MySQL修改connect_timeout（连接超时）全局变量

Java程序员儿反应服务器上的MySQL连上去之后，总是过一会儿就断开连接了，工作效率低，跟松哥提需求，增加连接时间，减少断开次数，和刷新页面的等待时间。我自己本地用telnet测试，读秒试了下，果然是过了几秒就断开了。

telnet 测试数据库的连接超时时间
telnet 121.43.161.35 3306

1.登录mysql数据库
[root@iZbp11rfoyeescusr9ha9qZ conf]# mysql -u root -p

2.查询匹配“timeout”的全局变量
MySQL [(none)]> show global variables like '%timeout%';
+----------------------------------------+--------------+
| Variable_name | Value |
+----------------------------------------+--------------+
| connect_timeout | 10 |
| delayed_insert_timeout | 300 |
| have_statement_timeout | YES |
| innodb_flush_log_at_timeout | 1 |
| innodb_lock_wait_timeout | 120 |
| innodb_rollback_on_timeout | OFF |
| interactive_timeout | 28800 |
| lock_wait_timeout | 31536000 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| rpl_stop_slave_timeout | 31536000 |
| slave_net_timeout | 60 |
| wait_timeout | 28800 |
+-----------------------------------------+--------------+
13 rows in set (0.01 sec)

3.设置全局变量connect_timeout为12小时（12*3600=43200）
MySQL [(none)]> SET GLOBAL connect_timeout = 43200;
Query OK, 0 rows affected (0.00 sec)

4.再次查看，确认参数是否修改成功
MySQL [(none)]> show global variables like '%timeout%';
+----------------------------------------+--------------+
| Variable_name | Value |
+----------------------------------------+--------------+
| connect_timeout | 43200 |
| delayed_insert_timeout | 300 |
| have_statement_timeout | YES |
| innodb_flush_log_at_timeout | 1 |
| innodb_lock_wait_timeout | 120 |
| innodb_rollback_on_timeout | OFF |
| interactive_timeout | 28800 |
| lock_wait_timeout | 31536000 |
| net_read_timeout | 30 |
| net_write_timeout | 60 |
| rpl_stop_slave_timeout | 31536000 |
| slave_net_timeout | 60 |
| wait_timeout | 28800 |
+-----------------------------------------+--------------+
13 rows in set (0.00 sec)

5.退出数据库
MySQL [(none)]> exit
Bye