使用redis的Django芹菜多次执行相同的任务。

Question

我试图创建一个后台任务，Django，芹菜和Redis作为经纪人。当模型发布保存时，将从模型发送此任务。但问题是，相同的任务正在执行1000次(其他调试或添加任务运行良好)。我已经尝试过这个方法，但这并没有解决问题。请找到以下代码供您参考和帮助解决。提前谢谢。

models.py

from django.db.models.signals import post_save
from django.dispatch import receiver
from student.tasks import create_student_subject_tryout_result, add

@receiver(post_save, sender=TryoutSubmission, 
dispatch_uid='create_student_subject_tryout_result')
def result_calculation(sender, instance, **kwargs):
    if instance.status == 'C':
       print('Calculating result')
       create_student_subject_tryout_result.delay(instance.student.id, 
       instance.tryout.id)

celery.py

import os
from celery import Celery

os.environ.setdefault('DJANGO_SETTINGS_MODULE', 'eec.settings')

app = Celery('eec')

app.config_from_object('django.conf:settings', namespace='CELERY')
app.conf.broker_transport_options = {'visibility_timeout': 3600} .

app.autodiscover_tasks()


@app.task(bind=True)
def debug_task(self):
    print(f'Request: {self.request!r}')

tasks.py

from celery import shared_task
import tryout.models

@shared_task(bind=True)
def create_student_subject_tryout_result(self, student_id, tryout_id):
    tryout_submission=tryout.models.TryoutSubmission.objects.get(
        student_id=student_id, tryout_id=tryout_id
    )                                                           
    tryout_questions = tryout_submission.tryout.tryoutquestion_set.all().count()
    answered_qs = tryout_submission.tryout.tryoutanswersubmission_set.filter(
            is_answered=True).count() 
    correct_ans = tryout_submission.tryout.tryoutanswersubmission_set.filter(
            is_correct=True).count()
    tryout_submission.total_questions = tryout_questions
    tryout_submission.answered_questions = answered_qs
    tryout_submission.correct_answers = correct_ans
    tryout_submission.total_time = tryout_submission.end_time - tryout_submission.start_time
    tryout_submission.save()
    return "Result created"

settings.py

CELERY_RESULT_BACKEND = 'django-db'
CELERY_CACHE_BACKEND = 'django-cache'
CELERY_BROKER_URL = 'redis://localhost:6379'
CELERY_ACCEPT_CONTENT = ['application/json']
CELERY_TASK_SERIALIZER = 'json'
CELERY_RESULT_SERIALIZER = 'json'
CELERY_TIMEZONE = 'Asia/Kolkata'
CELERY_BEAT_SCHEDULER = 'django_celery_beat.schedulers:DatabaseScheduler'

Answer 1

如果你看你的接收器，你是在听你的模型上的post_save。

post_save信号还提供了一个boolean来表示是否创建了它。与其检查instance.status == 'C'，不如检查创建的：

from django.db.models.signals import post_save
from django.dispatch import receiver
from student.tasks import create_student_subject_tryout_result, add

@receiver(post_save, sender=TryoutSubmission, 
dispatch_uid='create_student_subject_tryout_result')
def result_calculation(sender, instance, raw, created, **kwargs):
    if created:
       print('Calculating result')
       create_student_subject_tryout_result.delay(
        instance.student.id,
        instance.tryout.id
       )