celery task raise an error while redis backend connection socket timeout

Question

I am using celery to run task one by one with redis broker, but when i run 2 task then after completing the first redis given an timeout socket error for second task so that second task would be failed.

File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/result.py", line 194, in get
on_message=on_message,
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/backends/async.py", line 189, in wait_for_pending
for _ in self._wait_for_pending(result, **kwargs):
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/backends/async.py", line 256, in _wait_for_pending
on_interval=on_interval):
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/backends/async.py", line 57, in drain_events_until
yield self.wait_for(p, wait, timeout=1)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/backends/async.py", line 66, in wait_for
wait(timeout=timeout)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/celery/backends/redis.py", line 69, in drain_events
m = self._pubsub.get_message(timeout=timeout)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/client.py", line 2513, in get_message
response = self.parse_response(block=False, timeout=timeout)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/client.py", line 2430, in parse_response
return self._execute(connection, connection.read_response)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/client.py", line 2408, in _execute
return command(*args)
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/connection.py", line 624, in read_response
response = self._parser.read_response()
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/connection.py", line 284, in read_response
response = self._buffer.readline()
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/connection.py", line 216, in readline
self._read_from_socket()
File "/home/ubuntu/.virtualenvs/aide_venv/local/lib/python2.7/site-packages/redis/connection.py", line 187, in _read_from_socket
raise TimeoutError("Timeout reading from socket")
TimeoutError: Timeout reading from socket

I am running celery by using this command:

celery -A flask_application.celery worker --loglevel=info --max-tasks-per-child=1 --concurrency=1

I am calling celery task by using: .delay() function

celery_response = run_algo.run_pipeline.delay(request.get_json())

Getting output by using: .get() function

output_file_path = celery_response.get()

Answer 1

在AsyncResult.get的文档中有一个警告说，在异步任务中调用它可能会导致死锁，这可能是这里发生的事情，尽管没有更多上下文来了解这些东西在哪里被调用很难说清楚。