RabbitMQ is an open-source message broker software written in Erlang. It uses exchanges to route messages from producers to queues based on routing keys or patterns. There are four main exchange types - direct, fanout, topic, and headers. Mule connects to RabbitMQ using the AMQP connector. Flows in Mule can send messages to and receive messages from RabbitMQ queues via exchanges. For example, one flow may send a message to a queue using a direct exchange, while a receiving flow gets messages from the same queue via the direct exchange.

1. RabbitMQ in Mule

2. RabbitMQ is well known and popular message broker and it has many powerful features. It is
open source message broker software and is written in the Erlang programming language and is
built on the Open Telecom Platform framework for clustering and failover

3. Features :-
• Robust messaging for applications
• Easy to use
• Runs on all major operating systems
• Supports a huge number of developer platforms
• Open source and commercially supported
Source :- RabbitMQ website

4. RabbitMQ works on a concept called Exchanges
Exchanges :- An exchange accepts messages from a producer application and routes them to
message queues. They can be thought of as the "mailboxes" of the AMQP world. Unlike some
other messaging middleware products and protocols, in AMQP, messages are not published
directly to queues. Messages are published to exchanges that route them to queue(s) using pre-
arranged criteria called bindings.
Source :- http://rubybunny.info/articles/exchanges.html

5. Exchange attributes :-
Exchanges have several attributes associated with them:
• Name
• Type (direct, fanout, topic, headers or some custom type)
• Durability
• Whether the exchange is auto-deleted when no longer used
• Other metadata (sometimes known as X-arguments)
Source :- http://rubybunny.info/articles/exchanges.html

6. Exchange types
There are four built-in exchange types in AMQP :
• Direct :- The exchange does a direct match between the routing key provided in the message
and the routing criteria used when a queue is bound to this exchange.
• Fanout:- Queues are bound to this exchange with no arguments. Hence any message sent to
this exchange will be forwarded to all queues bound to this exchange.
• Topic:- The exchange does a wildcard match between the routing key and the routing pattern
specified in the binding. The routing key is treated as zero or more words, delimited by ‘.’ and
supports special wildcard characters. “*” matches a single word and ‘#’ matches zero or more
words.
• Headers:- Queues are bound to this exchange with a table of arguments containing headers
and values (optional). A special argument named “x-match” determines the matching
algorithm, where “all” implies an AND (all pairs must match) and “any” implies OR (at least
one pair must match).
Source :- http://rajith.2rlabs.com/2007/10/13/amqp-in-10-mins-part4-standard-exchange-types-and-
supporting-common-messaging-use-cases/

7. So, how can we connect RabbitMQ with Mule ????

8. Mule connects with RabbitMq with AMQP connector available in Mule

9. Let’s consider there are 2 flows to send and receive message to and from RabbitMQ queue
using direct exchange

10. Our Mule Config will be :-
As you can see there are 2 flows , the first will send the message to the queue called new using Direct
Exchange and the receiver flow will receive the message from queue using the same Direct Exchange

11. To test the application, if we hit the url http://localhost:1080/orders4 , like the following :-

12. You will get the following into in the log:-
You can see the first flow send the message into the queue new, and the second flow receive the
message from the queue new. Both the flows have used the Direct Exchange technique

13. In my next slide I will bring some other techniques in Mule implementation .
Hope you have enjoyed this simpler version.
Keep sharing your knowledge and let our Mule community grow 