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

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Configurable limits for Otel.API.Logs.LogRecord attribute collections (logs/sdk.md §LogRecord Limits L321-348).

Holds the two limit values and exposes a single apply/2 entry point that returns the limited LogRecord together with the dropped-attributes count for the orchestrator to forward into Otel.SDK.Logs.LogRecord.dropped_attributes_count. Composition ordering and the spec-required discard message (logs/sdk.md L345-348) remain the orchestrator's responsibility — see Otel.SDK.Logs.Logger.build_log_record/3.

Configurable parameters

FieldDefaultSpec
attribute_count_limit128common/README.md L305 — "Maximum allowed attribute count per record"
attribute_value_length_limit:infinitycommon/README.md L306 — "Maximum allowed attribute value length (applies to string values and byte arrays)"

Both fields accept any non_neg_integer/0 (per the spec value-range definition in sdk-environment-variables.md L197-L204 "Valid values are non-negative") — 0 is a valid setting that drops every attribute or truncates every value to empty.

Configuration sources

Spec env vars OTEL_LOGRECORD_ATTRIBUTE_COUNT_LIMIT and OTEL_LOGRECORD_ATTRIBUTE_VALUE_LENGTH_LIMIT are not read at this layer. Configuration flows through two paths: the struct defaults shown above, and explicit programmatic overrides via Otel.SDK.Logs.LoggerProvider.start_link/1. A future cross-cutting env-config helper may surface those env vars uniformly across modules; the per-module API is unchanged either way.

Truncation rules

LogRecord.attributes values are the full primitive_any/0 per spec (opentelemetry-proto/opentelemetry/proto/logs/v1/logs.proto L178 — repeated KeyValue where KeyValue.value = AnyValue). Truncation applies recursively per common/README.md L260-L274:

Value shapeTruncation
String.t()character (grapheme) count via String.slice/3 (spec L262-263 "counting any character in it as 1")
{:bytes, binary()}byte count via binary_part/3 (spec L265-267 "counting each byte as 1")
[primitive_any()]element-wise recursion — covers both homogeneous primitive arrays (spec L268-269) and heterogeneous AnyValue arrays (spec L270-271)
%{String.t() => primitive_any()}recursion over map values (spec L272-273)
boolean(), integer(), float(), nilpasses through unchanged (spec L274 "otherwise a value MUST NOT be truncated")

References

  • OTel Logs SDK §LogRecord Limits: opentelemetry-specification/specification/logs/sdk.md L321-348
  • OTel Common §Attribute Limits: opentelemetry-specification/specification/common/README.md L249-299
  • OTel Common §Configurable Parameters: opentelemetry-specification/specification/common/README.md L303-306
  • Mapping to non-OTLP §Dropped Attributes Count: opentelemetry-specification/specification/common/mapping-to-non-otlp.md L73-79
  • Env vars: opentelemetry-specification/specification/configuration/sdk-environment-variables.md L197-L204

Summary

Types

primitive()
primitive_any()
t()

Functions

apply(log_record, log_record_limits)

Applies all attribute limits to a LogRecord.

Types

primitive()

@type primitive() ::
  String.t() | {:bytes, binary()} | boolean() | integer() | float() | nil

primitive_any()

@type primitive_any() ::
  primitive() | [primitive_any()] | %{required(String.t()) => primitive_any()}

t()

@type t() :: %Otel.SDK.Logs.LogRecordLimits{
  attribute_count_limit: non_neg_integer(),
  attribute_value_length_limit: non_neg_integer() | :infinity
}

Functions

apply(log_record, log_record_limits)

@spec apply(log_record :: Otel.API.Logs.LogRecord.t(), limits :: t()) ::
  {Otel.API.Logs.LogRecord.t(), non_neg_integer()}

Applies all attribute limits to a LogRecord.

Returns {limited_record, dropped_attributes_count}. The count is the size delta from the count-limit drop step (truncation precedes drop and preserves map size, so the delta is exclusively the dropped-attribute count that belongs in Otel.SDK.Logs.LogRecord.dropped_attributes_count and the OTLP proto field of the same name).