2.3. Message Producer (Sender)

Message producing applications send messages to an exchange on the message broker. The exchange then distributes the messages to the queues that are subscribed to the exchange. Depending on the type of exchange and the parameters used to subscribe the queue, messages are filtered so that each queue subscribed to the exchange gets only the messages that are of interest.

Message producers can send their messages with no knowledge of or interest in the consumers. Because they send to an exchange, they are decoupled from the receivers of the messages. Consumers can then control how and what messages they receive. Producers can also control how their messages are consumed by creating and subscribing a queue, and route the messages they send to the exchange to that queue. In this way a wide range of designs are possible.