在5.7.16搭建多源复制时，出现如下错误：
mysql> change master to master_host='192.168.56.156',master_user='repl',master_password='oracle',master_port=3306,MASTER_AUTO_POSITION = 1 for channel 'master-15633006';
ERROR 3077 (HY000): To have multiple channels, repository cannot be of type FILE; Please check the repository configuration and convert them to TABLE.
错误原因：
需要在从库配置下面两个参数
master_info_repository =table
relay_log_info_repository =table