DruidCheckOperator(sql:str, druid_broker_conn_id:str='druid_broker_default', *args, **kwargs)¶
Performs checks against Druid. The
DruidCheckOperatorexpects a sql query that will return a single row. Each value on that first row is evaluated using python
boolcasting. If any of the values return
Falsethe check is failed and errors out.
Note that Python bool casting evals the following as
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.
Return the druid db api hook.
Executes the druid sql to druid broker and returns the first resulting row.
sql (str) – the sql statement to be executed (str)