Issue 1:
Checklist

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

#5467

#2573

Possible Duplicates

#1163

Environment & Settings

Celery version:

celery report Output:

software -> celery:4.4.0rc1 (cliffs) kombu:4.6.1 py:3.6.6
billiard:3.6.0.0 py-amqp:2.5.0
platform -> system:Darwin arch:64bit
kernel version:18.5.0 imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> transport:amqp results:redis://localhost:6379/0

broker_url: 'amqp://guest:********@localhost:5672//'
result_backend: 'redis://localhost:6379/0'

Steps to Reproduce

Required Dependencies

Minimal Python Version: N/A or Unknown

Minimal Celery Version: N/A or Unknown

Minimal Kombu Version: N/A or Unknown

Minimal Broker Version: N/A or Unknown

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: N/A or Unknown

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

Other Dependencies

N/A

Minimally Reproducible Test Case

# myapp.py
from celery import Celery

app = Celery(
'myapp',
broker='amqp://guest@localhost//',
backend='redis://localhost:6379/0'
)

@app.task
def b(zz):
import time
print('start: {}'.format(zz))
time.sleep(5)
print('end: {}'.format(zz))
return zz

@app.task
def a(zz):
print(zz)
return zz
if __name__ == '__main__':
app.start()

and run celery worker with concurrency=3

worker -A myapp -l debug --concurrency=3

send tasks:

group1 = group(b.si('group1 job1'), b.si('group1 job2'))
group2 = group(a.si('group2 job1'), a.si('group2 job2'))
res = chain(group1, group2)

Expected Behavior

tasks in group2 not run until group1 returns

expect output:

start: group1 job1
start: group1 job2
end: group1 job1
end: group1 job2
group2 job1
group2 job2

Actual Behavior

they are run in parallel and the out put is:

start: group1 job1
start: group1 job2
group2 job1
group2 job2
end: group1 job1
end: group1 job2

Issue 2:
Checklist

I have verified that the issue exists against the master branch of Celery.

This has already been asked to the discussion group first.

I have read the relevant section in the

contribution guide

on reporting bugs.

I have checked the issues list

for similar or identical bug reports.

I have checked the pull requests list

for existing proposed fixes.

I have checked the commit log

to find out if the bug was already fixed in the master branch.

I have included all related issues and possible duplicate issues

in this issue (If there are none, check this box anyway).

Mandatory Debugging Information

I have included the output of celery -A proj report in the issue.

(if you are not able to do this, then at least specify the Celery

version affected).

I have verified that the issue exists against the master branch of Celery.

I have included the contents of pip freeze in the issue.

I have included all the versions of all the external dependencies required

to reproduce this bug.

Optional Debugging Information

I have tried reproducing the issue on more than one Python version

and/or implementation.

I have tried reproducing the issue on more than one message broker and/or

result backend.

I have tried reproducing the issue on more than one version of the message

broker and/or result backend.

I have tried reproducing the issue on more than one operating system.

I have tried reproducing the issue on more than one workers pool.

I have tried reproducing the issue with autoscaling, retries,

ETA/Countdown & rate limits disabled.

I have tried reproducing the issue after downgrading

and/or upgrading Celery and its dependencies.

Related Issues and Possible Duplicates

Related Issues

#3932

boto/boto3#1777

Possible Duplicates

None

Environment & Settings

Celery version: 5.0.5

celery report Output:

Steps to Reproduce

Required Dependencies

Minimal Python Version: 3.9

Minimal Celery Version: 5.0.5

Minimal Kombu Version: N/A or Unknown

Minimal Broker Version: N/A or Unknown

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: N/A or Unknown

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

Other Dependencies

Running celery with the AWS SQS backend.

Minimally Reproducible Test Case

I can not reproduce this error at the moment, but i assume it has something to do with the SQS service from AWS not being available. They had a big issue this night (news article). I found an old open issue from boto3 which i linked above.

I also want to add that we had the same error on two completly separated systems at almost the same time (5 seconds difference).

Expected Behavior

Celery worker should continou running even when the SQS service is temporarily not available.

Actual Behavior

The celery worker threw and execption and stoppen running.

[2021-06-10 23:26:37,315: CRITICAL/MainProcess] Unrecoverable error: ClientError('An error occurred (Unknown) when calling the GetQueueUrl operation (reached max retries: 4): Unknown')
Traceback (most recent call last):
File "/app/venv/lib/python3.8/site-packages/celery/worker/worker.py", line 203, in start
self.blueprint.start(self)
File "/app/venv/lib/python3.8/site-packages/celery/bootsteps.py", line 116, in start
step.start(parent)
File "/app/venv/lib/python3.8/site-packages/celery/bootsteps.py", line 365, in start
return self.obj.start()
File "/app/venv/lib/python3.8/site-packages/celery/worker/consumer/consumer.py", line 311, in start
blueprint.start(self)
File "/app/venv/lib/python3.8/site-packages/celery/bootsteps.py", line 116, in start
step.start(parent)
File "/app/venv/lib/python3.8/site-packages/celery/worker/consumer/consumer.py", line 592, in start
c.loop(*c.loop_args())
File "/app/venv/lib/python3.8/site-packages/celery/worker/loops.py", line 81, in asynloop
next(loop)
File "/app/venv/lib/python3.8/site-packages/kombu/asynchronous/hub.py", line 298, in create_loop
item()
File "/app/venv/lib/python3.8/site-packages/vine/promises.py", line 160, in __call__
return self.throw()
File "/app/venv/lib/python3.8/site-packages/vine/promises.py", line 157, in __call__
retval = fun(*final_args, **final_kwargs)
File "/app/venv/lib/python3.8/site-packages/kombu/transport/SQS.py", line 513, in _schedule_queue
self._get_bulk_async(
File "/app/venv/lib/python3.8/site-packages/kombu/transport/SQS.py", line 530, in _get_bulk_async
return self._get_async(queue, maxcount, callback=callback)
File "/app/venv/lib/python3.8/site-packages/kombu/transport/SQS.py", line 539, in _get_async
return self._get_from_sqs(
File "/app/venv/lib/python3.8/site-packages/kombu/transport/SQS.py", line 566, in _get_from_sqs
queue_url = connection.get_queue_url(queue)
File "/app/venv/lib/python3.8/site-packages/kombu/asynchronous/aws/sqs/connection.py", line 43, in get_queue_url
res = self.sqs_connection.get_queue_url(QueueName=queue)
File "/app/venv/lib/python3.8/site-packages/botocore/client.py", line 386, in _api_call
return self._make_api_call(operation_name, kwargs)
File "/app/venv/lib/python3.8/site-packages/botocore/client.py", line 705, in _make_api_call
raise error_class(parsed_response, operation_name)
botocore.exceptions.ClientError: An error occurred (Unknown) when calling the GetQueueUrl operation (reached max retries: 4): Unknown