Listening

Listening Options

Wolverine's Rabbit MQ integration comes with quite a few options to fine tune listening performance as shown below:

using var host = await Host.CreateDefaultBuilder()
    .UseWolverine(opts =>
    {
        // *A* way to configure Rabbit MQ using their Uri schema
        // documented here: https://www.rabbitmq.com/uri-spec.html
        opts.UseRabbitMq(new Uri("amqp://localhost"));

        // Set up a listener for a queue
        opts.ListenToRabbitQueue("incoming1")
            .PreFetchCount(100)
            .ListenerCount(5) // use 5 parallel listeners
            .CircuitBreaker(cb =>
            {
                cb.PauseTime = 1.Minutes();
                // 10% failures will cause the listener to pause
                cb.FailurePercentageThreshold = 10;
            })
            .UseDurableInbox();

        // Set up a listener for a queue, but also
        // fine-tune the queue characteristics if Wolverine
        // will be governing the queue setup
        opts.ListenToRabbitQueue("incoming2", q =>
        {
            q.PurgeOnStartup = true;
            q.TimeToLive(5.Minutes());
        });
    }).StartAsync();

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To optimize and tune the message processing, you may want to read more about the Rabbit MQ prefetch count and prefetch size concepts.

Listen to a Queue

Setting up a listener to a specific Rabbit MQ queue is shown below:

using var host = await Host.CreateDefaultBuilder()
    .UseWolverine(opts =>
    {
        // *A* way to configure Rabbit MQ using their Uri schema
        // documented here: https://www.rabbitmq.com/uri-spec.html
        opts.UseRabbitMq(new Uri("amqp://localhost"));

        // Set up a listener for a queue
        opts.ListenToRabbitQueue("incoming1")
            .PreFetchCount(100)
            .ListenerCount(5) // use 5 parallel listeners
            .CircuitBreaker(cb =>
            {
                cb.PauseTime = 1.Minutes();
                // 10% failures will cause the listener to pause
                cb.FailurePercentageThreshold = 10;
            })
            .UseDurableInbox();

        // Set up a listener for a queue, but also
        // fine-tune the queue characteristics if Wolverine
        // will be governing the queue setup
        opts.ListenToRabbitQueue("incoming2", q =>
        {
            q.PurgeOnStartup = true;
            q.TimeToLive(5.Minutes());
        });
    }).StartAsync();

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