2 Replies Latest reply on Sep 20, 2010 7:15 PM by gus888

s:button produces concurrent call to conversation

ammarc Jun 23, 2010 1:56 AM

Dear all,

I have the problem that double-clicking on a seam button produces Error 503 - Concurrent call to conversation. I'm using Joss-Seam-2.2.1 and my code looks like this:

<s:button
 action="#{sessionStatus.setShowAll(false)}"
 value="#{messages.myLabel} #{messages.resourcesLabel}"
 rendered="#{sessionStatus.showAll}" />

The s:button calls a method inside a long-running conversation, I have no problems when using view. I have the impression that it is caused when calling the same method before the first finished. I received no answers through google, there are solutions for Ajax buttons (eventsQueue, ignoreDupResponses, requestDelay as described on http://docs.jboss.org/seam/2.0.1.GA/reference/en/html/conversations.html), but this does not work for s:button.

I would be glad for hints...

Cheers

1. Re: s:button produces concurrent call to conversation

matinh Jun 23, 2010 3:42 AM (in response to ammarc)
Hi Aleks!

I'm having the same problem and already did some more research. There are many similar forum posts, of which most are having Problems with AJAX requests. At least this posting [0] describes the problem without AJAX and it seems there is no simple solution for the problem.

You should probably read Seam's documentation chapters 7.12. Concurrent calls to conversational components [1] and 4.1.10. Concurrency model [2] which are relevant for this kind of problem but both chapters do (IMHO) not provide a satisfying solution.

The solutions (or workarounds) I've found so far are the following:

use a poll-based approach with AJAX on the client side to work around the concurrent requests on the server

disable all links and buttons in the UI, once a request was sent (with a modal panel for example)

If you find out anything new, please let me know.

hth,

- martin

[0] http://seamframework.org/Community/ConcurrentRequestTimeoutExceptionWhenDoubleclickingInJBPM

[1] http://docs.jboss.com/seam/2.1.2/reference/en-US/html/conversations.html#d0e6535

[2] http://docs.jboss.com/seam/2.1.2/reference/en-US/html/concepts.html#concurrency
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2. Re: s:button produces concurrent call to conversation

gus888 Sep 20, 2010 7:15 PM (in response to ammarc)

I resolved the problem with the following simplest solution: changed s:link or s:button to h:commandLink or p:commandLink (PrimeFace) for redirecting to a new conversation page. I found the conversation id didn't change when I used s:link to redirect a new page with a new conversation, but h:commandLink did. Hope it is helpful.
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