我正在努力配置Tomcat JDBC连接池以实现可靠性。当前的问题是，在测试环境中，我在webapp中有以下scanerio：

• 第一天：一切正常
• 第2天：webapp几个小时无法与MySQL通信，日志中有很多“断管”
• 第3天：令人惊讶的是，一切再次正常运行（无需输入或重新启动）

我已经配置validationInterval，validationQuery，validationTimeout。这是我的数据源配置：

<bean id="dataSource" class="org.apache.tomcat.jdbc.pool.DataSource"
    destroy-method="close">
    <property name="driverClassName" value="com.mysql.jdbc.Driver" />
    <property name="username" value="${dbUser}" />
    <property name="password" value="${dbPass}" />
    <property name="url" value="${dbUrl}" />
    <property name="defaultAutoCommit" value="false" />
    <property name="defaultTransactionIsolation">
    <util:constant static-field="java.sql.Connection.TRANSACTION_SERIALIZABLE" />
    </property>

    <property name="maxActive" value="300" />
    <property name="maxIdle" value="25" />
    <property name="initialSize" value="5" />

    <property name="validationInterval" value="5000" />
    <property name="validationQuery" value="SELECT 1"/>
    <property name="validationQueryTimeout" value="3" />

    <property name="minIdle" value="5" />
    <property name="initSQL" value="SET time_zone = '+00:00';" />
</bean>

我autoReconnect=true在连接URL中没有参数，只有UTF8编码。

确切的错误是：

Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:
The last packet successfully received from the server was 38,700,615
milliseconds ago.  The last packet sent successfully to the server was
38,700,615 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.
Caused by: java.net.SocketException: Broken pipe