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


 
  • 摘要:今天在使用JDBC操作mysql时遇到下面的异常信息:引用Thelastpacketsentsuccessfullytotheserverwas0millisecondsago.Thedriverhasnotreceivedanypacketsfromtheserver.atcom.tomymap.galaxy.virgo.util.DbService.getConnection(DbService.java:66)atcom.tomymap.galaxy.virgo.util
  • 标签:Server
今天在使用JDBC操作mysql时遇到下面的 异常信息: 
引用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.Db Service.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:ubuntu10.105.1.49-1ubuntu8.1mysql-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

(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 

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