Fred Loney wrote: > There can be multiple MDB queue receivers. The MDB container delegates > to a single available MDB instance whose selector matches the message > attributes. The JMS spec does not specify which potential receiver gets > the message, but does specify that at most one receiver gets the queued > message. The queue MDBs should partition the messages based on selector. > Otherwise, a pub/sub topic is a better choice. > > An interesting variation is two MDBs, a specialist and a generalist, for > the same queue. The specialist MDB has a selector, the generalist does > not. The desired behavior is that the specialist grabs the message if > the selector matches, otherwise the generalist handles the message. > AFAIK the way to do that is to add a selector to the generalist that > excludes messages handled by the specialist. Is there a good > alternative?
Specialist gets the message, and sends it to a queue for the generalist if it has not been handled. > Fred Loney > Spirited Software, Inc. > www.spiritedsw.com > > ----- Original Message ----- > From: "Alvin Wang" <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Sent: Thursday, February 28, 2002 6:53 AM > Subject: Can one queue have multiple comsumers? > > > >>Hi! If I setup multiple MDB listening to the same queue, is it >> > possible? > >>what will happen? Will they race against each other? Or one will >> > override > >>the others? Or all the listener will receive the message whenever >> > there is > >>one available (same as pub/sub)? And can I also use selector to let >> > the MDB > >>select there own messages exclusively? >> >>Thanks! >> >> > > =========================================================================== > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff EJB-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". > > > =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff EJB-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
