RQ Scheduler

0.14.0 · active · verified Tue Apr 14

RQ Scheduler provides a job scheduling layer for RQ (Redis Queue), allowing users to schedule jobs to run at specific times or on recurring cron-like schedules. It is an active project, currently at version 0.14.0, with releases coinciding with major RQ updates and feature additions.

Warnings

breaking RQ Scheduler v0.14.0 and later support RQ 2.0+. Using older versions of `rq-scheduler` with RQ 2.0+ or newer `rq-scheduler` with older RQ versions can lead to compatibility issues or errors.
Fix: Ensure your `rq-scheduler` and `rq` package versions are compatible. For `rq-scheduler==0.14.0`, use `rq>=2.0.0`. Check `rq-scheduler` release notes for specific `rq` version requirements.
breaking Starting with v0.13.0, `rq-scheduler` requires Python 3.6 or newer. Older Python versions are no longer supported.
Fix: Upgrade your Python environment to 3.6 or newer. If you must use an older Python, stick to `rq-scheduler<0.13.0`.
gotcha The `rq-scheduler` process is separate from `rq` worker processes. You must run `rq-scheduler` via its command-line tool (`rq-scheduler`) and `rq` workers via `rq worker` for scheduled jobs to be added to the queue and then processed.
Fix: Start both `rq-scheduler` and `rq worker` processes concurrently. E.g., in separate terminal tabs or managed by a process supervisor (like Supervisord or systemd).
gotcha The `rq-scheduler` instance must connect to the same Redis database as your `rq` workers and application. Using different Redis connections will result in jobs not being scheduled or processed correctly.
Fix: Pass the same `redis.Redis` connection object or connection parameters (e.g., `REDIS_URL`) to both your `Scheduler` instance and your `rq` workers.

Install

pip install rq-scheduler Install latest version

Imports

Scheduler
```
from rq_scheduler import Scheduler
```

Quickstart

This quickstart demonstrates how to instantiate `rq_scheduler.Scheduler` and schedule a job to run at a specific future time using `enqueue_at` and a recurring job using `cron`. Ensure your Redis server is running and that both `rq-scheduler` and `rq worker` processes are started separately for the scheduled jobs to be processed.

import os
from redis import Redis
from rq_scheduler import Scheduler
from datetime import datetime, timedelta

def my_job(arg1, arg2):
    print(f'Running job with args: {arg1}, {arg2}')
    return arg1 + arg2

# Ensure a Redis connection is available. Use a default if REDIS_URL not set.
redis_url = os.environ.get('REDIS_URL', 'redis://localhost:6379')
redis_conn = Redis.from_url(redis_url)

# Instantiate the scheduler with the Redis connection
scheduler = Scheduler(connection=redis_conn)

# Example 1: Schedule a job to run once at a specific time
job_at_time = datetime.utcnow() + timedelta(seconds=10)
scheduler.enqueue_at(
    job_at_time,              # Time to run the job
    my_job,                   # Function to be called
    'hello', 'world'          # Arguments for the function
)
print(f"Scheduled 'my_job' to run at {job_at_time} UTC")

# Example 2: Schedule a recurring job using cron syntax (every minute)
# Note: This will repeatedly add the job to the queue based on the cron string.
# Ensure 'rq-scheduler' process is running for this to work.
scheduler.cron(
    '*/1 * * * *',            # Cron string (every minute)
    func=my_job,              # Function to be called
    args=('cron_arg1', 'cron_arg2'), # Arguments for the function
    repeat=None,              # Run indefinitely
    queue_name='default'      # Queue to add the job to
)
print("Scheduled 'my_job' to run every minute via cron")

# To run the scheduler, you would execute `rq-scheduler` in your terminal.
# To process jobs, you would execute `rq worker` in your terminal.

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