4

过去几天我在对我的产品进行性能测试时遇到了这个奇怪的问题，我使用的是 java 6、struts 3 框架和 tomcat 7 服务器

在性能测试期间，我们开始加载数千个 UI 请求访问服务器，最初它运行良好，但几个小时后请求开始被阻止，随后 CPU 使用率飙升至 100%，甚至 UI 变得无法访问。当我接受用于分析以下问题的线程转储是我一直得到的。

""http-nio-8443"-exec-1305" daemon prio=10 tid=0x00007f0458538000 nid=0x56dd waiting for monitor entry [0x00007f04345c9000]
   java.lang.Thread.State: BLOCKED (on object monitor)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1663)
    - locked <0x00000000a162f0c0> (a org.apache.catalina.loader.WebappClassLoader)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1521)
    at java.beans.Introspector.instantiate(Introspector.java:1448)
    at java.beans.Introspector.findExplicitBeanInfo(Introspector.java:431)
    at java.beans.Introspector. (Introspector.java:380)
    at java.beans.Introspector.getBeanInfo(Introspector.java:232)
    at java.beans.Introspector.getBeanInfo(Introspector.java:218)
    at com.googlecode.jsonplugin.JSONWriter.bean(JSONWriter.java:169)
    at com.googlecode.jsonplugin.JSONWriter.process(JSONWriter.java:152)
    at com.googlecode.jsonplugin.JSONWriter.value(JSONWriter.java:120)
    at com.googlecode.jsonplugin.JSONWriter.write(JSONWriter.java:88)
    at com.googlecode.jsonplugin.JSONUtil.serialize(JSONUtil.java:90)
    at com.googlecode.jsonplugin.JSONResult.execute(JSONResult.java:119)
    at com.opensymphony.xwork2.DefaultActionInvocation.executeResult(DefaultActionInvocation.java:348)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:253)
    at com.facetime.imauditor.sreach.action.CustomRequestInterceptorJson.intercept(CustomRequestInterceptorJson.java:69)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:221)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:150)
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:48)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:123)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:167)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:105)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:83)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:207)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:74)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:127)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.interceptor.ProfilingActivationInterceptor.intercept(ProfilingActivationInterceptor.java:107)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:206)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:115)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:143)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:121)
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:86)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:170)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:123)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:224)
    at com.opensymphony.xwork2.DefaultActionInvocation$2.doProfiling(DefaultActionInvocation.java:223)
    at com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:455)
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:221)
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:50)
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:504)
    at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:419)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at com.facetime.imcoreserver.registration.AbsoluteSendRedirectFilter.doFilter(AbsoluteSendRedirectFilter.java:48)
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:243)
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:240)
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:164)
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:462)
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:164)
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:100)
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:403)
    at org.apache.coyote.http11.Http11NioProcessor.process(Http11NioProcessor.java:369)
    at org.apache.coyote.http11.Http11NioProtocol$Http11ConnectionHandler.process(Http11NioProtocol.java:317)
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.run(NioEndpoint.java:1532)
    - locked <0x00000000abb53778> (a org.apache.tomcat.util.net.SecureNioChannel)
    at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
    at java.lang.Thread.run(Thread.java:662)

以下是线程的统计信息。

Threads locking monitor=1
Threads sleeping on monitor=0
Threads waiting to lock monitor=1097

在这方面的任何帮助都会非常有帮助，在此先感谢。

4

4 回答 4

3

这是 struts2 json 插件中的一个错误：

https://issues.apache.org/jira/browse/WW-3902

于 2012-10-17T13:42:23.573 回答
1

更新：

我最近遇到了类似的问题。有时，当 Web 应用程序没有很好地编程时，它可能无法正确清理网络 (TCP) 套接字……例如数据库连接类。导致主机（Tomcat JVM）进程上打开的文件描述符过多。这可能会导致您面临同样的不负责任。

因此，在我的情况下，我通过使用 ThreadLocal 泛型在每个线程的基础上设计数据库连接来解决问题。这是在我的 Web-Apps 服务托管 bean 中管理的。：

private static ThreadLocal<YourConnectionClass> connection = new ThreadLocal<YourConnectionClass>();

public static YourConnectionClass getConnection(){
    if (connection.get() == null) connection.set(driver.getConnection());
    return connection.get();
}

这将确保每个 tomcat 执行程序线程只打开一个 TCP 套接字。如果该问题适用于您，并且您添加了与我提到的类似的修复程序，那么您的问题将消失。好吧，但它仍然只是一个“猜测”。Tou 可以通过简单地将其输入服务器 unix/linux 控制台来验证这是否适用于您：

netstat | grep <YOUR_TCP_PORT>

或使用 lsof （列出打开的文件）。因为 TCP 套接字的处理方式类似于打开文件句柄。

lsof <YOUR_JVM_PID>

如果在tomcat启动后打开的套接字数量很少或很少，另一方面当你的责任问题发生时是毁灭性的高，那么你可能有一个打开的套接字文件描述符泄漏。

作为第二个猜测，如果没有正确清理 Java 对象的 HashTable（在 Web 应用服务器代码中的某个位置），即使在 Java 中也可能会导致 HashTable 内存泄漏。但正如我在上面的评论中看到的那样，情况可能并非如此。

干杯，

将要

我的老答案：

我打赌它的垃圾收集策略。

通过设置正确的 JVM OPTS 尝试使用另一个：

-XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:SurvivorRatio=2 -XX:NewRatio=8

检查此链接：

http://www.petefreitag.com/articles/gctuning/

http://www.idevelopment.info/data/Programming/java/miscellaneous_java/Java_Options_For_Garbage_Collection.html

于 2012-10-04T13:58:24.410 回答
1

该问题可以通过升级到 Tomcat 8.0.16 或更高版本并将 Loader 类设置为 org.apache.catalina.loader.ParallelWebappClassLoader 来解决。

在 [TOMCAT_HOME]/conf/context.xml 中，添加以下行并重新启动

<Loader loaderClass="org.apache.catalina.loader.ParallelWebappClassLoader" />

我们遇到了类似的问题，Hibernate 和 Spring JDBC 会尝试将 db 结果集行转换为对象。这种锁定行为严重影响了运行大量线程和大型结果集的 tomcat。

我建议用户在 Tomcat7 到 Tomcat 8 上运行 Hibernate 和 Spring JDBC 应用程序并打开 ParallelWebappClassLoader 以获得更好的性能。

于 2015-05-25T07:58:15.270 回答
0

由于在 WebappClassLoader 上同步，我发现了类似的问题；任何时候出现大量 loadClass 调用 - 不幸的是，许多 3rd 方库都会这样做。理想的解决方法是不要一直调用 loadClass，但这可能不是一个选择。

这源于作为错误 48903/44041/48694 的一部分引入 Tomcat 的更改，以修复一些用户遇到的死锁。

http://svn.apache.org/viewvc?view=revision&revision=927565

在我看来，修复对同步过于悲观，希望我能接受一个修复，允许在进入监视器之前检查本地缓存；这应该会让这个消失。

于 2013-08-28T22:12:21.980 回答