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MDBs and transactions
MDBs and transactions
You can set these properties with the DDEditor. From the Console, navigate the tree
on the left until you find the module containing your MDBs. Right-click the module and
select DDEditor. When the DDEditor appears, select the bean node in the Navigation
Pane to open the editor's panels for that bean. Select the “Properties” tab from the
Content pane, and Add properties.
For information about using JMS within transactions, go to Chapter 23, “Using JMS.”
This section deals exclusively with using MDBs in transactions.
A common scenario for using the onMessage() method of MDBs involves transactions
requiring two-phase commit (2PC). Such an MDB has the REQUIRED transaction
attribute. The onMessage() method is written to access and possibly update an external
resource. Completion of the container managed transaction for the MDB method must
include receipt of the message that triggered the method, and any work performed
against the external resource from within the method. To achieve this, the transaction
must be coordinated by a 2PC transaction service, such as the OTS engine. Refer to
EJBs and 2PC Transactions section in Chapter 19, “Transaction management” for
more details on optimal ways to use the OTS engine with MDBs.
Chapter 20: Message-Driven Beans and JMS 189