MYSQL错误

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
service mysqld start
vim /etc/my.cnf
      [mysqld]
             skip-grant-tables
service mysqld restart
update user set authentication_string=password("xxxx") where user='root';
update user set Host = '%' where user = 'root';
flush privileges;
quit;

validate_password_policy有以下取值：

Policy	Tests Performed
0 or LOW	Length
1 or MEDIUM	Length; numeric, lowercase/uppercase, and special characters
2 or STRONG	Length; numeric, lowercase/uppercase, and special characters; dictionary file

默认是1，即MEDIUM，所以刚开始设置的密码必须符合长度，且必须含有数字，小写或大写字母，特殊字符。

set global validate_password_policy=0;
set password=password('xxxx');
select @@validate_password_length;
mysql> SHOW VARIABLES LIKE 'validate_password%';
+--------------------------------------+-------+
 |  Variable_name                        | Value
 |+--------------------------------------+-------+
 | validate_password_dictionary_file | |
 | validate_password_length        | 6 |
 | validate_password_mixed_case_count | 2 |
 | validate_password_number_count | 1 |
 | validate_password_policy         | LOW |
 | validate_password_special_char_count | 1 
|+--------------------------------------+-------+