MySQL插入单行数据较大时报Row size too large错误
向目的MySQL写入数据时，单行数据较大，遇到插入失败，报错信息如下：
Error 'Row size too large (> 8126). Changing some columns to TEXT or BLOB or using ROW_FORMAT=DYNAMIC or ROW_FORMAT=COMPRESSED may help. In current row format, BLOB prefix of 768 bytes is stored inline.' on query. ......原因：
MySQL根据配置文件会限制Server端接受的数据包大小。当插入和更新的单行数据较大时，可能会受制于配置文件的参数限制max_allowed_packet，导致写入或者更新失败。配置文件/etc/my.cnf及时没有配置对应的参数，系统也会有默认限制。
相关配置参数：
max_allowed_packet: 服务器发送和接受的最大包长度，当单行数据较大时，需要调整该参数。
innodb_log_file_size: 该参数确定数据日志文件的大小，更大的设置可以提高性能，但也会增加恢复故障数据库所需的时间。
innodb_log_buffer_size: 该参数确定日志文件所用的内存大小，设置时用M单位进行设置。缓冲区更大能提高性能，但意外的故障将会丢失数据。MySQL开发人员建议设置为1~8M之间的值。
MariaDB 5.5.41 & MySQL 5.7.21在配置文件没有配置参数的情况下，系统的默认值为：
| MariaDB5.5.41 | MySQL5.7.21 |
| max_allowed_packet = 1048576 #1M | max_allowed_packet = 4194304 #4M |
| innodb_log_file_size = 5242880 #5M | innodb_log_file_size = 50331648 #48M |
| innodb_log_buffer_size = 8388608 #8M | innodb_log_buffer_size = 16777216 #16M |
MariaDB [(none)]> select version();
+--------------------+| version() |
+--------------------+
| 5.5.41-MariaDB-log |
+--------------------+
1 row in set (0.00 sec)
MariaDB [(none)]> show variables like '%max_allowed_packet%';
+--------------------------+------------+
| Variable_name | Value |
+--------------------------+------------+
| max_allowed_packet | 1048576 |
| slave_max_allowed_packet | 1073741824 |
+--------------------------+------------+
2 rows in set (0.00 sec)
MariaDB [(none)]> show variables like '%innodb_log_file_size%';
+----------------------+---------+
| Variable_name | Value |
+----------------------+---------+
| innodb_log_file_size | 5242880 |
+----------------------+---------+
1 row in set (0.00 sec)
MariaDB [(none)]> show variables like '%innodb_log_buffer_size%';
+------------------------+---------+
| Variable_name | Value |
+------------------------+---------+
| innodb_log_buffer_size | 8388608 |
+------------------------+---------+
1 row in set (0.00 sec)
MariaDB [(none)]>
MySQL 5.7.21的默认值：
mysql> select version();
+-----------+
| version() |
+-----------+
| 5.7.21 |
+-----------+
1 row in set (0.00 sec)
mysql> show variables like '%max_allowed_packet%';
+--------------------------+------------+
| Variable_name | Value |
+--------------------------+------------+
| max_allowed_packet | 4194304 |
| slave_max_allowed_packet | 1073741824 |
+--------------------------+------------+
2 rows in set (0.01 sec)
mysql> show variables like '%innodb_log_file_size%';
+----------------------+----------+
| Variable_name | Value |
+----------------------+----------+
| innodb_log_file_size | 50331648 |
+----------------------+----------+
1 row in set (0.00 sec)
mysql> show variables like '%innodb_log_buffer_size%';
+------------------------+----------+
| Variable_name | Value |
+------------------------+----------+
| innodb_log_buffer_size | 16777216 |
+------------------------+----------+
1 row in set (0.01 sec)
解决办法：
vim /etc/my.cnf，根据实际情况进行参数调整：
[mysqld]
max_allowed_packet = 1G
innodb_log_file_size = 30M
innodb_log_buffer_size = 512M
修改之后，重启mysql服务。