[Building Sakai] Elluminate (Collaborate) - Unique Constraint Error

[Sam Ottenhoff]

My guess is that the developers of this tool incorrectly use the Hibernate
sequence generator called "increment" despite it being non-cluster-safe:

   http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/mapping.html

Look in the Hibernate definition files (end in .hbm.xml) and look for:

  <generator class="increment"/>

That is bad and won't work for anyone that runs more than one Sakai server
(everyone).

Use "native" instead and your database will generate sequences correctly:

  <generator class="native"/>

Do the developers of this integration maintain the integration as open
source?

--Sam

On Wed, May 16, 2012 at 11:36 AM, Paul Dagnall <pdagnall1 at udayton.edu>wrote:

> Hi
> We're getting a bizarre error using the Elluminate (now Blackboard
> Collaborate) synchronous integration. The problem is, all works fine on app
> server Sakai2 but I get "ORA-00001: unique constraint" when I do the same
> thing on Sakai1. This error tells me that it's trying to insert a record
> with a duplicate primary key. The code is identical on both servers.
>
> Using Sakai2 (the one that works) I can create records and I see the ID
> column in ELL_SESSION_DATA table increment by 1 appropriately. Updates work
> fine. It just seems to be inserts from Sakai1 only that cause the conflict.
>
> It gets stranger. On a whim I decided to redeploy the tool and bounce
> tomcat. Afterward everything was fine on both servers for a time, but later
> the problem resurfaced but it switched servers. The problem is only
> happening on the other one now. Grrrr!
>
> We're new to using multiple app servers. Other tools are fine. Am I
> missing something? Could there be a sequence missing? Have you ever heard
> of a sequencing conflict like this occurring with multiple app servers
> connected to the same database?
>
> Thanks!
>
> Paul Dagnall
> Application Developer & Administrator
> University of Dayton
>
>
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