[ https://issues.jboss.org/browse/WFLY-4929?page=com.atlassian.jira.plugin.... ] Hardy Ferentschik commented on WFLY-4929: ----------------------------------------- Is there a work-around for this issue? I am seeing the same issue using Wildfly 9. I am trying to use a symmetrical cluster setup based on this example - https://github.com/foogaro/wildfly-cookbook/tree/master/cluster-jms-repli... (from the _WildFly Cookbook_). When using this setup the initial startup works. I then kill the first node and the backup node takes over. Then I re-start the first node. In some cases even this initial fail-back did not work (not quite sure how to reproduce it though), but if the first fail-back worked and I then stop the first node again, a fail-over does not happen anymore. I see a {{NullPointerException}} in the logs of the second node (not sure whether they are the cause of the problem): {noformat} 16:44:26,430 ERROR [org.xnio.listener] (default I/O-6) XNIO001007: A channel event listener threw an exception: java.lang.NullPointerException at org.jboss.as.messaging.HTTPUpgradeService$2.handleEvent(HTTPUpgradeService.java:151) at org.jboss.as.messaging.HTTPUpgradeService$2.handleEvent(HTTPUpgradeService.java:143) at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92) at io.undertow.server.handlers.ChannelUpgradeHandler$1.handleUpgrade(ChannelUpgradeHandler.java:149) at io.undertow.server.protocol.http.HttpReadListener.exchangeComplete(HttpReadListener.java:350) at io.undertow.server.protocol.http.HttpServerConnection.exchangeComplete(HttpServerConnection.java:225) at io.undertow.server.HttpServerExchange.invokeExchangeCompleteListeners(HttpServerExchange.java:1192) at io.undertow.server.HttpServerExchange.terminateResponse(HttpServerExchange.java:1412) at io.undertow.server.Connectors.terminateResponse(Connectors.java:100) at io.undertow.server.protocol.http.HttpTransferEncoding$3.handleEvent(HttpTransferEncoding.java:197) at io.undertow.server.protocol.http.HttpTransferEncoding$3.handleEvent(HttpTransferEncoding.java:195) at io.undertow.conduits.ChunkedStreamSinkConduit.invokeFinishListener(ChunkedStreamSinkConduit.java:291) at io.undertow.conduits.ChunkedStreamSinkConduit.flush(ChunkedStreamSinkConduit.java:263) at org.xnio.conduits.ConduitStreamSinkChannel.flush(ConduitStreamSinkChannel.java:162) at io.undertow.channels.DetachableStreamSinkChannel.flush(DetachableStreamSinkChannel.java:119) at io.undertow.server.HttpServerExchange.closeAndFlushResponse(HttpServerExchange.java:1561) at io.undertow.server.HttpServerExchange.endExchange(HttpServerExchange.java:1539) at io.undertow.server.handlers.ChannelUpgradeHandler.handleRequest(ChannelUpgradeHandler.java:152) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:199) at io.undertow.server.protocol.http.HttpReadListener.handleEventWithNoRunningRequest(HttpReadListener.java:227) at io.undertow.server.protocol.http.HttpReadListener.handleEvent(HttpReadListener.java:128) at io.undertow.server.protocol.http.HttpReadListener.handleEvent(HttpReadListener.java:56) at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92) at org.xnio.conduits.ReadReadyHandler$ChannelListenerHandler.readReady(ReadReadyHandler.java:66) at org.xnio.nio.NioSocketConduit.handleReady(NioSocketConduit.java:88) at org.xnio.nio.WorkerThread.run(WorkerThread.java:539) 16:44:26,434 ERROR [org.xnio.listener] (default I/O-7) XNIO001007: A channel event listener threw an exception: java.lang.NullPointerException at org.jboss.as.messaging.HTTPUpgradeService$2.handleEvent(HTTPUpgradeService.java:151) at org.jboss.as.messaging.HTTPUpgradeService$2.handleEvent(HTTPUpgradeService.java:143) at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92) at io.undertow.server.handlers.ChannelUpgradeHandler$1.handleUpgrade(ChannelUpgradeHandler.java:149) at io.undertow.server.protocol.http.HttpReadListener.exchangeComplete(HttpReadListener.java:350) at io.undertow.server.protocol.http.HttpServerConnection.exchangeComplete(HttpServerConnection.java:225) at io.undertow.server.HttpServerExchange.invokeExchangeCompleteListeners(HttpServerExchange.java:1192) at io.undertow.server.HttpServerExchange.terminateResponse(HttpServerExchange.java:1412) at io.undertow.server.Connectors.terminateResponse(Connectors.java:100) at io.undertow.server.protocol.http.HttpTransferEncoding$3.handleEvent(HttpTransferEncoding.java:197) at io.undertow.server.protocol.http.HttpTransferEncoding$3.handleEvent(HttpTransferEncoding.java:195) at io.undertow.conduits.ChunkedStreamSinkConduit.invokeFinishListener(ChunkedStreamSinkConduit.java:291) at io.undertow.conduits.ChunkedStreamSinkConduit.flush(ChunkedStreamSinkConduit.java:263) at org.xnio.conduits.ConduitStreamSinkChannel.flush(ConduitStreamSinkChannel.java:162) at io.undertow.channels.DetachableStreamSinkChannel.flush(DetachableStreamSinkChannel.java:119) at io.undertow.server.HttpServerExchange.closeAndFlushResponse(HttpServerExchange.java:1561) at io.undertow.server.HttpServerExchange.endExchange(HttpServerExchange.java:1539) at io.undertow.server.handlers.ChannelUpgradeHandler.handleRequest(ChannelUpgradeHandler.java:152) at io.undertow.server.Connectors.executeRootHandler(Connectors.java:199) at io.undertow.server.protocol.http.HttpReadListener.handleEventWithNoRunningRequest(HttpReadListener.java:227) at io.undertow.server.protocol.http.HttpReadListener.handleEvent(HttpReadListener.java:128) at io.undertow.server.protocol.http.HttpReadListener.handleEvent(HttpReadListener.java:56) at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92) at org.xnio.conduits.ReadReadyHandler$ChannelListenerHandler.readReady(ReadReadyHandler.java:66) at org.xnio.nio.NioSocketConduit.handleReady(NioSocketConduit.java:88) at org.xnio.nio.WorkerThread.run(WorkerThread.java:539) {noformat} It looks like the fail-over and fail-back does not work consistently and repeatedly. -- This message was sent by Atlassian JIRA (v6.3.15#6346)