activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From chago <>
Subject Re: Looking for Help ActiveMQ and Jetty
Date Mon, 17 Sep 2007 13:22:19 GMT

I have tried your example and it works for me with my new amq.js file and the
one that is in the head. I suspect that their is some component outside the
javascript and servlets that is silently failing for you. FWIW, I have
disabled persistence in my configuration:


The first two connections that you see should be a GET and a POST. 

The POST should will look like this:
  - destination=channel://gnip
  - message=gnip
  - type=listen

(Note: the response from the server is an empty string)

The first GET should have a timeout value of 0 and looks like this:
  - timeout=0

Both of these should return very quickly. Then another GET request is made
without a timeout value. The MessageListenerServlet uses a default timeout
of 25 secs. These GET requests are the long polls and are the basis for the
Comet approach to AJAX calls. It works very well with an asynchronous
interface like JMS.

As for debugging, here are some general approaches I have used.

#1 - Firebug
Firebug is a developer's plugin for Firefox browser that lets you easily
monitor XmlHttpRequest (AJAX) calls made by the client. It shows you the
message that was sent out and the response returned by the server. It shows
you these in real time so you can see your request sending and waiting for a

By using this, you can make sure that the client is actually sending the
message. You can also verify that the server responds with a reply; proper
or not. There is also a two connection limit to the server, so this tool
will show you how many outstanding connections there are.

#2 - Live Debugging
I sometime remote debug or debug an embedded Jetty server by placing
breakpoints in MessageListenerServlet.

#3 - Debug Logging
I generally turn on full debug output for as many components that I can. The
MessageListenerServlet has debug statements that are useful when faced with
a strange problem.

Hope it helps.

Feel free to Skype me if you want to walk thru it in more detail. You will
find me by searching for

Zanderfax wrote:
> Attached is the logfile with debug info. 
> I started activemq, then jetty, loaded the web page and sent 2 messages. 
> I see the connections but there is nothing transfered.
> Any ideas?
> activemq.log  
> chago wrote:
>> Zanderfax wrote:
>>> I made the changes with no apparent effect.  Where would I look for the
>>> debug log or stack trace if they exist?

View this message in context:
Sent from the ActiveMQ - User mailing list archive at

View raw message