Issue 1:
Checklist

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

This has already been asked to the discussions forum 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

None

Possible Duplicates

None

Environment & Settings

Celery version: 5.2.1 (dawn-chorus)

celery report Output:

Output from celery report

software -> celery:5.2.1 (dawn-chorus) kombu:5.2.2 py:3.7.4
billiard:3.6.4.0 py-amqp:5.0.9
platform -> system:Darwin arch:64bit
kernel version:20.5.0 imp:CPython
loader -> celery.loaders.default.Loader
settings -> transport:amqp results:disabled

deprecated_settings: None

Steps to Reproduce

Required Dependencies

Minimal Python Version: I've been testing under multiple virtual environments of python: 3.7.4, 3.8.5, 3.9.6

Minimal Celery Version: master

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: MacOS Big Sur 11.4

Minimal Broker Client Version: N/A or Unknown

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

(3.7.4/envs/stellar_3_7) pinchas.lev@Pinchass-MacBook-Pro celery % pip3 freeze
amqp==5.0.9
appdirs==1.4.4
asgiref==3.4.1
astroid==2.6.6
attrs==21.2.0
autopep8==1.5.7
Babel==2.9.1
backports.entry-points-selectable==1.1.1
bcrypt==3.2.0
beautifulsoup4==4.10.0
before-after==1.0.1
billiard==3.6.4.0
black==21.7b0
bleach==4.1.0
boto3==1.20.26
botocore==1.23.26
cached-property==1.5.2
cachetools==4.2.4
cairocffi==1.1.0
CairoSVG==2.5.2
cchardet==2.1.7
celery==5.2.1
celery-once==3.0.1
certifi==2021.5.30
cffi==1.14.6
cfgv==3.3.1
chardet==3.0.4
charset-normalizer==2.0.7
click==8.0.3
click-didyoumean==0.3.0
click-plugins==1.1.1
click-repl==0.2.0
colorama==0.4.3
cryptography==3.4.8
cssselect2==0.4.1
customerio==1.0
Cython==0.29.22
defusedxml==0.7.1
distlib==0.3.4
dj-database-url==0.5.0
Django==3.2.9
django-add-default-value==0.9.1
django-admin-autocomplete-filter==0.6.1
django-appconf==1.0.4
django-axes==5.2.2
django-better-admin-arrayfield==1.4.2
django-ckeditor==5.8.0
django-compressor==2.4.1
django-cryptography==1.0
django-csp==3.7
django-debug-toolbar==3.1.1
django-dirtyfields==1.7.0
django-guardian==2.4.0
django-ipware==2.1.0
django-js-asset==1.2.2
django-libsass==0.9
django-migration-linter==2.5.3
django-pglocks==1.0.4
django-polymorphic==3.0.0
django-redis==5.0.0
django-silk==4.1.0
django-storages==1.8
django-termsandconditions==2.0.9
django-user-sessions==1.7.1
django-webpack-loader==1.4.1
django-widget-tweaks==1.4.9
djangorestframework==3.11.0
djangorestframework-datatables==0.5.1
dnspython==1.16.0
docutils==0.15.2
dparse==0.5.1
elasticsearch==7.12.1
et-xmlfile==1.1.0
eventlet==0.30.2
expiringdict==1.2.1
filelock==3.4.0
flower==0.9.3
freezegun==0.3.13
future==0.18.2
fuzzywuzzy==0.18.0
geoip2==2.9.0
gevent==1.4.0
gprof2dot==2021.2.21
greenlet==1.1.0
gunicorn==20.1.0
html5lib==1.1
identify==2.4.0
idna==2.8
importlib-metadata==4.6.1
influxdb==5.2.3
iniconfig==1.1.1
isodate==0.6.0
isort==5.9.3
jdcal==1.4.1
Jinja2==3.0.1
jmespath==0.9.4
kombu==5.2.2
lazy-object-proxy==1.6.0
libsass==0.21.0
lxml==4.6.3
MarkupSafe==2.0.1
marshmallow==2.20.5
maxminddb==2.0.3
mccabe==0.6.1
mock==1.0.1
more-itertools==8.10.0
moto==2.2.19
msgpack==1.0.3
mypy-extensions==0.4.3
newrelic==7.2.4.171
nodeenv==1.6.0
numpy==1.19.5
openpyxl==3.0.3
packaging==21.0
pandas==0.25.3
paramiko==2.8.0
pathspec==0.9.0
pep8==1.7.1
phonenumbers==8.12.36
Pillow==8.3.1
platformdirs==2.4.0
pluggy==1.0.0
pre-commit==2.16.0
prompt-toolkit==3.0.24
psutil==5.8.0
psycopg2-binary==2.8.6
py==1.11.0
pycodestyle==2.5.0
pycparser==2.20
pyflakes==2.3.1
Pygments==2.9.0
pylint==2.9.6
pymongo==4.0.1
PyNaCl==1.4.0
pyparsing==2.4.7
pyphen==0.11.0
pysftp==0.2.9
pytest==6.2.5
pytest-celery==0.0.0
pytest-subtests==0.5.0
pytest-timeout==1.4.2
python-crontab==2.5.1
python-dateutil==2.8.2
python-Levenshtein==0.12.2
python3-saml==1.9.0
pytz==2021.3
pyx12==2.3.3
PyYAML==6.0
rcssmin==1.0.6
redis==3.5.3
regex==2021.8.3
requests==2.26.0
responses==0.16.0
rjsmin==1.1.0
s3transfer==0.5.0
safety==1.8.5
si-prefix==1.2.2
simplejson==3.17.5
six==1.16.0
sodapy==2.0.0
soupsieve==2.2.1
sqlparse==0.4.1
structlog==19.2.0
tblib==1.7.0
tenacity==6.2.0
tinycss2==1.0.2
toml==0.10.2
tomli==1.2.1
tornado==5.1.1
typed-ast==1.4.3
typing==3.7.4.3
typing-extensions==3.10.0.0
urllib3==1.25.7
vine==5.0.0
virtualenv==20.10.0
wcwidth==0.2.5
WeasyPrint==52.5
webencodings==0.5.1
Werkzeug==2.0.2
whitenoise==5.3.0
wrapt==1.12.1
xlrd==1.2.0
xmlsec==1.3.11
xmltodict==0.12.0
zipp==3.5.0

Other Dependencies

N/A

Minimally Reproducible Test Case

pytest t/unit

Expected Behavior

I expected all tests to pass

Actual Behavior

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

None

Possible Duplicates

None

Environment & Settings

Celery version: 4.4.0 (cliffs)

celery report Output:

software -> celery:4.4.0 (cliffs) kombu:4.6.7 py:3.8.1
billiard:3.6.1.0 redis:3.3.11
platform -> system:Darwin arch:64bit
kernel version:18.7.0 imp:CPython
loader -> celery.loaders.app.AppLoader
settings -> transport:redis results:disabled

BROKER_URL: 'redis://localhost:6379/1'
CELERYD_PREFETCH_MULTIPLIER: 1
CELERY_ACCEPT_CONTENT: ['json']
CELERY_RESULT_SERIALIZER: 'json'
CELERY_TASK_ACKS_LATE: True
CELERY_TASK_RESULT_EXPIRES: 86400
CELERY_TASK_SERIALIZER: 'json'
CELERY_TIMEZONE: 'Asia/Chongqing'
CELERY_INCLUDE: ['proj.tasks']

Steps to Reproduce

Required Dependencies

Minimal Python Version: 3.8.1

Minimal Celery Version: 4.4.0

Minimal Kombu Version: 4.6.7

Minimal Broker Version: redis_version:4.0.10

Minimal Result Backend Version: N/A or Unknown

Minimal OS and/or Kernel Version: Mac; Centos

Minimal Broker Client Version: redis 3.3.11

Minimal Result Backend Client Version: N/A or Unknown

Python Packages

pip freeze Output:

amqp==2.5.2
billiard==3.6.1.0
celery==4.4.0
gevent==1.4.0
greenlet==0.4.15
kombu==4.6.7
pytz==2019.3
redis==3.3.11
vine==1.3.0

Other Dependencies

N/A

Minimally Reproducible Test Case

Expected Behavior

I have many task with countdown in celery, I hope the worker can prefetch the task one by one. But worker will almost prefetch all of the tasks. This is my worker start cmd:

celery -A proj.celery.app worker -l info -c 1

It will prefetch all of the tasks.

Actual Behavior