Telemetry

Copy Markdown View Source

Telemetry events are emitted under:

[:<telemetry_id>, :connection, <event>]

Events

  • :success
  • :failure
  • :disconnected
  • :timeout
  • :status

Measurements

  • :success -> %{count: 1}
  • :failure -> %{count: 1}
  • :disconnected -> %{count: 1}
  • :timeout -> %{count: 1}

  • :status -> %{value: 0 | 1}

Metadata

  • :success includes %{url: String.t()}
  • :failure includes %{reason: term()}
  • :disconnected includes %{reason: term()}

Notes

  • connection-success telemetry is emitted only after websocket upgrade and successful :on_upgrade bootstrap, if configured
  • frame-handler failures are reported through the connection failure path

Example

:telemetry.attach(
  "off-broadway-websocket-success",
  [:websocket_producer, :connection, :success],
  fn event, measurements, metadata, _config ->
    IO.inspect({event, measurements, metadata}, label: "telemetry")
  end,
  nil
)