Question

我们在一些复杂的单元测试中使用sqlalchemy。在每次测试结束时，我们使用drop_all完全拆除数据库。偶尔会有人忘记关闭嵌入在单元测试中的会话。然后，我们必须花费相当多的时间来弄清楚出了什么问题，并最终关闭sqlalchemy会话。

我们希望能够可靠地强制关闭所有与数据库的连接。我们尝试了session.close_all()，但这并没有按照我的描述进行。

编辑：下面是我们在进程挂起尝试删除数据库时看到的mysql进程列表。据推测，Id 285是违规的过程：

+-----+------+-----------------+----------+---------+------+---------------------------------+------------------------------+
| Id  | User | Host            | db       | Command | Time | State                           | Info                         |
+-----+------+-----------------+----------+---------+------+---------------------------------+------------------------------+
| 172 | root | localhost       | mydb     | Query   |    0 | init                            | show processlist             |
| 285 | root | localhost:47147 | mydb     | Sleep   |    6 |                                 | NULL                         |
| 289 | root | localhost:47152 | mydb     | Query   |    5 | Waiting for table metadata lock | DROP TABLE `mytable`         |
+-----+------+-----------------+----------+---------+------+---------------------------------+------------------------------+

编辑：每个请求，我还包括事务日志：

------------
TRANSACTIONS
------------
Trx id counter 1144929
Purge done for trx's n:o < 1144827 undo n:o < 0 state: running but idle
History list length 398
LIST OF TRANSACTIONS FOR EACH SESSION:
---TRANSACTION 0, not started
MySQL thread id 37, OS thread handle 0x8f46bb40, query id 776 localhost root init
show engine innodb status
---TRANSACTION 0, not started
MySQL thread id 45, OS thread handle 0x8f2ceb40, query id 774 localhost 127.0.0.1 root Waiting for table metadata lock
DROP TABLE `mytable`
---TRANSACTION 1144823, ACTIVE 12 sec
MySQL thread id 41, OS thread handle 0x8f2ffb40, query id 595 localhost 127.0.0.1 root cleaning up
Trx read view will not see trx with id >= 1144824, sees < 1144824

Answer 1

在烧瓶中，这应该可以解决问题：

@app.teardown_appcontext
def teardown_db(exception):
    db.session.commit()
    db.session.close()

sqlalchemy强制所有连接关闭mysql

1 个答案: