<a4j:push /> works on Tomcat 7, but not Weblogic 12c

[vace117]

Greetings,

I've been trying to figure out why this does not work, and I am out of ideas, so I could use some help.

Page.xhtml:

<a4j:push address="systemLinks" >
  <a4j:ajax event="dataavailable" render="systemLinksPanel" />
</a4j:push>

<a4j:outputPanel id="systemLinksPanel">
     stuff here
</a4j:outputPanel>

Startup log:

INFO: Installed AtmosphereHandler org.atmosphere.handler.ReflectorServletProcessor mapped to context-path: /*
INFO: Atmosphere is using async support: org.atmosphere.container.Servlet30CometSupport running under container:
WebLogic Server 12.1.2.0.0 Fri Jun 7 15:16:15 PDT 2013 1530982 WLS_12.1.2.0.0_GENERIC_130607.1100
Oracle WebLogic Server Module Dependencies 12.1 Tue May 21 06:02:40 PDT 2013  using javax.servlet/3.0
INFO: Installing Filter PushHandlerFilter
INFO: Using broadcaster class: org.atmosphere.cpr.DefaultBroadcaster

Java code:

TopicKey topicKey = new TopicKey("systemLinks");
TopicsContext topicsContext = TopicsContext.lookup();
topicsContext.publish(topicKey, "fly, you fools!");

On Tomcat 7 this work perfectly, and always refreshes 'systemLinksPanel' when data is published.

On Weblogic 12c, I am pretty sure the response is sent, but it is never received by the client 'XMLHttpRequest'. What I mean by that is that

ajaxRequest.readyState == 4

But

ajaxRequest.responseText == ""

So no events are triggered. I have examined the exchange with a network protocol analyzer, and I do see the response:

003b

<"topic":"systemLinks","data":"fly, you fools!","number":0>

Now I don't know where else to look. The data leaves the server, but does not arrive at the destination. What else can I check?

The only difference I see in the response from Tomcat is that the two leading zeros are not there. So '3b' instead of '003b'.

Library Versions:

richfaces-components-api-4.2.0.Final.jar

richfaces-components-ui-4.2.0.Final.jar

richfaces-core-api-4.2.0.Final.jar

richfaces-core-impl-4.2.0.Final.jar

javax.faces-2.1.7.jar

atmosphere-compat-jbossweb-0.8.4.jar

atmosphere-compat-jetty-0.8.4.jar

atmosphere-compat-tomcat-0.8.4.jar

atmosphere-compat-tomcat7-0.8.4.jar

atmosphere-compat-weblogic-0.8.4.jar

atmosphere-runtime-0.8.4.jar

[vace117]

I just found something useful.

I was able to get the data returned properly to the browser, by setting some breakpoints inside Atmposphere code after the message is flushed into the Writer. I found that if I allow the request to time out w/o completing the thread that flushed the writer, the response looks as follows and everything works:

003b

<"topic":"systemLinks","data":"fly, you fools!","number":0>

0000

However, if I allow the flushing thread to continue right away, the response looks like this and the browser never receives the data:

003b

<"topic":"systemLinks","data":"fly, you fools!","number":0>

Note the missing terminating zero.

[vace117]

ok, getting closer I think.

The offending line that cause the response to be terminated incorrectly in Weblogic is:

Servlet30CometSupport.action(AtmosphereResourceImpl actionEvent) {
....

            if (asyncContext != null && (config.getInitParameter(ApplicationConfig.RESUME_AND_KEEPALIVE) == null
                    || config.getInitParameter(ApplicationConfig.RESUME_AND_KEEPALIVE).equalsIgnoreCase("false"))) {
                asyncContext.complete();
            }

....
}

As long as I allow the request to timeout w/o executing that line, everything works fine.

To verify this I added the following to my servlet definition:

   <init-param>
       <param-name>org.atmosphere.cpr.AtmosphereServlet.resumeAndKeepAlive</param-name>
       <param-value>true</param-value>
   </init-param>

Now the pushed data is correct, but it does not come back until the request times out, so it's not immediate.

Did anyone else have this problem? I am still not sure what the correct fix for this might be.

[vace117]

The root cause and a workaround are described here: https://issues.jboss.org/browse/RF-13674