Deferred TI's `next_method` is not cleared when Clearing a Successful Task

[ReadytoRocc]

Apache Airflow version

2.2.0 (latest released)

Operating System

Container-Optimized OS with Containerd (cos_containerd) - GKE

Versions of Apache Airflow Providers

No response

Deployment

Astronomer

Deployment details

No response

What happened

I went to clear a successful task instance that is using a Deferred operator, and noticed it immediately went into a state of successful. The Operator is designed to run a trigger that will wait 1 minute from approximately task start. Upon investigation, I did not see the following in the second run's task log: {taskinstance.py:1332} INFO - Pausing task as DEFERRED..

What you expected to happen

I would expect the task to once again go into a state of deferred for approx. 1 minute and then succeed.

How to reproduce

Run the following DAG. Once a task instance is successful, clear it, and see the task fail. This confirms ti.next_method was not cleared, as execute did not rerun and reset execute_try_number. execute did not rerun, as ti.next_method was not cleared.

from datetime import datetime

from airflow import DAG
from airflow.exceptions import AirflowException
from airflow.models import BaseOperator
from airflow.triggers.testing import SuccessTrigger


class RetryOperator(BaseOperator):
    def execute(self, context):
        ti = context["ti"]
        next_method = ti.next_method
        try_number = ti.try_number

        self.log.info(
            f"In `execute`: try_number: {try_number}, next_method {next_method}."
        )

        self.defer(
            trigger=SuccessTrigger(),
            method_name="next",
            kwargs={"execute_try_number": try_number},
        )

    def next(self, context, execute_try_number, event=None):
        ti = context["ti"]
        next_method = ti.next_method
        try_number = ti.try_number

        self.log.info(
            f"In `next`: try_number: {try_number}, next_method {next_method}, execute_try_number: {execute_try_number}."
        )

        if execute_try_number != try_number:
            raise AirflowException("`execute` wasn't run during clear!")

        return None  # Success!


with DAG(
    "triggerer_clear", schedule_interval=None, start_date=datetime(2021, 10, 20)
) as dag:
    RetryOperator(task_id="clear")

Anything else

I believe this is due to ti.next_method (and ti.next_method_kwargs) not being cleared after a task has completed. A similar issue was raised in #18146.

Are you willing to submit PR?

• Yes I am willing to submit a PR!

Code of Conduct

• I agree to follow this project's Code of Conduct

[boring-cyborg]

Thanks for opening your first issue here! Be sure to follow the issue template!

[ephraimbuddy]

@ReadytoRocc assigned it to you. Let me know if you need help.