JMS Messages Refusing to participate in JTA transaction

Question

I have been working on this issue for several days, and I cannot find a path out.
I have a situation where I need to write to the database and also send out a JMS message. I want either both to work, or nothing to work, so its a straightforward JTA application, so I would think.
The JMS connection factory in use is set to participate in XA transactions (I have checked this 10 times).
I originally had a UserTransaction started and committed around these statements, but since this did not seem to be working, I put all the code in an EJB with transaction Required.
Either way, it is not working the way I expect.
I have a break point in the MDB that receives the message, as well as a break point on the publisher code and the code immediately after it. I find every time that as soon as I step past the JMS publish, the breakpoint in the MDB stops next, indicating that the JMS message was sent out, even though the publishers transaction is definitely not completed -- eventually the debugger will return back to the next line after the publish.
I am pretty sure we have done this many times in the past, and it has worked like I expect transacted code to work.
Anyone have any ideas on obvious things to check to determine why the JMS message is going out outside of the transaction? Or not so obvious...
Thanks in advance,
ken clark

Answer 1

Hi Ken,
You're right -- the use case is common, but there are a couple pitfalls that new users sometimes run into.
The break-point tracing results that you have are expected. A sender's message goes to the JMS server while the message send call is made. If the message is participating in the transaction, it is still sent, but it won't become visible to consumers until the transaction is later committed.
To ensure that a sent message participates in a transaction:
1 - ensure the connection factory is "XA enabled"
2 - ensure there's a transaction on the thread. For example: System.out.println("MY TX" + weblogic.transaction.TransactionHelper.getTransactionHelper().getTransaction());
3 - ensure that your connection.createSession() invoke passes "false" for the first parameter -- not true! if true and you're not using a resource ref, then the session becomes a "transacted" session, and JMS messages will participate in an independent local transaction rather than the global XA transaction
4 - If not using a WebLogic JMS to send, then you need to ensure that WebLogic automatically enlists the foreign vendor send call in the WL TX. All that is required is to use a standared JEE "resource reference" to obtain the CF. rather than directly looking up the foreign CF in the foreign JNDI provider. This lets WebLogic detect and wrap the application's foreign vendor calls, which in turn enables automatic enlistment. See the WebLogic JMS Interop FAQ for more info.
4B - If you're using AQ-JMS to send, more work is required, as AQ-JMS is fairly unique among JMS implementations. WL 10.3.1 and later provides features to simplify this work.
For a related FAQ see [ Integrating Remote JMS Providers | http://download.oracle.com/docs/cd/E15523_01/web.1111/e13727/interop.htm#JMSPG553 ], and for resource ref info see [ Enhanced Support for Using WebLogic JMS with EJBs and Servlets|http://download.oracle.com/docs/cd/E15523_01/web.1111/e13727/j2ee.htm#g1329180 ] (especially example 9-5).
Hope this helps,
Tom