为什么apscheduler sqlalchemyjobstore不能腌制作业，而是默认的内存jobstore可以？

Question

我有一个涉及SQLite数据库操作的工作，并且在后台使用应用程序调度程序为我做。如果使用默认的内存作业存储，它运行正常，但是如果它使用sqlalchemyjobstore，它会引发以下错误：

  File "/usr/lib/python3.8/site-packages/apscheduler/jobstores/sqlalchemy.py", line 95, in add_job
    'job_state': pickle.dumps(job.__getstate__(), self.pickle_protocol)
_pickle.PicklingError: Can't pickle <class 'sqlalchemy.orm.decl_api.Base'>: attribute lookup Base on sqlalchemy.orm.decl_api failed

这是i intiralise jirteriase Schedules

class DataManager:
    
    def __init__(self, periodic_refresh_db = False):
        self.data_hdl = DataHandler()
        self.db = Database(Base)
        self.scheduler = BackgroundScheduler(
            jobstores={
                'default': SQLAlchemyJobStore(url='sqlite:///jobs.sqlite')})
        self.refresh_interval_in_hr = 1
        self.scheduler.start()
        if periodic_refresh_db:
            self.start_periodic_refresh_db()
    
    def refresh_db(self):
        self.data_hdl.fetch_data()
        self.db.delete_unoccupied_nft()
        
        db_ready_data = self.data_hdl.db_ready_data
        db_ready_data = db_ready_data[~db_ready_data["slug"].isin(self.db.remain_slugs)]
        
        db_ready_data.to_sql(
            name = NftCollection.__tablename__,
            con = self.db.engine,
            if_exists="append",
            index = False
        )

nftCollection是orm对象，这是以下内容：

class NftCollection(Base):

    __tablename__ = "nft_collection"
    __table_args__ = {'sqlite_autoincrement': True}

    id = Column(Integer, primary_key=True, nullable=False)
    slug = Column(String(30), nullable=False)
    name = Column(String, nullable=False)
    floor = Column(Float, nullable=False, default=0.0)
    vol_1day = Column(Integer, nullable=False, default=0.0)
    vol_7day = Column(Integer, nullable=False, default=0.0)
    occupier = Column(String(100), nullable=True)
    occupy_min = Column(Integer, nullable=True)
    occupy_until = Column(DateTime, nullable=True)
    lock = Column(Boolean, default=False)

start_periodic_refresh_db涉及数据库操作，它写为以下

def start_periodic_refresh_db(self):
        self.scheduler.add_job(
            func=self.refresh_db,
            trigger="interval",
            hours= self.refresh_interval_in_hr,
            id = self.refresh_db.__name__,
            replace_existing = True,
            max_instances = 1,
            misfire_grace_time = None,
            name = "refresh database by crawling",
            next_run_time = datetime.now()
        )
        print(f"refresh_db scheduled periodically, next run time: {self.next_refresh_time}")

代码，除非删除JobStores 参数，即使用默认MOMEMEJOBSTORE

为什么？我该如何使SQL Jobs Store的行为能够按预期进行？谢谢

Answer 1

这是因为memoryJobstore不会腌制任何东西。引用：

MemoryJobStore stores jobs in memory as-is, without serializing them. This allows you to schedule callables that are unreachable globally and use job non-serializable job arguments.