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mysql: Communications link failure解决_MySQL

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Jun 01, 2016 pm 01:34 PM

mysqldatabaseprogram

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mysql: Communications link failure解决

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。

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。

解决办法有两个：

一是修改my.cnf：

[mysqld]

wait_timeout=31536000

interactive_timeout=31536000

将过期时间修改为1年。

二是在连接URL上添加参数：&autoReconnect=true&failOverReadOnly=false

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