apscheduler 定时任务结束时不会释放mysql内存资源？

[nswz]

No description provided.

[rettier]

I have the same issue, but with postgre sql. If a job makes a sql query during its execution a sql connection is kept and it will slowly exceed the connection limit.

[shuai93]

mee too.

[rettier]

the problem exists because django's connection manager creates a new connection per thread. Every time you access a model from a job, a connection is created for this thread and never cleaned up. We have fixed this for now by wrapping our job functions and calling django.db.connections.close_all() at the end. But this should definitely become part of django-apscheduler

[shuai93]

yeah, i have way to try. you can put a patch in django orm code like

import logging
from django.db.backends.base import base as django_db_base
try:
    import MySQLdb as mysqldb
except ImportError:
    mysqldb = None

log = logging.getLogger(__name__)

def mysql_connect_patch() -> None:
    _old_ensure_connection = django_db_base.BaseDatabaseWrapper.ensure_connection
    log.info('loading patch enseure connection is available')
    def ensure_connection_with_retries(self: django_db_base.BaseDatabaseWrapper) -> None:
        if self.connection:
            if self.autocommit:
                if mysqldb and isinstance(self.connection, mysqldb.connections.Connection):
                    # log.info('mysqldb ping confirm connection is available')
                    self.connection.ping(True)
        _old_ensure_connection(self)

    django_db_base.BaseDatabaseWrapper.ensure_connection = ensure_connection_with_retries


mysql_connect_patch()

this way may be cause extra database overhead

[nswz]

你好棒呀，我什么时候才能向你一样优秀

[jcass77]

I think django_apscheduler can probably be better at managing database connections.

Django does have some configuration options for managing persistent connections that could help. But this has limited application however and at some point (depending on job duration and throughput) the only viable option is to use a dedicated connection pooler like pgbouncer.