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Using FIFO with the Amazon Message Processing Framework for .NET

For use cases where message ordering and message deduplication are critical, the Amazon Message Processing Framework for .NET supports first-in-first-out (FIFO) Amazon SQS queues and Amazon SNS topics.

Publishing

When publishing messages to a FIFO queue or topic, you must set the message group ID, which specifies the group that the message belongs to. Messages within a group are processed in order. You can set this on the SQS-specific and SNS-specific message publishers.

await _sqsPublisher.PublishAsync(message, new SQSOptions
{
    MessageDeduplicationId = <message-deduplication-id>,
    MessageGroupId = <message-group-id>
});

Subscribing

When handling messages from a FIFO queue, the framework handles messages within a given message group in the order in which they were received for each ReceiveMessages call. The framework enters this mode of operation automatically when configured with a queue ending in .fifo.

await Host.CreateDefaultBuilder(args)
    .ConfigureServices(services =>
    {
        // Register the AWS Message Processing Framework for .NET.
        services.AddAWSMessageBus(builder =>
        {
            // Because this is a FIFO queue, the framework automatically handles these messages in order.
            builder.AddSQSPoller("https://sqs.us-west-2.amazonaws.com/012345678910/MPF.fifo");
            builder.AddMessageHandler<OrderMessageHandler, OrderMessage>();
        });
    })
    .Build()
    .RunAsync();