ERRATA CORRIGE - Re: OJB with distributed tx and BMT

[Francesco Russo <f....@cineca.it>]

Sorry for duplicating my post, but I made a mistake typing "Container 
Managed Persistence" instead of "Container Managed Transaction"!

Hi Thomas,
let's suppose I want to use OJB with distributed BMT. In such a
scenario, I guess I should do something like:

//* a generic SessionBean's method
...
UserTransaction utx = sessionCtx.getUserTransaction();
utx.begin();
//* acquire transactional resources which will be enlisted in the
current transaction
//* these resources will be XAResources according to the XOpen/XA
standard specification

... do work
utx.commit();
...


So, I am wondering how does OJB integrates itself in such a scenario.
Which OJB classes can support me in coding something like that? I have
downloaded your sources, but all the examples were involved with
Container Managed Transaction, so I thought it was simply not possible
to achieve distriuted BMT with OJB.

As in my previous mail, I repeat: I am a newbie to OJB, so maybe I am
just missing something, but I need you to prove that I am wrong, for
example pointing me out the classes I should better study and
investigate to fully understand that I am really wrong.

-- 
______________________________________________________
Francesco Russo
DLAB - Datawarehouse Laboratory
CINECA - Interuniversitary Computing Centre
via Magnanelli, 6/3
40033 Casalecchio di Reno (Bologna) - ITALY
e-mail: f.russo@cineca.it



Thomas Mahler wrote:

> Hi Francesco,
>
> OJB provides support for JTA integration, so you should be able to use 
> it in distributed BMT (and also CMT) environments.
> Our JTA Mechanism works well with several J2EE containers and also Non 
> J2EE-JTA implementation (as some CORBA ORB's with TransactionServer 
> implementation)
>
> I don't quite understand why you are talking about JCA in this context?
> JCA is not needed to work with distributed transactions.
>
> Please read http://db.apache.org/ojb/deployment.html for more details.
>
> Thomas
>
>
> Francesco Russo wrote:
>
>> Hi everybody,
>> I was wondering whether OJB could be used in a managed enviroinment 
>> with distributed BMTs (Bean Managed Transactions) or not. In order to 
>> find an answer to my doubts, I downloaded the srcs and started to 
>> look for some useful clues and I didn't find anything stating the 
>> above scenario can be implemented, rather a hint that made me think 
>> it was not yet implemented (but planned for the future?).
>>
>> That's what I found:
>> since, if I am not wrong, it is required to acquire a 
>> ManagedConnection from the Application Server implementation of the 
>> javax.resource.spi.ConnectionManager via a call to the  
>> allocateConnection(..., ...) method, I have searched for this call in 
>> the OJB srcs. As a result I got that the above call is issued only in 
>> two classes:
>>
>> 1. org.apache.ojb.otm.connector.JCAKit
>> 2. org.apache.ojb.otm.connector.OTMConnectionManager
>>
>> The former class calls the allocateConnection method over the latter 
>> one, so this entails that OJB provdes its own implementation of the 
>> javax.resource.spi.ConnectionManager, behaviour that is common to all 
>> those cases in which the application is outside a managed environment.
>>
>> Question 1: why not relaying on the Application Server implementation 
>> of the ConnectionManager?
>>
>> Furtheron, the javax.resource.spi.ManagedConnection returned as an 
>> org.apache.ojb.otm.connector.OTMJCAManagedConnection does not support 
>> the getXAResource() method, which is needed for enlisting the 
>> connections currently used by an application into the transactional 
>> context handled by the external TransactionManager according to the 
>> XOpen/XA Specification.
>>
>> As I stated before, all these things made me think it is not possible 
>> to use BMTs along with OJB in managed environmet with distributed 
>> transaction, but possibily I'm just missing something, that's why I'm 
>> asking your help.
>>
>> Any comments are appreciated
>>
>
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
> For additional commands, e-mail: ojb-user-help@db.apache.org
>
>


-- 
______________________________________________________
Francesco Russo
DLAB - Datawarehouse Laboratory
CINECA - Interuniversitary Computing Centre
via Magnanelli, 6/3
40033 Casalecchio di Reno (Bologna) - ITALY
e-mail: f.russo@cineca.it



---------------------------------------------------------------------
To unsubscribe, e-mail: ojb-user-unsubscribe@db.apache.org
For additional commands, e-mail: ojb-user-help@db.apache.org