mysql 5.7 多源复制
https://www.cnblogs.com/zhanmeiliang/p/5911558.html
https://blog.csdn.net/weixin_34381666/article/details/86339817
mysqldump --single-transaction --flush-logs --master-data=2 --quick --routines --triggers --set-gtid-purged=OFF --databases update >update_backup.sql
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000009', MASTER_LOG_POS=154;
change master to master_host='10.10.10.10',master_user='test',master_password='test',master_log_file='mysql-bin.000008',master_log_pos=154154 FOR CHANNEL 'update-channel';