Otel.SDK.Logs.Logger (otel v0.2.0)

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SDK implementation of the Otel.API.Logs.Logger behaviour (logs/sdk.md §Logger).

Emits log records by dispatching to all registered processors. Populates trace context from the resolved Context and sets observed_timestamp when not provided.

All functions are safe for concurrent use, satisfying spec logs/api.md L172-L176 (Status: Stable, #4885) — "Logger — all methods MUST be documented that implementations need to be safe for concurrent use by default."

Public API

FunctionRole
emit/3SDK (OTel API MUST) — logs/api.md L111-L131 + logs/sdk.md §Emit
enabled?/2SDK (OTel API SHOULD) — logs/api.md L133-L154 + logs/sdk.md §Enabled

LogRecord limits

build_log_record/3 composes the two Otel.SDK.Logs.LogRecordLimits helpers in order — truncate_attributes/2 first (so dropped count is taken on the post-truncation map), then drop_attributes/2. The dropped_attributes_count field on the record is the size delta across the drop step, satisfying mapping-to-non-otlp.md L73-79 ("OpenTelemetry dropped attributes count MUST be reported as a key-value pair ... otel.dropped_attributes_count").

Per logs/sdk.md L345-348, a single Logger.warning/1 is emitted per LogRecord whenever either limit took effect. The MUST "at most once per LogRecord" is satisfied structurally — build_log_record/3 runs once per emit/3 call.

Self-reference

The warning re-enters the OTel pipeline whenever Otel.LoggerHandler is installed. The re-entered record carries a single short-string attribute payload, well below the default limits, so it produces no additional warning — the recursion is bounded at depth 1. Matches opentelemetry-erlang: otel_log_handler.erl L233 emits ?LOG_WARNING(...) on exporter failure, and otel_exporter.erl / otel_configuration.erl use ?LOG_WARNING / ?LOG_INFO throughout — none filter their own warnings out of the OTel bridge.

References

  • OTel Logs SDK §Logger: opentelemetry-specification/specification/logs/sdk.md
  • OTel Logs API §Logger: opentelemetry-specification/specification/logs/api.md L99-L155
  • OTLP mapping-to-non-otlp.md §Dropped Attributes Count: L73-L79

Summary

Functions

emit(arg, ctx, log_record)

SDK (OTel API MUST) — Emit a LogRecord (logs/api.md L111-L131).

enabled?(arg, opts)

SDK (OTel API SHOULD) — Enabled (logs/api.md L133-L154 + logs/sdk.md §Enabled L256-L268).

Functions

emit(arg, ctx, log_record)

@spec emit(
  logger :: Otel.API.Logs.Logger.t(),
  ctx :: Otel.API.Ctx.t(),
  log_record :: Otel.API.Logs.LogRecord.t()
) :: :ok

SDK (OTel API MUST) — Emit a LogRecord (logs/api.md L111-L131).

Dispatches the limited record to every registered processor.

enabled?(arg, opts)

@spec enabled?(
  logger :: Otel.API.Logs.Logger.t(),
  opts :: Otel.API.Logs.Logger.enabled_opts()
) :: boolean()

SDK (OTel API SHOULD) — Enabled (logs/api.md L133-L154 + logs/sdk.md §Enabled L256-L268).

Returns false when no processors are registered, or when every processor implementing enabled?/4 returns false. The Development-status LoggerConfig filter legs (L259-L266 — enabled / minimum_severity / trace_based) are deferred per the project's Stable-only policy, mirroring how Otel.SDK.Trace.Tracer.enabled?/2 defers TracerConfig.