3/11/2023 0 Comments Using mediainfo .net core dockerThen we use a channel to send and receive messages over that connection. We create a ConnectionFactory object to establish and return a connection to the RabbitMQ server. But there’s some setup that takes place in the constructor. Our actual MessageService class only implements a single public method - Enqueue. NET Core because they make it easier to create unit tests against your classes, and because they allow other classes in your application to depend on abstractions rather than concrete types (more about this when we discuss dependency injection later.) Next, we declare an interface (IMessageService)that our new class (MessageService) implements. You’ll first note that we import the RabbitMQ.Client package, and that we define a namespace to hold our project’s services (publisher_api.Services). Either way, we’ve decoupled the two services, in the sense that if one goes down, the message still persists in the queue, and as long as we’ve scaled horizontally (multiple copies of the services) on both sides of the queue, we don’t have a single point of failure (besides the queue itself, but there are ways to ensure the queue is highly available). This can allow asynchronous communication for long-running tasks (enqueue and forget), or the caller can enqueue the message and wait for a consumer to return a response ( Remote Procedure Call pattern). Services can publish messages to a queue, and consumers will pull messages from that queue and process them. Instead of direct HTTP connections between services, we introduce a middleman. This is where message queues come into play. If one critical service goes down, the negative effects (latency and more failures) will quickly be felt throughout a highly coupled system. What appears to a client as a single RESTful API call may actually become many calls between interdependent services behind the scenes. But an unfortunate side effect of breaking down monolithic applications into multiple single-purpose services is high coupling between the new services. Microservices are all the rage in today’s distributed systems.
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