darq

[ ~ Dependencies scanned by PyUp.io ~ ]

Async task manager with Celery-like features. Fork of arq.

Features

• Celery-like @task decorator, adds .delay() to enqueue job
• Proper mypy type checking: all arguments passed to .delay() will be checked against the original function signature
• Graceful shutdown: waits until running tasks are finished

Installation

Darq uses aioredis 1.x as Redis client. Unfortunately, this library has been abandoned, and does not support Python 3.11. I made a fork with compatability fixes: evo-aioredis ().

Because of this, aioredis is not currently added as Darq dependency, and you must install it yourself:

For Python<3.11 you can use:

pip install aioredis<2.0.0

For Python 3.11 (and older versions too) you can use fork:

pip install evo-aioredis<2.0.0

Quick start

# some_project/darq_app.py
import asyncio
import darq

darq = darq.Darq(redis_settings=darq.RedisSettings(host='redis'))


@darq.task
async def add_to_42(a: int) -> int:
    return 42 + a


async def main():
    # Before adding tasks to queue we should connect darq instance to redis
    await darq.connect()

    # Direct call job as function:
    result = await add_to_42(5)  # result == 47

    # Celery-like add task to queue:
    await add_to_42.delay(a=5)

    await darq.disconnect()


if __name__ == '__main__':
    asyncio.run(main())

And start worker:

python3 -m darq.cli -A some_project.darq_app.darq worker

Worker output:

15:24:42: Starting worker for 1 functions: some_project.darq_app.add_to_42
15:24:42: redis_version=5.0.7 mem_usage=834.87K clients_connected=1 db_keys=2
15:25:08:   0.22s → 1315f27608e9408392bf5d3310bca38c:darq_app.add_to_42(a=5)
15:25:08:   0.00s ← 1315f27608e9408392bf5d3310bca38c:darq_app.add_to_42 ● 47

Changelog

0.11.2 (2024-01-18)

• Fix reconnecting after disconnect (thanks to @heimtathurs)

0.11.1 (2022-11-30)

• Add Python 3.11 support (with evo-aioredis dependency instead of aioredis)
• Remove pydantic dependency
• Remove aioredis from dependencies to allow choose between aioredis and evo-aioredis - fork with Python 3.11 compatability

0.11.0 (2022-08-03)

• Added ability to optionally pass ctx to the task, like this:

@task(with_ctx=True)
def foobar(ctx):
    log.info('Foobar try %s', ctx['job_try'])

ctx contains: job_id, job_try, enqueue_time, score, metadata

• all worker's ctx (including custom context which can be passed via on_startup). Thanks to @kindermax () !

0.10.2 (2022-02-03)

• Add proper typing for functions wrapped with the @task decorator. Mypy will now check that parameters are passed correctly when calling func() and func.delay()

0.10.1 (2021-07-29)

• Add sentinel_timeout (defaults to 0.2) param to RedisSettings

0.10.0 (2021-07-09)

• Breaking change: Rename darq.worker.Function to darq.worker.Task
• Made job to task naming migration
• Add max_jobs parameter to CLI (thanks to @antonmyronyuk)
• Fixed bug with expires argument: default_job_expires could not be replaced with None in @task or .apply_async

0.9.0 (2020-06-24)

• Breaking change: Add scheduler_ctx param to on_scheduler_startup and on_scheduler_shutdown to share data between this callbacks. It already has ctx['redis'] - instance of ArqRedis

0.8.0 (2020-06-22)

• Breaking change: Changed CLI command format. Before: darq some_project.darq_app.darq. Now: darq -A some_project.darq_app.darq worker
• Breaking change: Scheduler (cron jobs) now run's seperate from worker (see darq scheduler command)
• Breaking change: Changed some function signatures (rename arguments)
• Breaking change: Remove redis_pool param from Darq app
• Add on_scheduler_startup and on_scheduler_shutdown callbacks

0.7.2 (2020-06-18)

• Fix some types (cron, OnJobPrepublishType)
• on_job_prerun now runs before "task started" log and on_job_postrun now runs after "task finished" log

0.7.1 (2020-05-25)

• .apply_async: Make args and kwargs arguments optional

0.7.0 (2020-05-25)

• Fork arq to project and merge it with darq (It was easier to rewrite arq than to write a wrapper)
• Breaking change: Remove "magic" params from .delay. For enqueue job with special params added .apply_async.
• Add watch-mode to CLI.
• Fix: Now worker will not run cronjob if it's functions queue not match with worker's

0.6.0 (2020-03-08)

• Breaking change: Changed Darq constructor from single config param to separate params.
• arq_function.coroutine now has .delay method.

0.5.0 (2020-03-03)

• Add on_job_prepublish(metadata, arq_function, args, kwargs) callback. metadata is mutable dict, which will be available at ctx['metadata'].

0.4.0 (2020-03-03)

• Add default_job_expires param to Darq (if the job still hasn't started after this duration, do not run it). Default - 1 day
• Add expires param to @task (if set - overwrites default_job_expires)

0.3.1 (2020-03-02)

• Rewrite warm shutdown: now during warm shutdown cron is disabled, on second signal the warm shutdown will be canceled

0.3.0 (2020-02-27)

• Breaking change: on_job_prerun and on_job_postrun now accepts arq.worker.Function instead of the original function (it can still be accessed at arq_function.coroutine)

0.2.1 (2020-02-26)

• Fix add_cron_jobs method. Tests added.

0.2.0 (2020-02-26)

• Add on_job_prerun(ctx, function, args, kwargs) and on_job_postrun(ctx, function, args, kwargs, result) callbacks.

0.1.0 (2020-02-26)

• Breaking change: Jobs no longer explicitly get JobCtx as the first argument, as in 99.9% cases it doesn't need it. In future release will be possible to optionally pass JobCtx in some way.
• Breaking change: All cron jobs should be wrapped in @task decorator
• Directly pass functions to arq.Worker, not names.

0.0.3 (2020-02-25)

• .delay() now returns arq_redis.enqueue_job result (Optional[Job])
• Add py.typed file
• Fixed add_cron_jobs typing

0.0.2 (2020-02-24)

• Add add_cron_jobs method

0.0.1 (2020-02-21)

First release