Hi Fabien, The subscribeFromPeer() method is invoked when a subscription is added or removed on a peer server in the cluster that this server may need to know about. The NPE is happening because the destination that the subscription was added to or removed from doesn't exist on the current server.
Verify that your servers are both starting up correctly and that your destinations are fully symmetric. Best, Seth From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of fabien.deshayes Sent: Thursday, September 18, 2008 5:30 AM To: [email protected] Subject: [flexcoders] BlazeDS clustering Hello, I'm trying to install a cluster with BlazeDS. After some difficulties, I've reached a point where my 2 servers A and B know each other, and that when a client subscribe on a destination on server A, this server send a message to the server B. Unfortunately, this does not work and I've got this error: -------------------------------- [BlazeDS]09/18/2008 [ERROR] [Service.Cluster] Error handling message pushed from cluster: java.lang.NullPointerException [BlazeDS]09/18/2008 [ERROR] [Service.Cluster] Exception=java.lang.NullPointerException at flex.messaging.services.MessageService.subscribeFromPeer(MessageService.java:747) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at flex.messaging.cluster.JGroupsCluster$ServiceOperationHandler.handleBroadcast(JGroupsCluster.java:538) at flex.messaging.cluster.JGroupsCluster.handle(JGroupsCluster.java:417) at org.jgroups.blocks.MessageDispatcher.handle(MessageDispatcher.java:577) at org.jgroups.blocks.RequestCorrelator.handleRequest(RequestCorrelator.java:624) at org.jgroups.blocks.RequestCorrelator.receiveMessage(RequestCorrelator.java:533) at org.jgroups.blocks.RequestCorrelator.receive(RequestCorrelator.java:365) at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:736) at org.jgroups.JChannel.up(JChannel.java:1063) at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:325) at org.jgroups.protocols.pbcast.GMS.up(GMS.java:722) at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:234) at org.jgroups.protocols.pbcast.NAKACK.handleMessage(NAKACK.java:720) at org.jgroups.protocols.pbcast.NAKACK.up(NAKACK.java:546) at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:167) at org.jgroups.protocols.FD.up(FD.java:322) at org.jgroups.protocols.MERGE2.up(MERGE2.java:145) at org.jgroups.protocols.Discovery.up(Discovery.java:220) at org.jgroups.protocols.TP$IncomingPacket.handleMyMessage(TP.java:1486) at org.jgroups.protocols.TP$IncomingPacket.run(TP.java:1440) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) [Incoming Thread,default-cluster,10.193.137.195:7800] ERROR org.jgroups.blocks.RequestCorrelator - error invoking method flex.messaging.cluster.ClusterException: Unable to replicate a service operation received from a broadcast on cluster id 'default-cluster'. at flex.messaging.cluster.JGroupsCluster$ServiceOperationHandler.handleBroadcast(JGroupsCluster.java:552) at flex.messaging.cluster.JGroupsCluster.handle(JGroupsCluster.java:417) at org.jgroups.blocks.MessageDispatcher.handle(MessageDispatcher.java:577) at org.jgroups.blocks.RequestCorrelator.handleRequest(RequestCorrelator.java:624) at org.jgroups.blocks.RequestCorrelator.receiveMessage(RequestCorrelator.java:533) at org.jgroups.blocks.RequestCorrelator.receive(RequestCorrelator.java:365) at org.jgroups.blocks.MessageDispatcher$ProtocolAdapter.up(MessageDispatcher.java:736) at org.jgroups.JChannel.up(JChannel.java:1063) at org.jgroups.stack.ProtocolStack.up(ProtocolStack.java:325) at org.jgroups.protocols.pbcast.GMS.up(GMS.java:722) at org.jgroups.protocols.pbcast.STABLE.up(STABLE.java:234) at org.jgroups.protocols.pbcast.NAKACK.handleMessage(NAKACK.java:720) at org.jgroups.protocols.pbcast.NAKACK.up(NAKACK.java:546) at org.jgroups.protocols.VERIFY_SUSPECT.up(VERIFY_SUSPECT.java:167) at org.jgroups.protocols.FD.up(FD.java:322) at org.jgroups.protocols.MERGE2.up(MERGE2.java:145) at org.jgroups.protocols.Discovery.up(Discovery.java:220) at org.jgroups.protocols.TP$IncomingPacket.handleMyMessage(TP.java:1486) at org.jgroups.protocols.TP$IncomingPacket.run(TP.java:1440) at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) -------------------------------- The destination is dynamically created, with these lines: -------------------------------- MessageService service = getService(); MessageDestination destination = (MessageDestination) service.getDestination(destinationId); // set the cluster config ServerSettings serverSettings = new ServerSettings(); serverSettings.setBroadcastRoutingMode("server-to-server"); NetworkSettings netSettings = new NetworkSettings(); netSettings.setClusterId("default-cluster"); if (destination == null) { destination = (MessageDestination) service.createDestination(destinationId); } destination.setServerSettings(serverSettings); destination.setNetworkSettings(netSettings); if (service.isStarted()) { destination.start(); } -------------------------------- Also I do not see any activity on the other destination I have created with xml configuration files. Here is it: -------------------------------- <destination id="user-destination"> <properties> <network> <session-timeout>0</session-timeout> <cluster ref="default-cluster" shared-backend="true"/> </network> <server> <max-cache-size>1000</max-cache-size> <message-time-to-live>0</message-time-to-live> <durable>false</durable> <cluster-message-routing>server-to-server</cluster-message-routing> </server> </properties> </destination> -------------------------------- I am using BlazeDS 3.0.0.544 with JGroup 2.5.1. I have a hardware load-balancer in front of my 2 servers. I have googled some good tutorials or examples about BlazeDS clustering but the only source I've found is the BlazeDS Guide, which does not really help me. If someone can help me, it will be great. Thanks in advance, Fabien PS: sorry if there is some mistake in my english... :).
