The reason is that the method WeldListener.sessionDestroyed(event) is called twice. First call stack trace: Daemon Thread [http-/127.0.0.1:8080-1] (Suspended (breakpoint at line 90 in WeldListener)) owns: SessionBasedClusteredSession (id=778) WeldListener.sessionDestroyed(HttpSessionEvent) line: 90 SessionBasedClusteredSession(ClusteredSession).expire(boolean, boolean, boolean, ClusteredSessionNotificationCause) line: 1302 SessionBasedClusteredSession(ClusteredSession).invalidate() line: 629 StandardSessionFacade.invalidate() line: 150 NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method] NativeMethodAccessorImpl.invoke(Object, Object[]) line: 57 DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 43 Method.invoke(Object, Object...) line: 606 AstValue.invoke(EvaluationContext, Class[], Object[]) line: 258 MethodExpressionImpl.invoke(ELContext, Object[]) line: 278 WeldMethodExpression(ForwardingMethodExpression).invoke(ELContext, Object[]) line: 40 WeldMethodExpression.invoke(ELContext, Object[]) line: 50 TagMethodExpression.invoke(ELContext, Object[]) line: 105 MethodBindingMethodExpressionAdapter.invoke(FacesContext, Object[]) line: 87 ActionListenerImpl.processAction(ActionEvent) line: 101 HtmlCommandLink(UICommand).broadcast(FacesEvent) line: 315 UIViewRoot.broadcastEvents(FacesContext, PhaseId) line: 786 UIViewRoot.processApplication(FacesContext) line: 1251 InvokeApplicationPhase.execute(FacesContext) line: 81 InvokeApplicationPhase(Phase).doPhase(FacesContext, Lifecycle, ListIterator) line: 101 LifecycleImpl.execute(FacesContext) line: 118 FacesServlet.service(ServletRequest, ServletResponse) line: 593 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 295 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 214 StandardWrapperValve.invoke(Request, Response) line: 230 StandardContextValve.invoke(Request, Response) line: 149 JBossWebContext$RequestListenerValve.event(Request, Response, HttpEvent) line: 91 JBossWebContext$RequestListenerValve.invoke(Request, Response) line: 72 BasicAuthenticator(AuthenticatorBase).invoke(Request, Response) line: 499 ClusteredSessionValve.handleRequest(Request, Response, HttpEvent, boolean) line: 134 ClusteredSessionValve.invoke(Request, Response) line: 99 JvmRouteValve.invoke(Request, Response) line: 92 LockingValve.invoke(Request, Response) line: 64 SecurityContextAssociationValve.invoke(Request, Response) line: 169 StandardHostValve.invoke(Request, Response) line: 145 ErrorReportValve.invoke(Request, Response) line: 97 ClusteredSingleSignOn.invoke(Request, Response) line: 384 StandardEngineValve.invoke(Request, Response) line: 102 CoyoteAdapter.service(Request, Response) line: 336 Http11Processor.process(Socket) line: 856 Http11Protocol$Http11ConnectionHandler.process(Socket) line: 653 JIoEndpoint$Worker.run() line: 920 Thread.run() line: 724 Second call stack trace: Daemon Thread [http-/127.0.0.1:8080-1] (Suspended) owns: SessionBasedClusteredSession (id=853) owns: SessionBasedClusteredSession (id=778) WeldListener.sessionDestroyed(HttpSessionEvent) line: 93 SessionBasedClusteredSession(ClusteredSession).expire(boolean, boolean, boolean, ClusteredSessionNotificationCause) line: 1302 SessionBasedClusteredSession(ClusteredSession).expire() line: 649 ClusteredSingleSignOn.deregister(String) line: 494 ClusteredSingleSignOn.logout(String) line: 562 ClusteredSingleSignOn.sessionEvent(SessionEvent) line: 282 SessionBasedClusteredSession(ClusteredSession).fireSessionEvent(String, Object) line: 1790 SessionBasedClusteredSession(ClusteredSession).expire(boolean, boolean, boolean, ClusteredSessionNotificationCause) line: 1326 SessionBasedClusteredSession(ClusteredSession).invalidate() line: 629 StandardSessionFacade.invalidate() line: 150 NativeMethodAccessorImpl.invoke0(Method, Object, Object[]) line: not available [native method] NativeMethodAccessorImpl.invoke(Object, Object[]) line: 57 DelegatingMethodAccessorImpl.invoke(Object, Object[]) line: 43 Method.invoke(Object, Object...) line: 606 AstValue.invoke(EvaluationContext, Class[], Object[]) line: 258 MethodExpressionImpl.invoke(ELContext, Object[]) line: 278 WeldMethodExpression(ForwardingMethodExpression).invoke(ELContext, Object[]) line: 40 WeldMethodExpression.invoke(ELContext, Object[]) line: 50 TagMethodExpression.invoke(ELContext, Object[]) line: 105 MethodBindingMethodExpressionAdapter.invoke(FacesContext, Object[]) line: 87 ActionListenerImpl.processAction(ActionEvent) line: 101 HtmlCommandLink(UICommand).broadcast(FacesEvent) line: 315 UIViewRoot.broadcastEvents(FacesContext, PhaseId) line: 786 UIViewRoot.processApplication(FacesContext) line: 1251 InvokeApplicationPhase.execute(FacesContext) line: 81 InvokeApplicationPhase(Phase).doPhase(FacesContext, Lifecycle, ListIterator) line: 101 LifecycleImpl.execute(FacesContext) line: 118 FacesServlet.service(ServletRequest, ServletResponse) line: 593 ApplicationFilterChain.internalDoFilter(ServletRequest, ServletResponse) line: 295 ApplicationFilterChain.doFilter(ServletRequest, ServletResponse) line: 214 StandardWrapperValve.invoke(Request, Response) line: 230 StandardContextValve.invoke(Request, Response) line: 149 JBossWebContext$RequestListenerValve.event(Request, Response, HttpEvent) line: 91 JBossWebContext$RequestListenerValve.invoke(Request, Response) line: 72 BasicAuthenticator(AuthenticatorBase).invoke(Request, Response) line: 499 ClusteredSessionValve.handleRequest(Request, Response, HttpEvent, boolean) line: 134 ClusteredSessionValve.invoke(Request, Response) line: 99 JvmRouteValve.invoke(Request, Response) line: 92 LockingValve.invoke(Request, Response) line: 64 SecurityContextAssociationValve.invoke(Request, Response) line: 169 StandardHostValve.invoke(Request, Response) line: 145 ErrorReportValve.invoke(Request, Response) line: 97 ClusteredSingleSignOn.invoke(Request, Response) line: 384 StandardEngineValve.invoke(Request, Response) line: 102 CoyoteAdapter.service(Request, Response) line: 336 Http11Processor.process(Socket) line: 856 Http11Protocol$Http11ConnectionHandler.process(Socket) line: 653 JIoEndpoint$Worker.run() line: 920 Thread.run() line: 724