Celery Django 计时器中的错误：操作错误(2006 年，"MySQL 服务器已消失")

Question

我正在使用Django和芹菜来运行一些任务。我有6个并发为1的工作者，不同的任务被发送给不同的工作者。其中一个女巫在计时器中引发错误：OperationalError（2006年，"MySQL服务器已经消失"）。系统正常运行，直到出现问题，并且工作人员停止运行任务，直到手动重新启动。

I have:
Django==1.6
celery==3.1.5
django-celery==3.1.1
MySQL-python==1.2.4
kombu==3.0.6

追溯：

[2015-12-10 09:50:43,300: ERROR/MainProcess] Error in timer: OperationalError(2006, 'MySQL server has gone away')
Traceback (most recent call last):
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/kombu/async/timer.py", line 171, in apply_entry
    entry()
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/kombu/async/timer.py", line 64, in __call__
    return self.fun(*self.args, **self.kwargs)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/kombu/async/timer.py", line 132, in _reschedules
    return fun(*args, **kwargs)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/celery/events/snapshot.py", line 73, in capture
    self.state.freeze_while(self.shutter, clear_after=self.clear_after)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/celery/events/state.py", line 428, in freeze_while
    return fun(*args, **kwargs)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/celery/events/snapshot.py", line 70, in shutter
    self.on_shutter(self.state)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/snapshot.py", line 139, in on_shutter
    _handle_tasks()
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/snapshot.py", line 135, in _handle_tasks
    self.handle_task(task)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/snapshot.py", line 82, in handle_task
    (task.worker.hostname, task.worker),
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/snapshot.py", line 72, in handle_worker
    defaults={'last_heartbeat': self.get_heartbeat(worker)},
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/managers.py", line 87, in update_or_create
    return get_queryset(self).update_or_create(**kwargs)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/djcelery/managers.py", line 70, in update_or_create
    obj, created = self.get_or_create(**kwargs)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/query.py", line 373, in get_or_create
    return self.get(**lookup), False
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/query.py", line 301, in get
    num = len(clone)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/query.py", line 77, in __len__
    self._fetch_all()
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/query.py", line 854, in _fetch_all
    self._result_cache = list(self.iterator())
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/query.py", line 220, in iterator
    for row in compiler.results_iter():
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 710, in results_iter
    for rows in self.execute_sql(MULTI):
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/models/sql/compiler.py", line 781, in execute_sql
    cursor.execute(sql, params)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
    return self.cursor.execute(sql, params)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/utils.py", line 99, in __exit__
    six.reraise(dj_exc_type, dj_exc_value, traceback)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/backends/util.py", line 53, in execute
    return self.cursor.execute(sql, params)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/django/db/backends/mysql/base.py", line 124, in execute
    return self.cursor.execute(query, args)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/MySQLdb/cursors.py", line 205, in execute
    self.errorhandler(self, exc, value)
  File "/opt/virtualenvs/simocEnv/local/lib/python2.7/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
OperationalError: (2006, 'MySQL server has gone away')

Answer 1

如果使用flask，则可以在某些CRUD运算符之前使用db.session.close（）。

参考：

• OperationalError：（2006年，"MySQL服务器在从芹菜4.1.0升级到4.2.0后消失了"）
• OperationalError:（2006，"MySQL服务器已经消失"）