在某些类型的消息中使用MDB池的最佳实践

Question

将MDB与几种类型的消息一起使用，对多个消息使用多个队列，对一个类型的消息使用一个队列，或对具有不同激活规范选择器的所有类型使用一个队列并键入消息头的最佳实践是什么？

Answer 1

I think there are (as with anything) some trade-offs to think about:

Having a queue perform a single, well-defined function promotes good encapsulation, and allows your application to be as flexible and well encapsulated as possible. This would raise possibilities such as queue-specific thread pooling, so you can dedicate more resources to one message type, or ensure that long-running requests of once type don't block more urgent requests of another type.

On the other hand, adding a queue uses system resources, so having too many queues may be inefficient (although you'd need a lot before this is noticeable), or confusing if it makes it difficult to identify the correct queue for a particular message type.

One EIP which is worth considering is the command pattern - this uses a single queue to perform multiple actions. It's also worth bearing in mind the facade pattern - even if your application is internally using a number of different queues, you might prefer to use a facade to present this from client systems.