Django integration with RQ, a Redis
based Python queuing library. Django-RQ is a
simple app that allows you to configure your queues in django's settings.py
and easily use them in your project.
If you find django-rq useful, please consider supporting its development via Tidelift.
- Install
django-rq(or download from PyPI):
pip install django-rq- Add
django_rqtoINSTALLED_APPSinsettings.py:
INSTALLED_APPS = (
# other apps
"django_rq",
)- Configure your queues in django's
settings.py:
RQ_QUEUES = {
'default': {
'HOST': 'localhost',
'PORT': 6379,
'DB': 0,
'USERNAME': 'some-user',
'PASSWORD': 'some-password',
'DEFAULT_TIMEOUT': 360,
'REDIS_CLIENT_KWARGS': { # Eventual additional Redis connection arguments
'ssl_cert_reqs': None,
},
},
'with-sentinel': {
'SENTINELS': [('localhost', 26736), ('localhost', 26737)],
'MASTER_NAME': 'redismaster',
'DB': 0,
# Redis username/password
'USERNAME': 'redis-user',
'PASSWORD': 'secret',
'SOCKET_TIMEOUT': 0.3,
'CONNECTION_KWARGS': { # Eventual additional Redis connection arguments
'ssl': True
},
'SENTINEL_KWARGS': { # Eventual Sentinel connection arguments
# If Sentinel also has auth, username/password can be passed here
'username': 'sentinel-user',
'password': 'secret',
},
},
'high': {
'URL': os.getenv('REDISTOGO_URL', 'redis://localhost:6379/0'), # If you're on Heroku
'DEFAULT_TIMEOUT': 500,
},
'low': {
'HOST': 'localhost',
'PORT': 6379,
'DB': 0,
}
}
RQ_EXCEPTION_HANDLERS = ['path.to.my.handler'] # If you need custom exception handlers- Include
django_rq.urlsin yoururls.py:
urlpatterns += [
path('django-rq/', include('django_rq.urls'))
]Django-RQ allows you to easily put jobs into any of the queues defined in
settings.py. It comes with a few utility functions:
enqueue- push a job to thedefaultqueue:
import django_rq
django_rq.enqueue(func, foo, bar=baz)get_queue- returns anQueueinstance.
import django_rq
queue = django_rq.get_queue('high')
queue.enqueue(func, foo, bar=baz)In addition to name argument, get_queue also accepts default_timeout,
is_async, autocommit, connection and queue_class arguments. For example:
queue = django_rq.get_queue('default', autocommit=True, is_async=True, default_timeout=360)
queue.enqueue(func, foo, bar=baz)You can provide your own singleton Redis connection object to this function so that it will not create a new connection object for each queue definition. This will help you limit number of connections to Redis server. For example:
import django_rq
import redis
redis_cursor = redis.StrictRedis(host='', port='', db='', password='')
high_queue = django_rq.get_queue('high', connection=redis_cursor)
low_queue = django_rq.get_queue('low', connection=redis_cursor)get_connection- accepts a single queue name argument (defaults to "default") and returns a connection to the queue's Redis server:
import django_rq
redis_conn = django_rq.get_connection('high')get_worker- accepts optional queue names and returns a new RQWorkerinstance for specified queues (ordefaultqueue):
import django_rq
worker = django_rq.get_worker() # Returns a worker for "default" queue
worker.work()
worker = django_rq.get_worker('low', 'high') # Returns a worker for "low" and "high"To easily turn a callable into an RQ task, you can also use the @job
decorator that comes with django_rq:
from django_rq import job
@job
def long_running_func():
pass
long_running_func.delay() # Enqueue function in "default" queue
@job('high')
def long_running_func():
pass
long_running_func.delay() # Enqueue function in "high" queueYou can pass in any arguments that RQ's job decorator accepts:
@job('default', timeout=3600)
def long_running_func():
pass
long_running_func.delay() # Enqueue function with a timeout of 3600 seconds.It's possible to specify default for result_ttl decorator keyword argument
via DEFAULT_RESULT_TTL setting:
RQ = {
'DEFAULT_RESULT_TTL': 5000,
}With this setting, job decorator will set result_ttl to 5000 unless it's
specified explicitly.
django_rq provides a management command that starts a worker for every queue specified as arguments:
python manage.py rqworker high default low
If you want to run rqworker in burst mode, you can pass in the --burst flag:
python manage.py rqworker high default low --burst
If you need to use custom worker, job or queue classes, it is best to use global settings (see Custom queue classes and Custom job and worker classes). However, it is also possible to override such settings with command line options as follows.
To use a custom worker class, you can pass in the --worker-class flag
with the path to your worker:
python manage.py rqworker high default low --worker-class 'path.to.GeventWorker'
To use a custom queue class, you can pass in the --queue-class flag
with the path to your queue class:
python manage.py rqworker high default low --queue-class 'path.to.CustomQueue'
To use a custom job class, provide --job-class flag.
Starting from version 2.10, running RQ's worker-pool is also supported:
python manage.py rqworker-pool default low medium --num-workers 4
With RQ 1.2.0. you can use built-in scheduler for your jobs. For example:
from django_rq.queues import get_queue
queue = get_queue('default')
job = queue.enqueue_at(datetime(2020, 10, 10), func)If you are using built-in scheduler you have to start workers with scheduler support:
python manage.py rqworker --with-scheduler
Alternatively you can use RQ Scheduler.
After install you can also use the get_scheduler function to return a
Scheduler instance for queues defined in settings.py's RQ_QUEUES.
For example:
import django_rq
scheduler = django_rq.get_scheduler('default')
job = scheduler.enqueue_at(datetime(2020, 10, 10), func)You can also use the management command rqscheduler to start the scheduler:
python manage.py rqscheduler
If you have django-redis or django-redis-cache installed, you can instruct django_rq to use the same connection information from your Redis cache. This has two advantages: it's DRY and it takes advantage of any optimization that may be going on in your cache setup (like using connection pooling or Hiredis.)
To use configure it, use a dict with the key USE_REDIS_CACHE pointing to the
name of the desired cache in your RQ_QUEUES dict. It goes without saying
that the chosen cache must exist and use the Redis backend. See your respective
Redis cache package docs for configuration instructions. It's also important to
point out that since the django-redis-cache ShardedClient splits the cache
over multiple Redis connections, it does not work.
Here is an example settings fragment for django-redis:
CACHES = {
'redis-cache': {
'BACKEND': 'redis_cache.cache.RedisCache',
'LOCATION': 'localhost:6379:1',
'OPTIONS': {
'CLIENT_CLASS': 'django_redis.client.DefaultClient',
'MAX_ENTRIES': 5000,
},
},
}
RQ_QUEUES = {
'high': {
'USE_REDIS_CACHE': 'redis-cache',
},
'low': {
'USE_REDIS_CACHE': 'redis-cache',
},
}Sometimes you may want to suspend RQ to prevent it from processing new jobs. A classic example is during the initial phase of a deployment script or in advance of putting your site into maintenance mode. This is particularly helpful when you have jobs that are relatively long-running and might otherwise be forcibly killed during the deploy.
The suspend command stops workers on _all_ queues (in a single Redis database) from picking up new jobs. However currently running jobs will continue until completion.
# Suspend indefinitely
python manage.py rqsuspend
# Suspend for a specific duration (in seconds) then automatically
# resume work again.
python manage.py rqsuspend -d 600
# Resume work again.
python manage.py rqresumedjango_rq also provides a dashboard to monitor the status of your queues at
/django-rq/ (or whatever URL you set in your urls.py during installation.
You can also add a link to this dashboard link in /admin by adding
RQ_SHOW_ADMIN_LINK = True in settings.py. Be careful though, this will
override the default admin template so it may interfere with other apps that
modifies the default admin template.
These statistics are also available in JSON format via
/django-rq/
8000
stats.json, which is accessible to staff members.
If you need to access this view via other
HTTP clients (for monitoring purposes), you can define RQ_API_TOKEN and access it via
/django-rq/stats.json/<API_TOKEN>.
Note: Statistics of scheduled jobs display jobs from RQ built-in scheduler, not optional RQ scheduler.
Additionally, these statistics are also accessible from the command line.
python manage.py rqstats
python manage.py rqstats --interval=1 # Refreshes every second
python manage.py rqstats --json # Output as JSON
python manage.py rqstats --yaml # Output as YAML
Sentry
should be configured within the Django settings.py as described in the Sentry docs.
You can override the default Django Sentry configuration when running the rqworker command
by passing the sentry-dsn option:
./manage.py rqworker --sentry-dsn=https://*****@sentry.io/222222
This will override any existing Django configuration and reinitialise Sentry, setting the following Sentry options:
{
'debug': options.get('sentry_debug'),
'ca_certs': options.get('sentry_ca_certs'),
'integrations': [RedisIntegration(), RqIntegration(), DjangoIntegration()]
}RQ uses Python's logging, this means you can easily configure rqworker's logging mechanism in django's
settings.py. For example:
LOGGING = {
"version": 1,
"disable_existing_loggers": False,
"formatters": {
"rq_console": {
"format": "%(asctime)s %(message)s",
"datefmt": "%H:%M:%S",
},
},
"handlers": {
"rq_console": {
"level": "DEBUG",
"class": "rq.logutils.ColorizingStreamHandler",
"formatter": "rq_console",
"exclude": ["%(asctime)s"],
},
},
'loggers': {
"rq.worker": {
"handlers": ["rq_console", "sentry"],
"level": "DEBUG"
},
}
}By default, every queue will use DjangoRQ class. If you want to use a custom queue class, you can do so
by adding a QUEUE_CLASS option on a per queue basis in RQ_QUEUES:
RQ_QUEUES = {
'default': {
'HOST': 'localhost',
'PORT': 6379,
'DB': 0,
'QUEUE_CLASS': 'module.path.CustomClass',
}
}or you can specify DjangoRQ to use a custom class for all your queues in RQ settings:
RQ = {
'QUEUE_CLASS': 'module.path.CustomClass',
}Custom queue classes should inherit from django_rq.queues.DjangoRQ.
If you are using more than one queue class (not recommended), be sure to only run workers
on queues with same queue class. For example if you have two queues defined in RQ_QUEUES and
one has custom class specified, you would have to run at least two separate workers for each
queue.
Similarly to custom queue classes, global custom job and worker classes can be configured using
JOB_CLASS and WORKER_CLASS settings:
RQ = {
'JOB_CLASS': 'module.path.CustomJobClass',
'WORKER_CLASS': 'module.path.CustomWorkerClass',
}Custom job class should inherit from rq.job.Job. It will be used for all jobs
if configured.
Custom worker class should inherit from rq.worker.Worker. It will be used for running
all workers unless overridden by rqworker management command worker-class option.
For an easier testing process, you can run a worker synchronously this way:
from django.test import TestCase
from django_rq import get_worker
class MyTest(TestCase):
def test_something_that_creates_jobs(self):
... # Stuff that init jobs.
get_worker().work(burst=True) # Processes all jobs then stop.
... # Asserts that the job stuff is done.You can set the option ASYNC to False to make synchronous operation the
default for a given queue. This will cause jobs to execute immediately and on
the same thread as they are dispatched, which is useful for testing and
debugging. For example, you might add the following after you queue
configuration in your settings file:
# ... Logic to set DEBUG and TESTING settings to True or False ...
# ... Regular RQ_QUEUES setup code ...
if DEBUG or TESTING:
for queueConfig in RQ_QUEUES.values():
queueConfig['ASYNC'] = FalseNote that setting the is_async parameter explicitly when calling get_queue
will override this setting.
To run django_rq's test suite:
`which django-admin` test django_rq --settings=django_rq.tests.settings --pythonpath=.
Create an rqworker service that runs the high, default, and low queues.
sudo vi /etc/systemd/system/rqworker.service
[Unit]
Description=Django-RQ Worker
After=network.target
[Service]
WorkingDirectory=<<path_to_your_project_folder>>
ExecStart=/home/ubuntu/.virtualenv/<<your_virtualenv>>/bin/python \
<<path_to_your_project_folder>>/manage.py \
rqworker high default low
[Install]
WantedBy=multi-user.targetEnable and start the service
sudo systemctl enable rqworker
sudo systemctl start rqworkerAdd django-rq to your requirements.txt file with:
pip freeze > requirements.txtUpdate your Procfile to:
web: gunicorn --pythonpath="$PWD/your_app_name" config.wsgi:application
worker: python your_app_name/manage.py rqworker high default lowCommit and re-deploy. Then add your new worker with:
heroku scale worker=1See CHANGELOG.md.
