OpenTelemetry - java

API

• Fix W3CBaggagePropagator to allow empty baggage values per W3C spec (#8468)
• Fix baggage parsing for invalid percent-encoded members (#8480)

Incubating

• BREAKING Remove deprecated InstrumentationConfigUtil.peerServiceMapping (#8542)
• Fix EnvironmentGetter/EnvironmentSetter to not enumerate or normalize carrier entries, and normalize empty names consistently (#8474, #8481)

SDK

Traces

• Add BatchSpanProcessor.create(SpanExporter) convenience factory to mirror SimpleSpanProcessor.create(SpanExporter) (#8564)
• Fix BatchSpanProcessor benchmark aux counters (exportedSpans/droppedSpans) always reporting zero (#8539)

Metrics

• Fix PooledHashMap dropping live entries when an entry is removed during forEach (#8499)
• Safely initialize exemplar reservoir storage in FixedSizeExemplarReservoir (#8524)
• Use failExceptionally in PeriodicMetricReader when the exporter is busy (#8525)
• Only set valuesRecorded in AggregatorHandle when false (#8559)
• Use volatile instead of atomics in Double/LongLastValueAggregator (#8560)
• Randomize per-thread recording order in metric benchmarks to avoid concurrency hotspots (#8550)

Logs

• Fix BatchLogRecordProcessor worker thread being killed by non-runtime exceptions (#8529)

Exporters

• BREAKING Prometheus: Drop deprecated PrometheusMetricReader constructors (#8541)
• OTLP: Reject host-less endpoints in EndpointUtil.validateEndpoint (#8489)
• OTLP: Replace Jackson OTLP JSON serialization with a hand-rolled implementation (#8545)
• OTLP Profiles: Fix OtlpGrpcProfileExporter toString class name (#8492)
• Prometheus: Add translation strategy support (#8346)
• Prometheus: Fix serialization of array-valued scope and resource attributes to JSON strings (#8497)

Extensions

• BREAKING Declarative config: Move experimental types to internal package (#8530)
• Declarative config: Commit generated schema POJOs to git (#8408)
• Declarative config: Update to opentelemetry-configuration v1.1.0 (#8451)
• Declarative config: Adjust POJO toString/hashCode/equals to match AutoValue semantics (#8526)
• Declarative config: Add ref descriptions to generated model classes (#8540)
• Declarative config: Emit consistent @JsonProperty annotations on generated models (#8563)
• Declarative config: Remove duplicate resolver in DeclarativeConfigPropertyUtil (#8579)

Project tooling

• Add configuration policy guidance (#8429)
• Exclude certain GitHub Actions from running on forks (#8466)
• Add guidance to prefer parameterized tests (#8469)
• Make benchmark path configurable (#8557)

🙇 Thank you

This release was possible thanks to the following contributors who shared their brilliant ideas and awesome pull requests:

@abdessattar23 @ADITYA-CODE-SOURCE @atoulme @breedx-splk @brunobat @carlosalberto @dahyvuun @Develop-KIM @EvgeniiR @gfelbing @jack-berg @jaydeluca @jimbobbennett @jkwatson @Kielek @kropptrevor @opentelemetry-pr-dashboard @pellared @psx95 @seongjun-rpls @thswlsqls @trask @Vcode2407 @vivekp14 @zeitlinger