Telemetry integration for event tracing, metrics, and logging.

Redix connections (both Redix and Redix.PubSub) execute the following Telemetry events:

• [:redix, :disconnection] - executed when the connection is lost with the Redis server. There are no measurements associated with this event. Metadata are:

  • :reason - the disconnection reason as a Redix.ConnectionError struct.
  • :address - the address the connection was connected to.
  • :connection - the PID or registered name of the Redix connection that emitted the event.

• [:redix, :failed_connection] - executed when Redix can't connect to the specified Redis server, either when starting up the connection or after a disconnection. There are no measurements associated with this event. Metadata are:

  • :reason - the disconnection reason as a Redix.ConnectionError struct.
  • :address or :sentinel_address - the address the connection was trying to connect to (either a Redis server or a Redis Sentinel instance).
  • :connection - the PID or registered name of the Redix connection that emitted the event.

• [:redix, :reconnection] - executed when a Redix connection that had disconnected reconnects to a Redis server. There are no measurements associated with this event. Metadata are:

  • :address - the address the connection successfully reconnected to.
  • :connection - the PID or registered name of the Redix connection that emitted the event.

Redix connections execute the following Telemetry events when commands or pipelines of any kind are executed.

• [:redix, :pipeline] - executed when a pipeline (or command, which is a pipeline with just one command) is successfully sent to the server and a reply comes from the server. Measurements are:

  • :elapsed_time (integer) - the elapsed time that it took to send the pipeline to the server and get a reply. The elapsed time is expressed in the :native time unit. See System.convert_time_unit/3.

  Metadata are:

  • :connection - the connection that emitted the event. If the connection was registered with a name, the name is used here, otherwise the PID.
  • :commands - the commands sent to the server. This is always a list of commands, so even if you do Redix.command(conn, ["PING"]) than the list of commands will be [["PING"]].
  • :start_time - the system time when the pipeline was issued. This could be useful for tracing. The time unit is :native, see System.convert_time_unit/3.

• [:redix, :pipeline, :error] - executed when there's an error talking to the server. There are no measurements. Metadata are:

  • :connection - the connection that emitted the event. If the connection was registered with a name, the name is used here, otherwise the PID.
  • :commands - the commands sent to the server. This is always a list of commands, so even if you do Redix.command(conn, ["PING"]) than the list of commands will be [["PING"]].
  • :start_time - the system time when the pipeline was issued. This could be useful for tracing. The time unit is :native, see System.convert_time_unit/3.
  • :reason - the error reason.

More events might be added in the future and that won't be considered a breaking change, so if you're writing a handler for Redix events be sure to ignore events that are not known. All future Redix events will start with the :redix atom, like the ones above.

A default handler that logs these events appropriately is provided, see attach_default_handler/0. Otherwise, you can write your own handler to instrument or log events, see the Telemetry page in the docs.