What is RabbitMQ?

Exchange Type

The exchange parameter is the name of the exchange. The empty string denotes the default or nameless exchange: messages are routed to the queue with the name specified by routing_key, if it exists.

Topic can achieve fanout and direct

• fanout : Broadcasts all the messages it receives to all the queues it knows

• direct : Binding Exchange Name=Routing Key

• topic : All matching routing key queue will accept

Efficiency: fanout > direct > topic

如果Binding中的Routing key為# 或者 #.#, 則全部轉發，類似Fanout Exchange 如果指定了Exchange是Topic類型的，但是相應的Binding中的Routing key *，#都沒有，則相等才轉發，類似於Direct Exchange