JMS proxy and XA connection factory

Question

Hi all,
I would like to ask you what is the best practice to adopt about the scenario described below.
A JMS proxy retrieves a message and processes it.
Any error could occurr during processing it and, in case of errors, the JMS proxy error handler publishes the message on ad hoc recovery destination D.
(later another app will check failed messages for fixing & republishing them into ALSB).
In that scenario we have the JMS proxy and the jms business service that, in case of errors, publishes on destination D.
Should the JMS proxy and the business service use both a XA connection factory in order to perform all the above steps in one transaction ?
Otherwise if the business service itself fails publishing on destination D, the message retrieved by the JMS proxy is lost and not re-delivered to the JMS proxy.
Or XA connection factory is not needed and could I use
Routing Options with exactly once or both are needed ?
Thanks
ferp

Answer 1

Hi all,
I did some tests and follow what I've achieved.
Scenario 1.
- Precondition
-- A JMS proxy with XA factory + Error Destination (MyRecoveryQueue)
-- A business service BS with XA factory that publishes into MyOutboundQueue
-- No "exactly once" routing option used calling BS
-- an error is forced in the pipeline
- Flow
-- proxy retrieves a message and try to publish it using BS
-- an error is forced in the pipeline:
--- transaction is rolled back, message redelivered to proxy
--- the message is posted to the error destination after all the retries failed
Scenario 2.
- Precondition
-- As 1. but no error is forced in the pipeline
-- the MyOutboundQueue destination queue is paused
- Flow
-- proxy retrieves a message and try to publish it using BS
-- BS fails to publish it on MyOutboundQueue (because it is paused)
--- transaction is rolled back, message redelivered to proxy
--- the message is posted to the error destination after all the retries failed
Scenario 2A.
- Precondition
-- As 2. with MyOutboundQueue paused and resumed
- Flow:
-- proxy retrieves a message and try to publish it using BS
-- BS fails to publish it on MyOutboundQueue (because it is paused)
--- transaction is rolled back, message redelivered to proxy
--- before all the retries failed the queue is resumed
--- BS succeeds to publish the message
Scenario 3.
- Precondition
-- A JMS proxy with NO XA factory + Error Destination
-- A business service BS with NO XA factory
-- No "exactly once" routing option used calling BS
-- an error is forced in the pipeline
- Flow
-- proxy retrieves a message and try to publish it using BS
-- an error is forced in the pipeline:
--- transaction is NOT rolled back, message NOT redelivered to proxy
-- so
--- no message delivered to MyOutboundQueue2 destination
--- no message delivered to MyRecoveryQueue2 destination
--- message consumed from MyQueue2 and now is lost!
To publish message into MyRecoveryQueue2 a proxy error handler has to be added and here added explicit publish to MyRecoveryQueue2.
But naturally in that case if in the proxy error handler, the explicit publish fails or any error occurrs no message is delivered to recovery queue.
So if I'm not using an XAFactory the message is auto-acknowledged as soon as it is read and I've to use XA factory if I want the message to be put back in the queue in case of errors and the retry to happen.
So both my proxy service and business service use an XA factory.
Regards
ferp