由apscheduler引发的django.db.utils.InternalError: (1054, u”Unknown column ‘rms.go_datetime’ in ‘field list'”)

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apscheduler.scheduler:INFO 2019-03-01 10:22:53,849 Adding job tentatively -- it will be properly scheduled when the scheduler starts
apscheduler.scheduler:INFO 2019-03-01 10:22:53,849 Adding job tentatively -- it will be properly scheduled when the scheduler starts
Do first job!
Traceback (most recent call last):
File "manage.py", line 10, in <module>
execute_from_command_line(sys.argv)
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\core\management\__init__.py", line 364, in execute_from_command_line
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\utils\functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\urls\resolvers.py", line 407, in url_patterns
patterns = getattr(self.urlconf_module, "urlpatterns", self.urlconf_module)
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\utils\functional.py", line 35, in __get__
res = instance.__dict__[self.name] = self.func(instance)
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\urls\resolvers.py", line 400, in urlconf_module
return import_module(self.urlconf_name)
File "C:\Python27\Lib\importlib\__init__.py", line 37, in import_module
__import__(name)
File "F:\PyCharmProjects\B\B\B\urls.py", line 433, in <module>
import td.jobs # NOQA @isort:skip
File "F:\PyCharmProjects\B\B\td\jobs.py", line 174, in <module>
deal_with_first_jobs()
File "F:\PyCharmProjects\B\B\td\jobs.py", line 88, in deal_with_first_jobs
send_wechat_mini_app_push_message(rmds)
File "F:\PyCharmProjects\B\B\td\push.py", line 201, in send_wechat_mini_app_push_message
for rmd in rmds:
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\db\models\query.py", line 250, in __iter__
self._fetch_all()
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\db\models\query.py", line 1121, in _fetch_all
self._result_cache = list(self._iterable_class(self))
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\db\models\query.py", line 53, in __iter__
results = compiler.execute_sql(chunked_fetch=self.chunked_fetch)
File "F:\PyCharmProjects\B\venv\lib\site-packages\django\db\models\sql\compiler.py", line 899, in execute_sql
raise original_exception
django.db.utils.InternalError: (1054, u"Unknown column 'rms.go_datetime' in 'field list'")

刚开始以为是代码写错了,后来发现并不是,出错的地方在jobs.py中所以其实并不是代码的问题,而是在jobs中为了能够在服务启动的时候发送上一次运行停止之后遗漏的任务导致的。所以如果使用了apscheduler可以尝试将jobs.py清空再次尝试。

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Django APScheduler + uwsgi 定时任务重复运行

基于某些原因可能在开发的时候通过django的manage.py运行定时任务没有任何的问题,但是一旦到了线上环境通过nginx+uwsgi来运行就会发现定时任务不断的重复执行,并且基本都执行失败了。发生这个问题的原因在于uwsgi启动了多个进程来提供服务,于是每次启动的时候定时任务都会跟着再启动一次,于是有4个进程的话,对应的服务就会启动4次,除了第一次可能执行成功后面的基本都会挂掉。

要解决这个问题其实也不难,只要保证在第一次启动的时候添加定时任务并且执行,以后启动的进程不再处理定时任务即可。但是在这种条件下通过python的进程互斥其实貌似并不是非常好使,具体可以看这个:

uWSGI employs some tricks which disable the Global Interpreter Lock and with it, the use of threads which are vital to the operation of APScheduler. To fix this, you need to re-enable the GIL using the --enable-threads switch. See the uWSGI documentation for more details.

Also, assuming that you will run more than one worker process (as you typically would in production), you should also read the next section.

https://apscheduler.readthedocs.io/en/latest/faq.html#how-can-i-use-apscheduler-with-uwsgi

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