Service bus

A technique to offload notifications from the application into a separate system.

A service bus is a technique to offload notifications from the application into a separate system that is designed to keep track of the notifications and deliver them to all subscribing applications.

Notifications

A notification can be one of the following types:

• Single queue - Multiple applications subscribe to the same queue. All subscribers will process the queue together.
• Topic - Each application subscribes to a separate queue and the notification will be delivered to all application queues. All subscribers will individually process its queue.

When you create a new service bus you need to define if the queue should be a single queue or topic and provide a listener method that can process the notifications.

public class ServiceBusExample
{
    private readonly Litium.ServiceBus.ServiceBusQueue<MyMessage> _queue;
    private readonly Litium.ServiceBus.ServiceBusTopic<MyMessage> _topic;

    public ServiceBusExample(Litium.ServiceBus.ServiceBusFactory serviceBusFactory)
    {
        _queue = serviceBusFactory.CreateQueue(new Litium.ServiceBus.ServiceBusOptions<MyMessage>("My queue name", ProcessQueueMessage));
        _topic = serviceBusFactory.CreateTopic(new Litium.ServiceBus.TopicServiceBusOptions<MyMessage>("My topic name", ProcessTopicMessage));
    }
    public void SendToQueue(MyMessage message)
    {
        _queue.Send(message);
    }

    public void SendToTopic(MyMessage message)
    {
        _topic.Send(message);
    }

    private void ProcessQueueMessage(ServiceBusMessage<MyMessage> myMessage)
    {
        // Process queue message. This is distributed to all applications that are started and attached to the queue with the name "My queue name"
    }

    private void ProcessTopicMessage(ServiceBusMessage<MyMessage> myMessage)
    {
        // Process topic message. This is processed by all applications that are started and attached to the topic with the name "My topic name"
    }

    public class MyMessage
    {
        public string MySpecialValue { get; set; }
    }
}

Service bus implementations

To extend with your own implementation you should implement Litium.ServiceBus.ServiceBusFactory and dependency injection will automatically find and use that implementation.

Please read more about multi-server installation here.