Mysql提示 “ Got a packet bigger than 'max_allowed_packet' bytes”

为什么总是提示 “ Got a packet bigger than 'max_allowed_packet' bytes” 呢？

问题描述

迁移服务器，要把旧服务器上的mysql数据复制到新服务器的mysql上。

我先是把旧服务器的数据库用mysqldump复制了一份，然后想导入到新服务器，用命令导入，结果提示

            ERROR 1153 (08S01): Got a packet bigger than 'max_allowed_packet' bytes
            ERROR 2006 (HY000): MySQL server has gone away
            No connection. Trying to reconnect...
            Connection id:    54350

            ERROR 1231 (42000): Variable 'time_zone' can't be set to the value of 'NULL'
            ERROR 1231 (42000): Variable 'sql_mode' can't be set to the value of 'NULL'
            ERROR 1231 (42000): Variable 'foreign_key_checks' can't be set to the value of 'NULL'
            ERROR 1231 (42000): Variable 'unique_checks' can't be set to the value of 'NULL'
            ERROR 1231 (42000): Variable 'character_set_client' can't be set to the value of 'NULL'
            Query OK, 0 rows affected (0.00 sec)

            ERROR 1231 (42000): Variable 'collation_connection' can't be set to the value of 'NULL'
            ERROR 1231 (42000): Variable 'sql_notes' can't be set to the value of 'NULL'

根据网上说的方案，我在命令行加上--max_allowed_packet=128M

   mysql --max_allowed_packet=128M -u user -ppass database < database.sql 

结果还是提示 Got a packet bigger than 'max_allowed_packet' bytes

然后我又尝试用MysqlWorkBench客户端导入，还是提示 Got a packet bigger than 'max_allowed_packet' bytes 。

实在太奇怪了，明明这个.sql文件只有82K啊！

解决方案（感谢@blacktulip提供）

mysql -u root -p -e "set global net_buffer_length=1000000; set global max_allowed_packet=1000000000;"

然后重启 mysqld， 再正常导入就可以了……