exponential histogram measurements in go.opentelemetry.io/otel/sdk/metric. (Exponential histogram: defer computing count until collect #7702)
• Improve the concurrent performance of FixedSizeReservoir in go.opentelemetry.io/otel/sdk/metric/exemplar. (Optimize fixedsize reservoir #7447)
• The rpc.grpc.status_code attribute in the experimental metrics emitted from go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc is replaced with the rpc.response.status_code attribute to align with the semantic conventions. (Upgrade semconv use to v1.39.0 #7854)
• The rpc.grpc.status_code attribute in the experimental metrics emitted from go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploggrpc is replaced with the rpc.response.status_code attribute to align with the semantic conventions. (Upgrade semconv use to v1.39.0 #7854)

Fixed

• Fix bad log message when key-value pairs are dropped because of key duplication in go.opentelemetry.io/otel/sdk/log. (sdk/log: fix "limit reached" logging and Record.DroppedAttributes #7662)
• Fix DroppedAttributes on Record in go.opentelemetry.io/otel/sdk/log to not count the non-attribute key-value pairs dropped because of key duplication. (sdk/log: fix "limit reached" logging and Record.DroppedAttributes #7662)
• Fix SetAttributes on Record in go.opentelemetry.io/otel/sdk/log to not log that attributes are dropped when they are actually not dropped. (sdk/log: fix "limit reached" logging and Record.DroppedAttributes #7662)
• WithHostID detector in go.opentelemetry.io/otel/sdk/resource to use full path for ioreg command on Darwin (macOS). (resource: specify full path for ioreg command in Darwin host ID reader #7818)
• Fix missing request.GetBody in go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp to correctly handle HTTP2 GOAWAY frame. (support stdlib request.GetBody #7794)

Deprecated

• Deprecate go.opentelemetry.io/otel/exporters/zipkin. For more information, see the OTel blog post deprecating the Zipkin exporter. (Deprecate the zipkin exporter #7670)

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.7%. Comparing base (77785da) to head (7d6ed9c).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##            main   #7859     +/-   ##
=======================================
- Coverage   81.7%   81.7%   -0.1%     
=======================================
  Files        304     304             
  Lines      23235   23235             
=======================================
- Hits       18994   18991      -3     
- Misses      3859    3861      +2     
- Partials     382     383      +1     

Files with missing lines	Coverage Δ
bridge/opencensus/version.go	100.0% <100.0%> (ø)
...xporters/otlp/otlpmetric/otlpmetricgrpc/version.go	100.0% <100.0%> (ø)
...xporters/otlp/otlpmetric/otlpmetrichttp/version.go	100.0% <100.0%> (ø)
exporters/otlp/otlptrace/version.go	100.0% <100.0%> (ø)
sdk/metric/version.go	100.0% <100.0%> (ø)
sdk/version.go	100.0% <100.0%> (ø)
version.go	100.0% <100.0%> (ø)

... and 3 files with indirect coverage changes

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[Copilot]

Pull request overview

Updates the repository for the v1.40.0 release by bumping module/version constants across stable and experimental modules and publishing the corresponding changelog entry.

Changes:

• Bump stable module versions from v1.39.0 → v1.40.0 (and update all dependent go.mod files).
• Bump experimental metrics/logs module versions to v0.62.0 / v0.16.0.
• Add the 1.40.0 release section and update comparison links in CHANGELOG.md.

Reviewed changes

Copilot reviewed 41 out of 41 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
versions.yaml	Updates module-set versions for the release (stable/experimental).
version.go	Bumps core otel version string to 1.40.0.
trace/internal/telemetry/test/go.mod	Updates trace dependency to v1.40.0 for internal tests.
trace/go.mod	Aligns trace module dependency on otel to v1.40.0.
sdk/version.go	Bumps SDK version string to 1.40.0.
sdk/metric/version.go	Bumps metric SDK version string to 1.40.0.
sdk/metric/go.mod	Aligns SDK metric module dependencies to v1.40.0.
sdk/log/logtest/go.mod	Aligns logtest dependencies to v1.40.0 / v0.16.0.
sdk/log/go.mod	Aligns SDK log module dependencies to v1.40.0 / v0.16.0.
sdk/go.mod	Aligns SDK module dependencies to v1.40.0.
metric/go.mod	Aligns metric API module dependencies to v1.40.0.
log/logtest/go.mod	Aligns log API test module dependencies to v1.40.0 / v0.16.0.
log/go.mod	Aligns log API module dependencies to v1.40.0.
go.mod	Updates root module deps to v1.40.0.
exporters/zipkin/go.mod	Aligns Zipkin exporter deps to v1.40.0.
exporters/stdout/stdouttrace/internal/version.go	Bumps stdouttrace exporter version constant to 1.40.0.
exporters/stdout/stdouttrace/go.mod	Aligns stdouttrace exporter deps to v1.40.0.
exporters/stdout/stdoutmetric/internal/version.go	Bumps stdoutmetric exporter version constant to 1.40.0.
exporters/stdout/stdoutmetric/go.mod	Aligns stdoutmetric exporter deps to v1.40.0.
exporters/stdout/stdoutlog/go.mod	Aligns stdoutlog exporter deps to v1.40.0 / v0.16.0.
exporters/prometheus/internal/version.go	Bumps Prometheus exporter version constant to 0.62.0.
exporters/prometheus/go.mod	Aligns Prometheus exporter deps to v1.40.0.
exporters/otlp/otlptrace/version.go	Bumps OTLP trace exporter version to 1.40.0.
exporters/otlp/otlptrace/otlptracehttp/internal/version.go	Bumps OTLP HTTP trace exporter internal version constant to 1.40.0.
exporters/otlp/otlptrace/otlptracehttp/go.mod	Aligns OTLP HTTP trace exporter deps to v1.40.0.
exporters/otlp/otlptrace/otlptracegrpc/internal/version.go	Bumps OTLP gRPC trace exporter internal version constant to 1.40.0.
exporters/otlp/otlptrace/otlptracegrpc/go.mod	Aligns OTLP gRPC trace exporter deps to v1.40.0.
exporters/otlp/otlptrace/go.mod	Aligns OTLP trace exporter deps to v1.40.0.
exporters/otlp/otlpmetric/otlpmetrichttp/version.go	Bumps OTLP HTTP metric exporter version to 1.40.0.
exporters/otlp/otlpmetric/otlpmetrichttp/go.mod	Aligns OTLP HTTP metric exporter deps to v1.40.0.
exporters/otlp/otlpmetric/otlpmetricgrpc/version.go	Bumps OTLP gRPC metric exporter version to 1.40.0.
exporters/otlp/otlpmetric/otlpmetricgrpc/go.mod	Aligns OTLP gRPC metric exporter deps to v1.40.0.
exporters/otlp/otlplog/otlploghttp/internal/version.go	Bumps OTLP HTTP log exporter internal version constant to 0.16.0.
exporters/otlp/otlplog/otlploghttp/go.mod	Aligns OTLP HTTP log exporter deps to v1.40.0 / v0.16.0.
exporters/otlp/otlplog/otlploggrpc/internal/version.go	Bumps OTLP gRPC log exporter internal version constant to 0.16.0.
exporters/otlp/otlplog/otlploggrpc/go.mod	Aligns OTLP gRPC log exporter deps to v1.40.0 / v0.16.0.
bridge/opentracing/go.mod	Aligns opentracing bridge deps to v1.40.0.
bridge/opencensus/version.go	Bumps opencensus bridge version string to 1.40.0.
bridge/opencensus/test/go.mod	Aligns opencensus bridge test deps to v1.40.0.
bridge/opencensus/go.mod	Aligns opencensus bridge deps to v1.40.0.
CHANGELOG.md	Adds the 1.40.0 release section and updates release links.

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