v1.40.0 (2024-12-12)

Context

• Adds optional GetAll method to Getter in Propagation API, allowing for the retrieval of multiple values for the same key. #4295

Traces

• Add in-development support for otlp/stdout exporter via OTEL_TRACES_EXPORTER. (#4183)
• Remove the recommendation to not synchronize access to TracerConfig.disabled. (#4310)

Metrics

• Add in-development support for otlp/stdout exporter via OTEL_METRICS_EXPORTER. (#4183)
• Remove the recommendation to not synchronize access to MeterConfig.disabled. (#4310)

Logs

• Add in-development support for otlp/stdout exporter via OTEL_LOGS_EXPORTER. (#4183)
• Remove the recommendation to not synchronize access to LoggerConfig.disabled. (#4310)
• Remove the in-development isolating log record processor. (#4301)

Events

• Deprecate Events API and SDK in favor of having Events support in the Logs API and SDK. (#4319)
• Change event.name attribute into top-level event name field. (#4320)

Common

• Lay out core principles for Specification changes. (#4286)

Supplementary Guidelines

• Add core principles for evaluating specification changes. (#4286)

OTEPs

• The open-telemetry/oteps repository was merged into the specification repository. (#4288)

New Contributors

• @CharlieTLe made their first contribution in https://github.com/open-telemetry/opentelemetry-specification/pull/4289
• @jamesmoessis made their first contribution in https://github.com/open-telemetry/opentelemetry-specification/pull/4295