failed: Authentication plugin 'caching_sha2_password' cannot be loaded

使用PT工具连接mysql报错

failed: Authentication plugin 'caching_sha2_password' cannot be loaded: /usr/lib64/mysql/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory at /usr/local/bin/pt-online-schema-change line 2345.

原因是：mysql8 之前的版本中加密规则是mysql_native_password,而在mysql8之后,加密规则是caching_sha2_password。

处理办法
ALTER USER 'root'@'localhost' IDENTIFIED BY 'password' PASSWORD EXPIRE NEVER;

更新一下用户的密码
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password';