Server version: 5.7.9-log MySQLCommunity Server (GPL)

mysql> GRANT REPLICATION CLIENT ON .TO 'zabbix'@'%' IDENTIFIED BY ‘xxxxxxxx’;
ERROR 1819 (HY000): Your password does notsatisfy the current policy requirements

这个与validate_password_policy的值有关。
validate_password_policy有以下取值：

Polic                      Tests Performed
 0 or LOW            Length

1or MEDIUM Length; numeric, lowercase/uppercase, and special characters

2 or STRONG Length; numeric, lowercase/uppercase, and special characters; dictionary file

默认是1 ：符合长度，且必须含有数字，小写或大写字母，特殊字符。

如果是测试环境不想密码很复杂，可以修改：

set global validate_password_policy=0;