View Source Instrumentation and Logging

Oban provides integration with Telemetry, a dispatching library for metrics and instrumentation. It is easy to report Oban metrics to any backend by attaching to Telemetry events prefixed with :oban.

Default Logger

The Oban.Telemetry module provides a robust structured logger that handles all of Oban's telemetry events. As in the example above, attach it within your application module:

:ok = Oban.Telemetry.attach_default_logger()copy

For more details on the default structured logger and information on event metadata see docs for the Oban.Telemetry module.

Custom Handlers

Here is an example of an unstructured log handler:

defmodule MyApp.ObanLogger do
  require Logger

  def handle_event([:oban, :job, :start], measure, meta, _) do
    Logger.warning("[Oban] :started #{meta.worker} at #{measure.system_time}")
  end

  def handle_event([:oban, :job, event], measure, meta, _) do
    Logger.warning("[Oban] #{event} #{meta.worker} ran in #{measure.duration}")
  end
endcopy

Attach the handler to success and failure events in your application's Application.start/2 callback (usually in lib/my_app/application.ex):

def start(_type, _args) do
  events = [
    [:oban, :job, :start],
    [:oban, :job, :stop],
    [:oban, :job, :exception]
  ]

  :telemetry.attach_many("oban-logger", events, &MyApp.ObanLogger.handle_event/4, [])

  Supervisor.start_link(...)
endcopy