HareMq.Telemetry (hare_mq v1.4.0)

Telemetry events emitted by HareMq.

Attach handlers using :telemetry.attach/4 or :telemetry.attach_many/4.

Connection events

`[:hare_mq, :connection, :connected]`

Emitted when a broker connection is successfully opened.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:connection_name`	Registered process name (e.g. `{:global, HareMq.Connection}`)
metadata `:host`	AMQP URL string

`[:hare_mq, :connection, :disconnected]`

Emitted when a monitored connection process goes down unexpectedly.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:connection_name`	Registered process name
metadata `:reason`	Exit reason from the `:DOWN` message

`[:hare_mq, :connection, :reconnecting]`

Emitted whenever a reconnect attempt is scheduled (missing config or failed open).

Key	Value
measurements `:retry_delay_ms`	Milliseconds until next attempt
metadata `:connection_name`	Registered process name
metadata `:reason`	`:missing_config` or the connection error term

Consumer events

`[:hare_mq, :consumer, :connected]`

Emitted when a consumer channel is open and Basic.consume has been called.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:consumer`	Consumer module name
metadata `:queue`	Queue name
metadata `:exchange`	Exchange name
metadata `:routing_key`	Routing key
metadata `:stream`	`true` for stream consumers

`[:hare_mq, :consumer, :message, :start]`

`[:hare_mq, :consumer, :message, :stop]`

`[:hare_mq, :consumer, :message, :exception]`

Emitted by :telemetry.span/3 around the user-supplied consume/1 callback. Start/stop/exception events follow the standard :telemetry.span contract.

Start metadata:

Key	Value
metadata `:queue`	Queue name
metadata `:exchange`	Exchange name
metadata `:routing_key`	Routing key

Stop measurements additionally include :duration (native time units). Stop metadata additionally includes :result (:ok or :error).

Publisher events

`[:hare_mq, :publisher, :connected]`

Emitted when a publisher channel is open and ready to publish.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:publisher`	Publisher module name
metadata `:exchange`	Exchange name
metadata `:routing_key`	Routing key

`[:hare_mq, :publisher, :message, :published]`

Emitted after AMQP.Basic.publish/5 returns :ok.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:publisher`	Publisher module name
metadata `:exchange`	Exchange name
metadata `:routing_key`	Routing key

`[:hare_mq, :publisher, :message, :not_connected]`

Emitted when publish_message/1 is called but no channel is available.

Key	Value
measurements `:system_time`	`System.system_time()`
metadata `:publisher`	Publisher module name
metadata `:exchange`	Exchange name
metadata `:routing_key`	Routing key

Retry publisher events

`[:hare_mq, :retry_publisher, :message, :retried]`

Emitted when a failed message is sent to a delay queue.

Key	Value
measurements `:retry_count`	Current retry attempt number
measurements `:system_time`	`System.system_time()`
metadata `:queue`	Main queue name
metadata `:delay_queue`	Target delay queue name

`[:hare_mq, :retry_publisher, :message, :dead_lettered]`

Emitted when a message has exceeded retry_limit and is sent to the dead-letter queue.

Key	Value
measurements `:retry_count`	Final retry count
measurements `:system_time`	`System.system_time()`
metadata `:queue`	Main queue name
metadata `:dead_queue`	Dead-letter queue name

Example: attaching a simple logger handler

:telemetry.attach_many(
  "hare-mq-logger",
  [
    [:hare_mq, :connection, :connected],
    [:hare_mq, :connection, :disconnected],
    [:hare_mq, :consumer, :message, :stop],
    [:hare_mq, :retry_publisher, :message, :dead_lettered]
  ],
  fn event, measurements, metadata, _config ->
    require Logger
    Logger.info("[telemetry] #{inspect(event)} #{inspect(measurements)} #{inspect(metadata)}")
  end,
  nil
)