concurrent access?

[Forrest Xu]

Which of the following do NOT support concurrent access?
A. Stateful session beans
B. Stateless session beans
C. Entity beans
D. Message-driven beans
a and b,
right?

[Forrest Xu]

Seems A,B,D. Only Entity beans supports concurrent access.
But why choose 2 answer?

[rastin purr]

IMHO, any beans that supports reentrant to be set to true allows concurrent access.

[Pradeep bhatt]

Answers are
A. Stateful session beans
B. Stateless session beans

[rastin purr]

I think IMHO it should be ABD because all three Entity, Session and MDB does not support reentrant hence cannot be concurrently accessed.
regards

[Pradeep bhatt]

I think IMHO it should be ABD because all three Entity, Session and MDB does not support reentrant hence cannot be concurrently accessed.

Entity beans can be reentrant. IN MDB reentrant does not make sense because client cannot directly invoke the bean but the container does and container makes sure that no more than one request is made to a bean.

[Dragan Milic]

Originally posted by Pradeep Bhat:

Entity beans can be reentrant. IN MDB reentrant does not make sense because client cannot directly invoke the bean but the container does and container makes sure that no more than one request is made to a bean.

Just a note on the SLSB: IMHO reentrant SLSB is an oxymoron, since the container can use only one SLSB per business method call.

Dragan
[ August 29, 2003: Message edited by: Dragan Milic ]

[Pradeep bhatt]

Dragan SLSB cannot be reentrant.

[Dragan Milic]

Originally posted by Pradeep Bhat:
Dragan SLSB cannot be reentrant.

Hi,
as usually i did NOT read carefully the question (especially the NOT part of it ). So, forget what I said

Dragan

[rastin purr]

Sorry, I mean to say SFSB, SLSB and MDB not entity bean. Just notice that

therefore, I think that (IMHO) the answer should be ABD
[ August 29, 2003: Message edited by: rastin purr ]
[ August 29, 2003: Message edited by: rastin purr ]

[Pradeep bhatt]

D is also the answer. MDB concurrently processes JMS messages but the does not allow concurrent access. The EJB container ensures that an MDB instance processes only one JMS message at a time.
[ September 02, 2003: Message edited by: Pradeep Bhat ]

[Pradeep bhatt]

I always monitor your posts!
Just kidding!

Originally posted by Dragan Milic:

Hi,
as usually i did NOT read carefully the question (especially the NOT part of it ). So, forget what I said

Dragan

[Diana Finis]

Regarding Entity beans: I understand that concurrent access is allowed to entity object, and not entity instance, right? So if we are talking about entity instance the answer includes C too? Is that right?
Thanks,