用于群组广播的JMS架构

Question

I want to build a broadcasting system. It consists of several groups. Each group has one User who can broadcast a message to the other members of the same group. What is the appropriate JMS architecture for this kind of system?

Should I use a topic with durable subscription? I don't know much about pub/sub messaging style, can topic have multiple subscription? If so, then each subscription represents a group in the broadcasting system. If not, should I use a queue whereas each message has a header specifying the group and then use a JMS selector to filter the message so that each member receive only messages from groups he's in?

Also, I am thinking of persisting the messages after consumption. I decided to make each message to expire after one hour, and each member should check the database for every message he misses. But, how can I fire an action upon message expiration?

Answer 1

Topics can be used... Topics can have multiple subscribers. Each group can use a different topic. The user can send message to that topic and all the subscribers would receive it.

The durable subscribers are required only if the subscribers can go offline for sometime and the messages for the subscriber shouldn't be lost.

Queue doesn't suite well in one-to-many scenarios. But if you have a pre-defined set of receivers you can use a queue for each one of them and route messages to that. But this is a overhead to route the messages to the receiver's queue. JMS selector idea you have suggested would work but for a queue only one client can receive a message. In topics it distributed to all the clients interested in that topic.

Normally one would persist data to database and not the message itself. So you can persist to database and then create the message for delivery.