airflow.operators.druid_check_operator
¶
Module Contents¶
-
class
airflow.operators.druid_check_operator.
DruidCheckOperator
(sql, druid_broker_conn_id='druid_broker_default', *args, **kwargs)[source]¶ Bases:
airflow.operators.check_operator.CheckOperator
Performs checks against Druid. The
DruidCheckOperator
expects a sql query that will return a single row. Each value on that first row is evaluated using pythonbool
casting. If any of the values returnFalse
the check is failed and errors out.Note that Python bool casting evals the following as
False
:False
0
Empty string (
""
)Empty list (
[]
)Empty dictionary or set (
{}
)
Given a query like
SELECT COUNT(*) FROM foo
, it will fail only if the count== 0
. You can craft much more complex query that could, for instance, check that the table has the same number of rows as the source table upstream, or that the count of today’s partition is greater than yesterday’s partition, or that a set of metrics are less than 3 standard deviation for the 7 day average. This operator can be used as a data quality check in your pipeline, and depending on where you put it in your DAG, you have the choice to stop the critical path, preventing from publishing dubious data, or on the side and receive email alerts without stopping the progress of the DAG.- Parameters