<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/issues?utf8=%E2%9C%93&amp;q=is%3Aissue+label%3A%22Issue+Type%3A+Feature+Request%22+">issues list</a><br>
for similar or identical feature requests.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/pulls?utf8=%E2%9C%93&amp;q=is%3Apr+label%3A%22PR+Type%3A+Feature%22+">pull requests list</a><br>
for existing proposed implementations of this feature.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the if the same feature was already implemented in the<br>
master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li><a class="issue-link js-issue-link" data-error-text="Failed to load title" data-id="523300112" data-permission-text="Title is private" data-url="https://github.com/celery/celery/issues/5830" data-hovercard-type="issue" data-hovercard-url="/celery/celery/issues/5830/hovercard" href="https://github.com/celery/celery/issues/5830">#5830</a></li>
<li><a href="https://groups.google.com/g/celery-users/c/IGOBnp4n0gU" rel="nofollow">https://groups.google.com/g/celery-users/c/IGOBnp4n0gU</a></li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h1 dir="auto">Brief Summary</h1>

<p dir="auto">Currently, the only way to use <code class="notranslate">joblib</code> and <code class="notranslate">loky</code> (in some extent <code class="notranslate">multiprocessing</code> too) is to use <code class="notranslate">-P threads</code> instead of <code class="notranslate">-P processes</code>.</p>
<p dir="auto">Since <code class="notranslate">-P threads</code> is using <code class="notranslate">ThreadPoolExecutor</code> from the stdlib under the hood, the task in the same worker is not really running in parallel (but async). This is because of the Python GIL.</p>
<p dir="auto">The problem becomes even more important if the workload is split between the main code and the subprocesses (executed by <code class="notranslate">joblib</code>).</p>
<p dir="auto">Only the subprocesses are executed in parallel but not the main code. It adds a clear bottleneck that is not ideal.</p>
<h1 dir="auto">Architectural Considerations</h1>
<p dir="auto">I am not comfortable enough with Celery to propose an implementation. Feel free to throw your ideas below in this ticket.</p>
<h1 dir="auto">Potential workaround</h1>
<p dir="auto">A potential workaround is to have plenty of Celery worker replicas that execute only one task (concurrency of 1). So the task will have all the CPU time available for it and be free to use <code class="notranslate">joblib</code> at its convenience.</p>
<p dir="auto">But having all the Celery workers with a concurrency of 1 also imply some overhead in the underlying infrastructure that is not really wanted ideally.</p>
<p dir="auto">When using gevent as a pool, queuing a single task that uses <a href="https://channels.readthedocs.io/en/stable/topics/channel_layers.html#synchronous-functions" rel="nofollow">django-channel's group_send with async_to_sync</a> works, but queuing multiple tasks will result in the following error:</p>
<p dir="auto"><code class="notranslate">RuntimeError: You cannot use AsyncToSync in the same thread as an async event loop - just await the async function directly.</code></p>
<p dir="auto">Seems like celery is conditionally creating an event loop in the worker depending on load? I originally noticed this behavior when upgrading to celery 5.2.6 from 4.4.0 (and as a result python 3.7)</p>
<p dir="auto">Here's a repo with a reproducible test case: <a href="https://github.com/udbhav/celery-channels-test">https://github.com/udbhav/celery-channels-test</a></p>
<p dir="auto">Thanks in advance for looking at this and any help/insight you can provide.</p>

<h1 dir="auto">Checklist</h1>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> This has already been asked to the <a href="https://github.com/celery/celery/discussions">discussions forum</a> first.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have read the relevant section in the<br>
<a href="https://docs.celeryq.dev/en/master/contributing.html#other-bugs" rel="nofollow">contribution guide</a><br>
on reporting bugs.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/issues?q=is%3Aissue+label%3A%22Issue+Type%3A+Bug+Report%22+-label%3A%22Category%3A+Documentation%22">issues list</a><br>
for similar or identical bug reports.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/pulls?q=is%3Apr+label%3A%22PR+Type%3A+Bugfix%22+-label%3A%22Category%3A+Documentation%22">pull requests list</a><br>
for existing proposed fixes.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have checked the <a href="https://github.com/celery/celery/commits/master">commit log</a><br>
to find out if the bug was already fixed in the master branch.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all related issues and possible duplicate issues<br>
in this issue (If there are none, check this box anyway).</li>
</ul>
<h2 dir="auto">Mandatory Debugging Information</h2>
<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the output of <code class="notranslate">celery -A proj report</code> in the issue.<br>
(if you are not able to do this, then at least specify the Celery<br>
version affected).</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have verified that the issue exists against the <code class="notranslate">master</code> branch of Celery.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included the contents of <code class="notranslate">pip freeze</code> in the issue.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have included all the versions of all the external dependencies required<br>
to reproduce this bug.</li>
</ul>
<h2 dir="auto">Optional Debugging Information</h2>

<ul class="contains-task-list">
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue on more than one Python version<br>
and/or implementation.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one message broker and/or<br>
result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one version of the message<br>
broker and/or result backend.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one operating system.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue on more than one workers pool.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox"> I have tried reproducing the issue with autoscaling, retries,<br>
ETA/Countdown &amp; rate limits disabled.</li>
<li class="task-list-item"><input type="checkbox" id="" disabled="" class="task-list-item-checkbox" checked=""> I have tried reproducing the issue after downgrading<br>
and/or upgrading Celery and its dependencies.</li>
</ul>
<h2 dir="auto">Related Issues and Possible Duplicates</h2>

<h4 dir="auto">Related Issues</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h4 dir="auto">Possible Duplicates</h4>
<ul dir="auto">
<li>None</li>
</ul>
<h2 dir="auto">Environment &amp; Settings</h2>

<p dir="auto"><strong>Celery version</strong>:</p>

<details>
<summary><b><code class="notranslate">celery report</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="software -&gt; celery:5.2.6 (dawn-chorus) kombu:5.2.4 py:3.7.13
            billiard:3.6.4.0 py-amqp:5.1.0
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:5.10.47-linuxkit imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:pyamqp results:disabled

ABSOLUTE_URL_OVERRIDES: {
 }
ADMINS: []
ALLOWED_HOSTS: []
APPEND_SLASH: True
ASGI_APPLICATION: 'celery_channels_test.asgi.application'
AUTHENTICATION_BACKENDS: ['django.contrib.auth.backends.ModelBackend']
AUTH_PASSWORD_VALIDATORS: '********'
AUTH_USER_MODEL: 'auth.User'
BASE_DIR: PosixPath('/code/src')
CACHES: {
 'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
CACHE_MIDDLEWARE_ALIAS: 'default'
CACHE_MIDDLEWARE_KEY_PREFIX: '********'
CACHE_MIDDLEWARE_SECONDS: 600
CELERY_BROKER_URL: 'amqp://test:********@rabbit:5672//'
CELERY_TIMEZONE: 'UTC'
CHANNEL_LAYERS: {
    'default': {   'BACKEND': 'channels_redis.core.RedisChannelLayer',
                   'CONFIG': {'hosts': [('cache', 6379)]}}}
CSRF_COOKIE_AGE: 31449600
CSRF_COOKIE_DOMAIN: None
CSRF_COOKIE_HTTPONLY: False
CSRF_COOKIE_NAME: 'csrftoken'
CSRF_COOKIE_PATH: '/'
CSRF_COOKIE_SAMESITE: 'Lax'
CSRF_COOKIE_SECURE: False
CSRF_FAILURE_VIEW: 'django.views.csrf.csrf_failure'
CSRF_HEADER_NAME: 'HTTP_X_CSRFTOKEN'
CSRF_TRUSTED_ORIGINS: []
CSRF_USE_SESSIONS: False
DATABASES: {
    'default': {   'ATOMIC_REQUESTS': False,
                   'AUTOCOMMIT': True,
                   'CONN_MAX_AGE': 0,
                   'ENGINE': 'django.db.backends.sqlite3',
                   'HOST': '',
                   'NAME': PosixPath('/code/src/db.sqlite3'),
                   'OPTIONS': {},
                   'PASSWORD': '********',
                   'PORT': '',
                   'TEST': {   'CHARSET': None,
                               'COLLATION': None,
                               'MIGRATE': True,
                               'MIRROR': None,
                               'NAME': None},
                   'TIME_ZONE': None,
                   'USER': ''}}
DATABASE_ROUTERS: '********'
DATA_UPLOAD_MAX_MEMORY_SIZE: 2621440
DATA_UPLOAD_MAX_NUMBER_FIELDS: 1000
DATETIME_FORMAT: 'N j, Y, P'
DATETIME_INPUT_FORMATS: ['%Y-%m-%d %H:%M:%S',
 '%Y-%m-%d %H:%M:%S.%f',
 '%Y-%m-%d %H:%M',
 '%m/%d/%Y %H:%M:%S',
 '%m/%d/%Y %H:%M:%S.%f',
 '%m/%d/%Y %H:%M',
 '%m/%d/%y %H:%M:%S',
 '%m/%d/%y %H:%M:%S.%f',
 '%m/%d/%y %H:%M']
DATE_FORMAT: 'N j, Y'
DATE_INPUT_FORMATS: ['%Y-%m-%d',
 '%m/%d/%Y',
 '%m/%d/%y',
 '%b %d %Y',
 '%b %d, %Y',
 '%d %b %Y',
 '%d %b, %Y',
 '%B %d %Y',
 '%B %d, %Y',
 '%d %B %Y',
 '%d %B, %Y']
DEBUG: True
DEBUG_PROPAGATE_EXCEPTIONS: False
DECIMAL_SEPARATOR: '.'
DEFAULT_AUTO_FIELD: 'django.db.models.BigAutoField'
DEFAULT_CHARSET: 'utf-8'
DEFAULT_EXCEPTION_REPORTER: 'django.views.debug.ExceptionReporter'
DEFAULT_EXCEPTION_REPORTER_FILTER: 'django.views.debug.SafeExceptionReporterFilter'
DEFAULT_FILE_STORAGE: 'django.core.files.storage.FileSystemStorage'
DEFAULT_FROM_EMAIL: 'webmaster@localhost'
DEFAULT_HASHING_ALGORITHM: 'sha256'
DEFAULT_INDEX_TABLESPACE: ''
DEFAULT_TABLESPACE: ''
DISALLOWED_USER_AGENTS: []
EMAIL_BACKEND: 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST: 'localhost'
EMAIL_HOST_PASSWORD: '********'
EMAIL_HOST_USER: ''
EMAIL_PORT: 25
EMAIL_SSL_CERTFILE: None
EMAIL_SSL_KEYFILE: '********'
EMAIL_SUBJECT_PREFIX: '[Django] '
EMAIL_TIMEOUT: None
EMAIL_USE_LOCALTIME: False
EMAIL_USE_SSL: False
EMAIL_USE_TLS: False
FILE_UPLOAD_DIRECTORY_PERMISSIONS: None
FILE_UPLOAD_HANDLERS: ['django.core.files.uploadhandler.MemoryFileUploadHandler',
 'django.core.files.uploadhandler.TemporaryFileUploadHandler']
FILE_UPLOAD_MAX_MEMORY_SIZE: 2621440
FILE_UPLOAD_PERMISSIONS: 420
FILE_UPLOAD_TEMP_DIR: None
FIRST_DAY_OF_WEEK: 0
FIXTURE_DIRS: []
FORCE_SCRIPT_NAME: None
FORMAT_MODULE_PATH: None
FORM_RENDERER: 'django.forms.renderers.DjangoTemplates'
IGNORABLE_404_URLS: []
INSTALLED_APPS: ['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'channels']
INTERNAL_IPS: []
LANGUAGES: [('af', 'Afrikaans'),
 ('ar', 'Arabic'),
 ('ar-dz', 'Algerian Arabic'),
 ('ast', 'Asturian'),
 ('az', 'Azerbaijani'),
 ('bg', 'Bulgarian'),
 ('be', 'Belarusian'),
 ('bn', 'Bengali'),
 ('br', 'Breton'),
 ('bs', 'Bosnian'),
 ('ca', 'Catalan'),
 ('cs', 'Czech'),
 ('cy', 'Welsh'),
 ('da', 'Danish'),
 ('de', 'German'),
 ('dsb', 'Lower Sorbian'),
 ('el', 'Greek'),
 ('en', 'English'),
 ('en-au', 'Australian English'),
 ('en-gb', 'British English'),
 ('eo', 'Esperanto'),
 ('es', 'Spanish'),
 ('es-ar', 'Argentinian Spanish'),
 ('es-co', 'Colombian Spanish'),
 ('es-mx', 'Mexican Spanish'),
 ('es-ni', 'Nicaraguan Spanish'),
 ('es-ve', 'Venezuelan Spanish'),
 ('et', 'Estonian'),
 ('eu', 'Basque'),
 ('fa', 'Persian'),
 ('fi', 'Finnish'),
 ('fr', 'French'),
 ('fy', 'Frisian'),
 ('ga', 'Irish'),
 ('gd', 'Scottish Gaelic'),
 ('gl', 'Galician'),
 ('he', 'Hebrew'),
 ('hi', 'Hindi'),
 ('hr', 'Croatian'),
 ('hsb', 'Upper Sorbian'),
 ('hu', 'Hungarian'),
 ('hy', 'Armenian'),
 ('ia', 'Interlingua'),
 ('id', 'Indonesian'),
 ('ig', 'Igbo'),
 ('io', 'Ido'),
 ('is', 'Icelandic'),
 ('it', 'Italian'),
 ('ja', 'Japanese'),
 ('ka', 'Georgian'),
 ('kab', 'Kabyle'),
 ('kk', 'Kazakh'),
 ('km', 'Khmer'),
 ('kn', 'Kannada'),
 ('ko', 'Korean'),
 ('ky', 'Kyrgyz'),
 ('lb', 'Luxembourgish'),
 ('lt', 'Lithuanian'),
 ('lv', 'Latvian'),
 ('mk', 'Macedonian'),
 ('ml', 'Malayalam'),
 ('mn', 'Mongolian'),
 ('mr', 'Marathi'),
 ('my', 'Burmese'),
 ('nb', 'Norwegian Bokmål'),
 ('ne', 'Nepali'),
 ('nl', 'Dutch'),
 ('nn', 'Norwegian Nynorsk'),
 ('os', 'Ossetic'),
 ('pa', 'Punjabi'),
 ('pl', 'Polish'),
 ('pt', 'Portuguese'),
 ('pt-br', 'Brazilian Portuguese'),
 ('ro', 'Romanian'),
 ('ru', 'Russian'),
 ('sk', 'Slovak'),
 ('sl', 'Slovenian'),
 ('sq', 'Albanian'),
 ('sr', 'Serbian'),
 ('sr-latn', 'Serbian Latin'),
 ('sv', 'Swedish'),
 ('sw', 'Swahili'),
 ('ta', 'Tamil'),
 ('te', 'Telugu'),
 ('tg', 'Tajik'),
 ('th', 'Thai'),
 ('tk', 'Turkmen'),
 ('tr', 'Turkish'),
 ('tt', 'Tatar'),
 ('udm', 'Udmurt'),
 ('uk', 'Ukrainian'),
 ('ur', 'Urdu'),
 ('uz', 'Uzbek'),
 ('vi', 'Vietnamese'),
 ('zh-hans', 'Simplified Chinese'),
 ('zh-hant', 'Traditional Chinese')]
LANGUAGES_BIDI: ['he', 'ar', 'ar-dz', 'fa', 'ur']
LANGUAGE_CODE: 'en-us'
LANGUAGE_COOKIE_AGE: None
LANGUAGE_COOKIE_DOMAIN: None
LANGUAGE_COOKIE_HTTPONLY: False
LANGUAGE_COOKIE_NAME: 'django_language'
LANGUAGE_COOKIE_PATH: '/'
LANGUAGE_COOKIE_SAMESITE: None
LANGUAGE_COOKIE_SECURE: False
LOCALE_PATHS: []
LOGGING: {
    'disable_existing_loggers': False,
    'formatters': {   'timestamp': {   'format': '[{asctime}] {levelname} '
                                                 '[{name}]: {message}',
                                       'style': '{'}},
    'handlers': {   'console': {   'class': 'logging.StreamHandler',
                                   'formatter': 'timestamp',
                                   'level': 'DEBUG'}},
    'loggers': {   'celery': {'handlers': ['console'], 'level': 'DEBUG'},
                   'django': {'handlers': ['console'], 'level': 'INFO'}},
    'version': 1}
LOGGING_CONFIG: 'logging.config.dictConfig'
LOGIN_REDIRECT_URL: '/accounts/profile/'
LOGIN_URL: '/accounts/login/'
LOGOUT_REDIRECT_URL: None
MANAGERS: []
MEDIA_ROOT: ''
MEDIA_URL: '/'
MESSAGE_STORAGE: 'django.contrib.messages.storage.fallback.FallbackStorage'
MIDDLEWARE: ['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']
MIGRATION_MODULES: {
 }
MONTH_DAY_FORMAT: 'F j'
NUMBER_GROUPING: 0
PASSWORD_HASHERS: '********'
PASSWORD_RESET_TIMEOUT: '********'
PASSWORD_RESET_TIMEOUT_DAYS: '********'
PREPEND_WWW: False
ROOT_URLCONF: 'celery_channels_test.urls'
SECRET_KEY: '********'
SECURE_BROWSER_XSS_FILTER: False
SECURE_CONTENT_TYPE_NOSNIFF: True
SECURE_HSTS_INCLUDE_SUBDOMAINS: False
SECURE_HSTS_PRELOAD: False
SECURE_HSTS_SECONDS: 0
SECURE_PROXY_SSL_HEADER: None
SECURE_REDIRECT_EXEMPT: []
SECURE_REFERRER_POLICY: 'same-origin'
SECURE_SSL_HOST: None
SECURE_SSL_REDIRECT: False
SERVER_EMAIL: 'root@localhost'
SESSION_CACHE_ALIAS: 'default'
SESSION_COOKIE_AGE: 1209600
SESSION_COOKIE_DOMAIN: None
SESSION_COOKIE_HTTPONLY: True
SESSION_COOKIE_NAME: 'sessionid'
SESSION_COOKIE_PATH: '/'
SESSION_COOKIE_SAMESITE: 'Lax'
SESSION_COOKIE_SECURE: False
SESSION_ENGINE: 'django.contrib.sessions.backends.db'
SESSION_EXPIRE_AT_BROWSER_CLOSE: False
SESSION_FILE_PATH: None
SESSION_SAVE_EVERY_REQUEST: False
SESSION_SERIALIZER: 'django.contrib.sessions.serializers.JSONSerializer'
SETTINGS_MODULE: 'celery_channels_test.settings'
SHORT_DATETIME_FORMAT: 'm/d/Y P'
SHORT_DATE_FORMAT: 'm/d/Y'
SIGNING_BACKEND: 'django.core.signing.TimestampSigner'
SILENCED_SYSTEM_CHECKS: []
STATICFILES_DIRS: []
STATICFILES_FINDERS: ['django.contrib.staticfiles.finders.FileSystemFinder',
 'django.contrib.staticfiles.finders.AppDirectoriesFinder']
STATICFILES_STORAGE: 'django.contrib.staticfiles.storage.StaticFilesStorage'
STATIC_ROOT: None
STATIC_URL: '/static/'
TEMPLATES: [{'APP_DIRS': True,
  'BACKEND': 'django.template.backends.django.DjangoTemplates',
  'DIRS': [],
  'OPTIONS': {'context_processors': ['django.template.context_processors.debug',
                                     'django.template.context_processors.request',
                                     'django.contrib.auth.context_processors.auth',
                                     'django.contrib.messages.context_processors.messages']}}]
TEST_NON_SERIALIZED_APPS: []
TEST_RUNNER: 'django.test.runner.DiscoverRunner'
THOUSAND_SEPARATOR: ','
TIME_FORMAT: 'P'
TIME_INPUT_FORMATS: ['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
TIME_ZONE: 'UTC'
USE_I18N: True
USE_L10N: True
USE_THOUSAND_SEPARATOR: False
USE_TZ: True
USE_X_FORWARDED_HOST: False
USE_X_FORWARDED_PORT: False
WSGI_APPLICATION: 'celery_channels_test.wsgi.application'
X_FRAME_OPTIONS: 'DENY'
YEAR_MONTH_FORMAT: 'F Y'
is_overridden: &lt;bound method Settings.is_overridden of &lt;Settings &quot;celery_channels_test.settings&quot;&gt;&gt;
deprecated_settings: None"><pre class="notranslate"><code class="notranslate">software -&gt; celery:5.2.6 (dawn-chorus) kombu:5.2.4 py:3.7.13
            billiard:3.6.4.0 py-amqp:5.1.0
platform -&gt; system:Linux arch:64bit, ELF
            kernel version:5.10.47-linuxkit imp:CPython
loader   -&gt; celery.loaders.app.AppLoader
settings -&gt; transport:pyamqp results:disabled

ABSOLUTE_URL_OVERRIDES: {
 }
ADMINS: []
ALLOWED_HOSTS: []
APPEND_SLASH: True
ASGI_APPLICATION: 'celery_channels_test.asgi.application'
AUTHENTICATION_BACKENDS: ['django.contrib.auth.backends.ModelBackend']
AUTH_PASSWORD_VALIDATORS: '********'
AUTH_USER_MODEL: 'auth.User'
BASE_DIR: PosixPath('/code/src')
CACHES: {
 'default': {'BACKEND': 'django.core.cache.backends.locmem.LocMemCache'}}
CACHE_MIDDLEWARE_ALIAS: 'default'
CACHE_MIDDLEWARE_KEY_PREFIX: '********'
CACHE_MIDDLEWARE_SECONDS: 600
CELERY_BROKER_URL: 'amqp://test:********@rabbit:5672//'
CELERY_TIMEZONE: 'UTC'
CHANNEL_LAYERS: {
    'default': {   'BACKEND': 'channels_redis.core.RedisChannelLayer',
                   'CONFIG': {'hosts': [('cache', 6379)]}}}
CSRF_COOKIE_AGE: 31449600
CSRF_COOKIE_DOMAIN: None
CSRF_COOKIE_HTTPONLY: False
CSRF_COOKIE_NAME: 'csrftoken'
CSRF_COOKIE_PATH: '/'
CSRF_COOKIE_SAMESITE: 'Lax'
CSRF_COOKIE_SECURE: False
CSRF_FAILURE_VIEW: 'django.views.csrf.csrf_failure'
CSRF_HEADER_NAME: 'HTTP_X_CSRFTOKEN'
CSRF_TRUSTED_ORIGINS: []
CSRF_USE_SESSIONS: False
DATABASES: {
    'default': {   'ATOMIC_REQUESTS': False,
                   'AUTOCOMMIT': True,
                   'CONN_MAX_AGE': 0,
                   'ENGINE': 'django.db.backends.sqlite3',
                   'HOST': '',
                   'NAME': PosixPath('/code/src/db.sqlite3'),
                   'OPTIONS': {},
                   'PASSWORD': '********',
                   'PORT': '',
                   'TEST': {   'CHARSET': None,
                               'COLLATION': None,
                               'MIGRATE': True,
                               'MIRROR': None,
                               'NAME': None},
                   'TIME_ZONE': None,
                   'USER': ''}}
DATABASE_ROUTERS: '********'
DATA_UPLOAD_MAX_MEMORY_SIZE: 2621440
DATA_UPLOAD_MAX_NUMBER_FIELDS: 1000
DATETIME_FORMAT: 'N j, Y, P'
DATETIME_INPUT_FORMATS: ['%Y-%m-%d %H:%M:%S',
 '%Y-%m-%d %H:%M:%S.%f',
 '%Y-%m-%d %H:%M',
 '%m/%d/%Y %H:%M:%S',
 '%m/%d/%Y %H:%M:%S.%f',
 '%m/%d/%Y %H:%M',
 '%m/%d/%y %H:%M:%S',
 '%m/%d/%y %H:%M:%S.%f',
 '%m/%d/%y %H:%M']
DATE_FORMAT: 'N j, Y'
DATE_INPUT_FORMATS: ['%Y-%m-%d',
 '%m/%d/%Y',
 '%m/%d/%y',
 '%b %d %Y',
 '%b %d, %Y',
 '%d %b %Y',
 '%d %b, %Y',
 '%B %d %Y',
 '%B %d, %Y',
 '%d %B %Y',
 '%d %B, %Y']
DEBUG: True
DEBUG_PROPAGATE_EXCEPTIONS: False
DECIMAL_SEPARATOR: '.'
DEFAULT_AUTO_FIELD: 'django.db.models.BigAutoField'
DEFAULT_CHARSET: 'utf-8'
DEFAULT_EXCEPTION_REPORTER: 'django.views.debug.ExceptionReporter'
DEFAULT_EXCEPTION_REPORTER_FILTER: 'django.views.debug.SafeExceptionReporterFilter'
DEFAULT_FILE_STORAGE: 'django.core.files.storage.FileSystemStorage'
DEFAULT_FROM_EMAIL: 'webmaster@localhost'
DEFAULT_HASHING_ALGORITHM: 'sha256'
DEFAULT_INDEX_TABLESPACE: ''
DEFAULT_TABLESPACE: ''
DISALLOWED_USER_AGENTS: []
EMAIL_BACKEND: 'django.core.mail.backends.smtp.EmailBackend'
EMAIL_HOST: 'localhost'
EMAIL_HOST_PASSWORD: '********'
EMAIL_HOST_USER: ''
EMAIL_PORT: 25
EMAIL_SSL_CERTFILE: None
EMAIL_SSL_KEYFILE: '********'
EMAIL_SUBJECT_PREFIX: '[Django] '
EMAIL_TIMEOUT: None
EMAIL_USE_LOCALTIME: False
EMAIL_USE_SSL: False
EMAIL_USE_TLS: False
FILE_UPLOAD_DIRECTORY_PERMISSIONS: None
FILE_UPLOAD_HANDLERS: ['django.core.files.uploadhandler.MemoryFileUploadHandler',
 'django.core.files.uploadhandler.TemporaryFileUploadHandler']
FILE_UPLOAD_MAX_MEMORY_SIZE: 2621440
FILE_UPLOAD_PERMISSIONS: 420
FILE_UPLOAD_TEMP_DIR: None
FIRST_DAY_OF_WEEK: 0
FIXTURE_DIRS: []
FORCE_SCRIPT_NAME: None
FORMAT_MODULE_PATH: None
FORM_RENDERER: 'django.forms.renderers.DjangoTemplates'
IGNORABLE_404_URLS: []
INSTALLED_APPS: ['django.contrib.admin',
 'django.contrib.auth',
 'django.contrib.contenttypes',
 'django.contrib.sessions',
 'django.contrib.messages',
 'django.contrib.staticfiles',
 'channels']
INTERNAL_IPS: []
LANGUAGES: [('af', 'Afrikaans'),
 ('ar', 'Arabic'),
 ('ar-dz', 'Algerian Arabic'),
 ('ast', 'Asturian'),
 ('az', 'Azerbaijani'),
 ('bg', 'Bulgarian'),
 ('be', 'Belarusian'),
 ('bn', 'Bengali'),
 ('br', 'Breton'),
 ('bs', 'Bosnian'),
 ('ca', 'Catalan'),
 ('cs', 'Czech'),
 ('cy', 'Welsh'),
 ('da', 'Danish'),
 ('de', 'German'),
 ('dsb', 'Lower Sorbian'),
 ('el', 'Greek'),
 ('en', 'English'),
 ('en-au', 'Australian English'),
 ('en-gb', 'British English'),
 ('eo', 'Esperanto'),
 ('es', 'Spanish'),
 ('es-ar', 'Argentinian Spanish'),
 ('es-co', 'Colombian Spanish'),
 ('es-mx', 'Mexican Spanish'),
 ('es-ni', 'Nicaraguan Spanish'),
 ('es-ve', 'Venezuelan Spanish'),
 ('et', 'Estonian'),
 ('eu', 'Basque'),
 ('fa', 'Persian'),
 ('fi', 'Finnish'),
 ('fr', 'French'),
 ('fy', 'Frisian'),
 ('ga', 'Irish'),
 ('gd', 'Scottish Gaelic'),
 ('gl', 'Galician'),
 ('he', 'Hebrew'),
 ('hi', 'Hindi'),
 ('hr', 'Croatian'),
 ('hsb', 'Upper Sorbian'),
 ('hu', 'Hungarian'),
 ('hy', 'Armenian'),
 ('ia', 'Interlingua'),
 ('id', 'Indonesian'),
 ('ig', 'Igbo'),
 ('io', 'Ido'),
 ('is', 'Icelandic'),
 ('it', 'Italian'),
 ('ja', 'Japanese'),
 ('ka', 'Georgian'),
 ('kab', 'Kabyle'),
 ('kk', 'Kazakh'),
 ('km', 'Khmer'),
 ('kn', 'Kannada'),
 ('ko', 'Korean'),
 ('ky', 'Kyrgyz'),
 ('lb', 'Luxembourgish'),
 ('lt', 'Lithuanian'),
 ('lv', 'Latvian'),
 ('mk', 'Macedonian'),
 ('ml', 'Malayalam'),
 ('mn', 'Mongolian'),
 ('mr', 'Marathi'),
 ('my', 'Burmese'),
 ('nb', 'Norwegian Bokmål'),
 ('ne', 'Nepali'),
 ('nl', 'Dutch'),
 ('nn', 'Norwegian Nynorsk'),
 ('os', 'Ossetic'),
 ('pa', 'Punjabi'),
 ('pl', 'Polish'),
 ('pt', 'Portuguese'),
 ('pt-br', 'Brazilian Portuguese'),
 ('ro', 'Romanian'),
 ('ru', 'Russian'),
 ('sk', 'Slovak'),
 ('sl', 'Slovenian'),
 ('sq', 'Albanian'),
 ('sr', 'Serbian'),
 ('sr-latn', 'Serbian Latin'),
 ('sv', 'Swedish'),
 ('sw', 'Swahili'),
 ('ta', 'Tamil'),
 ('te', 'Telugu'),
 ('tg', 'Tajik'),
 ('th', 'Thai'),
 ('tk', 'Turkmen'),
 ('tr', 'Turkish'),
 ('tt', 'Tatar'),
 ('udm', 'Udmurt'),
 ('uk', 'Ukrainian'),
 ('ur', 'Urdu'),
 ('uz', 'Uzbek'),
 ('vi', 'Vietnamese'),
 ('zh-hans', 'Simplified Chinese'),
 ('zh-hant', 'Traditional Chinese')]
LANGUAGES_BIDI: ['he', 'ar', 'ar-dz', 'fa', 'ur']
LANGUAGE_CODE: 'en-us'
LANGUAGE_COOKIE_AGE: None
LANGUAGE_COOKIE_DOMAIN: None
LANGUAGE_COOKIE_HTTPONLY: False
LANGUAGE_COOKIE_NAME: 'django_language'
LANGUAGE_COOKIE_PATH: '/'
LANGUAGE_COOKIE_SAMESITE: None
LANGUAGE_COOKIE_SECURE: False
LOCALE_PATHS: []
LOGGING: {
    'disable_existing_loggers': False,
    'formatters': {   'timestamp': {   'format': '[{asctime}] {levelname} '
                                                 '[{name}]: {message}',
                                       'style': '{'}},
    'handlers': {   'console': {   'class': 'logging.StreamHandler',
                                   'formatter': 'timestamp',
                                   'level': 'DEBUG'}},
    'loggers': {   'celery': {'handlers': ['console'], 'level': 'DEBUG'},
                   'django': {'handlers': ['console'], 'level': 'INFO'}},
    'version': 1}
LOGGING_CONFIG: 'logging.config.dictConfig'
LOGIN_REDIRECT_URL: '/accounts/profile/'
LOGIN_URL: '/accounts/login/'
LOGOUT_REDIRECT_URL: None
MANAGERS: []
MEDIA_ROOT: ''
MEDIA_URL: '/'
MESSAGE_STORAGE: 'django.contrib.messages.storage.fallback.FallbackStorage'
MIDDLEWARE: ['django.middleware.security.SecurityMiddleware',
 'django.contrib.sessions.middleware.SessionMiddleware',
 'django.middleware.common.CommonMiddleware',
 'django.middleware.csrf.CsrfViewMiddleware',
 'django.contrib.auth.middleware.AuthenticationMiddleware',
 'django.contrib.messages.middleware.MessageMiddleware',
 'django.middleware.clickjacking.XFrameOptionsMiddleware']
MIGRATION_MODULES: {
 }
MONTH_DAY_FORMAT: 'F j'
NUMBER_GROUPING: 0
PASSWORD_HASHERS: '********'
PASSWORD_RESET_TIMEOUT: '********'
PASSWORD_RESET_TIMEOUT_DAYS: '********'
PREPEND_WWW: False
ROOT_URLCONF: 'celery_channels_test.urls'
SECRET_KEY: '********'
SECURE_BROWSER_XSS_FILTER: False
SECURE_CONTENT_TYPE_NOSNIFF: True
SECURE_HSTS_INCLUDE_SUBDOMAINS: False
SECURE_HSTS_PRELOAD: False
SECURE_HSTS_SECONDS: 0
SECURE_PROXY_SSL_HEADER: None
SECURE_REDIRECT_EXEMPT: []
SECURE_REFERRER_POLICY: 'same-origin'
SECURE_SSL_HOST: None
SECURE_SSL_REDIRECT: False
SERVER_EMAIL: 'root@localhost'
SESSION_CACHE_ALIAS: 'default'
SESSION_COOKIE_AGE: 1209600
SESSION_COOKIE_DOMAIN: None
SESSION_COOKIE_HTTPONLY: True
SESSION_COOKIE_NAME: 'sessionid'
SESSION_COOKIE_PATH: '/'
SESSION_COOKIE_SAMESITE: 'Lax'
SESSION_COOKIE_SECURE: False
SESSION_ENGINE: 'django.contrib.sessions.backends.db'
SESSION_EXPIRE_AT_BROWSER_CLOSE: False
SESSION_FILE_PATH: None
SESSION_SAVE_EVERY_REQUEST: False
SESSION_SERIALIZER: 'django.contrib.sessions.serializers.JSONSerializer'
SETTINGS_MODULE: 'celery_channels_test.settings'
SHORT_DATETIME_FORMAT: 'm/d/Y P'
SHORT_DATE_FORMAT: 'm/d/Y'
SIGNING_BACKEND: 'django.core.signing.TimestampSigner'
SILENCED_SYSTEM_CHECKS: []
STATICFILES_DIRS: []
STATICFILES_FINDERS: ['django.contrib.staticfiles.finders.FileSystemFinder',
 'django.contrib.staticfiles.finders.AppDirectoriesFinder']
STATICFILES_STORAGE: 'django.contrib.staticfiles.storage.StaticFilesStorage'
STATIC_ROOT: None
STATIC_URL: '/static/'
TEMPLATES: [{'APP_DIRS': True,
  'BACKEND': 'django.template.backends.django.DjangoTemplates',
  'DIRS': [],
  'OPTIONS': {'context_processors': ['django.template.context_processors.debug',
                                     'django.template.context_processors.request',
                                     'django.contrib.auth.context_processors.auth',
                                     'django.contrib.messages.context_processors.messages']}}]
TEST_NON_SERIALIZED_APPS: []
TEST_RUNNER: 'django.test.runner.DiscoverRunner'
THOUSAND_SEPARATOR: ','
TIME_FORMAT: 'P'
TIME_INPUT_FORMATS: ['%H:%M:%S', '%H:%M:%S.%f', '%H:%M']
TIME_ZONE: 'UTC'
USE_I18N: True
USE_L10N: True
USE_THOUSAND_SEPARATOR: False
USE_TZ: True
USE_X_FORWARDED_HOST: False
USE_X_FORWARDED_PORT: False
WSGI_APPLICATION: 'celery_channels_test.wsgi.application'
X_FRAME_OPTIONS: 'DENY'
YEAR_MONTH_FORMAT: 'F Y'
is_overridden: &lt;bound method Settings.is_overridden of &lt;Settings "celery_channels_test.settings"&gt;&gt;
deprecated_settings: None
</code></pre></div>
<p dir="auto"></p>
</details>
<h1 dir="auto">Steps to Reproduce</h1>
<h2 dir="auto">Required Dependencies</h2>

<ul dir="auto">
<li><strong>Minimal Python Version</strong>: 3.7</li>
<li><strong>Minimal Celery Version</strong>: 5.2.6</li>
<li><strong>Minimal Kombu Version</strong>: 5.2.4</li>
<li><strong>Minimal Broker Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Version</strong>: N/A or Unknown</li>
<li><strong>Minimal OS and/or Kernel Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Broker Client Version</strong>: N/A or Unknown</li>
<li><strong>Minimal Result Backend Client Version</strong>: N/A or Unknown</li>
</ul>
<h3 dir="auto">Python Packages</h3>

<details>
<summary><b><code class="notranslate">pip freeze</code> Output:</b></summary>
<p dir="auto">
</p><div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="aioredis==1.3.1
amqp==5.1.0
asgiref==3.5.0
async-timeout==4.0.2
attrs==21.4.0
autobahn==22.3.2
Automat==20.2.0
billiard==3.6.4.0
cached-property==1.5.2
celery==5.2.6
cffi==1.15.0
channels==3.0.4
channels-redis==3.4.0
click==8.1.2
click-didyoumean==0.3.0
click-plugins==1.1.1
click-repl==0.2.0
constantly==15.1.0
cryptography==36.0.2
daphne==3.0.2
Django==3.2.13
gevent==21.12.0
greenlet==1.1.2
hiredis==2.0.0
hyperlink==21.0.0
idna==3.3
importlib-metadata==4.11.3
incremental==21.3.0
kombu==5.2.4
msgpack==1.0.3
prompt-toolkit==3.0.29
pyasn1==0.4.8
pyasn1-modules==0.2.8
pycparser==2.21
pyOpenSSL==22.0.0
pytz==2022.1
service-identity==21.1.0
six==1.16.0
sqlparse==0.4.2
Twisted==22.4.0
txaio==22.2.1
typing_extensions==4.1.1
vine==5.0.0
wcwidth==0.2.5
zipp==3.8.0
zope.event==4.5.0
zope.interface==5.4.0"><pre class="notranslate"><code class="notranslate">aioredis==1.3.1
amqp==5.1.0
asgiref==3.5.0
async-timeout==4.0.2
attrs==21.4.0
autobahn==22.3.2
Automat==20.2.0
billiard==3.6.4.0
cached-property==1.5.2
celery==5.2.6
cffi==1.15.0
channels==3.0.4
channels-redis==3.4.0
click==8.1.2
click-didyoumean==0.3.0
click-plugins==1.1.1
click-repl==0.2.0
constantly==15.1.0
cryptography==36.0.2
daphne==3.0.2
Django==3.2.13
gevent==21.12.0
greenlet==1.1.2
hiredis==2.0.0
hyperlink==21.0.0
idna==3.3
importlib-metadata==4.11.3
incremental==21.3.0
kombu==5.2.4
msgpack==1.0.3
prompt-toolkit==3.0.29
pyasn1==0.4.8
pyasn1-modules==0.2.8
pycparser==2.21
pyOpenSSL==22.0.0
pytz==2022.1
service-identity==21.1.0
six==1.16.0
sqlparse==0.4.2
Twisted==22.4.0
txaio==22.2.1
typing_extensions==4.1.1
vine==5.0.0
wcwidth==0.2.5
zipp==3.8.0
zope.event==4.5.0
zope.interface==5.4.0
</code></pre></div>
<p dir="auto"></p>
</details>
<h3 dir="auto">Other Dependencies</h3>

<details>
<p dir="auto">
N/A
</p>
</details>
<h2 dir="auto">Minimally Reproducible Test Case</h2>

<p dir="auto">Here's a repo with a reproducible test case: <a href="https://github.com/udbhav/celery-channels-test">https://github.com/udbhav/celery-channels-test</a></p>
<h1 dir="auto">Expected Behavior</h1>

<p dir="auto">I would expect celery to behave the same when it comes to event loops regardless of load. There should either be an event loop created on startup or not. Having there be an event loop sometimes makes it difficult to write proper async code</p>
<h1 dir="auto">Actual Behavior</h1>

<p dir="auto">There is no event loop initially, and then one after queueing multiple tasks</p>