[ERROR]The last packet sent successfully to the server was 0 milliseconds ago.

 

转载:http://binma85.iteye.com/blog/1318477

 

今天在使用JDBC操作mysql时遇到下面的异常信息：

 

binma85 写道

The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
at com.tomymap.galaxy.virgo.util.DbService.getConnection(DbService.java:66)
at com.tomymap.galaxy.virgo.util.DbService.getConnection(DbService.java:46)
at com.tomymap.galaxy.virgo.dao.PNNDao.getConnection(PNNDao.java:51)
at com.tomymap.galaxy.virgo.dao.DaoBase.executeUpdate(DaoBase.java:69)
at com.tomymap.galaxy.virgo.dao.PNNDao.updatePNNRelation(PNNDao.java:161)
at com.tomymap.galaxy.virgo.pnn.PyramidNeuralNetwork.buildPNNRelations(PyramidNeuralNetwork.java:400)
at com.tomymap.galaxy.virgo.pnn.PyramidNeuralNetwork.incrementalGenPNN(PyramidNeuralNetwork.java:144)
at com.tomymap.galaxy.virgo.pnn.PyramidNeuralNetwork.main(PyramidNeuralNetwork.java:410)

 

着实让人崩溃的信息，花费了一天的时间来解决。 

不罗嗦，直接描述解决办法。 

配置：  
ubuntu10.10  
5.1.49-1ubuntu8.1  
mysql-connector-java-5.1.18.jar  

 
交互： 
300k records 
300k * 10 = 3M次访问mysql 
处理时间0.5h以内 

解决方法： 
（1）使用JDBC URL中使用autoReconnect属性，url添加

&autoReconnect=true&failOverReadOnly=false&maxReconnects=10 

 

（2） 修改MySQL的参数. /etc/my.cnf 添加 

[mysqld]  
wait_timeout=31536000  
interactive_timeout=31536000 

 
（3）重启mysql 

service mysql restart  

 

原因分析： 
（1）大量数据访问情况下，mysql connection连接有可能失效 
（2）长时间不妨问，connection会失效 

更多参考： 
http://dev.mysql.com/doc/refman/5.1/zh/database-administration.html#dynamic-system-variables  
http://www.blogjava.net/heweiya/archive/2006/01/18/28483.html