Thanks, Tommy.
I looked at the JTS spec after sending the original query, and it
does explain (at least in theory) how this is supposed to work. I'm
still unclear as to whether it works across vendor boundaries. I
wonder if there have been many successful attempts to do so. I
suspect that if there are any successful EBJ/CORBA coordinations,
they were successful within the context of a single vendor. I'd be
curious to find out what people have tried.
And we're currently debating the correctness of the ACID claims. From
what I understand, EJB's ability to deliver Isolation and Durability
depend on the capabilities of the various Resource Managers.
Consistency (and especially global consistency) still seems like it's
up to the application to maintain. Is there anything in the various
specs that defines global consistency and how it could be maintained?
Mark
>Mark, I think you can find answers to many of your questions in the
>JTS Spec, but I try to answer them anyway...
>
>
> >We would like to understand whether the EJB specification
> >defines/supports/prohibits transactions that cross container
> >boundaries, and, if so, how such transactions are coordinated. If a
> >transaction can span multiple containers/servers, which
> >container/server is considered to be the Transaction Coordinator?
>
>
>The container where the transaction started. (and you can only
>terminate the transaction from the same JVM as the transaction
>originator.)
>
>
> >We would also like to know whether such transactions could be carried
> >out among containers provided by multiple vendors, and what protocol
> >they would use to coordinate such transactions.
> >If not defined in the specification, are there vendors that are
> >solving this problem? How are they doing this?
>
>
>I think it *is* defined (in the JTS spec). The answer is OTS. Take a
>look at org.omg.CosTransactions and org.omg.CosTSPortability. I
>cannot say if there are any success for inter-ORB interoperability
>today. (I guess we hear from the vendors if it exist :-) )
>
> >Can CORBA objects participate in transactions coordinated by an EJB
> >Server? Can EJB components participate in transactions coordinated on
> >the CORBA side?
>
>
>According to the JTS spec it is optional to support CORBA
>application entities, i.e. Transactional Client, Recoverable Object,
>and so on. These entites use the interfaces defines in the
>CosTransaction module in that case. (So if you have access to the
>same transaction manager and uses the transaction manager directly
>from the CORBA object I guess it could work.)
>
> >Which of the ACID transaction properties are being (can be)
> >preserved/guaranteed for global transactions (within a container and
> >across container boundaries), given that serializability of local
> >transactions doesn't imply serializability of global transactions? We
> >know that atomicity is easy to achieve (via the two-phase commit
> >protocol) - what about the other properties?
>
>
>According to the JTS spec (again) the transaction manager must
>guarantee the checked transaction behavior, which means the
>transaction manager has to be sure that all the work has been
>completed for all the XA resources participating in the global
>transaction. This guarantees the transaction integrity. But the
>question is still there. Which of the properties are being
>preserved? I think atomicity, isolation and durability can be
>preserved, but how about Consistency?
>
>
>Hope this helps
>/Tommy
>
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____________________________________________________________
Mark Feblowitz GTE Laboratories Incorporated
[EMAIL PROTECTED] 40 Sylvan Road, Waltham, MA 02154-1120
http://macfebg3.gte.com/MarkFeblowitz
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