c3p0連接池內存泄漏重新部署tomcat

Question

我有這些代碼用於關閉c3p0連接管理器，但似乎還有一個未關閉的線程。 我錯過了什么嗎？

Oct 11, 2016 5:12:09 PM org.springframework.context.support.AbstractApplicationContext doClose
INFO: Closing WebApplicationContext for namespace 'dispatcherServlet-servlet': startup date [Tue Oct 11 17:11:58 PHT 2016]; parent: Root WebApplicationContext
2016-10-11 17:12:09 - [INFO ] CRMContextListener - Trying to Close
2016-10-11 17:12:09 - [INFO ] CRMContextListener - Close Success
Oct 11, 2016 5:12:09 PM      org.springframework.context.support.AbstractApplicationContext doClose
INFO: Closing Root WebApplicationContext: startup date [Tue Oct 11 17:11:44 PHT 2016]; root of context hierarchy
Oct 11, 2016 5:12:09 PM org.apache.catalina.loader.WebappClassLoader clearReferencesJdbc
SEVERE: A web application registered the JBDC driver [oracle.jdbc.OracleDriver] but failed to unregister it when the web application was stopped. To prevent a memory leak, the JDBC Driver has been forcibly unregistered. Oct 11, 2016 5:12:09 PM     org.apache.catalina.loader.WebappClassLoader clearReferencesThreads
SEVERE: A web application appears to have started a thread named [C3P0PooledConnectionPoolManager[identityToken->2xjsis9j1do3mrp1m3tqb8|fb6fd9c]-DeferredStatementDestroyerThread-#0] but has failed to stop it. This is very likely to create a memory leak.

這是我的servlet監聽器的代碼

public void contextDestroyed(ServletContextEvent sce) {
    logger.info("Trying to Close");

    for (Object o : C3P0Registry.getPooledDataSources()) {
        try {
            ((PooledDataSource) o).close();
        } catch (Exception e) {
            logger.info("No thread was open...");
        }
    }

    logger.info("Close Success");
}

這是我對c3p0 xml的配置

<bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource" destroy-method="close">
    <property name="driverClass" value="oracle.jdbc.driver.OracleDriver" />
    <property name="jdbcUrl" value="jdbc:oracle:thin:@sph-pdc-vm  1042:1521:DEV" />
    <property name="user" value="TSW" />
    <property name="password" value="TSW2015#" />
    <property name="minPoolSize" value="2" />
    <property name="maxPoolSize" value="20" />
    <property name="initialPoolSize" value="5" />
    <property name="testConnectionOnCheckin" value="true" />
    <property name="idleConnectionTestPeriod" value="100" />
    <property name="maxIdleTimeExcessConnections" value="5" />
    <property name="maxStatementsPerConnection" value="10" />
    <property name="acquireIncrement" value="1" />
    <property name="statementCacheNumDeferredCloseThreads" value="1" />
    <property name="acquireRetryAttempts" value="2" />
    <property name="acquireRetryDelay" value="2000" />
</bean>

提前致謝....

Answer 1

它可能不是真正的內存泄漏，而是誤報，因為c3p0的線程需要一些時間來關閉，而close()不等待它完成，它是異步的。 所以你有一個煩人的消息。 看看這個github問題 ，感謝github上的BuğraGedik。 如果你想測試這個理論，你可能會在調用close()后添加一秒左右的延遲[即調用Thread.sleep(1000) ]並查看消息是否消失。

雖然我認為這不是您的問題，但您可以考慮添加一些Tomcat參數，以確保嘗試關閉（）線程始終成功。 只需添加......

<property name="privilegeSpawnedThreads" value="true" />
<property name="contextClassLoaderSource" value="library" />

請參閱c3p0的文檔 。