用python-rq调度另一个redis作业的redis作业。

Question

我有两种类型的作业:一种是连续运行的，另一种是并行运行的。但是，我希望并行作业按顺序安排(如果您还在跟踪的话)。这就是：

1. Do A.
2. 等A，做B。
3. 等待B，并发执行C的2+版本。

我认为它有两个redis队列，一个只有一个工作人员的serial_queue。还有一个parallel_queue，上面有多个工作人员。

serial_queue.schedule(
    scheduled_time=datetime.utcnow(),
    func=job_a,
     ...)    
serial_queue.schedule(
    scheduled_time=datetime.utcnow(),
    func=job_b,
     ...)

def parallel_c():
    for task in range(args.n_tasks):
        queue_concurrent.schedule(
            scheduled_time=datetime.utcnow(),
            func=job_c,
            ...)

serial_queue.schedule(
    scheduled_time=datetime.utcnow(),
    func=parallel_c,
     ...)

但是目前这个设置给出了AttributeError: module '__main__' has no attribute 'schedule_fetch_tweets'的错误。如何为python-rq正确地打包此函数

Answer 1

解决方案需要一些体操，因为您必须导入当前脚本，就好像它是一个外部模块一样。

举个例子。schedule_twitter_jobs.py的内容如下：

from redis import Redis
from rq_scheduler import Scheduler
import schedule_twitter_jobs
# we are importing the very module we are executing

def schedule_fetch_tweets(args, queue_name):
    ''' This is the child process to schedule'''

    concurrent_queue = Scheduler(queue_name=queue_name+'_concurrent', connection=Redis())
    # this scheduler is created based on a queue_name that will be passed in
    for task in range(args.n_tasks):
        scheduler_concurrent.schedule(
            scheduled_time=datetime.utcnow(),
            func=app.controller.fetch_twitter_tweets,
            args=[args.statuses_backfill, fill_start_time])

serial_queue = Scheduler(queue_name='myqueue', connection=Redis())
serial_queue.schedule(
'''This is the first schedule.'''
   scheduled_time=datetime.utcnow(),
   func=schedule_twitter_jobs.schedule_fetch_tweets,
   #now we have a fully-qualified reference to the function we need to schedule.
   args=(args, ttl, timeout, queue_name)
   #pass through the args to the child schedule
   )