We deployed Apache Airflow 2.3.3 to Azure.
Webserver - Web App
Scheduler - ACI
Celery Worker - ACI
We were seeing errors on the Celery ACI console related to Postgres and Redis connection timeouts as below
[2022-09-22 18:55:50,650: WARNING/ForkPoolWorker-15] Failed operation _store_result. Retrying 2 more times.
Traceback (most recent call last):
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1803, in _execute_context
cursor, statement, parameters, context
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 719, in do_execute
cursor.execute(statement, parameters)
psycopg2.DatabaseError: could not receive data from server: Connection timed out
SSL SYSCALL error: Connection timed out
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/airflow/.local/lib/python3.7/site-packages/celery/backends/database/__init__.py", line 47, in _inner
return fun(*args, **kwargs)
File "/home/airflow/.local/lib/python3.7/site-packages/celery/backends/database/__init__.py", line 117, in _store_result
task = list(session.query(self.task_cls).filter(self.task_cls.task_id == task_id))
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/orm/query.py", line 2887, in __iter__
return self._iter().__iter__()
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/orm/query.py", line 2897, in _iter
execution_options={"_sa_orm_load_options": self.load_options},
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/orm/session.py", line 1689, in execute
result = conn._execute_20(statement, params or {}, execution_options)
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1614, in _execute_20
return meth(self, args_10style, kwargs_10style, execution_options)
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/sql/elements.py", line 326, in _execute_on_connection
self, multiparams, params, execution_options
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1491, in _execute_clauseelement
cache_hit=cache_hit,
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1846, in _execute_context
e, statement, parameters, cursor, context
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 2027, in _handle_dbapi_exception
sqlalchemy_exception, with_traceback=exc_info[2], from_=e
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/util/compat.py", line 207, in raise_
raise exception
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/base.py", line 1803, in _execute_context
cursor, statement, parameters, context
File "/home/airflow/.local/lib/python3.7/site-packages/sqlalchemy/engine/default.py", line 719, in do_execute
cursor.execute(statement, parameters)
sqlalchemy.exc.DatabaseError: (psycopg2.DatabaseError) could not receive data from server: Connection timed out
SSL SYSCALL error: Connection timed out
[SQL: SELECT celery_taskmeta.id AS celery_taskmeta_id, celery_taskmeta.task_id AS celery_taskmeta_task_id, celery_taskmeta.status AS celery_taskmeta_status, celery_taskmeta.result AS celery_taskmeta_result, celery_taskmeta.date_done AS celery_taskmeta_date_done, celery_taskmeta.traceback AS celery_taskmeta_traceback
FROM celery_taskmeta
WHERE celery_taskmeta.task_id = %(task_id_1)s]
[parameters: {'task_id_1': 'c5f9f53c-8afe-4d67-8d3b-d7ad84875de1'}]
(Background on this error at: https://sqlalche.me/e/14/4xp6)
[2022-09-22 18:55:50,929: INFO/ForkPoolWorker-15] [c5f9f53c-8afe-4d67-8d3b-d7ad84875de1] Executing command in Celery: ['airflow', 'tasks', 'run', 'CS_ALERTING', 'CheckRunningTasks', 'scheduled__2022-09-22T18:00:00+00:00', '--local', '--subdir', 'DAGS_FOLDER/CS_ALERTING.py']
[2022-09-22 18:55:51,241: INFO/ForkPoolWorker-15] Filling up the DagBag from /opt/airflow/platform_pam/dags/CS_ALERTING.py
[2022-09-22 18:55:53,467: INFO/ForkPoolWorker-15] Running <TaskInstance: CS_ALERTING.CheckRunningTasks scheduled__2022-09-22T18:00:00+00:00 [queued]> on host localhost
[2022-09-22 18:55:58,304: INFO/ForkPoolWorker-15] Task airflow.executors.celery_executor.execute_command[c5f9f53c-8afe-4d67-8d3b-d7ad84875de1] succeeded in 960.1964174450004s: None
[2022-09-22 19:29:25,931: WARNING/MainProcess] consumer: Connection to broker lost. Trying to re-establish the connection...
Traceback (most recent call last):
File "/home/airflow/.local/lib/python3.7/site-packages/redis/connection.py", line 706, in send_packed_command
sendall(self._sock, item)
File "/home/airflow/.local/lib/python3.7/site-packages/redis/_compat.py", line 9, in sendall
return sock.sendall(*args, **kwargs)
File "/usr/local/lib/python3.7/ssl.py", line 1034, in sendall
v = self.send(byte_view[count:])
File "/usr/local/lib/python3.7/ssl.py", line 1003, in send
return self._sslobj.write(data)
TimeoutError: [Errno 110] Connection timed out
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/home/airflow/.local/lib/python3.7/site-packages/celery/worker/consumer/consumer.py", line 332, in start
blueprint.start(self)
File "/home/airflow/.local/lib/python3.7/site-packages/celery/bootsteps.py", line 116, in start
step.start(parent)
File "/home/airflow/.local/lib/python3.7/site-packages/celery/worker/consumer/consumer.py", line 628, in start
c.loop(*c.loop_args())
File "/home/airflow/.local/lib/python3.7/site-packages/celery/worker/loops.py", line 97, in asynloop
next(loop)
File "/home/airflow/.local/lib/python3.7/site-packages/kombu/asynchronous/hub.py", line 301, in create_loop
poll_timeout = fire_timers(propagate=propagate) if scheduled else 1
File "/home/airflow/.local/lib/python3.7/site-packages/kombu/asynchronous/hub.py", line 143, in fire_timers
entry()
File "/home/airflow/.local/lib/python3.7/site-packages/kombu/asynchronous/timer.py", line 64, in __call__
return self.fun(*self.args, **self.kwargs)
File "/home/airflow/.local/lib/python3.7/site-packages/kombu/asynchronous/timer.py", line 126, in _reschedules
return fun(*args, **kwargs)
File "/home/airflow/.local/lib/python3.7/site-packages/kombu/transport/redis.py", line 557, in maybe_check_subclient_health
client.check_health()
File "/home/airflow/.local/lib/python3.7/site-packages/redis/client.py", line 3522, in check_health
check_health=False)
File "/home/airflow/.local/lib/python3.7/site-packages/redis/connection.py", line 726, in send_command
check_health=kwargs.get('check_health', True))
File "/home/airflow/.local/lib/python3.7/site-packages/redis/connection.py", line 718, in send_packed_command
(errno, errmsg))
redis.exceptions.ConnectionError: Error 110 while writing to socket. Connection timed out.
[2022-09-22 19:29:26,023: WARNING/MainProcess] /home/airflow/.local/lib/python3.7/site-packages/celery/worker/consumer/consumer.py:367: CPendingDeprecationWarning:
I referred the Airflow's documentation and found setting up database
We are modifying Airflow's docker image and adding a python file,
airflow.www.db_utils.db_config (This file is installed to site_packages) and defined the dictionary
keepalive_kwargs = {
"keepalives": 1,
"keepalives_idle": 30,
"keepalives_interval": 5,
"keepalives_count": 5,
}
Finally, we are setting
ENV AIRFLOW__DATABASE__SQL_ALCHEMY_CONNECT_ARGS="airflow.www.db_utils.db_config.keepalive_kwargs"
Unfortunately, the error stills persist. It will be great if someone helps me to resolve this issue.