主库：5.6
从库：5.5
报错： Last_IO_Error: Got fatal error 1236 from master when reading data from binary log: ‘Slave can not handle replication events with the checksum that master is configured to log; the first event ‘mysql-bin.000001’ at 451, the last event read from ‘https://blog.csdn.net/weixin_38576764/article/details/mysql-bin.000001’ at 451, the last byte read from ‘https://blog.csdn.net/weixin_38576764/article/details/mysql-bin.000001’ at 120.’
主库：
set global binlog_checksum=’NONE’;
show variables like ‘%checksum%’;
查看之后重新配置从库连接主库，问题得以解决。
ps:这样的话每次重启数据库需要重新输入命令。
也可以在my.cnf中加入 binlog_checksum=none; (但是我添加之后重启数据库命令不生效，why？)。