I am facing a design problem, here is some basic requirement: Aggregator 1. Separate service for blog,video,images and associations. 2. Each of the service should be completely separate, that means they run on separate tomcat. 3. And each aggregator must be able to query local database and other aggregators 4. Traversal of services must be asynchronous using a ring network.

For example, we have a ring like ws1->ws2->ws3->ws4->ws1. Each node represents one type of one aggregator. The traveral goes in this way: the query from ws1 to ws2, and ws1 is waiting for the response from ws2 asynchronously; ws2 to ws3, also ws2 wait for ws3 asynchronously. If ws3 has the data, reply to ws2 then to ws1, then reply.

However if ws3 goes away, the traversal should go back to ws2, then to ws1, then go to ws4, then go to ws3 again. then tells ws4 since ws3 fails.

The required technology is axis2 and tomcat 6.

Does anybody have any clue about it? If it is clear, I can clarify the question more clearly. Thanks very much.