JSF IdMapper can create repeated ids in clustered environments causing: IllegalStateException with postback

Reproducer test.zip ├── node1 │ └── deployments │ └── test-jsf.war <- test application ├── node2 │ └── deployments │ └── test-jsf.war <- test application ├── README.txt └── standalone └── configuration └── standalone.xml <- added the proxy configuration for ndoes test-jsf.war ├── META-INF │ └── MANIFEST.MF ├── view.xhtml └── WEB-INF ├── classes │ └── test │ └── bean │ ├── TestBean.class │ └── TestBean.java ├── faces-config.xml ├── lib └── web.xml <- added javax.faces.PARTIAL_STATE_SAVING=false Steps to reproduce 1. Install JBoss EAP 7.2.x. 2. unzip test.zip under the EAP_HOME 3. Execute the following commands under the EAP_HOME/bin. Run a proxy server $ ./standalone.sh Run nodes # node1 $ ./standalone.sh -c standalone-ha.xml -Djboss.server.base.dir=../node1 -Djboss.server.config.dir=../standalone/configuration/ -Djboss.server.name=node1 -Djboss.socket.binding.port-offset=100 # node2 $ ./standalone.sh -c standalone-ha.xml -Djboss.server.base.dir=../node2 -Djboss.server.config.dir=../standalone/configuration/ -Djboss.server.name=node2 -Djboss.socket.binding.port-offset=200 4. Open http://localhost:8080/test-jsf/view.jsf 5. If you push the submit button, the following error would be output either node. 13:34:29,098 SEVERE [javax.enterprise.resource.webcontainer.jsf.application] (default task-1) Error Rendering View[/view.xhtml]: java.lang.IllegalStateException: Component ID j_idt2 has already been found in the view. at com.sun.faces.util.Util.checkIdUniqueness(Util.java:1127) at com.sun.faces.util.Util.checkIdUniqueness(Util.java:1111) at com.sun.faces.application.view.JspStateManagementStrategy.saveView(JspStateManagementStrategy.java:298) at com.sun.faces.application.StateManagerImpl.saveView(StateManagerImpl.java:89) at com.sun.faces.application.view.WriteBehindStateWriter.getState(WriteBehindStateWriter.java:334) at com.sun.faces.application.view.WriteBehindStateWriter.flushToWriter(WriteBehindStateWriter.java:228) at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:507) at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:194) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:151) at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:151) at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:126) ...