MySQL默认一个连接空闲8小时候就会自动断开,而这时程序以为连接还能使用,然后在使用的时候就会出现Communications link failure异常. 这时需要进行两步设置,有时候只设置MySQL就可以了. 一.在MySQL的配置文件(linux配置文件是my.cnf,windows配置文件为my.ini)中添加以下两行(默认值为28800,下面的值代表一年.听说windows下的MySQL不支持一年,可以适当减少尝试) wait_timeout=31536000 interactiv…

使用Connector/J连接MySQL数据库,程序运行较长时间后就会报以下错误: Communications link failure,The last packet successfully received from the server was *** millisecond ago.The last packet successfully sent to the server was *** millisecond ago. 其中错误还会提示你修改wait_timeout或是使用Co…

问题现象 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server. I spend some days to solve this…

想必大家在用MySQL时都会遇到连接超时的问题,如下图所示: 就是这个异常(com.mysql.jdbc.exceptions.jdbc4.Communication***ception:Communications link failure Last packet sent to the server was X ms ago),是由于MySQL服务在长时间不连接之后断开了,断开之后的首次请求会抛出这个异常.那么既然是连接超时的问题,就要去MySQL中探究一下连接时间是怎么控制的.打开MySQ…

.配置通用查询日志,需要在配置文件my.cnf中增加如下: () 在mysql的安装目录下,修改my.cnf配置文件,增加general_log = () 重启mysql,可执行命令/etc/init.d/mysql restart 备注:当general_log 参数功能打开时,可以用来追踪相关语句. .配置慢查询日志,需要在配置文件my.cnf增加如下参数: slow_query_log = 备注:增加配置参数后,需要重新启动mysql. .配置mysql的错误日志,需要在my.cnf中追加…

很长的报错,截取   ERROR c.a.d.p.DruidDataSource - discard connection   com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure       The last packet successfully received from the server was 44,866 milliseconds ago. The last pac…

09:00:30.307 [http-8080-6] ERROR org.hibernate.transaction.JDBCTransaction -JDBC begin failed com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 56,237,340 mi…

-- 查询mysql 数据库链接空闲时间持有最大空闲时间,单位为秒 SHOW VARIABLES WHERE VAriable_name = 'interactive_timeout'; -- 会出现wait_timeout与该参数意思相近,修改时,一起修改 SHOW VARIABLES WHERE VAriable_name = '%timeout'; -- 解决问题 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Commun…

异常描述 这个异常通常有如下信息: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 59,977 milliseconds ago. The last packet sent successfully to the server was 1 millisecon…

前端时间到客户那去进行项目的上线测试,将项目部署好之后,运行都是正常的,可是每到了第二天早上访问的时候,就会报一个Could not open Hibernate session for transaction 异常,Caused by: com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception,当时很摸不着头脑,后来就开始从数据库连接的源头开始找,本次项目中用的…