API

• Fix ConfigUtil#getString ConcurrentModificationException (#6841)

SDK

Traces

• Stabilize ExceptionEventData (#6795)

Metrics

• Stabilize metric cardinality limits (#6794)
• Refactor metrics internals to remove MeterSharedState (#6845)

Exporters

• Add memory mode option to stdout exporters (#6774)
• Log a warning if OTLP endpoint port is likely incorrect given the protocol (#6813)
• Fix OTLP gRPC retry mechanism for unsuccessful HTTP responses (#6829)
• Add ByteBuffer field type marshaling support (#6686)
• Fix stdout exporter format by adding newline after each export (#6848)
• Enable reusuable_data memory mode by default for OtlpGrpc{Signal}Exporter, OtlpHttp{Signal}Exporter, OtlpStdout{Signal}Exporter, and PrometheusHttpServer (#6799)

Extension

• Rebrand file configuration to declarative configuration in documentation (#6812)
• Fix declarative config file_format validation (#6786)
• Fix declarative config env substitution by disallowing '}' in default value (#6793)
• Set declarative config default OTLP protocol to http/protobuf (#6800)
• Stabilize autoconfigure disabling of resource keys via otel.resource.disabled.keys (#6809)

Tooling

• Run tests on Java 23 (#6825)
• Test Windows in CI (#6824)
• Add error prone checks for internal javadoc and private constructors (#6844)

🙇 Thank you

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

@breedx-splk @cyrille-leclerc @hboutemy @jack-berg @jaydeluca @jhalliday @JiwonKKang @jkwatson @laurit @neugartf @OrangeFlag @trask @vasantteja @zeitlinger