SLA misses and notifications in Apache Airflow - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is an SLA in Apache Airflow?

SLA stands for Service Level Agreement. In Airflow, it is a time limit set on tasks to finish by a certain deadline.

beginner

What happens when a task misses its SLA in Airflow?

Airflow records the SLA miss and can trigger notifications to alert users about the delay.

intermediate

How do you enable SLA notifications in Airflow?

You set the 'sla_miss_callback' function in your DAG to define what happens when an SLA is missed, like sending an email.

beginner

What is the role of 'sla' parameter in Airflow tasks?

The 'sla' parameter sets a deadline (a datetime.timedelta) for the task to complete. If the task runs longer, it triggers an SLA miss.

intermediate

Can SLA misses trigger automatic retries in Airflow?

No, SLA misses only notify about delays. Retries are controlled separately by the 'retries' and 'retry_delay' parameters.

What does SLA stand for in Airflow?

A Scheduled Log Action

B System Log Alert

C Service Level Agreement

D Service Load Average

SLA means Service Level Agreement, a deadline for task completion.

Which Airflow parameter sets the deadline for a task?

A execution_timeout

B retry_delay

C start_date

D sla

The 'sla' parameter defines the time limit for task completion.

What happens when a task misses its SLA?

A Airflow triggers an SLA miss notification

B The task automatically retries

C The DAG stops running

D Nothing happens

Airflow records the SLA miss and can notify users.

How do you customize SLA miss notifications?

A By setting 'sla_miss_callback' in the DAG

B By changing 'retry_delay'

C By modifying 'start_date'

D By setting 'max_active_runs'

The 'sla_miss_callback' function defines actions on SLA misses.

Do SLA misses cause task retries automatically?

A Yes, always

B No, retries are separate from SLA misses

C Only if 'sla_retry' is true

D Only for PythonOperator tasks

Retries depend on 'retries' and 'retry_delay', not SLA misses.

Explain how SLA misses work in Airflow and how you can notify users when they happen.

Think about deadlines on tasks and what happens if they are late.

Describe the difference between SLA misses and task retries in Airflow.

Consider what each feature is meant to do.