I have figured out the problem: When using this code:

public void changeActualPosition(long ms) throws Exception  {
  for(int i=1; i<50; i++)
{
setActualPosition(i);
Thread.sleep(ms);
log.info("actual Pos: #0", i);
}

}

My logger tell me that failure (so this is the reason why my values are not updated by the poll):

11:58:45,219 WARN  [arjLoggerI18N] [com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator_4] TwoPhaseCoordinator.afterCompletion - returned failure for com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple@1dc6a3b
11:58:45,219 WARN  [arjLoggerI18N] [com.arjuna.ats.arjuna.coordinator.TwoPhaseCoordinator_4] TwoPhaseCoordinator.afterCompletion - returned failure for com.arjuna.ats.internal.jta.resources.arjunacore.SynchronizationImple@1c27073
11:58:45,219 ERROR [CachedConnectionValve] Application error: Faces Servlet did not complete its transaction
11:58:45,781 INFO  [STDOUT] BeforePhase: RESTORE_VIEW 1
11:58:45,797 INFO  [STDOUT] AfterPhase: RESTORE_VIEW 1
11:58:46,297 WARN  [SeamPhaseListener] uncaught exception, passing to exception handler
org.jboss.seam.ConcurrentRequestTimeoutException: Concurrent call to conversation
    at org.jboss.seam.core.Manager.restoreAndLockConversation(Manager.java:641)
    at org.jboss.seam.core.Manager.restoreConversation(Manager.java:603)
    at org.jboss.seam.jsf.SeamPhaseListener.afterRestoreView(SeamPhaseListener.java:390)
    at org.jboss.seam.jsf.SeamPhaseListener.afterServletPhase(SeamPhaseListener.java:228)
    at org.jboss.seam.jsf.SeamPhaseListener.afterPhase(SeamPhaseListener.java:194)
    at com.sun.faces.lifecycle.LifecycleImpl.phase(LifecycleImpl.java:280)
    at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:117)

So you see, the seam error "Concurrent call to conversation" is thrown!

How can I avoid it?

(It makes no difference, if I use @Asynchronous - the same error occurs "Concurrent call to conversation"!).

I must admit, I have not ever used the <a4j:queue>.

But I guess, my problem lays in the fact,

that a action of a bean (which also serves the value for my polled data), is not invoked in another thread.

I have no clue.

I am using this code:

{code}
<a4j:outputPanel id="my_panel"> 

 
 <!--My Poll-Region -->
 
 <a4j:region> 
  <h:form id="form_poll">

    <a4j:poll id="poll" interval="1000" enabled="true" reRender="polled_region" 

       limitToList="true" ajaxSingle="true" ignoreDubResponse="polled_region"></a4j:poll>

  </h:form>

 </a4j:region>

<!-- MY REGION WHICH IS POLLED -->

 <a4j:outputPanel id="polled_region">

    <h:outputText value="#{myBean.actualDate}></h:outputText>

 </a4j:outputPanel>

<!-- MY FORM WHICH INVOKES A ACTION

- Triggering the Action disturbes the polled region to update as long as the action is running!

- After action ends, the polled region starts updating again!

- But I need the polled update also while action is running! -->

<h:form id="formTrigger">

    <a4j:commandButton action="#{myBean.updateRows}" value="update Data">
    </a4j:commandButton>     

</h:form>

</a4j:outputPanel>

{code}

my Bean -Action for getting the actual date:

{code}
@Name("myBean")
@Scope(CONVERSATION)
public class MyBean{
 
// this method can end after a long time (for example 20 seconds)
// and while this method is active, the a4j:poll is disturbed
public void updateRows() throws Exception{
 
// do database operations...
 
}
...
 
// this returns the polled value
public Date getDate()
{
return new Date();
}
..
{code}

The poll works, the date gets updated each second.

But when I trigger the action "updateRows",

then the polled region disturbs as long as the action takes and after action has completed, the polled region is continuing to update its date.

The polled region is disturbed by this exception (which is thrown via updateRows):

{code}
16:31:31,548 WARN  [SeamPhaseListener] uncaught exception, passing to exception handler

org.jboss.seam.ConcurrentRequestTimeoutException: Concurrent call to conversation

    at org.jboss.seam.core.Manager.restoreAndLockConversation(Manager.java:641)

    at org.jboss.seam.core.Manager.restoreConversation(Manager.java:603)

    at org.jboss.seam.jsf.SeamPhaseListener.afterRestoreView(SeamPhaseListener.java:390)

    at org.jboss.seam.jsf.SeamPhaseListener.afterServletPhase(SeamPhaseListener.java:228)
 
{code}

This exception comes after each second (poll-interval="1000") while "updateRows"-Method is running.

After "updateRows"-Method ends, the polled region works correctly again without any exception.

How can a4j:poll updates its region while action "updateRows" is running?

Should I put the Method "updateRows" in another thread?

I really have no clue.

Okay I found the problem.

According to RF-documentation:

{quote}
Try to avoid updating the same server data that might be updated by the 
Ajax requests produced by the user activities. If you need this, be sure your code
allows to access the data from parallel thread without conflicts;
{quote}

This is my problem, I have to get the current Values from within another thread while the updateRows-Method excecutes in the actual Thread.

So I tried it this way:

{code}
@Name("myBean")

@Scope(CONVERSATION)

public class MyBean{
 
public void updateRows() throws Exception
{
 
MyThread polledThread = new MyThread();

 polledThread.start();
 
//long running process..
...
 
}
 
public class MyThread extends Thread

{
@Override

public void run()

{
for (int i = 0; i < 100; i++)

{
   v = i;
 
   date = new Date();

   try  { sleep(1000); }

   catch (Exception e) {}
}

}

}
 
 
private Integer v;

public Integer getValue() { return v; }

public void setValue(Integer i) { v = i;}
 
private Date date;

public void setDate(Date date) {this.date = date;}

public Date getDate() {return date;}
{code}

But I get the same failure as without using a additional thread:

org.jboss.seam.ConcurrentRequestTimeoutException: Concurrent call to conversation..

Hello Ilya,

thanks for the information.

I have used the a4j:queue, but there is a dilemma in using the a4j:queue with a4j:push and a4j:poll. I figured out the problem in a new thread:

http://community.jboss.org/thread/148777