![]() ![]() Running ApplicationĮnsuring we have both applications set to run on startup, we can simply run the applications with F5, which as a result will open a console window ( Subscriber) and a browser window with the Swagger UI ( Producer). We must also add a port mapping for 5672, which is the default port RabbitMQ uses for communication. In order for us to access the management UI, we open a browser window and navigate to localhost:15672, using the default login of guest/guest. We are using the rabbitmq:3-management image from DockerHub which will provide us with a UI, available on port 15672, to view our queues/message throughput, for instance. Given that Docker is installed, we’ll open a command-line terminal and use the docker run command to spin up our server:ĭocker run -d -hostname my-rabbitmq-server -name rabbitmq -p 5672:5672 -p 15672:15672 rabbitmq:3-management Running RabbitMQ in Dockerįirst and foremost, we need to spin up a RabbitMQ server, which we can do simply using Docker. #MASSTRANSIT LISTENER CODE#With our Producer and Subscriber code now in place, let’s take a look at how we actually run the application. ![]() ![]() Finally, we pass in our consumer object, which has our custom Received event handler logic which will be executed when we receive a message. Next, we set autoAck to true, which will automatically handle acknowledgment of messages. We specify the queue we want to start consuming messages from. The final thing we must do is to start the consumer: channel.BasicConsume(queue: "orders", autoAck: true, consumer: consumer) Messages will be pushed to us asynchronously, therefore we define a callback method for the Received event, which will give us access to the message body through the eventArgs parameter. Var message = (body) įirst, we create a consumer. Now we can implement the logic required to receive messages from the queue: var consumer = new EventingBasicConsumer(channel) Ĭonsumer.Received += (model, eventArgs) => Without it, there would be no queue to subscribe to. We need to ensure to declare the queue, in case the Subscriber starts before the Producer. Using var channel = connection.CreateModel() Var connection = factory.CreateConnection() Then, we want to create a connection to the RabbitMQ server in the SendMessage method: var factory = new ConnectionFactory Now we are going to implement this interface, using the RabbitMQProducer class: public class RabbitMQProducer : IMessageProducer Learning Web API? Get our eBook ASP.NET Core Web API Best Practices and become an expert for FREE! > GET THE BOOK (T message) So why would we choose RabbitMQ, over something such as Azure Service Bus or Amazon Simple Queue Service? We can apply the same argument of loosely coupled applications to that of our choice of a message broker. Using a message queue, we can have multiple Subscribers which would each take one or more messages off the queue and process them, without affecting the performance of our Producer or overall application. ![]() For example, we can use messages to inform Subscribers of a long-running task that needs processing. Having a message broker, like RabbitMQ, manage our inter-application communication, allows our system as a whole to scale much easier. As long as we keep the message contract the same we can change Producers and Subscribers independently of each other. When we introduce message queues into our application architecture, our Producers and Subscribers don’t have to be aware of each other. We don’t want to create tight coupling between our applications, because doing so would mean we couldn’t independently change one application without causing breaking changes in another application. Message queues allow us to build decoupled applications while improving the performance, reliability, and scalability of our applications. What Are the Advantages of Message Queues? ![]()
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