Application Server 3  4  5 and 6
  1. Application Server 3 4 5 and 6
  2. JBAS-7260

Performance issue: VFSClassLoaderPolicy uses URL.hashCode(), causing a DNS lookup

    Details

    • Type: Bug Bug
    • Status: Closed Closed (View Workflow)
    • Priority: Major Major
    • Resolution: Done
    • Affects Version/s: JBossAS-5.1.0.GA
    • Fix Version/s: 6.0.0.M1
    • Component/s: ClassLoading
    • Security Level: Public (Everyone can see)
    • Labels:
      None
    • Similar Issues:
      Show 7 results 

      Description

      There is a performance issue in JBoss AS 5.1.0.GA caused by the use of a ConcurrentHashMap with URL objects as the hash key. The offending usage is in VFSClassLoaderPolicy, in a member field named manifestCache. The field manifestCache is initialized as ConcurrentHashMap<URL, Manifest>();

      The underlying issue is that URL.hashCode() is a non-trivial operation, often requiring a DNS lookup. This DNS lookup can take a long time to timeout, adding up to 1-minute to the startup time of the application server .The issue is also encountered during runtime if certain class loader features are used (ie. getResource), causing up to a 1-minute delay when such features are used.

      The DNS lookups will never resolve in most cases, as the URL objects in question are usually in the form of:

      vfsmemory:aa15-xok7cr-fznfpulr-1-fznfpxto-7...

      A simple fix is to use the String returned form URL.toString() as the map key.

      Backtrace showing URL.hashCode causing a DNS lookup when used in ConcurrentHashMap from VFSClassLoaderPolicy:
      Inet6AddressImpl.lookupAllHostAddr(String) line: not available [native method]
      InetAddress$1.lookupAllHostAddr(String) line: 849
      InetAddress.getAddressFromNameService(String, InetAddress) line: 1200
      InetAddress.getAllByName0(String, InetAddress, boolean) line: 1153
      InetAddress.getAllByName(String, InetAddress) line: 1083
      InetAddress.getAllByName(String) line: 1019
      InetAddress.getByName(String) line: 969
      Handler(URLStreamHandler).getHostAddress(URL) line: 420
      Handler(URLStreamHandler).hashCode(URL) line: 337
      URL.hashCode() line: 857 [local variables unavailable]
      ConcurrentHashMap<K,V>.get(Object) line: 768
      VFSClassLoaderPolicy.getClassPackageInformation(String, String) line: 606
      BaseClassLoader.definePackage(String, URL) line: 722
      BaseClassLoader$2.run() line: 567
      BaseClassLoader$2.run() line: 532
      AccessController.doPrivileged(PrivilegedAction<T>, AccessControlContext) line: not available [native method]
      BaseClassLoader.loadClassLocally(String, boolean) line: 530
      BaseClassLoader.loadClassLocally(String) line: 507
      DelegateLoader(BaseDelegateLoader).loadClass(String) line: 134
      ClassLoadingTask$ThreadTask.run() line: 452
      ClassLoaderManager.nextTask(Thread, ClassLoadingTask) line: 251
      ClassLoaderManager.process(Thread, ClassLoadingTask) line: 150
      ClassLoaderDomain(BaseClassLoaderDomain).loadClass(BaseClassLoader, String, boolean) line: 265
      ClassLoaderDomain(BaseClassLoaderDomain).loadClass(BaseClassLoader, String) line: 1119
      BaseClassLoader.loadClassFromDomain(String, boolean) line: 798
      BaseClassLoader.loadClass(String, boolean) line: 441
      BaseClassLoader(ClassLoader).loadClass(String) line: 252
      ToClassInvoker.toClass(ToClassInvokerPoolReference, CtClass, String, ClassLoader, ProtectionDomain) line: 88
      JBossClDelegatingClassPool.toClass(CtClass, ClassLoader, ProtectionDomain) line: 81
      CtNewClass(CtClass).toClass(ClassLoader, ProtectionDomain) line: 1094
      TransformerCommon$ToClassAction$2.toClass(CtClass, ClassLoader, ProtectionDomain) line: 331
      TransformerCommon.toClass(CtClass, ClassLoader, ProtectionDomain) line: 139
      ProxyFactory.createProxyClass(ClassLoader, ProxyMixin[], Class<?>[]) line: 126
      ProxyFactory.createInterfaceProxy(GUID, ClassLoader, Class<?>[], ProxyMixin[], InstanceAdvisor) line: 96
      ProxyFactory.createInterfaceProxy(GUID, ClassLoader, Class<?>[]) line: 86
      Remoting.createRemoteProxy(Object, ClassLoader, Class[], InvokerLocator, List<Interceptor>, String) line: 102
      ManagedOperationProxyFactory.createDispatcherProxy() line: 203
      ManagedOperationProxyFactory.start() line: 109
      NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
      NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
      DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
      Method.invoke(Object, Object...) line: 597
      ReflectionUtils.invoke(Method, Object, Object[]) line: 59
      ReflectMethodInfoImpl.invoke(Object, Object[]) line: 150
      BasicMethodJoinPoint.dispatch() line: 66
      KernelControllerContextAction$JoinpointDispatchWrapper.execute() line: 241
      KernelControllerContextAction$JoinpointDispatchWrapper(ExecutionWrapper).execute(AccessControlContext) line: 47
      KernelControllerContextAction.dispatchExecutionWrapper(KernelControllerContext, ExecutionWrapper) line: 109
      KernelControllerContextAction.dispatchJoinPoint(KernelControllerContext, Joinpoint) line: 70
      StartStopLifecycleAction(LifecycleAction).installActionInternal(KernelControllerContext) line: 221
      StartStopLifecycleAction(InstallsAwareAction).installAction(KernelControllerContext) line: 54
      StartStopLifecycleAction(InstallsAwareAction).installAction(ControllerContext) line: 42
      StartStopLifecycleAction(SimpleControllerContextAction<T>).simpleInstallAction(T) line: 62
      StartStopLifecycleAction(AccessControllerContextAction<S,T>).install(ControllerContext) line: 71
      KernelControllerContextActions(AbstractControllerContextActions).install(ControllerContext, ControllerState, ControllerState) line: 51
      AbstractKernelControllerContext(AbstractControllerContext).install(ControllerState, ControllerState) line: 348
      AbstractKernelController(AbstractController).install(ControllerContext, ControllerState, ControllerState) line: 1631
      AbstractKernelController(AbstractController).incrementState(ControllerContext, boolean) line: 934
      AbstractKernelController(AbstractController).resolveContexts(ControllerState, ControllerState, boolean) line: 1082
      AbstractKernelController(AbstractController).resolveContexts(boolean) line: 984
      AbstractKernelController(AbstractController).install(ControllerContext, boolean) line: 774
      AbstractKernelController(AbstractController).install(ControllerContext) line: 540
      ServiceController.doInstall(KernelController, ServiceControllerContext) line: 670
      ServiceController.register(ObjectName, Collection<ObjectName>, boolean, Object) line: 373
      ServiceControllerRegistrationLifecycleCallback.install(ControllerContext) line: 104
      NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
      NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
      DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
      Method.invoke(Object, Object...) line: 597
      ReflectionUtils.invoke(Method, Object, Object[]) line: 59
      ReflectMethodInfoImpl.invoke(Object, Object[]) line: 150
      BasicMethodJoinPoint.dispatch() line: 66
      AbstractBeanInfo.invoke(Object, String, String[], Object[]) line: 300
      AbstractKernelControllerContext.invoke(String, Object[], String[]) line: 286
      AbstractLifecycleCallbackItem.install(ControllerContext) line: 87
      AbstractKernelController(AbstractController).handleLifecycleCallbacks(ControllerContext, ControllerState, boolean) line: 1568
      AbstractKernelController(AbstractController).handleInstallLifecycleCallbacks(ControllerContext, ControllerState) line: 1533
      AbstractKernelController(AbstractController).incrementState(ControllerContext, boolean) line: 943
      AbstractKernelController(AbstractController).resolveContexts(ControllerState, ControllerState, boolean) line: 1082
      AbstractKernelController(AbstractController).resolveContexts(boolean) line: 984
      AbstractKernelController(AbstractController).change(ControllerContext, ControllerState, boolean) line: 822
      AbstractKernelController(AbstractController).change(ControllerContext, ControllerState) line: 553
      ServiceController.doChange(KernelController, ServiceControllerContext, ControllerState, String) line: 688
      ServiceController.start(ObjectName) line: 460
      ServiceControllerStartStopLifecycleCallback.install(ControllerContext) line: 44
      NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method]
      NativeMethodAccessorImpl.invoke(Object, Object[]) line: 39
      DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 25
      Method.invoke(Object, Object...) line: 597
      ReflectionUtils.invoke(Method, Object, Object[]) line: 59
      ReflectMethodInfoImpl.invoke(Object, Object[]) line: 150
      BasicMethodJoinPoint.dispatch() line: 66
      AbstractBeanInfo.invoke(Object, String, String[], Object[]) line: 300
      AbstractKernelControllerContext.invoke(String, Object[], String[]) line: 286
      AbstractLifecycleCallbackItem.install(ControllerContext) line: 87
      AbstractKernelController(AbstractController).handleLifecycleCallbacks(ControllerContext, ControllerState, boolean) line: 1568
      AbstractKernelController(AbstractController).handleInstallLifecycleCallbacks(ControllerContext, ControllerState) line: 1533
      AbstractKernelController(AbstractController).incrementState(ControllerContext, boolean) line: 943
      AbstractKernelController(AbstractController).resolveContexts(ControllerState, ControllerState, boolean) line: 1082
      AbstractKernelController(AbstractController).resolveContexts(boolean) line: 984
      AbstractKernelController(AbstractController).install(ControllerContext, boolean) line: 774
      AbstractKernelController(AbstractController).install(ControllerContext) line: 540
      BeanMetaDataDeployer.deploy(DeploymentUnit, BeanMetaData) line: 121
      BeanMetaDataDeployer.deploy(DeploymentUnit, Object) line: 51
      BeanMetaDataDeployer(AbstractSimpleRealDeployer<T>).internalDeploy(DeploymentUnit) line: 62
      BeanMetaDataDeployer(AbstractRealDeployer).deploy(DeploymentUnit) line: 50
      DeployerWrapper.deploy(DeploymentUnit) line: 171
      DeployersImpl.doDeploy(Deployer, DeploymentUnit) line: 1439
      DeployersImpl.doInstallParentFirst(Deployer, DeploymentContext) line: 1157
      DeployersImpl.doInstallParentFirst(Deployer, DeploymentContext) line: 1178
      DeployersImpl.install(ControllerContext, ControllerState, ControllerState) line: 1098
      DeploymentControllerContext(AbstractControllerContext).install(ControllerState, ControllerState) line: 348
      AbstractKernelController(AbstractController).install(ControllerContext, ControllerState, ControllerState) line: 1631
      AbstractKernelController(AbstractController).incrementState(ControllerContext, boolean) line: 934
      AbstractKernelController(AbstractController).resolveContexts(ControllerState, ControllerState, boolean) line: 1082
      AbstractKernelController(AbstractController).resolveContexts(boolean) line: 984
      AbstractKernelController(AbstractController).change(ControllerContext, ControllerState, boolean) line: 822
      AbstractKernelController(AbstractController).change(ControllerContext, ControllerState) line: 553
      DeployersImpl.process(List<DeploymentContext>, List<DeploymentContext>) line: 781
      MainDeployerImpl.process() line: 702
      MainDeployerAdapter.process() line: 117
      ProfileDeployAction.install(Profile) line: 70
      ProfileDeployAction(AbstractProfileAction).install(ProfileContext) line: 53
      AbstractProfileService.install(ControllerContext, ControllerState, ControllerState) line: 361
      ProfileContext(AbstractControllerContext).install(ControllerState, ControllerState) line: 348
      ScopedProfileServiceController(AbstractController).install(ControllerContext, ControllerState, ControllerState) line: 1631
      ScopedProfileServiceController(AbstractController).incrementState(ControllerContext, boolean) line: 934
      ScopedProfileServiceController(AbstractController).resolveContexts(ControllerState, ControllerState, boolean) line: 1082
      ScopedProfileServiceController(AbstractController).resolveContexts(boolean) line: 984
      ScopedProfileServiceController(AbstractController).change(ControllerContext, ControllerState, boolean) line: 822
      ScopedProfileServiceController(AbstractController).change(ControllerContext, ControllerState) line: 553
      AbstractProfileService.activateProfile(ProfileKey) line: 306
      ProfileServiceBootstrap.start(Server) line: 271
      ServerImpl(AbstractServerImpl).start() line: 461
      Main.boot(String[]) line: 221
      Main$1.run() line: 556
      Thread.run() line: 619

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            • Assignee:
              Jason Greene
              Reporter:
              Tolga Tarhan
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              • Created:
                Updated:
                Resolved: