[jboss-jira] [JBoss JIRA] Resolved: (JBAS-7260) Performance issue: VFSClassLoaderPolicy uses URL.hashCode(), causing a DNS lookup

Performance issue: VFSClassLoaderPolicy uses URL.hashCode(), causing a DNS lookup --------------------------------------------------------------------------------- Key: JBAS-7260 URL: https://jira.jboss.org/jira/browse/JBAS-7260 Project: JBoss Application Server Issue Type: Bug Security Level: Public(Everyone can see) Components: ClassLoading Affects Versions: JBossAS-5.1.0.GA Reporter: Tolga Tarhan Assignee: Jason T. Greene Fix For: JBossAS-5.2.0.Beta1 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