APScheduler：修复对重构、重命名或移动模块中已更改方法的引用

Question

I've hada project in python3.7 for a while with a PostgreSQL database and APScheduler 3.X. I'm using a SQLAlchemyJobStore and have several types of jobs configured, both as cron/interval and as single time events.

I had to refactor the code in order to improve the structure and dockerize in a simpler way, and as a result, some folders were renamed. As a result, APScheduler cannot find the methods, as they were stored using the earlier file references and imports. This is the resulting error when it tries to run a job:

Traceback (most recent call last):
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/jobstores/sqlalchemy.py", line 141, in _get_jobs
2023-01-27 11:44:43     jobs.append(self._reconstitute_job(row.job_state))
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/jobstores/sqlalchemy.py", line 128, in _reconstitute_job
2023-01-27 11:44:43     job.__setstate__(job_state)
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/job.py", line 272, in __setstate__
2023-01-27 11:44:43     self.func = ref_to_obj(self.func_ref)
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/util.py", line 305, in ref_to_obj
2023-01-27 11:44:43     raise LookupError('Error resolving reference %s: could not import module' % ref)
2023-01-27 11:44:43 LookupError: Error resolving reference app.scheduler.daily_dump:execDailyDumpEntryPoint: could not import module
2023-01-27 11:44:43 Unable to restore job "7e62c8b0b1144edfbace7e898af5c557" -- removing it
2023-01-27 11:44:43 Traceback (most recent call last):
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/util.py", line 303, in ref_to_obj
2023-01-27 11:44:43     obj = __import__(modulename, fromlist=[rest])
2023-01-27 11:44:43 ModuleNotFoundError: No module named 'app'
2023-01-27 11:44:43 
2023-01-27 11:44:43 During handling of the above exception, another exception occurred:
2023-01-27 11:44:43 
2023-01-27 11:44:43 Traceback (most recent call last):
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/jobstores/sqlalchemy.py", line 141, in _get_jobs
2023-01-27 11:44:43     jobs.append(self._reconstitute_job(row.job_state))
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/jobstores/sqlalchemy.py", line 128, in _reconstitute_job
2023-01-27 11:44:43     job.__setstate__(job_state)
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/job.py", line 272, in __setstate__
2023-01-27 11:44:43     self.func = ref_to_obj(self.func_ref)
2023-01-27 11:44:43   File "/usr/local/lib/python3.7/site-packages/apscheduler/util.py", line 305, in ref_to_obj
2023-01-27 11:44:43     raise LookupError('Error resolving reference %s: could not import module' % ref)
2023-01-27 11:44:43 LookupError: Error resolving reference app.scheduler.daily_dump:execDailyDumpEntryPoint: could not import module

and here's my scheduler setup:

jobstores = {
    'default': SQLAlchemyJobStore(engine=engine,
                                  tablename="scheduled_jobs")
}
executors = {
    'default': ThreadPoolExecutor(10),
    'processpool': ProcessPoolExecutor(5)
}
job_defaults = {
    'coalesce': False,
    'max_instances': 30,
    'misfire_grace_time': 1200
}
scheduler = BackgroundScheduler(jobstores=jobstores, executors=executors,
                                job_defaults=job_defaults, timezone="America/Santiago",
                            )

I've noticed APScheduler hashes it's job configuration although I don't know if I can manually access and update the jobs with the new references in any way. Is there a simple way to update all modules referenced in the database to the new structure?

Answer 1

APScheduler (3.x) does not hash its job configurations, but it does serialize them with pickle . If you want to preserve the jobs but change the target function, you need to do two things:

1. Create a module with the old name (containing the target functions) so that the jobs can be loaded
2. Call sched.modify_job() for each job, setting the func parameter to the corresponding new function object