小贝子编程

Tomcat 8 停止 Tomcat 时出现内存泄漏警告



实现一个小型微服务架构，有以下系统架构：

2 个 Tomcat8 实例在同一台计算机上运行，实例 A 位于端口 8080 上，实例 B 位于端口 8081 上。

它们通过 Websocket-connection (javax.websocket.server.ServerEndpoint 连接( 连接

。InstanceA 是

Websocket-client，InstanceB 是 WebSocketServer。实现 ServletContextListener 接口时，contextInitialized(ServletContextEvent arg0) 方法在 tomcat 启动时被调用。当调用此方法时，我通过以下方式打开与WebSocketServer的Websocket连接

ContainerProvider.getWebSocketContainer().connectToServer(MyClientEndpoint.class, new URI(arService.getProtocol() + "://" + arService.getIp() + ":" + arService.getPort() + arService.getEndPointUrl()));

连接工作正常，但是当我关闭实例A时，我得到以下堆栈跟踪：

WARNING: The web application [AuronGateway] appears to have started a thread named [Thread-5] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 sun.misc.Unsafe.park(Native Method)
 java.util.concurrent.locks.LockSupport.park(Unknown Source)
 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 java.lang.Thread.run(Unknown Source)

奇怪的是，我只在使用Oracle JDK的Microsoft Windows上收到此警告(在Win7和Win10上进行了测试-相同的警告(。使用 OpenJDK 在 Ubuntu14.04 上部署相同的代码时，我没有收到警告。我使用 Eclipse 在这两个系统上部署 WebApplication 和 Java 8/Tomcat8。

在调试应用程序时，我注意到websocket-Connection正确关闭。

编辑：在websocket服务器端(实例B(上，我在onError方法中得到以下异常：

java.io.IOException: Eine vorhandene Verbindung wurde vom Remotehost geschlossen
    at sun.nio.ch.SocketDispatcher.write0(Native Method)
    at sun.nio.ch.SocketDispatcher.write(Unknown Source)
    at sun.nio.ch.IOUtil.writeFromNativeBuffer(Unknown Source)
    at sun.nio.ch.IOUtil.write(Unknown Source)
    at sun.nio.ch.SocketChannelImpl.write(Unknown Source)
    at org.apache.tomcat.util.net.NioChannel.write(NioChannel.java:124)
    at org.apache.tomcat.util.net.NioSelectorPool.write(NioSelectorPool.java:183)
    at org.apache.coyote.http11.upgrade.NioServletOutputStream.doWriteInternal(NioServletOutputStream.java:94)
    at org.apache.coyote.http11.upgrade.NioServletOutputStream.doWrite(NioServletOutputStream.java:61)
    at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.writeInternal(AbstractServletOutputStream.java:165)
    at org.apache.coyote.http11.upgrade.AbstractServletOutputStream.write(AbstractServletOutputStream.java:132)
    at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.onWritePossible(WsRemoteEndpointImplServer.java:99)
    at org.apache.tomcat.websocket.server.WsRemoteEndpointImplServer.doWrite(WsRemoteEndpointImplServer.java:80)
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.writeMessagePart(WsRemoteEndpointImplBase.java:452)
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessage(WsRemoteEndpointImplBase.java:340)
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:272)
    at org.apache.tomcat.websocket.WsSession.sendCloseMessage(WsSession.java:586)
    at org.apache.tomcat.websocket.WsSession.doClose(WsSession.java:488)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.onError(WsHttpUpgradeHandler.java:150)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.access$300(WsHttpUpgradeHandler.java:48)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onError(WsHttpUpgradeHandler.java:211)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:194)
    at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
    at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:647)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)

编辑2：我发现当仅连接到websocket服务器时，警告不适用。它仅在通过以下方式发送某些文本时才会出现

session.getBasicRemote().sendText("TestMessage");

编辑3：设置一个测试项目，它是WebSocketClient的实现：
启动.java

package de.test.client;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
import javax.websocket.ContainerProvider;
import javax.websocket.DeploymentException;
import javax.websocket.Session;
public class Startup implements ServletContextListener
{
    Session session = null;
    @Override
    public void contextDestroyed(ServletContextEvent arg0) {
        System.out.println("stopped Session");
    }
    @Override
    public void contextInitialized(ServletContextEvent arg0) {
        System.out.println("try to establish Connection");
            try {
                this.session = ContainerProvider.getWebSocketContainer().connectToServer(TestClient.class,
                        new URI("ws://127.0.0.1:8081/TestServer/wsEndMessageBroker"));
                session.getBasicRemote().sendText("Hello WebsocketServer");
            } catch (DeploymentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (URISyntaxException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
    }
}

测试客户端.java

package de.test.client;
import javax.websocket.ClientEndpoint;
import javax.websocket.CloseReason;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
@ClientEndpoint
public class TestClient {
        @OnOpen
        public void onOpen(final Session userSession)
        {
            System.out.println("Connection established");
        }
        @OnClose
        public void onClose(final Session userSession, final CloseReason reason)
        {
            System.out.println("close am Clientendpoint(MessageBroker-Service)");
        }
        @OnMessage
        public void onMessage(String jsonMessage)
        {
            System.out.println("message: " + jsonMessage);
        }
        @OnError
        public void onError(Throwable error)
        {
            error.printStackTrace();
        }
}

WebSocket服务器：

测试服务器.java

package de.test.server;
import javax.websocket.OnClose;
import javax.websocket.OnError;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;
@ServerEndpoint("/wsEndMessageBroker")
public class TestServer
{
    public TestServer()
    {
        System.out.println("TestServer started");
    }
    @OnOpen
    public void onOpen(Session session)
    {
        System.out.println("New Connection established SessionID: " + session.getId());
    }
    @OnMessage
    public void message(Session session, String jsonMessage)
    {
        System.out.println("new Message: " + jsonMessage);
    }
    @OnClose
    public void onClose(Session session)
    {
        System.out.println("Closed Connection: " + session.getId());
    }
    @OnError
    public void onError(Throwable error)
    {
        error.printStackTrace();
        System.out.println("Connection were closed unexpected");
    }
}

日志客户端

INFORMATION: Initializing ProtocolHandler ["http-nio-8080"]
Feb 12, 2016 9:54:29 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFORMATION: Using a shared selector for servlet write/read
Feb 12, 2016 9:54:29 AM org.apache.coyote.AbstractProtocol init
INFORMATION: Initializing ProtocolHandler ["ajp-nio-8009"]
Feb 12, 2016 9:54:29 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFORMATION: Using a shared selector for servlet write/read
Feb 12, 2016 9:54:29 AM org.apache.catalina.startup.Catalina load
INFORMATION: Initialization processed in 787 ms
Feb 12, 2016 9:54:29 AM org.apache.catalina.core.StandardService startInternal
INFORMATION: Starting service Catalina
Feb 12, 2016 9:54:29 AM org.apache.catalina.core.StandardEngine startInternal
INFORMATION: Starting Servlet Engine: Apache Tomcat/8.0.32
Feb 12, 2016 9:54:30 AM org.apache.jasper.servlet.TldScanner scanJars
INFORMATION: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 12, 2016 9:54:30 AM org.apache.jasper.servlet.TldScanner scanJars
INFORMATION: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Versuche Verbindung aufzubauen
Connection established
Feb 12, 2016 9:54:30 AM org.apache.coyote.AbstractProtocol start
INFORMATION: Starting ProtocolHandler ["http-nio-8080"]
Feb 12, 2016 9:54:30 AM org.apache.coyote.AbstractProtocol start
INFORMATION: Starting ProtocolHandler ["ajp-nio-8009"]
Feb 12, 2016 9:54:30 AM org.apache.catalina.startup.Catalina start
INFORMATION: Server startup in 956 ms
Feb 12, 2016 9:54:34 AM org.apache.catalina.core.StandardServer await
INFORMATION: A valid shutdown command was received via the shutdown port. Stopping the Server instance.
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol pause
INFORMATION: Pausing ProtocolHandler ["http-nio-8080"]
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol pause
INFORMATION: Pausing ProtocolHandler ["ajp-nio-8009"]
Feb 12, 2016 9:54:34 AM org.apache.catalina.core.StandardService stopInternal
INFORMATION: Stopping service Catalina
stopped Session
Feb 12, 2016 9:54:34 AM org.apache.catalina.loader.WebappClassLoaderBase clearReferencesThreads
WARNUNG: The web application [TestClient] appears to have started a thread named [Thread-5] but has failed to stop it. This is very likely to create a memory leak. Stack trace of thread:
 sun.misc.Unsafe.park(Native Method)
 java.util.concurrent.locks.LockSupport.park(Unknown Source)
 java.util.concurrent.locks.AbstractQueuedSynchronizer$ConditionObject.await(Unknown Source)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
 java.util.concurrent.ScheduledThreadPoolExecutor$DelayedWorkQueue.take(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor.getTask(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
 java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
 java.lang.Thread.run(Unknown Source)
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol stop
INFORMATION: Stopping ProtocolHandler ["http-nio-8080"]
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol stop
INFORMATION: Stopping ProtocolHandler ["ajp-nio-8009"]
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol destroy
INFORMATION: Destroying ProtocolHandler ["http-nio-8080"]
Feb 12, 2016 9:54:34 AM org.apache.coyote.AbstractProtocol destroy
INFORMATION: Destroying ProtocolHandler ["ajp-nio-8009"]

日志服务器端

Feb 12, 2016 9:54:26 AM org.apache.coyote.AbstractProtocol init
INFORMATION: Initializing ProtocolHandler ["http-nio-8081"]
Feb 12, 2016 9:54:26 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFORMATION: Using a shared selector for servlet write/read
Feb 12, 2016 9:54:26 AM org.apache.coyote.AbstractProtocol init
INFORMATION: Initializing ProtocolHandler ["ajp-nio-8010"]
Feb 12, 2016 9:54:26 AM org.apache.tomcat.util.net.NioSelectorPool getSharedSelector
INFORMATION: Using a shared selector for servlet write/read
Feb 12, 2016 9:54:26 AM org.apache.catalina.startup.Catalina load
INFORMATION: Initialization processed in 992 ms
Feb 12, 2016 9:54:26 AM org.apache.catalina.core.StandardService startInternal
INFORMATION: Starting service Catalina
Feb 12, 2016 9:54:26 AM org.apache.catalina.core.StandardEngine startInternal
INFORMATION: Starting Servlet Engine: Apache Tomcat/8.0.32
Feb 12, 2016 9:54:27 AM org.apache.jasper.servlet.TldScanner scanJars
INFORMATION: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 12, 2016 9:54:27 AM org.apache.jasper.servlet.TldScanner scanJars
INFORMATION: At least one JAR was scanned for TLDs yet contained no TLDs. Enable debug logging for this logger for a complete list of JARs that were scanned but no TLDs were found in them. Skipping unneeded JARs during scanning can improve startup time and JSP compilation time.
Feb 12, 2016 9:54:27 AM org.apache.coyote.AbstractProtocol start
INFORMATION: Starting ProtocolHandler ["http-nio-8081"]
Feb 12, 2016 9:54:27 AM org.apache.coyote.AbstractProtocol start
INFORMATION: Starting ProtocolHandler ["ajp-nio-8010"]
Feb 12, 2016 9:54:27 AM org.apache.catalina.startup.Catalina start
INFORMATION: Server startup in 895 ms
TestServer started
New Connection established SessionID: 0
new Message: Hello WebsocketServer
java.io.IOException: Unable to write the complete message as the WebSocket connection has been closed
    at org.apache.tomcat.websocket.WsSession.registerFuture(WsSession.java:664)
    at org.apache.tomcat.websocket.FutureToSendHandler.get(FutureToSendHandler.java:92)
    at org.apache.tomcat.websocket.WsRemoteEndpointImplBase.startMessageBlock(WsRemoteEndpointImplBase.java:277)
    at org.apache.tomcat.websocket.WsSession.sendCloseMessage(WsSession.java:586)
    at org.apache.tomcat.websocket.WsSession.doClose(WsSession.java:488)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.onError(WsHttpUpgradeHandler.java:150)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler.access$300(WsHttpUpgradeHandler.java:48)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onError(WsHttpUpgradeHandler.java:211)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:194)
    at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
    at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:647)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Connection were closed unexpected
Closed Connection: 0
java.io.IOException: Eine vorhandene Verbindung wurde vom Remotehost geschlossen
    at sun.nio.ch.SocketDispatcher.read0(Native Method)
    at sun.nio.ch.SocketDispatcher.read(Unknown Source)
    at sun.nio.ch.IOUtil.readIntoNativeBuffer(Unknown Source)
    at sun.nio.ch.IOUtil.read(Unknown Source)
    at sun.nio.ch.SocketChannelImpl.read(Unknown Source)
    at org.apache.tomcat.util.net.NioChannel.read(NioChannel.java:137)
    at org.apache.coyote.http11.upgrade.NioServletInputStream.fillReadBuffer(NioServletInputStream.java:136)
    at org.apache.coyote.http11.upgrade.NioServletInputStream.doRead(NioServletInputStream.java:80)
    at org.apache.coyote.http11.upgrade.AbstractServletInputStream.read(AbstractServletInputStream.java:124)
    at org.apache.tomcat.websocket.server.WsFrameServer.onDataAvailable(WsFrameServer.java:60)
    at org.apache.tomcat.websocket.server.WsHttpUpgradeHandler$WsReadListener.onDataAvailable(WsHttpUpgradeHandler.java:186)
    at org.apache.coyote.http11.upgrade.AbstractServletInputStream.onDataAvailable(AbstractServletInputStream.java:198)
    at org.apache.coyote.http11.upgrade.AbstractProcessor.upgradeDispatch(AbstractProcessor.java:96)
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:647)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1500)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1456)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
    at java.lang.Thread.run(Unknown Source)
Connection were closed unexpected

堆栈跟踪显示创建了一个名为"Thread-5"的线程，该线程在应用程序关闭时尚未停止。这可能只是被认为是警告，因为雄猫能够处理此类问题。但它也可能是内存泄漏的原因，当您在重新部署应用程序后每次都不重新启动 tomcat 时。

您可以在 java.lang.Thread 类中设置一个条件断点，以便找出名为"Thread-5"的线程是从哪里创建的。找到线程的创建者后，可以研究如何正常关闭创建此线程的组件。

关闭功能可以放在 ServletContextListener 的 contextDestroy(( 方法中，也可以放在带有 Spring @PreDestroy 注释的方法中。

相关内容

  • 没有找到相关文章

最新更新


热门标签：

javascript python java c# php android html jquery c++ css ios sql mysql arrays asp.net json python-3.x ruby-on-rails .net sql-server django objective-c excel regex ruby linux ajax iphone xml vba spring asp.net-mvc database wordpress string postgresql wpf windows xcode bash git oracle list vb.net multithreading eclipse algorithm macos powershell visual-studio image forms numpy scala function api selenium