1 Reply Latest reply on Aug 27, 2002 1:44 PM by Dain Sundstrom

    Trouble using UserTx with BMP and Castor

    Bruce Newbie

      I'm noticing some odd behavior with JBoss 2.4.4 on Linux when using the
      CastorJDO plugin with Castor 0.9.3.9 and UserTransactions when calling a
      BMP, BMT EJB. The requirements for the appliction I'm developing specify
      the need to use UserTransactions to provide developers control over
      the transactions.

      The CastorJDO plugin tells Castor to make use of JBoss tx manager by
      fetching it from java:/TransactionManager. This tells Castor to begin
      and commit transactions based on the JBoss tx manager's tx contexts.

      Here is the sequence that must take place from the client app that makes
      calls to the EJB to perform database operations via Castor:

      // fetch the EJB from JNDI
      service = ServiceBroker.getFooService();

      service.startSession(); // start a UserTx
      ... // do some work here using the EJB
      service.endSession(); // commit the UserTx

      For each business method that I execute inside of one of the above
      sessions, there might be, say, three calls to Castor to perform database
      operations (e.g. a finder method, a remover method, a creator method).

      Anyway, upon tracking the tx contexts that Castor creates, they do not
      correlate to each UserTx like I thought they would. I assumed that for
      every UserTx that is started from the client app that it would correlate
      one-to-one with a tx created by the JBoss tx manager. However, what I'm
      seeing is very different. I'm seeing behavior that indicates that for
      each call to Castor, the JBoss tx manager creates a tx. This causes
      my app to fail with exceptions because the objects I'm removing are
      not part of a transaction, and I think that this is due to the extra
      transactions that are created. It's causing objects to be out of scope
      of the tx. This behavior of creating extra transactions seems like more
      a CMT model than a BMT model. Incidentally, I've also gotten around this
      whole problem by using CMT. But I can't use CMT on this app.

      Can anyone confirm that this behavior (the extra transactions) is either
      correct or incorrect for BMT?

      BTW, I am aware of this post/bug as well:

      http://jboss.org/forums/thread.jsp?forum=46&thread=14400&message=3714144&q=castor+bmt#3714144

      This bug has not been confirmed or denied and yet is it from Noveber 2001.