mirror of https://github.com/jumpserver/jumpserver
81 lines
3.3 KiB
Python
81 lines
3.3 KiB
Python
import logging
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from celery.utils.log import get_logger
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from django.db import close_old_connections
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from django.core.exceptions import ObjectDoesNotExist
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from django.db.utils import DatabaseError, InterfaceError
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from django_celery_beat.schedulers import DatabaseScheduler as DJDatabaseScheduler
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logger = get_logger(__name__)
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debug, info, warning = logger.debug, logger.info, logger.warning
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__all__ = ['DatabaseScheduler']
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class DatabaseScheduler(DJDatabaseScheduler):
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def sync(self):
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if logger.isEnabledFor(logging.DEBUG):
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debug('Writing entries...')
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_tried = set()
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_failed = set()
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try:
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close_old_connections()
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while self._dirty:
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name = self._dirty.pop()
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try:
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# 源码
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# self.schedule[name].save()
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# _tried.add(name)
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"""
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::Debug Description (2023.07.10)::
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如果调用 self.schedule 可能会导致 self.save() 方法之前重新获取数据库中的数据, 而不是临时设置的 last_run_at 数据
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如果这里调用 self.schedule
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那么可能会导致调用 save 的 self.schedule[name] 的 last_run_at 是从数据库中获取回来的老数据
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而不是任务执行后临时设置的 last_run_at (在 __next__() 方法中设置的)
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当 `max_interval` 间隔之后, 下一个任务检测周期还是会再次执行任务
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::Demo::
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任务信息:
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beat config: max_interval = 60s
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任务名称: cap
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任务执行周期: 每 3 分钟执行一次
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任务最后执行时间: 18:00
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任务第一次执行: 18:03 (执行时设置 last_run_at = 18:03, 此时在内存中)
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任务执行完成后,
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检测到需要 sync, sync 中调用了 self.schedule,
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self.schedule 中发现 schedule_changed() 为 True, 需要调用 all_as_schedule()
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此时，sync 中调用的 self.schedule[name] 的 last_run_at 是 18:00
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这时候在 self.sync() 进行 self.save()
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beat: Waking up 60s ...
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任务第二次执行: 18:04 (因为获取回来的 last_run_at 是 18:00, entry.is_due() == True)
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::解决方法::
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所以这里为了避免从数据库中获取，直接使用 _schedule #
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"""
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self._schedule[name].save()
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_tried.add(name)
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except (KeyError, TypeError, ObjectDoesNotExist):
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_failed.add(name)
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except DatabaseError as exc:
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logger.exception('Database error while sync: %r', exc)
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except InterfaceError:
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warning(
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'DatabaseScheduler: InterfaceError in sync(), '
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'waiting to retry in next call...'
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)
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finally:
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# retry later, only for the failed ones
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self._dirty |= _failed
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