另一個文件中的函數調用在 Django rest 框架中不起作用

Question

當管理員發布博客文章時，我使用 Django 信號觸發任務（使用 Django celery 包向訂閱者發送大量電子郵件）。 信號被觸發但任務文件中的任務函數沒有被調用。 這是因為我在任務函數中放置了一個不打印的打印函數。

我的 signlas.py 文件：

from apps.blogs.celery_files.tasks import send_mails
from apps.blogs.models import BlogPost,Subscribers
from django.db.models.signals import post_save
from django.dispatch import receiver

def email_task(sender, instance, created, **kwargs):
    if created:
        print("@signals.py")
        send_mails.delay(5)


post_save.connect(email_task, sender=BlogPost,dispatch_uid="email_task")

我的 task.py 文件

from __future__ import absolute_import, unicode_literals
from celery import shared_task
# from celery.decorators import task
from apps.blogs.models import BlogPost,Subscribers
from django.core.mail import send_mail
from travel_crm.settings import EMAIL_HOST_USER
from time import sleep

@shared_task
def send_mails(duration,*args, **kwargs):
    print("@send_mails.py")
    subscribers = Subscribers.objects.all()
    blog = BlogPost.objects.latest('date_created')
    for abc in subscribers:
        sleep(duration)
        print("i am inside loop")
        emailad = abc.email
        send_mail('New Blog Post ', f" Checkout our new blog with title {blog.title} ",
                  EMAIL_HOST_USER, [emailad],
                  fail_silently=False)

這里。 不執行 print("@send_mails.py") 但執行了signals.py文件中的 print("@signals.py") 。 因此，在創建 Blogpost 模型對象后接收信號，但不會執行 task.py 中的 send_mails 函數。

我已經安裝了 celery 和 redis 服務器，並且都運行良好。

最重要的是，如果我從信號文件中刪除 .delay(5) 而只是在 email_task 中使用 send_mails() ，它可以完美運行並且我正在收到電子郵件。 但是一旦我添加了 delay() 函數，任務文件中的功能就不會被調用。 什么問題？？

我運行工人信息時的回溯：

-------------- celery@DESKTOP-AQPSFR9 v5.1.2 (sun-harmonics)
--- ***** -----
-- ******* ---- Windows-10-10.0.18362-SP0 2021-07-18 11:06:10
- *** --- * ---
- ** ---------- [config]
- ** ---------- .> app:         travel_crm:0x15c262afcd0
- ** ---------- .> transport:   redis://localhost:6379//
- ** ---------- .> results:     redis://localhost:6379/
- *** --- * --- .> concurrency: 4 (prefork)
-- ******* ---- .> task events: OFF (enable -E to monitor tasks in this worker)
--- ***** -----
 -------------- [queues]
                .> celery           exchange=celery(direct) key=celery


[tasks]
  . apps.blogs.celery_files.celery.debug_task
  . apps.blogs.celery_files.tasks.send_mails
  . travel_crm.celery.debug_task

[2021-07-18 11:06:11,465: INFO/SpawnPoolWorker-1] child process 9276 calling self.run()
[2021-07-18 11:06:11,475: INFO/SpawnPoolWorker-2] child process 8792 calling self.run()
[2021-07-18 11:06:11,496: INFO/SpawnPoolWorker-4] child process 1108 calling self.run()
[2021-07-18 11:06:11,506: INFO/SpawnPoolWorker-3] child process 7804 calling self.run()
[2021-07-18 11:06:13,145: INFO/MainProcess] Connected to redis://localhost:6379//
[2021-07-18 11:06:17,206: INFO/MainProcess] mingle: searching for neighbors
[2021-07-18 11:06:24,287: INFO/MainProcess] mingle: all alone
[2021-07-18 11:06:32,396: WARNING/MainProcess] c:\users\user\desktop\travelcrm\myvenv\lib\site-packages\celery\fixups\django.py:203: UserWarning: Using settings.DEBUG leads to a memory
            leak, never use this setting in production environments!
  warnings.warn('''Using settings.DEBUG leads to a memory

[2021-07-18 11:06:32,396: INFO/MainProcess] celery@DESKTOP-AQPSFR9 ready.
[2021-07-18 11:06:32,596: INFO/MainProcess] Task apps.blogs.celery_files.tasks.send_mails[6bbac0ae-8146-4fb0-b64b-a07755123e1d] received
[2021-07-18 11:06:32,612: INFO/MainProcess] Task apps.blogs.celery_files.tasks.send_mails[25d3b32a-f223-4ae4-812b-fa1cfaedaddd] received
[2021-07-18 11:06:34,633: ERROR/MainProcess] Task handler raised error: ValueError('not enough values to unpack (expected 3, got 0)')
Traceback (most recent call last):
  File "c:\users\user\desktop\travelcrm\myvenv\lib\site-packages\billiard\pool.py", line 362, in workloop
    result = (True, prepare_result(fun(*args, **kwargs)))
  File "c:\users\user\desktop\travelcrm\myvenv\lib\site-packages\celery\app\trace.py", line 635, in fast_trace_task
    tasks, accept, hostname = _loc
ValueError: not enough values to unpack (expected 3, got 0)
[2021-07-18 11:06:34,633: ERROR/MainProcess] Task handler raised error: ValueError('not enough values to unpack (expected 3, got 0)')
Traceback (most recent call last):
  File "c:\users\user\desktop\travelcrm\myvenv\lib\site-packages\billiard\pool.py", line 362, in workloop
    result = (True, prepare_result(fun(*args, **kwargs)))
  File "c:\users\user\desktop\travelcrm\myvenv\lib\site-packages\celery\app\trace.py", line 635, in fast_trace_task
    tasks, accept, hostname = _loc
ValueError: not enough values to unpack (expected 3, got 0)

Answer 1

堆棧跟蹤有助於確定問題與調用 celery 函數有關。

ValueError: not enough values to unpack (expected 3, got 0)

這是代碼的這一部分：

send_mails.delay(5)

嘗試使用apply_async調用該函數。

send_mails.apply_async(args=(5, ))

如果這不起作用，請從def send_mails(duration):刪除*arg和**kwargs 。 我不明白為什么需要這些參數。

更多信息可以在這個答案中找到： https : //stackoverflow.com/a/48910727/7838574

或在此處的文檔中： https : //docs.celeryproject.org/en/latest/userguide/calling.html#basics

Answer 2

嘗試從 celery 任務中刪除duration, args and kwargs 。

@shared_task
def send_mails():
    subscribers = Subscribers.objects.all()
    blog = BlogPost.objects.latest('date_created')
    emails = [abc.email for abc in subscribers]
    send_mail('New Blog Post ', f" Checkout our new blog with title {blog.title} ", EMAIL_HOST_USER, emails, fail_silently=False)

現在在信號

def email_task(sender, instance, created, **kwargs):
    if created:
        print("@signals.py")
        send_mails.delay()

如果您想在倒計時后執行任務，您可以在此處使用apply_async文檔以獲取更多信息，但我認為這里沒有必要。