Airflow architecture (scheduler, webserver, executor, metadata DB) - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start the Airflow scheduler service.

Apache Airflow

airflow [1]

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Awebserver

Btriggerer

Cscheduler

Dworker

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'webserver' starts the web UI instead of the scheduler.

The correct command to start the Airflow scheduler is airflow scheduler.

2fill in blank

medium

Complete the code to start the Airflow webserver on port 8080.

Apache Airflow

airflow webserver [1] 8080

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A-p

B--port

C-port

D/p

Attempts:

3 left

💡 Hint

Common Mistakes

Using '-p' or '-port' causes the command to fail or ignore the port setting.

The correct flag to specify the port is --port.

3fill in blank

hard

Fix the error in the executor configuration line to use the CeleryExecutor.

Apache Airflow

executor = [1]Executor

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ACelery

BLocal

CSequential

DKubernetes

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'LocalExecutor' or 'SequentialExecutor' changes how tasks run and may not support distributed execution.

The correct executor name is CeleryExecutor to enable distributed task execution.

4fill in blank

hard

Fill both blanks to complete the metadata database connection string for PostgreSQL.

Apache Airflow

sql_alchemy_conn = postgresql+psycopg2://[1]:[2]@localhost/airflow

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Aairflow_user

Bpassword123

Cadmin

Dairflow_pass

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping username and password or using incorrect credentials causes connection failures.

The connection string requires the username and password. Here, airflow_user is the username and password123 is the password.

5fill in blank

hard

Fill all three blanks to define a DAG with a schedule interval and default arguments.

Apache Airflow

dag = DAG(dag_id='example_dag', default_args=[1], schedule_interval=[2], catchup=[3])

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A{'owner': 'airflow', 'start_date': datetime(2024, 1, 1)}

B'@daily'

CFalse

DTrue

Attempts:

3 left

💡 Hint

Common Mistakes

Using catchup=True causes many backfill runs. Using wrong schedule_interval strings causes scheduling errors.

The default_args is a dictionary with owner and start_date. The schedule_interval is '@daily' for daily runs. catchup is set to False to avoid running past missed intervals.