How to dynamicly change message selector?

[paulbandler]

I need to be able to programatally manage a Q (stop/start) it - that's fine. But I also need to be able to modify the message selector that MDB's use to retreive messages from the Q. Is there a way to achieve this?

regards,

Paul Bandler

[adrian.brock]

The message selector is in the deployment
descriptor.

<message-driven>
...
<message-selector>whatever</message-selector>
...
</message-driven>

Regards,
Adrian

[paulbandler]

> The message selector is in the deployment
> descriptor.

Yes, but can that be manipulated programatically while the MDB is running? If I modify the DeploymentDescriptor attribute of the org.jboss.management.j2ee.EJBModule MBean instance that represents the deployed MDB, will that information be propogated to the MDB and take effect in real-time?

[paulbandler]

> The message selector is in the deployment
> descriptor.

Yes, but can that be manipulated programatically while the MDB is running? If I modify the DeploymentDescriptor attribute of the org.jboss.management.j2ee.EJBModule MBean instance that represents the deployed MDB, will that information be propogated to the MDB and take effect in real-time?

[adrian.brock]

The deployment descriptor in MEJB is informational
it has no affect on the EJB.

The message selector is established when
the MDB subscribes to Queue/Topic, i.e.
at deployment.
Actually, it is done by the JMSContainerInvoker,
it might be possible to make the selector
available through the MDB container jmx interface
and force a restart of the invoker (similar to
connection recovery processing).
But that is a bit of a hack and would be jboss
specific.

In the case of Durable Topic subscriptions,
if you change the selector,
it effectively does an unsubscribe/subscribe
so you will lose any previous messages in
the subscription.

Regards,
Adrian

[paulbandler]

Adrian,

> Actually, it is done by the JMSContainerInvoker,
> it might be possible to make the selector
> available through the MDB container jmx interface

I already have a locally 'enhanced' JMSContainerInvoker which adds a slightly more elaborate recovery / retry scheme so I am willing to do a further enhancement to this. However when I tried to find the JMX identity of the invoker I couldn't find it - it doesn't show up on the console and when I added 'getServiceName()' to its debug calls it printed 'null'.

Could you please clarify whether/how the invoker is JMX managable?

rgds,

Paul

[adrian.brock]

The invokers aren't registered in the MBeanServer.
They are under the control of the relevent
container.
i.e. MessageDrivenContainer

Regards,
Adrian

[paulbandler]

> The invokers aren't registered in the MBeanServer.
> They are under the control of the relevent
> container.
> i.e. MessageDrivenContainer

Thanks for your patience Adrian....

... but what is the MessageDrivenContainer MBean service name and how can I use it pass control/data down to the JMSContainerInvoker? In my test configuration I see an MBean instance called:

service=EjbModule,url=file%/C%/JBoss/jboss/server/default/deploy/ejb-Testrig1-rmpframework.jar

- is this what you mean by the container?

I see that the EjbModule contains a MessageDrivenContainer instance within its collection of Containers and I see that it is the MessageDrivenContainer that gets configured somehow with the ContainerInvoker. So are you suggesting that to get JMX control of the ContainerInvoker I would need to extend the EjbModule JMX interface with the operations I need and delegate them down to MessageDrivenContainer(s)?

Just taking a step back in case there is an easier solution - what I am trying to achieve is programatically enable/disable a particular MDB deployment and when it is enabled I need to tell it to only select messages that have a timestamp later than a particular time. The scenario is one where a 'backup' node is taking over from a failed primary node and needs to only pickup messages later than a particular time.

thanks,

Paul

[paulbandler]

Adrian,

Will a start/stop on the EjbModule MBean be safely and repeatably be delegated down to the startService/stopService entry points on the JMSContainerInvoker?

Tried to follow it thru' the source but got a bit lost where the EjbModule uses

serviceController.start(con.getJmxName());

to propagate the operation.

If I can use this start/stop and somehow put the timestamp I need to be inspected by the Invoker into a well-known JNDI accessable object perhaps I have the building blocks I need...

cheers,

Paul