mysql8.0认证方式修改

使用xtrabackup备份mysql8.0的时候报如下错误:
[root@localhost bin]# ./innobackupex --defaults-file=/opt/mha/mysql8/conf/my.cnf --user=root --password=mysql -P13306 --socket=/opt/mha/mysql8/mysql.sock /opt/mha/xbackup
190923 15:27:03 innobackupex: Starting the backup operation


IMPORTANT: Please check that the backup run completes successfully.
           At the end of a successful backup run innobackupex
           prints "completed OK!".


190923 15:27:03  version_check Connecting to MySQL server with DSN 'dbi:mysql:;mysql_read_default_group=xtrabackup;port=13306;mysql_socket=/opt/mha/mysql8/mysql.sock' as 'root'  (using password: YES).
Failed to connect to MySQL server: DBI connect(';mysql_read_default_group=xtrabackup;port=13306;mysql_socket=/opt/mha/mysql8/mysql.sock','root',...) 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 - line 1314.
190923 15:27:03 Connecting to MySQL server host: localhost, user: root, password: set, port: 13306, socket: /opt/mha/mysql8/mysql.sock
Failed to connect to MySQL server: Authentication plugin 'caching_sha2_password' cannot be loaded: /mnt/workspace/percona-xtrabackup-2.4-binary-tarball/label_exp/centos6-64/TARGET/xtrabackup-build.FdAMXd/percona-xtrabackup-2.4.7-Linux-x86_64/lib/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory.


解决办法:
1.兼容新老版本的认证方式
ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'mysql';


2.修改配置文件,加入如下项,并重启动
[mysqld]
default_authentication_plugin=mysql_native_password