huey¶
a lightweight alternative.
huey is:
a task queue
written in python
clean and simple API
redis, sqlite, file-system, or in-memory storage
huey supports:
multi-process, multi-thread or greenlet task execution models
schedule tasks to execute at a given time, or after a given delay
schedule recurring tasks, like a crontab
automatically retry tasks that fail
task prioritization
task result storage
task expiration
task locking
task pipelines and chains
At a glance¶
task() and periodic_task() decorators turn
functions into tasks executed by the consumer:
from huey import RedisHuey, crontab
huey = RedisHuey('my-app', host='redis.myapp.com')
@huey.task()
def add_numbers(a, b):
return a + b
@huey.task(retries=2, retry_delay=60)
def flaky_task(url):
# This task might fail, in which case it will be retried up to 2 times
# with a delay of 60s between retries.
return this_might_fail(url)
@huey.periodic_task(crontab(minute='0', hour='3'))
def nightly_backup():
sync_all_data()
Calling a task-decorated function will enqueue the function call for
execution by the consumer. A special result handle is returned immediately,
which can be used to fetch the result once the task is finished:
>>> from demo import add_numbers
>>> res = add_numbers(1, 2)
>>> res
<Result: task 6b6f36fc-da0d-4069-b46c-c0d4ccff1df6>
>>> res()
3
Tasks can be scheduled to run in the future:
>>> res = add_numbers.schedule((2, 3), delay=10) # Will be run in ~10s.
>>> res(blocking=True) # Will block until task finishes, in ~10s.
5
For much more, check out the Guide or take a look at the example code.
Running the consumer¶
Run the consumer with four worker processes:
$ huey_consumer.py my_app.huey -k process -w 4
To run the consumer with a single worker thread (default):
$ huey_consumer.py my_app.huey
If your work-loads are mostly IO-bound, you can run the consumer with threads or greenlets instead. Because greenlets are so lightweight, you can run quite a few of them efficiently:
$ huey_consumer.py my_app.huey -k greenlet -w 32
For more information, see the Consuming Tasks document.
Table of contents¶
Huey is named in honor of my cat
