Google Cloud Composer DAG 未被触发

Question

我计划从今天 2020/08/11 开始，在东部标准时间（纽约州）星期二至星期六上午 04:00 运行安排 DAG。编写代码并部署后，我预计 DAG 会被触发。我刷新了 Airflow UI 页面几次，但它仍然没有触发。我正在使用带有 python 3.

的 Airflow 版本 v1.10.9-composer

这是我的 DAG 代码：

"""
This DAG executes a retrieval job
"""

# Required packages to execute DAG

from __future__ import print_function
import pendulum
from airflow.models import DAG
from airflow.models import Variable
from datetime import datetime, timedelta
from airflow.contrib.operators.ssh_operator import SSHOperator
from airflow.operators.dummy_operator import DummyOperator
from airflow.utils.trigger_rule import TriggerRule


local_tz = pendulum.timezone("America/New_York")

# DAG parameters

default_args = {
    'owner': 'Me',
    'depends_on_past': False,
    'start_date': datetime(2020, 8, 10, 4, tzinfo=local_tz),
    'dagrun_timeout': None,
    'email': Variable.get('email'),
    'email_on_failure': True,
    'email_on_retry': False,
    'provide_context': True,
    'retries': None,
    'retry_delay': timedelta(minutes=5)
}

# create DAG object with Name and default_args
with DAG(
        'retrieve_files',
        schedule_interval='0 4 * * 2-6',
        description='Retrieves files from sftp',
        max_active_runs=1,
        catchup=True,
        default_args=default_args
) as dag:
    # Define tasks - below are dummy tasks and a task instantiated by SSHOperator- calling methods written in other py class
    start_dummy = DummyOperator(
        task_id='start',
        dag=dag
    )

    end_dummy = DummyOperator(
        task_id='end',
        trigger_rule=TriggerRule.NONE_FAILED,
        dag=dag
    )

    retrieve_file = SSHOperator(
        ssh_conn_id="my_conn",
        task_id='retrieve_file',
        command='/usr/bin/python3  /path_to_file/getFile.py',
        dag=dag)


    dag.doc_md = __doc__

    retrieve_file.doc_md = """\
    #### Task Documentation
    Connects to sftp and retrieves files.
    """

    start_dummy >> retrieve_file >> end_dummy

Answer 1

参考official documentation：

The scheduler runs your job one schedule_interval AFTER the start date.

If your start_date is 2020-01-01 and schedule_interval is @daily, the first run will be created on 2020-01-02 i.e., after your start date has passed.

为了在每天的特定时间（包括今天）运行 DAG，需要将 start_date 设置为过去的时间并且 schedule_interval 需要cron 格式的所需时间。正确设置昨天的日期时间非常重要，否则触发器将不起作用。

在这种情况下，我们应该将 start_date 设置为上一周的星期二，即：(2020, 8, 4)。自开始日期以来应该有 1 周的时间间隔，因为运行每周一次。

让我们来看看下面的例子，它展示了如何运行一份工作 04:00 AM，星期二到星期六 EST：

from datetime import datetime, timedelta
from airflow import models
import pendulum
from airflow.operators import bash_operator

local_tz = pendulum.timezone("America/New_York")

default_dag_args = {
    'start_date': datetime(2020, 8, 4, 4, tzinfo=local_tz),
    'retries': 0,
}

with models.DAG(
        'Test',
        default_args=default_dag_args,
        schedule_interval='00 04 * * 2-6') as dag:
       # DAG code
    print_dag_run_conf = bash_operator.BashOperator(
        task_id='print_dag_run_conf', bash_command='echo {{ dag_run.id }}')

我建议您查看 what’s the deal with start_date 文档。

Google Cloud Composer DAG 未被触发

Google Cloud Composer DAG is not getting triggered

python

cron

airflow

google-cloud-composer

pendulum