airflow.sensors.base

Module Contents

Classes

PokeReturnValue

Sensors can optionally return an instance of the PokeReturnValue class in the poke method.

BaseSensorOperator

Sensor operators are derived from this class and inherit these attributes.

Functions

poke_mode_only(cls)

Class Decorator for child classes of BaseSensorOperator to indicate
class airflow.sensors.base.PokeReturnValue(is_done, xcom_value=None)[source]

Sensors can optionally return an instance of the PokeReturnValue class in the poke method. If an XCom value is supplied when the sensor is done, then the XCom value will be pushed through the operator return value. :param is_done: Set to true to indicate the sensor can stop poking. :param xcom_value: An optional XCOM value to be returned by the operator.

__bool__()[source]
class airflow.sensors.base.BaseSensorOperator(*, poke_interval=60, timeout=conf.getfloat('sensors', 'default_timeout'), soft_fail=False, mode='poke', exponential_backoff=False, **kwargs)[source]

Bases: airflow.models.baseoperator.BaseOperator, airflow.models.skipmixin.SkipMixin

Sensor operators are derived from this class and inherit these attributes.

Sensor operators keep executing at a time interval and succeed when a criteria is met and fail if and when they time out.

Parameters

  • soft_fail (bool) – Set to true to mark the task as SKIPPED on failure

  • poke_interval (float) – Time in seconds that the job should wait in between each tries

  • timeout (float) – Time, in seconds before the task times out and fails.

  • mode (str) – How the sensor operates. Options are: { poke | reschedule }, default is poke. When set to poke the sensor is taking up a worker slot for its whole execution time and sleeps between pokes. Use this mode if the expected runtime of the sensor is short or if a short poke interval is required. Note that the sensor will hold onto a worker slot and a pool slot for the duration of the sensor’s runtime in this mode. When set to reschedule the sensor task frees the worker slot when the criteria is not yet met and it’s rescheduled at a later time. Use this mode if the time before the criteria is met is expected to be quite long. The poke interval should be more than one minute to prevent too much load on the scheduler.

  • exponential_backoff (bool) – allow progressive longer waits between pokes by using exponential backoff algorithm

ui_color :str = #e6f1f2[source]
valid_modes :Iterable[str] = ['poke', 'reschedule'][source]
deps[source]
poke(context)[source]

Function that the sensors defined while deriving this class should override.

execute(context)[source]

This is the main method to derive when creating an operator. Context is the same dictionary used as when rendering jinja templates.

Refer to get_template_context for more context.

prepare_for_execution()[source]

Lock task for execution to disable custom action in __setattr__ and returns a copy of the task

property reschedule[source]

Define mode rescheduled sensors.

classmethod get_serialized_fields()[source]

Stringified DAGs and operators contain exactly these fields.

airflow.sensors.base.poke_mode_only(cls)[source]

Class Decorator for child classes of BaseSensorOperator to indicate that instances of this class are only safe to use poke mode.

Will decorate all methods in the class to assert they did not change the mode from ‘poke’.

Parameters

cls – BaseSensor class to enforce methods only use ‘poke’ mode.

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