Amazon-SQS-FIFO.md

MassTransit With Amazon SQS FIFO Queue

Benefits of FIFO (First In, First Out)

• Strictly-preserved message ordering
• Exactly-once message delivery
• High throughput, up to 300 publishes/second
• Subscription protocols: SQS

Configuration for FIFO

• Set Entity Name of the FIFO Message with postfix .fifo

• Set the Publish topic attributes

    x.UsingAmazonSqs((context, cfg) =>
    {
        ...
  
        cfg.Message<FifoMessage>(x =>
        {
            // required
            x.SetEntityName("message.fifo");
        });
  
        cfg.Publish<FifoMessage>(x =>
        {
            // required
            x.TopicAttributes["FifoTopic"] = "true";
  
            // optional
            x.TopicAttributes.Add("ContentBasedDeduplication", "true");
        });
  
        ...
    });

• Define custom Consumer Definition

    public class  FifoMessageConsumerDefinition 
        : ConsumerDefinition<FifoMessageConsumer>
    {
        public  FifoMessageConsumerDefinition()
        {
            Endpoint(x =>
            {
                x.Name = "message.fifo";
                x.ConcurrentMessageLimit = 1;
                x.PrefetchCount = 1;
            });
        }
  
        protected override void ConfigureConsumer(
            IReceiveEndpointConfigurator endpointConfigurator, 
            IConsumerConfigurator< FifoMessageConsumer> consumerConfigurator)
        {
            var sqsEndpointConfigurator = (IAmazonSqsReceiveEndpointConfigurator)endpointConfigurator;
            sqsEndpointConfigurator.QueueAttributes["FifoQueue"] = "true";
  
            // Enable for Content based Deduplication
            // sqsEndpointConfigurator.QueueAttributes["ContentBasedDeduplication"] = true;
  
            // Enable for Attribute based Deduplication
            // sqsEndpointConfigurator.QueueAttributes["MessageDeduplicationId"] = "DeduplicationId";
        }
    }