In the code below from jBoss, in delistResource its calling XAResource.end
(xid, Status.STATUS_ACTIVE), which is not even a valid parameter, except
possibly by coincidence. Is it supposed to be XAResource.TMSUCCESS? Are
resources not allowed to fail?
I have a non-distributed implementation of JTA that is further along than
jBoss but nowhere near Tyrex. I built it with Tyrex, jBoss, Jonas, and the
JTA spec in hand. I did NOT have the XA Spec, although I've just ordered
it.
When I started testing I entered a world of pain. First, using Minerva XA
wrappers with InstantDB I hit deadlock problems. Then with Informix JDBC
2.11 the second XAResource hangs on a socket read and the server never
responds. So I gave up, made a "fake" JTA for my immediate needs, and
ordered the XA spec.
Has anybody had success with JDBC/XA (with more than one XAResource
involved)?
If you're interested in more detail/code let me know.
;-J
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of marc fleury
> Sent: Thursday, July 27, 2000 5:56 PM
> To: jBoss Developer
> Subject: RE: [jBoss-Dev] TransactionImpl
>
>
> Carlos,
>
> 1- Please restrain from sending formated text, send plain text
> when you can
>
> 2- I just came back from a deep dive in the current TM package. To be
> honest it is not really up to snuff and I am considering nipping it
> altogether. I have put stop gap fixes in there just to get the
> TxInterceptor and the container behaving properly.
>
> You seem a fellow keen on JTS/JTA do you have spare cycles for the
> integration of a TM?
> When I integrated Jonas' TM it took me a day (most the code is
> simple) heck
> I'll do it.
>
> marc
>
> -----Original Message-----
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED]]On Behalf Of Carlos Pita
> Sent: Thursday, July 27, 2000 5:44 PM
> To: [EMAIL PROTECTED]
> Subject: [jBoss-Dev] TransactionImpl
>
>
> Hi!
>
> I have a question (it could be an observation if already had more
> self-confidence) about enlisting/delisting xa resources in the Transaction
> implementation. Here are the sources of both methods as they were in last
> week CVS repository (remember that resources is a Vector):
>
> public boolean delistResource(XAResource xaRes, int flag)
> {
> try {
> xaRes.end(xid, Status.STATUS_ACTIVE);
> // resources.removeElement(xaRes);
> return true;
> } catch(XAException e) {
> e.printStackTrace();
> return false;
> }
> }
>
> public boolean enlistResource(XAResource xaRes)
> throws RollbackException
> {
> // Check rollback only
> if (status == Status.STATUS_MARKED_ROLLBACK)
> {
> throw new RollbackException();
> }
>
> // Add resource
> try {
> xaRes.start(xid, Status.STATUS_ACTIVE);
> resources.addElement(xaRes);
> return true;
> } catch(XAException e) {
> e.printStackTrace();
> return false;
> }
> }
>
> When the transaction commits (or rollback) the algorithm is:
> [...]
> for (int i = 0; i < resources.size(); i++)
> {
> try
> {
> ((XAResource)resources.elementAt(i)).commit(xid, false);
> } catch (XAException e)
> {
> try {
> ((XAResource)resources.elementAt(i)).forget(xid);
> } catch(XAException another) {}
> e.printStackTrace();
> // TODO: what to do here?
> }
> }
>
> So the question is:
>
> What if we have more than one xa resource enlisted in the transaction
> corresponding to the same resource manager? I think that in this scenario
> the algorithm will run the 2 phase protocol against the same resource
> manager and for the same transaction more than once.
>
> Regard this, the JTA spec says:
>
> "
> The enlistResource request results in the Transaction Manager
> informing the
> resource manager to start associating the transaction with the work
> performed through
> the corresponding resource�by invoking the XAResource.start method. The
> Transaction Manager is responsible for passing the appropriate flag in its
> XAResource.start method call to the resource manager. The XAResource
> interface
> is described in section 3.4.
> If the target transaction already has another XAResource object
> participating in the
> transaction, the Transaction Manager invokes the
> XAResource.isSameRM method
> to
> determine if the specified XAResource represents the same resource manager
> instance.
> This information allows the TM to group the resource managers who are
> performing
> work on behalf of the transaction.
>
> 1.Transaction Branch is defined in the X/Open XA spec [1] as follows: 'A
> global transaction has one or
> more transaction branches. A branch is a part of the work in support of a
> global transaction for which the
> TM and the RM engage in a separate but coordinated transaction commitment
> protocol. Each of the RM�s
> internal units of work in support of a global transaction is part
> of exactly
> one branch. .. After the TM begins
> the transaction commitment protocol, the RM receives no additional work to
> do on that transaction branch.
> The RM may receive additional work on behalf of the same transaction, from
> different branches. The differ-ent
> branches are related in that they must be completed atomically. Each
> transaction branch identifier (or
> XID) that the TM gives the RM identifies both a global transaction and a
> specific branch. The RM may use
> this information to optimise its use of shared resources and locks.'
> "
>
> That's all for now.
> Thank you,
> Carlos
>
