我正在尝试从Django

时间:2019-07-08 22:41:08

标签: python django multithreading infinite-loop indefinite

我有一个工作线程,唯一的任务是每10分钟从数据库中查询活动用户列表,并在满足一定条件时(每分钟检查一次)向他们发送一条SMS消息;而且工作线程根本不会阻碍主应用程序。

到目前为止,我设法使线程正常运行并发送SMS也可以。但是,由于某些原因,线程会在某个随机时间(小时)后停止/被杀死。我运行try:除了e:Exception之外,在一段时间内为True,以捕获发生的错误。另外,我打印出一条消息,指出发生了什么错误。

好吧,我再也没有看到任何消息,线程肯定已关闭。因此,我怀疑Gunicorn或Django会优雅地杀死我的线程。

我已经在整个代码中放置了日志和打印语句,但是没有发现任何指示我的线程被杀死的原因。

我的wsgi.py函数在其中调用该函数以启动线程

"""
WSGI config for django_web project.

It exposes the WSGI callable as a module-level variable named ``application``.

For more information on this file, see
https://docs.djangoproject.com/en/2.1/howto/deployment/wsgi/
"""

import os

from django.core.wsgi import get_wsgi_application


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

application = get_wsgi_application()

'''
Start background services
Import has to happen after "get_wsgi_application()"; otherwise docker container crashes
'''
try:
    from threading import Thread
    from timesheet.admin import runWorkmateServices

    runWorkmateServices()

except Exception as exp:
    print(exp)

从wsgi.py内部调用的函数。我仔细检查了线程是否已启动,以避免两个线程同时启动并运行。

def runWorkmateServices(request=None):
    service_name = 'TimeKeeperWorkMateReminderService'

    thread_found = False
    for thread in threading.enumerate():
        if service_name in thread.name:
            thread_found = True
            break  # Leave loop now

    if thread_found:
        print(f'Service has already been started: {service_name}')
        if request:
            messages.add_message(request, messages.ERROR, f'Service has already been started:: {service_name}')
    else:
        Thread(target=WorkMateReminders, args=(), name=service_name, daemon=True).start()
        print(f'Started Service: {service_name}')
        if request:
            messages.add_message(request, messages.SUCCESS, f'Started Service: {service_name}')

工作线程本身

def WorkMateReminders():
    print('Thread Started: WorkMateReminders')
    timer = 0
    employees = User.objects.none()

    while True:

        try:
            # Update user list every n * sleep time (10 minutes)
            if timer % 10 == 0:
                timer = 0
                # Get active employees
                employees = User.objects.filter(is_active=True, profile__workmate_sms_reminders_activated=True)
                print(f'Employees updated at {datetime.now().date()} - {datetime.now().time()}: {employees}')

            WorkMateCheckClockOffTimes(employees=employees)

            WorkMateClockOnReminder(employees=employees)

            WorkMateEndOfBreakReminder(employees=employees)

            timer += 1  # increment timer

        except Exception as exp:
            print(f'Error: {exp}')

        time.sleep(60 * 1)

我的目标是让此工作线程在Django启动期间一直运行。

1 个答案:

答案 0 :(得分:1)

大多数WSGI服务器都会定期生成/杀死工作线程,而从这些工作线程中生成线程并不是解决问题的最佳方法。有几种解决方法

Cron

Create a management command执行所需的操作,并将cron配置为每10分钟运行一次

芹菜/芹菜节

设置一个celery工作者,这是一个与Django应用程序异步运行的过程,使用celerybeat您可以使任务间隔运行