Apache Airflow Sequential Executor

The Sequential Executor is an executor in Apache Airflow that runs tasks one at a time, in the order that they are scheduled. The Sequential Executor is the default executor in Airflow and is well-suited for simple pipelines that do not require parallel execution.

To use the Sequential Executor, you do not need to do anything special. Simply define your tasks and specify the dependencies between them, and the Sequential Executor will execute the tasks in the correct order.

Example of Sequential Executor

Here is an example of a DAG that uses the Sequential Executor:

Copyfrom airflow import DAG 
from airflow.operators.bash import BashOperator 

dag = DAG( 
	'my_dag', 
	default_args={ 
		'owner': 'me', 
	}, 
	schedule_interval=None, 
) 

task1 = BashOperator( 
	task_id='task1', 
	bash_command='echo "Hello, World!"', 
	dag=dag, 
) 

task2 = BashOperator( 
	task_id='task2', 
	bash_command='echo "Goodbye, 
	World!"', 
	dag=dag, 
) 

task1 >> task2 

In this example, the task1 operator will be executed first, followed by the task2 operator.

More Detail

Here are a few more things to consider when using the Sequential Executor:

• The Sequential Executor does not support parallel execution of tasks. If you have tasks that can be run concurrently, you may want to consider using a different executor, such as the Local Executor or the Celery Executor.
• The Sequential Executor does not have any special configuration options. To use the Sequential Executor, you simply need to define your tasks and their dependencies as usual.
• The Sequential Executor is well-suited for simple pipelines that do not require parallel execution. If you have a complex pipeline with many tasks that can be run concurrently, you may want to consider using a different executor to take advantage of parallelism.