ETS-backed FIFO queue for log records awaiting export.

Each row is {key, %Otel.Logs.LogRecord{}, inserted_at_ms} where the key is :erlang.unique_integer([:positive]) — a positive integer guaranteed to be unique within the BEAM lifetime — and inserted_at_ms is the millisecond timestamp stamped at insert/1 time, used solely by the sweep loop. The underlying table is :set (hash-based), matching Otel.Trace.SpanStorage's shape and giving O(1) insert in the hot emit path. Take order is hash-iteration order (not emission order); this is fine because each log record carries its own timestamp / observed_timestamp and the collector orders by those.

Logs are atomic events — there is no :active / :completed lifecycle like spans. Records enter via insert/1 and leave via take/1 when the exporter drains them.

Public API

Mutation flow used by Otel.Logs.Logger:

Otel.Logs.LogRecordStorage.insert(record)

No get or update — log records are immutable once enqueued.

Concurrency

Multi-writer + single-reader (the Exporter):

• insert/1 runs on the caller process and writes to ETS directly (write_concurrency makes this lock-free).
• take/1 is called only by Otel.Logs.LogRecordExporter (single reader — no take/insert races).

Backpressure

insert/1 silently drops the record when the ETS table is already at @max_queue_size, matching the spec's maxQueueSize parameter for the Batching processor (logs/sdk.md L540-L541 "After the size is reached logs are dropped"). Drop is a normal lifecycle event, not a failure — callers don't branch on the result.

Sweep — stale records

The GenServer runs a self-scheduled sweep every @sweep_interval_ms (10 minutes) that issues a single :ets.select_delete/2 removing rows whose inserted_at_ms (row position 3) is older than @log_record_ttl_ms (30 minutes). This is the safety net for records that never get drained — if Otel.Logs.LogRecordExporter is dead or hung, records would otherwise pile up until the @max_queue_size backpressure starts dropping fresh records. With the sweep, the oldest stale records age out instead so fresh inserts keep landing.

Defaults match Otel.Trace.SpanStorage's sweeper for symmetry. Sweep strategy is drop only — exporting half-aged records serves no spec purpose.

References

• OTel Logs SDK §LogRecordProcessor: opentelemetry-specification/specification/logs/sdk.md L468-L545
• Erlang :erlang.unique_integer/1: https://www.erlang.org/doc/man/erlang#unique_integer-1