Rheo.Telemetry (rheo v1.0.0)

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Thin helpers around :telemetry for Rheo operations.

Events

Backend spans (:start / :stop / :exception suffix, metadata stream and, where relevant, group):

  • [:rheo, :append], [:rheo, :append_batch], [:rheo, :query], [:rheo, :fetch], [:rheo, :lease, :renew], [:rheo, :ack], [:rheo, :retry], [:rheo, :reject]

Backend counters (count measurement):

  • [:rheo, :stream, :create], [:rheo, :group, :create] — stream, group
  • [:rheo, :lease] — leases handed out by one fetch; stream, group, consumer_id
  • [:rheo, :redelivery], [:rheo, :dead_letter] — stream, group, event_id
  • [:rheo, :group, :frontier], [:rheo, :group, :replay], [:rheo, :group, :reset]

Runtime (Rheo.Group, Rheo.Producer, Rheo.Broadway.Acknowledger):

  • [:rheo, :consumer, :start | :stop], [:rheo, :producer, :start | :stop] — stream, group, consumer_id

  • [:rheo, :fetch, :error] — stream, group, reason (Rheo.Settle)
  • [:rheo, :lease, :renew] — stream, group, event_id, result (:ok or a Rheo.Settle reason)

  • [:rheo, :ack | :retry | :reject, :error] — stream, group, event_id, reason (Rheo.Settle)

  • [:rheo, :handler, :error] — a handler raised or threw; event_id, reason
  • [:rheo, :worker, :crash] — a handler task exited; event_id, reason

  • [:rheo, :broadway, :ack | :retry | :reject] — settled through the acknowledger

Metadata never includes event payloads. Attach handlers with :telemetry.attach/4 in your application.

Summary

Functions

execute(event, measurements, metadata)

Emits a telemetry event with measurements and metadata.

span(event, metadata, fun)

Executes fun while emitting start/stop (or exception) telemetry events.

Functions

execute(event, measurements, metadata)

@spec execute([atom()], map(), map()) :: :ok

Emits a telemetry event with measurements and metadata.

Arguments

  • event — full event name, e.g. [:rheo, :lease]
  • measurements — map of numeric measurements
  • metadata — map of contextual metadata

Examples

iex> Rheo.Telemetry.execute([:rheo, :doctest_execute], %{count: 1}, %{stream: "demo"})
:ok

Returns

:ok

span(event, metadata, fun)

@spec span([atom()], map(), (-> result)) :: result when result: term()

Executes fun while emitting start/stop (or exception) telemetry events.

Arguments

  • event — event name prefix as a list of atoms, e.g. [:rheo, :append]
  • metadata — map attached to all emissions
  • fun — zero-arity function to run

Examples

iex> Rheo.Telemetry.span([:rheo, :doctest_span], %{demo: true}, fn -> :ok end)
:ok

Returns

The return value of fun.

Errors / raises

Re-raises any exception, throw, or exit from fun after emitting an :exception event.