登录openstack的在dashboard,提示说权限验证错误，有2种情况： 1. 密码被人改了。 2. 系统发生了问题。

密码确认没人改，所以查看/var/log/keystone-all.log日志，发现一堆错误：

File "/usr/lib/python2.6/site-packages/keystone/assignment/core.py", line 262, in get_domain    return self.driver.get_domain(domain_id)  File "/usr/lib/python2.6/site-packages/keystone/assignment/backends/sql.py", line 526, in get_domain    return self._get_domain(session, domain_id).to_dict()  File "/usr/lib/python2.6/site-packages/keystone/assignment/backends/sql.py", line 519, in _get_domain    ref = session.query(Domain).get(domain_id)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 775, in get    return self._load_on_ident(key)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 2512, in _load_on_ident    return q.one()  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 2184, in one    ret = list(self)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 2227, in __iter__    return self._execute_and_instances(context)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 2240, in _execute_and_instances    close_with_result=True)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/query.py", line 2231, in _connection_from_session    **kw)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/session.py", line 777, in connection    close_with_result=close_with_result)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/orm/session.py", line 783, in _connection_for_bind    return engine.contextual_connect(**kwargs)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/engine/base.py", line 2489, in contextual_connect    self.pool.connect(),  File "/usr/lib64/python2.6/site-packages/sqlalchemy/pool.py", line 236, in connect    return _ConnectionFairy(self).checkout()  File "/usr/lib64/python2.6/site-packages/sqlalchemy/pool.py", line 474, in checkout    self)  File "/usr/lib64/python2.6/site-packages/sqlalchemy/event.py", line 377, in __call__    fn(*args, **kw)  File "/usr/lib/python2.6/site-packages/keystone/common/sql/core.py", line 204, in mysql_on_checkout    dbapi_conn.cursor().execute('select 1')  File "/usr/lib64/python2.6/site-packages/MySQLdb/cursors.py", line 205, in execute    self.errorhandler(self, exc, value)  File "/usr/lib64/python2.6/site-packages/MySQLdb/connections.py", line 36, in defaulterrorhandler    raise errorclass, errorvalueOperationalError: (1047, 'Unknown command')

这里可以看出，是mysqldb引擎连接mysql进行数据操作mysql返回的错误，所以，基本判断是mysql出问题了，登录mysql,查询admin的密码，发现连mysql的use命令都无法使用。所以引出了mysql的galera的问题。

mysql的galera是一种多主的mysql的HA方案，由单独开发一段程序在mysql底层实现数据的复制，而在各个服务器操作mysql上基本和单机没有区别。 但是在线上没有做任何修改，一直运行的过程中，发生了一个错误：

[root@node-10 conf.d]# mysqlWelcome to the MySQL monitor.  Commands end with ; or \g.Your MySQL connection id is 30631Server version: 5.5.28Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> use keystone;ERROR 1047 (08S01): Unknown command

我们应该知道mysql的use命令肯定是存在的。如果我们真实输入一个不存在的命令，提示也应该是这样的：

Copyright (c) 2000, 2012, Oracle and/or its affiliates. All rights reserved.Oracle is a registered trademark of Oracle Corporation and/or itsaffiliates. Other names may be trademarks of their respectiveowners.Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.mysql> test    -> ;ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'test' at line 1

这里先初步解决，让服务器运行起来，重启服务即可

service mysql restart

注意，这里/etc/init.d/mysql这个文件是使用了galera的定制化的脚本，理论上是将集群中所有的mysql服务重启，如果失败，可以手动kill -9即可。

然后再登录openstack的HA环境，就可以成功了。