mysql从库io进程停止，发错如下：
Got fatal error 1236 from master when reading data from binary log: 'log event entry exceeded max_allowed_packet; Increase max_allowed_packet on master; the first event 'xxxx-master-binlog.000504' at 4212238517, the last event read from '/xxxx/xxxx/logs/binlog/xxxx-master-binlog.000504' at 123, the last byte read from '/xxxx/xxxx/logs/binlog/xxxx-master-binlog.000504' at 4212238536.'Got fatal error 1236 from
