1、error connecting to master 'repl@192.168.0.21:3306' - retry-time: 60 retries: 4 message: Authentication plugin 'caching_sha2_password' reported error: Authentication requires secure connection.
查看从MySQL状态：
show slave status\G;
出现以下错误：
Slave_IO_Running: Connecting Slave_SQL_Running: Yes error connecting to master 'repl@192.168.0.11:3306' - retry-time: 60 retries: 4 message: Authentication plugin 'caching_sha2_password' reported error: Authentication requires secure connection.
解决办法
在主MySQL上重新修改从用户密码：
alter USER username@'xxx.xxx.xxx.%' IDENTIFIED WITH sha256_password BY 'password';
2、 Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.
出现以下错误：
Slave_IO_Running: No Slave_SQL_Running: No Fatal error: The slave I/O thread stops because master and slave have equal MySQL server UUIDs; these UUIDs must be different for replication to work.
通过下面命令可以查看mysql的uuid ：
show variables like '%server_uuid%';
解决办法：
修改 主和 从 MySQL中的任意一个ID使其不同即可，uuid位于 auto.cnf 文件内。
通过下面命令查找 auto.cnf 文件位置，然后修改uuid即可：
find / -name auto.cnf