mysql重连，连接丢失：The Last Packet Successfully Received From the Server

最新推荐文章于 2025-09-15 12:02:24 发布

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本文探讨了在使用MySQL数据库时遇到的连接超时错误，提供了通过添加autoReconnect属性来解决该问题的方法，并详细解释了如何在不同环境中实现这一解决方案。

源：http://nkcoder.github.io/
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1.1 错误信息：

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was 20,820,001 milliseconds ago. The last packet sent successfully to the server was 20,820,002 milliseconds ago. is longer than the server configured value of 'wait_timeout'. You should consider either expiring and/or testing connection validity before use in your application, increasing the server configured values for client timeouts, or using the Connector/J connection property 'autoReconnect=true' to avoid this problem.
at sun.reflect.GeneratedConstructorAccessor29.newInstance(Unknown Source) ~[na:na]
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[na:1.7.0_51]
at java.lang.reflect.Constructor.newInstance(Constructor.java:526) ~[na:1.7.0_51]
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1129) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.MysqlIO.send(MysqlIO.java:3988) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2598) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2778) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2828) ~[mysql-connector-java-5.1.29.jar:na]
at com.mysql.jdbc.ConnectionImpl.setAutoCommit(ConnectionImpl.java:5372) ~[mysql-connector-java-5.1.29.jar:na]
at com.mchange.v2.c3p0.impl.NewProxyConnection.setAutoCommit(NewProxyConnection.java:881) ~[c3p0-0.9.1.1.jar:0.9.1.1]
at org.quartz.impl.jdbcjobstore.AttributeRestoringConnectionInvocationHandler.setAutoCommit(AttributeRestoringConnectionInvocationHandler.java:98) ~[quartz-2.2.1.jar:na]

1.2 解决方法
– 如果使用的是JDBC，在JDBC URL上添加?autoReconnect=true，如：

jdbc:mysql://10.10.10.10:3306/mydb?autoReconnect=true

– 如果是在Spring中使用DBCP连接池，在定义datasource增加属性validationQuery和testOnBorrow，如：

<bean id="vrsRankDataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${countNew.jdbc.url}" />
<property name="username" value="${countNew.jdbc.user}" />
<property name="password" value="${countNew.jdbc.pwd}" />
<property name="validationQuery" value="SELECT 1" />
<property name="testOnBorrow" value="true"/>
</bean>

– 如果是在Spring中使用c3p0连接池，则在定义datasource的时候，添加属性testConnectionOnCheckin和testConnectionOnCheckout，如：

<bean name="cacheCloudDB" class="com.mchange.v2.c3p0.ComboPooledDataSource">
<property name="driverClass" value="${jdbc.driver}"/>
<property name="jdbcUrl" value="${cache.url}"/>
<property name="user" value="${cache.user}"/>
<property name="password" value="${cache.password}"/>
<property name="initialPoolSize" value="10"/>
<property name="maxPoolSize" value="${cache.maxPoolSize}"/>
<property name="testConnectionOnCheckin" value="false"/>
<property name="testConnectionOnCheckout" value="true"/>
<property name="preferredTestQuery" value="SELECT 1"/>
</bean>

参考

MySQL reconnect issues