python - 尝试从 jobstore 获取作业时 APScheduler python 崩溃

Question

我有工作人员使用 APScheduler 执行任务。它第一天运行完美，然后在尝试获取下一个作业时崩溃了。在出现此类异常后我可以做一些重试吗？或者更好地防止这种情况发生？

这是调度程序代码:

__jbs_name = 'default1'
__jbs_tn = 'Framework_Jobs'
__jbs_class = 'apscheduler.jobstore.%s.class' % __jbs_name
__jbs_url = 'apscheduler.jobstore.%s.url' % __jbs_name
__jbs_table = 'apscheduler.jobstore.%s.tablename' % __jbs_name
__jbs_sqlalchemy = 'apscheduler.jobstores.sqlalchemy_store:SQLAlchemyJobStore'
__db_username = '******'
__db_password = '*************'
__db_location = 'localhost'
__db_dbname = 'djangoTest'
__db_url = 'mysql://%s:%s@%s/%s' % \
           (__db_username, __db_password,
            __db_location, __db_dbname)
# APScheduler (preferred) default configuration
_g_aps_default_sql_config = {
    'apscheduler.misfire_grace_time': 15 * 60,
    'apscheduler.coalesce': True,
    'apscheduler.daemonic': True,
    'apscheduler.standalone': True,
    __jbs_class: __jbs_sqlalchemy,
    __jbs_url: __db_url,
    __jbs_table: __jbs_tn
}

sched = BackgroundScheduler()
sched.configure(gconfig=_g_aps_default_sql_config)

这是我的日志:

2017-02-04 05:42:00;DEBUG;Looking for jobs to run
Exception in thread APScheduler:
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
  File "/usr/local/lib/python2.7/dist-packages/apscheduler/schedulers/blocking.py", line 30, in _main_loop
    wait_seconds = self._process_jobs()
  File "/usr/local/lib/python2.7/dist-packages/apscheduler/schedulers/base.py", line 924, in _process_jobs
    for job in jobstore.get_due_jobs(now):
  File "/usr/local/lib/python2.7/dist-packages/apscheduler/jobstores/sqlalchemy.py", line 71, in get_due_jobs
    return self._get_jobs(self.jobs_t.c.next_run_time <= timestamp)
  File "/usr/local/lib/python2.7/dist-packages/apscheduler/jobstores/sqlalchemy.py", line 133, in _get_jobs
    for row in self.engine.execute(selectable):
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1991, in execute
    return connection.execute(statement, *multiparams, **params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 914, in execute
    return meth(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/sql/elements.py", line 323, in _execute_on_connection
    return connection._execute_clauseelement(self, multiparams, params)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1010, in _execute_clauseelement
    compiled_sql, distilled_params
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1146, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1341, in _handle_dbapi_exception
    exc_info
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/util/compat.py", line 202, in raise_from_cause
    reraise(type(exception), exception, tb=exc_tb, cause=cause)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/base.py", line 1139, in _execute_context
    context)
  File "/usr/local/lib/python2.7/dist-packages/sqlalchemy/engine/default.py", line 450, in do_execute
    cursor.execute(statement, parameters)
  File "/usr/lib/python2.7/dist-packages/MySQLdb/cursors.py", line 174, in execute
    self.errorhandler(self, exc, value)
  File "/usr/lib/python2.7/dist-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler
    raise errorclass, errorvalue
OperationalError: (_mysql_exceptions.OperationalError) (2006, 'MySQL server has gone away') [SQL: u'SELECT apscheduler_jobs.id, apscheduler_jobs.job_state \nFROM apscheduler_jobs \nWHERE apscheduler_jobs.next_run_time <= %s ORDER BY apsc
heduler_jobs.next_run_time'] [parameters: (1486179720.090187,)]

Answer 1

我运行的是 3.2 版本，此功能出现在 3.3 版本中

最新的至少可以过一段时间重试(jobstore_retry_interval设置默认为10(秒))。

除此之外，我不建议出于任何目的使用 MySQL。如果您可以切换的话，我推荐使用 PostgreSQL。

感谢亚历克斯的回答: https://groups.google.com/forum/#!topic/apscheduler/SplRuAB9l78