This is expected. A queue browser takes a shapshot of the queue through a
short lived consumer. The network bridge is by default a demand forwarder,
such that messages are only forwarded when there are consumers on other
brokers.
With the browser, the consumer (and hence demand) is transient, so it may
take a snapshot before the forwarding has a chance to kick in. And the
forwarding stops when the consumer goes away once the browse shapshot
completes.
One way to make this more deterministic would be to have a statically
configured destination in the network connector configuration such that
messages for that destination are forwarded irrespective of demand.
2009/12/11 ant elder <ant.el...@gmail.com>
> I'm trying to track down an problem where a queue browser on a VM
> connection to one AMQ broker is sometimes not seeing messages put on a
> queue from a VM connection to another broker in the same network. The
> code below can recreate the problem, running the put() on JVM and the
> browse() on another JVM the first QueueBrowser never sees the message
> but the second QueueBrowser does though sometimes it doesn't without
> the Thread.sleep for a few seconds.
>
> Is there anything obviously wrong with this setup or are there any
> config settings that could help?
>
> ...ant
>
> The code to put a message on a queue:
>
> public void put() throws Exception {
> BrokerService broker1 = new BrokerService();
> broker1.setBrokerName("default");
> broker1.setPersistent(false);
> broker1.setUseJmx(false);
> TransportConnector tc = broker1.addConnector("tcp://localhost:0");
> tc.setDiscoveryUri(URI.create("multicast://default"));
> broker1.addNetworkConnector("multicast://default");
> broker1.start();
>
> Connection conn1 = new
> ActiveMQConnectionFactory("vm://default?create=false").createConnection();
> conn1.start();
> Session sess1 = conn1.createSession(false, 1);
> Queue d1 = sess1.createQueue("d1");
> MessageProducer p1 = sess1.createProducer(d1);
> TextMessage m1 = sess1.createTextMessage("test");
> p1.send(m1);
> }
>
>
> The code to browse the messages on the queue:
>
> public void browse() throws Exception {
>
> BrokerService broker2 = new BrokerService();
> broker2.setBrokerName("default");
> broker2.setPersistent(false);
> broker2.setUseJmx(false);
> TransportConnector tc = broker2.addConnector("tcp://localhost:0");
> tc.setDiscoveryUri(URI.create("multicast://default"));
> broker2.addNetworkConnector("multicast://default");
> broker2.start();
>
> Connection conn2 = new
> ActiveMQConnectionFactory("vm://default?create=false").createConnection();
> conn2.start();
> Session sess2 = conn2.createSession(false, 1);
> Queue d1 = sess2.createQueue("d1");
> QueueBrowser b = sess2.createBrowser(d1);
>
> Enumeration x2 = b.getEnumeration();
> while (x2.hasMoreElements()) {
> System.out.println(x2.nextElement()); // this never gets
> the message
> }
>
> Thread.sleep(5000);
>
> b = sess2.createBrowser(d1);
> Enumeration x2a = b.getEnumeration();
> while (x2a.hasMoreElements()) {
> System.out.println(x2a.nextElement()); // this does get the
> message
> }
>
> }
>
--
http://blog.garytully.com
Open Source Integration
http://fusesource.com
