I am using JBOSS Messaging 1.0.1.GA. with JBOSS 4.0.5 GA and not using transacted session. I am trying to fetch messages from a pre-configured Queue in CLIENT_ACKNOWLEDGE_MODE. The queue had already a large number of message say 40000. Each time I use queueReceiver.receive(), multiple messages are getting lost.

That is even before explict acknowledgement, the message count in JBOSS Queue decreases by 80/100.

Please have a look at the following Snippet :

public class Consumer {

public static void main(String[] args)
{
QueueConnection qConnection =null;
QueueSession queueSession=null;
Queue queue=null;
QueueReceiver queueReceiver=null;
ObjectMessage message;
try
{
qConnection=createConnection("queue/XMLQueue");
queueSession = RequestSender.getQueueSessionClient(qConnection,"queue/XMLQueue");
queue=createQueue("queue/XMLQueue");
queueReceiver=queueSession.createReceiver(queue);

for(int i=0;i<114;i++)
{
message=getNewMessage(qConnection,queueReceiver);
}
}
catch(Exception e)
{
e.printStackTrace();
}
finally
{
if( qConnection != null )
{
try
{
// Closing the queueReceiver, queueSession & qConnection
}
catch(Exception jMSException)
{
jMSException.printStackTrace();
}
}
}
}
public static ObjectMessage getNewMessage(QueueConnection qConnection,QueueReceiver queueReceiver)
{
ObjectMessage message=null;
try
{
System.out.println("Just Before Receive -"+queueReceiver);
qConnection.start();
Message msg = queueReceiver.receive(1000);
// Here we found more than one messages are being lost. We put a delay and monitored the Queue Depth. System.out.println("Just After Received -"+msg);
qConnection.stop();
if (msg instanceof ObjectMessage)
{
message = (ObjectMessage) msg;
}

}
catch(JMSException jMSException)
{
jMSException.printStackTrace();
}
catch(Exception exception)
{
exception.printStackTrace();
}
return message;
}
public static QueueConnection createConnection()
{
QueueConnection queueConnection = null;
// Creates a Queue Connection and return the session
try
{
// Create a Queue Connection
queueConnection = queueConnectionFactory.createQueueConnection();
}
catch(JMSException jMSException)
{
jMSException.printStackTrace();
}
return queueConnection;
}
public static QueueSession getQueueSessionClient(QueueConnection qConnection,String prefix) throws JMSException
{
QueueSession qSession = null;
try
{
if( qConnection == null )
{
qConnection = createConnection();
}
if( null != qConnection )
{
qSession = qConnection.createQueueSession(false,Session.CLIENT_ACKNOWLEDGE);
}
}
catch(JMSException jMSException)
{
throw jMSException;
}
return qSession;
}
public static Queue createQueue(String queueName) throws Exception
{
String queueName = null;
Queue queue = null;
try
{
if(queueNameQueueMap.containsKey(queueName))
{
queue=queueNameQueueMap.get(queueName);
}
else
{
Queue queueLookedUp = (Queue) jndiContext.lookup(queueName);
queue=queueLookedUp;
queueNameQueueMap.put(queueName,queueLookedUp);
}
}
catch(NamingException namingException)
{
throw namingException;
}
return queue;
}
}