Superset连接本地MySQL异常

发表于 2024-12-25 更新于 2024-12-28 分类于数据库， MySQL 阅读次数： 40 Changyan： 0

将Superset的元数据库配置为MySQL，配置方法见Superset配置。配置完成后，在启动Superset的时候，出现以下异常信息：

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2024-09-01 16:28:36,614:ERROR:flask_appbuilder.security.sqla.manager:DB Creation and initialization failed: (MySQLdb.OperationalError) (2002, "Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)")
(Background on this error at: https://sqlalche.me/e/14/e3q8)
Loaded your LOCAL configuration at [/home/zhangjc/github/superset/superset_config.py]

这个错误跟连接MySQL的方式有关，详细信息见无法连接本地MySQL。我的连接配置信息如下：

1	SQLALCHEMY_DATABASE_URI = 'mysql://superset:superset%4001@localhost/superset'

如果想快速解决问题，可将连接串中的localhost改为127.0.0.1。但作为技术人，还是需要深究下。

根据Superset配置中的描述，连接MySQL用的是mysqlclient驱动，问题可能出现在该驱动上。用以下方式进行验证：

$ python
Python 3.11.9 (main, Aug 28 2024, 23:13:21) [GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import MySQLdb
>>> from MySQLdb import _mysql
>>> db=_mysql.connect(host="localhost",user="superset", password="superset@01", database="superset")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
MySQLdb.OperationalError: (2002, "Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)")
>>> db=_mysql.connect(host="localhost",user="superset", password="superset@01", database="superset", unix_socket='/tmp/mysql.sock')
>>>

从上面的验证可以看出，问题出在mysqlclient默认使用的Unix socket文件与MySQL服务的不同，在指定正确的Unix socket文件后，问题解决。

如何在superset中配置指定MySQL连接的Unix socket文件呢？查看MySQL官方文档，可以看到在连接串中通过socket参数设置。

参见：Base Connection Parameters

修改Superset元数据库连接串配置，如下：

1	SQLALCHEMY_DATABASE_URI = 'mysql://superset:superset%4001@localhost/superset?socket=(/tmp/mysql.sock)'

启动Superset出现以下错误：

$ superset run -p 8088 --with-threads --reload --debugger
Loaded your LOCAL configuration at [/home/zhangjc/github/superset/superset_config.py]
logging was configured successfully
2024-09-05 11:45:16,426:INFO:superset.utils.logging_configurator:logging was configured successfully
2024-09-05 11:45:16,433:INFO:root:Configured event logger of type <class 'superset.utils.log.DBEventLogger'>
/home/zhangjc/frin/python/venvs/superset/lib/python3.11/site-packages/flask_limiter/extension.py:333: UserWarning: Using the in-memory storage for tracking rate limits as no storage was explicitly specified. This is not recommended for production use. See: https://flask-limiter.readthedocs.io#configuring-a-storage-backend for documentation about configuring the storage backend.
  warnings.warn(
2024-09-05 11:45:16,438:ERROR:flask_appbuilder.security.sqla.manager:DB Creation and initialization failed: 'socket' is an invalid keyword argument for connect()