Off-Topic: JMS Design Question...

[Ajay Chitre <AC...@InterAsset.com>]

Hello,
 
This is kind of off-topic, so I apologize in advance.  We do have some
J2EE gurus on this mailing list so I decided to ask it here.  (Is there
any other *active* mailing list where I can post JMS related questions?)
 
Anyway, I need some help to develop a JMS based solution. Here's what we
are trying to accomplish;
 
We need to send XML messages (as well as other types of messages) back &
forth between two Application Servers. In other words, a Web Application
created by us will send a message to the application server of our
client and vice versa. 
 
This is what I was thinking of doing;
 
1) When it's time to send a message on our side, we will write it to a
Topic in our App Server.
2) A MDB on our side will retrieve the message and send it to the Topic
of our client.
 
The same logic will apply for incoming messages;
1) Client will write a message to our Topic.
2) A MDB on our side will then pick up this message and process it.
 
If this sounds okay, then I am wondering how I can handle Exception
conditions.  For example;
 
1)  If Client's App Server is down, then our MDB should keep resending
till the message is sent successfully.  How can I do this in JMS?
2)  If our JMS Server is down (shouldn't happen, but let's say it does)
what should the Web App do?  Would "Durable Subscriptions" help in this
case?
 
I would greatly appreciate any input in this matter. Thanks (a lot) for
your time.
 
- Ajay