airflow.sensors.external_task

Module Contents

Bases: airflow.models.BaseOperatorLink

Operator link for ExternalTaskSensor. It allows users to access DAG waited with ExternalTaskSensor.

name = External DAG[source]
class airflow.sensors.external_task.ExternalTaskSensor(*, external_dag_id: str, external_task_id: Optional[str] = None, allowed_states: Optional[Iterable[str]] = None, failed_states: Optional[Iterable[str]] = None, execution_delta: Optional[datetime.timedelta] = None, execution_date_fn: Optional[Callable] = None, check_existence: bool = False, **kwargs)[source]

Bases: airflow.sensors.base.BaseSensorOperator

Waits for a different DAG or a task in a different DAG to complete for a specific execution_date

Parameters

  • external_dag_id (str) – The dag_id that contains the task you want to wait for

  • external_task_id (str or None) – The task_id that contains the task you want to wait for. If None (default value) the sensor waits for the DAG

  • allowed_states (Iterable) – Iterable of allowed states, default is ['success']

  • failed_states (Iterable) – Iterable of failed or dis-allowed states, default is None

  • execution_delta (Optional[datetime.timedelta]) – time difference with the previous execution to look at, the default is the same execution_date as the current task or DAG. For yesterday, use [positive!] datetime.timedelta(days=1). Either execution_delta or execution_date_fn can be passed to ExternalTaskSensor, but not both.

  • execution_date_fn (Optional[Callable]) – function that receives the current execution date as the first positional argument and optionally any number of keyword arguments available in the context dictionary, and returns the desired execution dates to query. Either execution_delta or execution_date_fn can be passed to ExternalTaskSensor, but not both.

  • check_existence (bool) – Set to True to check if the external task exists (when external_task_id is not None) or check if the DAG to wait for exists (when external_task_id is None), and immediately cease waiting if the external task or DAG does not exist (default value: False).

template_fields = ['external_dag_id', 'external_task_id'][source]
ui_color = #19647e[source]

Return operator extra links

poke(self, context, session=None)[source]
_check_for_existence(self, session)[source]
get_count(self, dttm_filter, session, states)[source]

Get the count of records against dttm filter and states

Parameters

  • dttm_filter (list) – date time filter for execution date

  • session (SASession) – airflow session object

  • states (list) – task or dag states

Returns

count of record against the filters

_handle_execution_date_fn(self, context)[source]

This function is to handle backwards compatibility with how this operator was previously where it only passes the execution date, but also allow for the newer implementation to pass all context variables as keyword arguments, to allow for more sophisticated returns of dates to return.

class airflow.sensors.external_task.ExternalTaskMarker(*, external_dag_id: str, external_task_id: str, execution_date: Optional[Union[str, datetime.datetime]] = '{{ execution_date.isoformat() }}', recursion_depth: int = 10, **kwargs)[source]

Bases: airflow.operators.dummy.DummyOperator

Use this operator to indicate that a task on a different DAG depends on this task. When this task is cleared with “Recursive” selected, Airflow will clear the task on the other DAG and its downstream tasks recursively. Transitive dependencies are followed until the recursion_depth is reached.

Parameters

  • external_dag_id (str) – The dag_id that contains the dependent task that needs to be cleared.

  • external_task_id (str) – The task_id of the dependent task that needs to be cleared.

  • execution_date (str or datetime.datetime) – The execution_date of the dependent task that needs to be cleared.

  • recursion_depth – The maximum level of transitive dependencies allowed. Default is 10. This is mostly used for preventing cyclic dependencies. It is fine to increase this number if necessary. However, too many levels of transitive dependencies will make it slower to clear tasks in the web UI.

template_fields = ['external_dag_id', 'external_task_id', 'execution_date'][source]
ui_color = #19647e[source]
__serialized_fields :Optional[FrozenSet[str]][source]
classmethod get_serialized_fields(cls)[source]

Serialized ExternalTaskMarker contain exactly these fields + templated_fields .

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