incubator-airflow/docs/metrics.rst

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Metrics
=======

Airflow can be set up to send metrics to `StatsD <https://github.com/etsy/statsd>`__.

Setup
-----

First you must install statsd requirement:

.. code-block:: bash

   pip install 'apache-airflow[statsd]'

Add the following lines to your configuration file e.g. ``airflow.cfg``

.. code-block:: ini

    [scheduler]
    statsd_on = True
    statsd_host = localhost
    statsd_port = 8125
    statsd_prefix = airflow

If you want to avoid send all the available metrics to StatsD, you can configure an allow list of prefixes to send only
the metrics that start with the elements of the list:

.. code-block:: ini

    [scheduler]
    statsd_allow_list = scheduler,executor,dagrun

If you want to redirect metrics to different name, you can configure ``stat_name_handler`` option
in ``[scheduler]`` section.  It should point to a function that validate the statsd stat name, apply changes
to the stat name if necessary and return the transformed stat name. The function may looks as follow:

.. code-block:: python

    def my_custom_stat_name_handler(stat_name: str) -> str:
        return stat_name.lower()[:32]

If you want to use a custom Statsd client outwith the default one provided by Airflow the following key must be added
to the configuration file alongside the module path of your custom Statsd client. This module must be available on
your PYTHONPATH.

.. code-block:: ini

    [scheduler]
    statsd_custom_client_path = x.y.customclient

Counters
--------

======================================= ================================================================
Name                                    Description
======================================= ================================================================
``<job_name>_start``                    Number of started ``<job_name>`` job, ex. ``SchedulerJob``, ``LocalTaskJob``
``<job_name>_end``                      Number of ended ``<job_name>`` job, ex. ``SchedulerJob``, ``LocalTaskJob``
``operator_failures_<operator_name>``   Operator ``<operator_name>`` failures
``operator_successes_<operator_name>``  Operator ``<operator_name>`` successes
``ti_failures``                         Overall task instances failures
``ti_successes``                        Overall task instances successes
``zombies_killed``                      Zombie tasks killed
``scheduler_heartbeat``                 Scheduler heartbeats
``dag_processing.processes``            Number of currently running DAG parsing processes
``scheduler.tasks.killed_externally``   Number of tasks killed externally
======================================= ================================================================

Gauges
------

=================================================== ========================================================================
Name                                                Description
=================================================== ========================================================================
``dagbag_size``                                     DAG bag size
``dag_processing.import_errors``                    Number of errors from trying to parse DAG files
``dag_processing.total_parse_time``                 Seconds taken to scan and import all DAG files once
``dag_processing.last_runtime.<dag_file>``          Seconds spent processing ``<dag_file>`` (in most recent iteration)
``dag_processing.last_run.seconds_ago.<dag_file>``  Seconds since ``<dag_file>`` was last processed
``dag_processing.processor_timeouts``               Number of file processors that have been killed due to taking too long
``executor.open_slots``                             Number of open slots on executor
``executor.queued_tasks``                           Number of queued tasks on executor
``executor.running_tasks``                          Number of running tasks on executor
``pool.open_slots.<pool_name>``                     Number of open slots in the pool
``pool.used_slots.<pool_name>``                     Number of used slots in the pool
``pool.starving_tasks.<pool_name>``                 Number of starving tasks in the pool
=================================================== ========================================================================

Timers
------

=========================================== =================================================
Name                                        Description
=========================================== =================================================
``dagrun.dependency-check.<dag_id>``        Milliseconds taken to check DAG dependencies
``dag.<dag_id>.<task_id>.duration``         Milliseconds taken to finish a task
``dag_processing.last_duration.<dag_file>`` Milliseconds taken to load the given DAG file
``dagrun.duration.success.<dag_id>``        Milliseconds taken for a DagRun to reach success state
``dagrun.duration.failed.<dag_id>``         Milliseconds taken for a DagRun to reach failed state
``dagrun.schedule_delay.<dag_id>``          Milliseconds of delay between the scheduled DagRun
                                            start date and the actual DagRun start date
=========================================== =================================================