Hi SM dev team,
SM is delivered with activeMQ. I am doing some tests on sm-jms component
and I found some problems...
In fact, as sm-jms only uses jms api, it may be possible to change the
implementation.
The problem is that sm-jms is not fully jms compliant. I have identified
at least two problems :
1) Destinations creation
2) session use
1) Destinations creation
The MultiplexingConsumerProcessor and the MultiplexingProviderProcessor
create destinations using session.createQueue and session.createTopic.
It is written in the jms spec that :
"This facility is provided for the rare cases where clients need to
dynamically manipulate queue identity. It allows the creation of a queue
identity with a provider-specific name. Clients that depend on this
ability are not portable. Note that this method is not for creating the
physical queue. The physical creation of queues is an administrative
task and is not to be initiated by the JMS API."
So the sm-jms can't use any implementation. I think that there is an
added functionnality in activeMQ which make the created destination
available outside of the jms server... A correct use will use the admin
api of the jms provider...
2) session use
The MultiplexingProviderProcessor is using sessions in a wrong way.
It is written in the spec that :
"A JMS Session is a single-threaded context* for producing and consuming
messages.
* There are no restrictions on the number of threads that can use a
Session object or those it creates. The restriction
is that the resources of a Session should not be used concurrently by
multiple threads. It is up to the user
to insure that this concurrency restriction is met. The simplest way to
do this is to use one thread. In the case
of asynchronous delivery, use one thread for setup in stopped mode and
then start asynchronous delivery.
In more complex cases the user must provide explicit synchronization."
I have added traces in sm source code to verify that the thread which
creates the session on the doStart method is not the same as the ones
using the session to send messages for example (process method)
I think the way to do that is to close the session after the creation of
the temporary destination (if needed) and to create producers and
consumers just before using them...
I made the test and it is running well.
In conclusion,
1) Is it possible to integrate into sm-jms the correct source code to
support JORAM jms implementation ? Perhaps we can perform a verification
to know which impl we should use and then use the one of activemq or the
one of joram (config file ?)
2) Can you update sm-jms to use sessions in a single thread ?
Any remarks is welcome !!
I can create a jira if you want and I can give you the joram code to use
to create dynamically a queue thanks to administration (I tried it) !
Thanks,
Charles
