Kevin Lohmann [http://community.jboss.org/people/kevin.lohmann] created the discussion "Re: PingTimerTask in JBoss AS 5.0.1.GA EAP" To view the discussion, visit: http://community.jboss.org/message/560203#560203 -------------------------------------------------------------- Hi there again, I've created a simple standalone-client-scenario to reproduce the above warnings: public class TestScenario {     // ############### CONFIG #################     private final static String sJMS_CONNECTION_FACTORY_NAME = "ClusteredConnectionFactory";     private final static int sCONCURRENT_CALLS = 25;     private final static long sSLEEP_TIME = sCONCURRENT_CALLS * 100;     // ########################################         private final static CountDownLatch sCDL = new CountDownLatch(sCONCURRENT_CALLS);     private final static SimpleDateFormat sDATE_FORMATER = new SimpleDateFormat("HH:mm:ss.SSS ");         public static void main(String[] args) {         for (int i = 0; i < sCONCURRENT_CALLS; i++) {             final int lIteration = i;             Thread lThread = new Thread(new Runnable() {                 @Override                 public void run() {                     try {                         doIteration();                     } catch (Throwable t) {                         t.printStackTrace();                     }                 }             }, "Thread-no." + lIteration);             lThread.setDaemon(true);             lThread.start();         }         try {             Thread.sleep(sSLEEP_TIME);         } catch (InterruptedException e) {             e.printStackTrace();         }         log("...ready!");             }     /**      * @throws NamingException      */     private static void doIteration() throws NamingException {         log("...lookup JMSConnectionFactory...");         ConnectionFactory lConnectionFactory = lookUpJMSConnectionFactory();         sCDL.countDown();                 Connection lConnection;         try {             log("...create JMSConnection...");             lConnection = lConnectionFactory.createConnection();             log("...close JMSConnection...");             lConnection.close();         } catch (JMSException e) {             e.printStackTrace();         }         log("...ready!");     }     /**      * @return      * @throws NamingException      */     private static ConnectionFactory lookUpJMSConnectionFactory() throws NamingException {         Context lContext = new InitialContext();         return (ConnectionFactory) lContext.lookup(sJMS_CONNECTION_FACTORY_NAME);     }     private static void log(String pLog) {         System.out.println(sDATE_FORMATER.format(new Date()) + Thread.currentThread().getName() + pLog);     }     } This will create +${sCONCURRENT_CALLS}+ daemon threads. Each thread gets a jms connectionfactory, creates a connection and closes the connection. The main thread will sleep +${sSLEEP_TIME}+ milli seconds before terminating. With the above config, I receive everytime the following ConcurrentModificationException within the client: Exception in thread "Thread-1" java.util.ConcurrentModificationException     at java.util.WeakHashMap$HashIterator.nextEntry(WeakHashMap.java:762)     at java.util.WeakHashMap$KeyIterator.next(WeakHashMap.java:795)     at org.jboss.jms.client.delegate.ClientClusteredConnectionFactoryDelegate$FinalizerShutdownHook.run(ClientClusteredConnectionFactoryDelegate.java:462) In server.log the following can be seen: 2010-09-02 11:57:05,510 WARN  [org.jboss.remoting.transport.bisocket.BisocketClientInvoker] (Timer-4) Unable to send ping: shutting down PingTimerTask java.net.SocketException: Connection reset by peer: socket write error     at java.net.SocketOutputStream.socketWrite0(Native Method)     at java.net.SocketOutputStream.socketWrite(Unknown Source)     at java.net.SocketOutputStream.write(Unknown Source)     at org.jboss.remoting.transport.bisocket.BisocketClientInvoker$PingTimerTask.run(BisocketClientInvoker.java:723)     at java.util.TimerThread.mainLoop(Unknown Source)     at java.util.TimerThread.run(Unknown Source) And: 2010-09-02 11:56:59,401 ERROR [org.jboss.remoting.transport.socket.ServerThread] (WorkerThread#40[10.3.4.124:4488]) WorkerThread#40[10.3.4.124:4488] failed java.io.IOException: Connection reset by peer: socket write error     at java.net.SocketOutputStream.socketWrite0(Native Method)     at java.net.SocketOutputStream.socketWrite(Unknown Source)     at java.net.SocketOutputStream.write(Unknown Source)     at java.io.BufferedOutputStream.flushBuffer(Unknown Source)     at java.io.BufferedOutputStream.flush(Unknown Source)     at java.io.DataOutputStream.flush(Unknown Source)     at org.jboss.jms.wireformat.NullResponse.write(NullResponse.java:53)     at org.jboss.jms.wireformat.JMSWireFormat.write(JMSWireFormat.java:237)     at org.jboss.remoting.transport.socket.ServerThread.versionedWrite(ServerThread.java:1051)     at org.jboss.remoting.transport.socket.ServerThread.completeInvocation(ServerThread.java:807)     at org.jboss.remoting.transport.socket.ServerThread.processInvocation(ServerThread.java:721)     at org.jboss.remoting.transport.socket.ServerThread.dorun(ServerThread.java:575)     at org.jboss.remoting.transport.socket.ServerThread.run(ServerThread.java:234) I assume, these warnings and errors occur because the clients brake away. Can anyone confirm this? Thanks, Kevin -------------------------------------------------------------- Reply to this message by going to Community [http://community.jboss.org/message/560203#560203] Start a new discussion in JBoss Remoting at Community [http://community.jboss.org/choose-container!input.jspa?contentType=1&...]