Airflow DAGs failed to be triggered - airflow

I just started working with Airflow recently and after writing a simple DAG to transfer data from sftp server to s3, I ran into this error when I triggered the DAG: AttributeError: 'NoneType' object has no attribute 'create_dagrun'. Does anyone have experience with this? Thank you so much
with dag:
# test ssh connection
t1 = SFTPOperator( task_id='download_file_from_sftp',
ssh_conn_id='sendeffect_evania',
local_filepath="/tmp/test.csv",
remote_filepath='sftp://evania#11335-04.root.nessus.at/files/download/evania_daily_bounce.csv',
operation='get' )

From what you have shared i think you have not used proper syntax to write the DAG.
Try to use the below:
import datetime as datetime
from airflow.models import DAG
with DAG('my_dag', start_date=datetime(2016, 1, 1)) as dag:
(
t1 = SFTPOperator( task_id='download_file_from_sftp',
ssh_conn_id='sendeffect_evania',
local_filepath="/tmp/test.csv",
remote_filepath='sftp://evania#11335-04.root.nessus.at/files/download/evania_daily_bounce.csv',
operation='get' )
)

Related

Working DAG fails when triggered from another dag in CLI

I have a simple DAG which connects to an impala db and runs an sql script. The dag runs fine when running independently:
airflow dags test original_dag_name 2022-9-27
However, when I test using TriggerDagRunOpertor from another DAG, the DAG fails:
airflow tasks test other_dag_name trigger_task 2022-9-27
Looking at the logs for original_dag_name I see the following:
[Cloudera][ODBC] (11560) Unable to locate SQLGetPrivateProfileString function
...which appears to be driver related, which doesn't make sense as it works fine when I trigger the DAG on its own. Is there some sort of config not getting set correctly when triggering via TriggerDagRunOperator?
Here is the TriggerDagRunOperator task:
task_run_original_dag = TriggerDagRunOperator (
task_id='run_original_dag',
trigger_dag_id='original_dag_name',
execution_date='{{ ds }}',
reset_dag_run=True,
wait_for_completion=True,
poke_interval=60
)

Issues installing airflow locally

I installed airflow locally because i am testing sftp operator in airflow (2.0.0). When I try running this code
from airflow.providers.sftp.operators import sftp_operator
from airflow import DAG
import datetime
dag = DAG(
'test_dag',
start_date = datetime.datetime(2020,1,8,0,0,0),
schedule_interval = '#daily'
)
get_operation = SFTPOperator(
task_id="operation",
ssh_conn_id="ssh_default",
local_filepath="route_to_local_file",
remote_filepath="remote_route_to_copy",
operation="get",
dag=dag
)
get_operation
When I run this code python code I am getting this error.
Traceback (most recent call last):
File "test_dags.py", line 1, in <module>
from airflow.providers.sftp.operators import sftp_operator
ModuleNotFoundError: No module named 'airflow.providers.sftp'
can anyone please tell if I am missing anything in my installation?
Since you don't specify how you installed Airflow I'm assuming you did something like pip install apache-airflow>=2.0.0. If you look at the Python dependencies in that environment with pip freeze you won't see apache-airflow-providers-sftp because as of version 2, Airflow extracts its functionality into provider packages, the vast majority of which need to installed manually, eg: pip install apache-airflow-providers-sftp. Now it should work. Supporting documentation https://airflow.apache.org/docs/apache-airflow-providers/packages-ref.html#apache-airflow-providers-sftp.

Dag Seems to be missing

I have a dag which checks for new workflows to be generated (Dynamic DAG) at a regular interval and if found, creates them. (Ref: Dynamic dags not getting added by scheduler )
The above DAG is working and the dynamic DAGs are getting created and listed in the web-server. Two issues here:
When clicking on the DAG in web url, it says "DAG seems to be missing"
The listed DAGs are not listed using "airflow list_dags" command
Error:
DAG "app01_user" seems to be missing.
The same is for all other dynamically generated DAGs. I have compiled the Python script and found no errors.
Edit1:
I tried clearing all data and running "airflow run". It ran successfully but no Dynamic generated DAGs were added to "airflow list_dags". But when running the command "airflow list_dags", it loaded and executed the DAG, (which generated Dynamic DAGs). The dynamic DAGs are also listed as below:
[root#cmnode dags]# airflow list_dags
sh: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8\nLANG=en_US.UTF-8)
sh: warning: setlocale: LC_ALL: cannot change locale (en_US.UTF-8\nLANG=en_US.UTF-8)
[2019-08-13 00:34:31,692] {settings.py:182} INFO - settings.configure_orm(): Using pool settings. pool_size=15, pool_recycle=1800, pid=25386
[2019-08-13 00:34:31,877] {__init__.py:51} INFO - Using executor LocalExecutor
[2019-08-13 00:34:32,113] {__init__.py:305} INFO - Filling up the DagBag from /root/airflow/dags
/usr/lib/python2.7/site-packages/airflow/operators/bash_operator.py:70: PendingDeprecationWarning: Invalid arguments were passed to BashOperator (task_id: tst_dyn_dag). Support for passing such arguments will be dropped in Airflow 2.0. Invalid arguments were:
*args: ()
**kwargs: {'provide_context': True}
super(BashOperator, self).__init__(*args, **kwargs)
-------------------------------------------------------------------
DAGS
-------------------------------------------------------------------
app01_user
app02_user
app03_user
app04_user
testDynDags
Upon running again, all the above generated 4 dags disappeared and only the base DAG, "testDynDags" is displayed.
When I was getting this error, there was an exception showing up in the webserver logs. Once I resolved that error and I restarted the webserver it went through normally.
From what I can see this is the error that is thrown when the webserver tried to parse the dag file and there is an error. In my case it was an error importing a new operator I added to a plugin.
Usually, I check in Airflow UI, sometimes the reason of broken DAG appear in there. But if it is not there, I usually run the .py file of my DAG, and error (reason of DAG cant be parsed) will appear.
I never got to work on dynamic DAG generation but I did face this issue when DAG was not present on all nodes ( scheduler, worker and webserver ). In case you have airflow cluster, please make sure that DAG is present on all airflow nodes.
Same error, the reason was I renamed my dag_id in uppercase. Something like "import_myclientname" into "import_MYCLIENTNAME".
I am little late to the party but I faced the error today:
In short: try executing airflow dags report and/or airflow dags reserialize
Check out my comment here:
https://stackoverflow.com/a/73880927/4437153
I found that airflow fails to recognize a dag defined in a file that does not have from airflow import DAG in it, even if DAG is not explicitly used in that file.
For example, suppose you have two files, a.py and b.py:
# a.py
from airflow import DAG
from airflow.operators.dummy_operator import DummyOperator
def makedag(dag_id="a"):
with DAG(dag_id=dag_id) as dag:
DummyOperator(task_id="nada")
dag = makedag()
and
# b.py
from a import makedag
dag = makedag(dag_id="b")
Then airflow will only look at a.py. It won't even look at b.py at all, even to notice if there's a syntax error in it! But if you add from airflow import DAG to it and don't change anything else, it will show up.

How to find the number of upstream tasks failed in Airflow?

I am having a tough time in figuring out how to find the failed task for the same dag run running twice on same day(same execution day).
Consider an example when a dag with dag_id=1 has failed on the first run (due to any reason lets say connection timeout maybe) and task got failed. TaskInstance table will contain the entry of the failed task when we try to query it. GREAT!!
But, If I re-run the same dag(note that dag_id is still 1) then in the last task(it has the rule of ALL_DONE so irrespective of the whether upstream task was failed or was successful it will be executed) I want to calculate the number of tasks failed in the current dag_run ignoring the previous dag_runs. I came across dag_run id which could be useful if we can relate it to TaskInstance but I could not. Any suggestions/help is appreciated.
In Airflow 1.10.x the same result can be achieved by much simpler code that avoids touching ORM directly.
from airflow.utils.state import State
def your_python_operator_callable(**context):
tis_dagrun = context['ti'].get_dagrun().get_task_instances()
failed_count = sum([True if ti.state == State.FAILED else False for ti in tis_dagrun])
print(f"There are {failed_count} failed tasks in this execution"
The one unfortunate problem is that context['ti'].get_dagrun() does not return instance of DAGRun when running test of a single task from CLI. In the effect, manual testing of that single task will fail but the standard run will work as expected.
You could create a PythonOperator task which queries the Airflow database to find the information you're looking for. This has the added benefit of passing along the information you need to query for the data you want:
from contextlib import closing
from airflow import models, settings
from airflow.utils.state import State
def your_python_operator_callable(**context):
with closing(settings.Session()) as session:
print("There are {} failed tasks in this execution".format(
session.query(
models.TaskInstance
).filter(
models.TaskInstance.dag_id == context["dag"].dag_id,
models.TaskInstance.execution_date == context["execution_date"],
models.TaskInstance.state == State.FAILED).count()
)
Then add the task to your DAG with a PythonOperator.
(I have not tested the above, but hopefully will send you on the right path)

Airflow: Simple DAG with one task never finishes

I have made a very simple DAG that looks like this:
from datetime import datetime
from airflow import DAG
from airflow.operators.bash_operator import BashOperator
cleanup_command = "/home/ubuntu/airflow/dags/scripts/log_cleanup/log_cleanup.sh "
dag = DAG(
'log_cleanup',
description='DAG for deleting old logs',
schedule_interval='10 13 * * *',
start_date=datetime(2018, 3, 30),
catchup=False,
)
t1 = BashOperator(task_id='cleanup_task', bash_command=cleanup_command, dag=dag)
The task finishes successfully but despite of this the DAG remains in "running" status. Any idea what could cause this. The screenshot below show the issue with the DAG remaining running. The earlier runs are only finished because I manually mark status as success. [Edit: I had originally written: "The earlier runs are only finished because I manually set status to running."]
The earlier runs are only finished because I manually set status to running.
Are you sure your scheduler is running? You can start it with $ airflow scheduler, and check the scheduler CLI command docs You shouldn't have to manually set tasks to running.
Your code here seems fine. One thing you might try is restarting your scheduler.
In the Airflow metadata database, DAG run end state is disconnected from task run end state. I've seen this happen before, but usually it resolves itself on the scheduler's next loop when it realizes all of the tasks in the DAG run have reached a final state (success, failed, or skipped).
Are you running the LocalExecutor, SequentialExecutor, or something else here?

Resources