重启数据库后,数据库大部分时间连不上了:连续请求不会报错,请求间隔时间稍微长一点就会报错报错如图: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure The last packet successfully received from the server was 7,008 milliseconds ago. The last packet sent successfully to

事情的起因: 某项目的开发同学突然Q我们组的某同学,要求我们调整MySQL的连接等待超时参数wait_timeout.要求我们从28800s调整到31536000s(也就是一年) 应用端测试环境的tomcat报错日志如下图: 恩.报错很明显.这个问题百度后的解决方案大部分都是要求数据库端更改连接等待超时时间.那么这种解决方法是否可行呢? 遗憾的是,这是不可行的. 主要原因还是性能考量.Wait_timeout参数的含义是指MySQL将断开指定时间内没有任何操作的连接(Connection).这个

一.报错的问题: 测试环境在做压力测试的时候爆出错误 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure INFO | jvm 1 | 2013/10/24 14:22:28 | INFO | jvm 1 | 2013/10/24 14:22:28 | The last packet successfully received from the server was 26,071

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

现象: 报错:Exception in thread "main" com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure 解决办法: 更换 mysql-connector-java-8.0.11.jar 为 mysql-connector-java-8.0.16.jar, 下载位置:https://mvnrepository.com/artifact/mysql/mysql-c

2017-12-29 10:43:19,776 ERROR [com.alibaba.druid.pool.DruidDataSource] - <init datasource error, url: jdbc:mysql://localhost:3306/hxrc> com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure Last packet sent to the serv

环境情况,MySQL版本如下: 报错情况如下(看上去是和数据库有关): com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure The last packet successfully received from the server was 59 milliseconds ago. The last packet sent successfully to the server wa

-- 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

问题描述 App Service使用jdbc连接MySQL服务,出现大量的  Communications link failure: com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received

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C

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

# #错误日志 2016-11-10 16:19:20,834 ERROR [org.quartz.core.JobRunShell] - Job DEFAULT.jobtask threw an unhandled Exception: org.springframework.scheduling.quartz.JobMethodInvocationFailedException: Invocation of method 'execute' on target class [class co

不多说,直接上干货! 问题详情 [hadoop@bigdatamaster oozie--cdh5.5.4]$ bin/ooziedb.sh create -sqlfile oozie.sql -run DB Connection [hadoop@bigdatamaster oozie--cdh5.5.4]$ bin/ooziedb.sh create -sqlfile oozie.sql -run DB Connection setting CATALINA_OPTS="$CATALINA_O

一,异常现象 com.bill99.inf.ibatis.DBException: queryForList error::sqlId=orgOrderAssetsMapping.queryModelOrgOrderAssetsMapping param:com.bill99.boss.domain.org.model.OrderAssetsMapping@51ab0a47 at com.bill99.inf.ibatis.SqlMapDao.queryForList(SqlMapDao.jav

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

一菜单方式: 打开plsql,点击[File]-[New]-[Database link],打开如下图所示窗口 填好各项信息后,点击[Apply]即可完成Database Link的创建. 二SQL方式 -- Drop existing database link drop public database link dblink_name; -- Create database link create public database link dblink_name connect to SYS

报错: MySQL第二天早上第一次连接超时报错, com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 原因: 上述问题是由mysql5数据库的配置引起的.mysql5将其连接的等待时间(wait_timeout .interactive_timeout)缺省为8小时.在其客户程序中可以这样来查看其值: mysql> show global variables like 'wait

本文是针对特定的情景下的特定错误,不是所有Communications link failure错误都是这个引起的,重要的区分特点是:程序是不是在卡主后两个小时(服务器的设置)后程序才感知到,才抛出了异常. 本文系转载,原文地址:https://jingyan.baidu.com/article/fc07f98922615a12ffe519ce.html 在公网,不同机房的环境下,相互访问数据库出现操作卡顿的情况,数据库会出现错误:java.sql.SQLException: Communica

最近在搞一个Spring boot + Mybatis + Mysql的项目,用Mybatis访问数据库时,报了如下的错误,先在网上搜索了,试了各种办法都不行, 奇葩的是,连接另外1个数据库又没问题.  最后发现是因为Mybatis的Mapper.xml文件中的SQL语句后面,多了个分号[;],导致SQL查询要等待很久,直到返回下面的报错. com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link f

2019-11-22 17:15:27,705 FATAL [IPC Server handler 13 on 44844] org.apache.hadoop.mapred.TaskAttemptListenerImpl: Task: attempt_1574410493054_0011_m_000000_0 - exited : java.lang.RuntimeException: java.lang.RuntimeException: com.mysql.jdbc.exceptions.

数据库连接失败 一.例如我在SpringBoot项目中使用了阿里的数据库连接池Driud. 有次在启动的时候,会报这样的错: Caused by: com.mysql.cj.exceptions.CJCommunicationsException: Communications link failure The last packet successfully received from the server was 319 milliseconds ago. The last packet s