数据库学习笔记(十)Communications link failure,The last packet successfully received from the server was
2015-03-27 20:30
567 查看
出处:http://blog.csdn.net/mqboss/article/details/6659001
最近做测试,发现Mysql 过一段时间会无法连接,导致数据库数据不一至,极其郁闷。
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Connector/J的autoReconnect属性避免该错误。
后来查了一些资料,才发现遇到这个问题的人还真不少,大部分都是使用连接池方式时才会出现这个问题,短连接应该很难出现这个问题。这个问题的原因:
MySQL服务器默认的“wait_timeout”是28800秒即8小时,意味着如果一个连接的空闲时间超过8个小时,MySQL将自动断开该连接,而连接池却认为该连接还是有效的(因为并未校验连接的有效性),当应用申请使用该连接时,就会导致上面的报错。
1.按照错误的提示,可以在JDBC URL中使用autoReconnect属性,实际测试时使用了autoReconnect=true&failOverReadOnly=false,不过并未起作用,使用的是5.1版本,可能真像网上所说的只对4之前的版本有效。
2.没办法,只能修改MySQL的参数了,wait_timeout最大为31536000即1年,在my.cnf中加入:
[mysqld]
wait_timeout=31536000
interactive_timeout=31536000
重启生效,需要同时修改这两个参数。
最近做测试,发现Mysql 过一段时间会无法连接,导致数据库数据不一至,极其郁闷。
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Connector/J的autoReconnect属性避免该错误。
后来查了一些资料,才发现遇到这个问题的人还真不少,大部分都是使用连接池方式时才会出现这个问题,短连接应该很难出现这个问题。这个问题的原因:
MySQL服务器默认的“wait_timeout”是28800秒即8小时,意味着如果一个连接的空闲时间超过8个小时,MySQL将自动断开该连接,而连接池却认为该连接还是有效的(因为并未校验连接的有效性),当应用申请使用该连接时,就会导致上面的报错。
1.按照错误的提示,可以在JDBC URL中使用autoReconnect属性,实际测试时使用了autoReconnect=true&failOverReadOnly=false,不过并未起作用,使用的是5.1版本,可能真像网上所说的只对4之前的版本有效。
2.没办法,只能修改MySQL的参数了,wait_timeout最大为31536000即1年,在my.cnf中加入:
[mysqld]
wait_timeout=31536000
interactive_timeout=31536000
重启生效,需要同时修改这两个参数。
相关文章推荐
- Communications link failure,The last packet successfully received from the server was *** millisecon
- Communications link failure,The last packet successfully received from the server was *** millisecon
- MYSQL Communications link failure,The last packet successfully received from the server was
- Communications link failure,The last packet successfully received from the server was *** millisecon
- Communications link failure,The last packet successfully received from the server was × millisecon..
- Communications link failure,The last packet successfully received from the server was *** millisecon
- mysql 报错Communications link failure,The last packet successfully received from the server was × mill
- MySQL: Communications link failure,The last packet successfully received from the server
- Communications link failure The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received
- 【错误】:Could not open JDBC Connection for transaction; nested exception is: Communications link failure;The last packet sent successfully to the server was 1 milliseconds ago
- Communications link failure:The last packet sent successfully to the server was 0 milliseconds ago.
- The last packet successfully received from the server was 2,926,157 milliseconds ago. The last packet sent successfully to the server was 2,926,158 milliseconds ago. is longer than the server configured value of 'wait_timeout'. 解决办法
- mysql Communications link failure Last packet sent to the server was X ms ago
- The last packet successfully received from the server was XXX seconds ago
- com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 152,219,305 milliseconds ago.
- 错误Communications link failure,The last packet successfully received from the server was的解决方法
- (2)Mysql ----- The last packet successfully received from the server was *** millisecond ago.The
- 彻底解决"The last packet successfully received from the server was * milliseconds ago"问题
- The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.