Celery任务在任务成功后调用自己而没有celerybeat

Question

我想在当前任务完成后的每30分钟偶尔调用我的芹菜任务，但由于任务从远程服务器下载文件，有时需要的时间比预期的要长。所以我不想使用celeryBeat。另外，使用自我。重试仅适用于我想错误发生的时间。这是我的任务：

@shared_task(name="download_big", bind=True, acks_late=true, autoretry_for=(Exception, requests.exceptiosn.RequestException), retry_kwargs={"max_retries": 4, "countdown": 3}):
def download_big(self):
    my_file = session.get('example.com/hello.mp4')
    if my_file.status_code == requests.codes["OK"]:
        open("hello.mp4", "wb").write(my_file.content)
    else:
        self.retry()

更新：

好吧，我改变了我的结构：

@shared_task(name="download_big", bind=True, acks_late=true, autoretry_for=(Exception, requests.exceptiosn.RequestException), retry_kwargs={"max_retries": 4, "countdown": 3}):
def download_big(url):
    my_file = session.get(url, name)
    if my_file.status_code == requests.codes["OK"]:
        open(name, "wb").write(my_file.content)
    else:
        self.retry()

@shared_task(name="download_all", bind=True, acks_late=true, autoretry_for=(Exception, requests.exceptiosn.RequestException), retry_kwargs={"max_retries": 4, "countdown": 3}):
def download_all(self):
    my_list = [...]  # bunch of urls with names
    jobs = []
    for name, url in my_list:
        jobs.append(download_big.si(url, name))
    group(jobs)()

所以在这种情况下，我必须调用download_all方法而不是download_big，这样我可以并行下载文件，当所有组任务完成后，它需要在30分钟后再次调用自己。

Answer 1

您可以尝试使用运行一组任务的chord，当它们完成时，将运行一个可用于重新安排的回调。

EG

from celery import chord

@shared_task(name="download_big", bind=True, acks_late=true, autoretry_for=(Exception, requests.exceptiosn.RequestException), retry_kwargs={"max_retries": 4, "countdown": 3}):
def download_big(url):
    my_file = session.get(url, name)
    if my_file.status_code == requests.codes["OK"]:
        open(name, "wb").write(my_file.content)
    else:
        self.retry()

@shared_task(name="download_all", bind=True, acks_late=true, autoretry_for=(Exception, requests.exceptiosn.RequestException), retry_kwargs={"max_retries": 4, "countdown": 3}):
def download_all(self):
    my_list = [...]  # bunch of urls with names
    jobs = []
    for name, url in my_list:
        jobs.append(download_big.si(url, name))

    # Run the group and reschedule once all tasks complete
    chord(jobs)(download_all.apply_async(countdown=1800))