BaseClassLoader blocks.
I have an application where I am seeing a lot of blocks on the synchronized block of BaseClassloader (when I look at thread dumps) which I would not normally expect (I would expect most of the time to see the stack traces doing database IO or some-such, but mostly I see thread blocked on classloading). The thread that is holding the lock (I believe) has the stack trace below. It seems to me that a lot of work is going on with the classloading when I would expect most classes to be cached (this stack trace is after the app has been running several hours). Do I have something mis-configured, or am I simply ignorant in some fashion (ok, that is a given, I know :-) ) ? An extra bit of information: I am using EJB3's over http. Thanks for any help
java.net.URLClassLoader.findClass(URLClassLoader.java:188)
java.lang.ClassLoader.loadClass(ClassLoader.java:306)
- locked <0x52cc95d> (a org.jboss.system.NoAnnotationURLClassLoader)
java.lang.ClassLoader.loadClass(ClassLoader.java:251)
java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
- locked <0x52cc95d> (a org.jboss.system.NoAnnotationURLClassLoader)
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:247)
org.jboss.classloader.plugins.loader.ClassLoaderToLoaderAdapter.loadClass(ClassLoaderToLoaderAdapter.java:173)
org.jboss.classloader.spi.ClassLoaderDomain.loadClassFromParent(ClassLoaderDomain.java:352)
org.jboss.classloader.spi.ClassLoaderDomain.loadClassBefore(ClassLoaderDomain.java:307)
org.jboss.classloader.spi.base.BaseClassLoaderDomain.loadClass(BaseClassLoaderDomain.java:243)
org.jboss.classloader.spi.base.BaseClassLoaderDomain.loadClass(BaseClassLoaderDomain.java:1099)
org.jboss.classloader.spi.base.BaseClassLoader.loadClassFromDomain(BaseClassLoader.java:735)
org.jboss.classloader.spi.base.BaseClassLoader.loadClass(BaseClassLoader.java:378)
- locked <0x611c3b04> (a org.jboss.classloader.spi.base.BaseClassLoader)
java.lang.ClassLoader.loadClass(ClassLoader.java:251)
org.jboss.aop.util.MarshalledValueInputStream.resolveClass(MarshalledValueInputStream.java:58)
java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1575)
java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:1583)
java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1496)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1732)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
java.util.HashMap.readObject(HashMap.java:1030)
sun.reflect.GeneratedMethodAccessor252.invoke(Unknown Source)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:597)
java.io.ObjectStreamClass.invokeReadObject(ObjectStreamClass.java:974)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1849)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
java.io.ObjectInputStream.defaultReadFields(ObjectInputStream.java:1947)
java.io.ObjectInputStream.readSerialData(ObjectInputStream.java:1871)
java.io.ObjectInputStream.readOrdinaryObject(ObjectInputStream.java:1753)
java.io.ObjectInputStream.readObject0(ObjectInputStream.java:1329)
java.io.ObjectInputStream.readObject(ObjectInputStream.java:351)
org.jboss.aop.util.MarshalledValue.get(MarshalledValue.java:87)
org.jboss.aop.metadata.SimpleMetaData$MetaDataValue.get(SimpleMetaData.java:88)
org.jboss.aop.metadata.SimpleMetaData.getMetaData(SimpleMetaData.java:211)
- locked <0x725b298b> (a org.jboss.aop.metadata.SimpleMetaData)
org.jboss.aop.metadata.SimpleMetaData.resolve(SimpleMetaData.java:283)
- locked <0x725b298b> (a org.jboss.aop.metadata.SimpleMetaData)
org.jboss.aop.joinpoint.InvocationBase.getMetaData(InvocationBase.java:251)
org.jboss.aop.joinpoint.MethodInvocation.getMetaData(MethodInvocation.java:240)
org.jboss.ejb3.security.Ejb3AuthenticationInterceptorv2.invoke(Ejb3AuthenticationInterceptorv2.java:78)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
org.jboss.ejb3.ENCPropagationInterceptor.invoke(ENCPropagationInterceptor.java:41)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
org.jboss.ejb3.asynchronous.AsynchronousInterceptor.invoke(AsynchronousInterceptor.java:106)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
org.jboss.ejb3.BlockContainerShutdownInterceptor.invoke(BlockContainerShutdownInterceptor.java:65)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
org.jboss.aspects.currentinvocation.CurrentInvocationInterceptor.invoke(CurrentInvocationInterceptor.java:67)
org.jboss.aop.joinpoint.MethodInvocation.invokeNext(MethodInvocation.java:102)
org.jboss.ejb3.stateless.StatelessContainer.dynamicInvoke(StatelessContainer.java:486)
org.jboss.ejb3.session.InvokableContextClassProxyHack._dynamicInvoke(InvokableContextClassProxyHack.java:56)
org.jboss.aop.Dispatcher.invoke(Dispatcher.java:91)
org.jboss.aspects.remoting.AOPRemotingInvocationHandler.invoke(AOPRemotingInvocationHandler.java:82)
org.jboss.remoting.ServerInvoker.invoke(ServerInvoker.java:908)
org.jboss.remoting.transport.servlet.ServletServerInvoker.processRequest(ServletServerInvoker.java:309)
org.jboss.remoting.util.ServletSecurityUtility.processRequest(ServletSecurityUtility.java:53)
org.jboss.remoting.transport.servlet.web.ServerInvokerServlet.processRequest(ServerInvokerServlet.java:128)
org.jboss.remoting.transport.servlet.web.ServerInvokerServlet.doPost(ServerInvokerServlet.java:157)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.jboss.web.tomcat.filters.ReplyHeaderFilter.doFilter(ReplyHeaderFilter.java:96)
org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:235)
org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:191)
org.jboss.web.tomcat.security.SecurityAssociationValve.invoke(SecurityAssociationValve.java:190)
org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:433)
org.jboss.web.tomcat.security.JaccContextValve.invoke(JaccContextValve.java:92)
org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.process(SecurityContextEstablishmentValve.java:126)
org.jboss.web.tomcat.security.SecurityContextEstablishmentValve.invoke(SecurityContextEstablishmentValve.java:70)
org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:127)
org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:102)
org.jboss.web.tomcat.service.jca.CachedConnectionValve.invoke(CachedConnectionValve.java:158)
org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:330)
org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:828)
org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:601)
org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
java.lang.Thread.run(Thre
