About Question enthuware.oce-ejbd.v6.2.412 :

[admin]

"If the client does not have a transaction context, only one transaction context will be used."

This seems to be a better option compared to assuming XBean is already in transaction by default.

Did you read the explanation for option 3? It explains exactly why 2 transactions will be created whether the client has a transaction or not.

HTH,
Paul.

[ssoltanid]

I read this topic and the answer to the question.
could be asked This kind of question at the exam ?

[admin]

Yes, it is possible.

[renatumb]

Hello,

REQUIRED is the default so even if you don't see it, you should assume it as REQUIRED. This is also noted in the explanation for option 3.

HTH,
Paul.

Just a complement:
YBean is annotated with REQUIRED, even without this annotation it would run in a transaction context.. As Paul had said:
".. if you don't see it, you should assume it as REQUIRED" ... so, 2 transactions context will be used!

[himaiMinh]

If the client does not have a transaction context ...

There are two scenarios:
1. The client of XBean does not have a transaction context. But XBean 's regularM () is executed in a transaction by default. YBean's asyncM() executes in its own separate transaction. Therefore, there are only 2 transaction contexts, one is for regularM(), another one is for asyncM()

2. The client refers to XBean, maybe ? If XBean's regularM() has a transaction attribute NotSuppported, then, there is only one transaction context for asyncM().

In my opinion, we need to clarify who the client this option is refering to.

[admin]

"If XBean's regularM() has a transaction attribute NotSuppported" cannot happen because the question clearly says< "In absence of any other deployment information or annotations related to these beans". Where there is no such information, then the transaction attributed is assumed to be Required.

[aazizi.tarik]

This "In absence of any other deployment information or annotations related to these beans" doesn't mean that the bean is not a BMT, in that case there will be only one Tx context I guess

[admin]

As per section 13.3.1:

Typically enterprise beans will be specified to have container-managed transaction demarcation. This is the default if no transaction management type is specified.

[aazizi.tarik]

Ok, I thought "absence of any other deployment information or annotations" means that some annotation exist and we don't have the information. sorry its my english wich is bad

[johnlong]

a new one is created for YBean also.

Where exactly does this new transaction demarcation start : in XBean.regularM() or in YBean.AsyncM?

[admin]

The container starts a new one just before it invokes YBean.AsyncM method. It happens in container's code. Not in application code.

[johnlong]

I see, will this transaction cover any application code in this particular example?

[admin]

Yes, it will cover asycnM method.

[johnlong]

So transactional context will propagate into asycnM method and it will be new transaction as if RequiresNew transactional attribute specified on asyncM method?

[admin]

Yes, REQUIRED behaves like REQUIRES_NEW in case of asynchronous calls.

[johnlong]

Sorry for the off-topic. But I have another question about transaction propagation.
Excerpt from O'reilly EJB 3.1 book

If an EJB calls another EJB with a different transaction scope, the persistence context, regardless of whether it is extended, is not propagated.

I think this is wrong, as transaction shall propagate from BMT to CMT. Could you please clarify? Thank you.

[admin]

I am not sure in what context the book says that but you might want to talk to the author of the book about it.

It is true that Persistence context is propagated along with the transaction. But if two beans have different transaction attributes that require different transactions to be started, the persistence context cannot propagate.
You should also see Section 7.6.3 Persistence Context Propagation of JPA Specification.
HTH,
Paul

[johnlong]

Thank you.