Threadline.Telemetry (Threadline v0.5.0)

Telemetry integration helpers for Threadline.

Threadline emits four telemetry events:

[:threadline, :transaction, :committed] — after an AuditTransaction is committed. Automatically emitted (with table_count: 0) when Threadline.record_action/2 succeeds. For accurate per-transaction counts, call Threadline.Telemetry.transaction_committed/2 explicitly after a known DB transaction commit.
[:threadline, :action, :recorded] — after Threadline.record_action/2 completes (success or failure).
[:threadline, :health, :checked] — after Threadline.Health.trigger_coverage/1 returns. Measurements: %{covered: integer, uncovered: integer, expected_uncovered: integer}. The expected_uncovered measurement was added in Phase 66 (additive — subscribers that destructure only covered and uncovered keep working).
[:threadline, :health, :checked, :error] — sibling event emitted when a polled coverage check raises (Phase 66 D-30c). Metadata: %{error: message}. The dashboard keeps the last-good snapshot and reschedules the next poll; this event lets adopters alert on transient or sustained failure.

Usage

Attach handlers in your application's start/2 callback:

:telemetry.attach(
  "my-app-audit",
  [:threadline, :action, :recorded],
  &MyApp.Instrumentation.handle_event/4,
  nil
)

Summary

Functions

emit_health_checked(covered, uncovered, expected_uncovered)

Emits the [:threadline, :health, :checked] event with covered / uncovered / expected_uncovered measurements.

emit_health_checked_error(error_message)

Emits the [:threadline, :health, :checked, :error] event when a polled coverage check fails (Phase 66 D-30c). The dashboard keeps the last-good snapshot and ALWAYS reschedules the next poll; this event lets adopters alert on transient or sustained failure.

transaction_committed(transaction, opts \\ [])

Emits [:threadline, :transaction, :committed] with the given table count.

Functions

emit_health_checked(covered, uncovered, expected_uncovered)

Emits the [:threadline, :health, :checked] event with covered / uncovered / expected_uncovered measurements.

Phase 66 added the expected_uncovered measurement key (additive). External subscribers that destructure only %{covered: c, uncovered: u} continue to work unchanged.

emit_health_checked_error(error_message)

transaction_committed(transaction, opts \\ [])

Emits [:threadline, :transaction, :committed] with the given table count.

Call this after a DB transaction that you know produced AuditTransaction records, when you need accurate table_count measurements.

Example

{:ok, txn} = MyApp.Repo.transaction(fn ->
  # ... your writes ...
end)
Threadline.Telemetry.transaction_committed(txn, table_count: 3)