Multi dag run

This plugin contains operators for triggering a DAG run multiple times and you can dynamically specify how many DAG run instances create.

It can be useful when you have to handle a big data and you want to split it into chunks and run multiple instances of the same task in parallel.

When you see a lot launched target DAGs you can set up more workers. So this makes it pretty easy to scale.

Install

pip install airflow_multi_dagrun

Example

Code for scheduling dags

import datetime as dt
from airflow import DAG

from airflow_multi_dagrun.operators import TriggerMultiDagRunOperator


def generate_dag_run():
    for i in range(100):
        yield {'index': i}


default_args = {
    'owner': 'airflow',
    'start_date': dt.datetime(2015, 6, 1),
}


dag = DAG('reindex_scheduler', schedule_interval=None, default_args=default_args)


ran_dags = TriggerMultiDagRunOperator(
    task_id='gen_target_dag_run',
    dag=dag,
    trigger_dag_id='example_target_dag',
    python_callable=generate_dag_run,
)

This code will schedule dag with id example_target_dag 100 times and pass payload to it.

Example of triggered dag:

dag = DAG(
   dag_id='example_target_dag',
   schedule_interval=None,
   default_args={'start_date': datetime.utcnow(), 'owner': 'airflow'},
)


def run_this_func(dag_run, **kwargs):
   print("Chunk received: {}".format(dag_run.conf['index']))


chunk_handler = PythonOperator(
   task_id='chunk_handler',
   provide_context=True,
   python_callable=run_this_func,
   dag=dag
)

Run example

There is docker-compose config, so it requires docker to be installed: docker, docker-compose

1. make init - create db
2. make add-admin - create admin user (is asks a password)
3. make web - start docker containers, run airflow webserver
4. make scheduler - start docker containers, run airflow scheduler

make down will stop and remove docker containers

Contributions

If you have found a bug or have some idea for improvement feel free to create an issue or pull request.

License

Apache 2.0